# •MASSPIR

G Massachusett

s Publi c Interes t Researc h Grou p 4 4 Winte rStree t Boston , M A0210 8 (617 ) 292-480 0 (ph ) masspirg@pirg.or

g www.masspirg.or

g (617 ) 292-805 7 (fx )



### Jun e 24 , 200 4 Rober t Donaldso

n Departmen

t o f Environmenta

l Protectio n Burea u o f Wast e Prevention On e Winte r Street, 8t h floo r Boston , M A 0210 8 Dea r Mr . Donaldson , Attache dpleas

e fin dthre

e document

s tha t constitut e testimon

y an dcomment

s o f th e Massachusett

s Publi c Interest

Researc h Grou p (MASSPIRG ) o

n th e Department' s proposedemission s regulation s fo r engines an

dturbines . The document

s are :

• "Testimon

y o f MASSPIRG, " • "Healt hRisks o f

Exhaust fro mDiesel-FueledElectri c Generators " by Geof f Keit ho f Synapse Energ

y Economics , an

d • "Micropower

a t th e Crossroads, " arepor

t b y MASSPIRG . "Micropower

a t th e Crossroads " contain s th e analysi s I referre dto i n m y ora l testimon y when I estimate

dtha t existin g distribute dgenerator s i n th e metr o Boston are

acoul demi

t approximately 2. 7 ton s pe r da y o f NOx durin g pea

k use . A s I mentionedthi s i s aroug h calculatio n (an

dI woul dappreciat

e you r observation s o

r comment s o n ou r analysis) , bu

t i t i s ausefu l indicator

o f th e size o f th e ai r pollutio n proble

mtha t th e Departmen

t i s workin g t o solve b y implementin g thes

e regulations . Igreatly appreciat

e you r attentio n t

o thi s issue , an

da mavailable anytim

e t o discus s ou

r comments . Sincerely , fram e piork

e Energ y Advocat

e 617.747.431 6

# MASSPIR

G Testimon y o f MASSPIR G o

n th e Emissio n Standard s fo rStationar y Engines an

d Combustion Turbine s a t310 CM R7.2

0 Fran kGorke , Energy Advocat e June 24, 200

4 Th e Massachusett

s Publi c Interest

Researc h Grou p (MASSPIRG ) appreciate s thi s opportunit

y t o commen

t on th e Department' s Propose

dAmendments t

o 31 0 CMR7.0

0 an d31 0 CM R70.00 issue

di n Ma y 2004 . MASSPIRGstrongly supports th e Department' s intent

an dphilosoph

y i npromulgatin g emission s standards fo r engines an

d combustion turbines , an

dgreatly appreciate s th

e Department' s wor

k i npreparing an

d promulgatin g thi s regulation . Th e adoption o f

update dan dne w emission s standard

s fo r engine s an

dturbine s use

dfo r onsit e generation o f

electrica l powe r ("Distribute dGeneration " o r "DG" ) i s critical given th e increasing usage o f

these technologies . Whil e D Ghold s th e potentia

l t o increase th

e efficienc y o f

the electrica

l syste man dprovide othe

r benefits , D G als o present s a n environmenta

l threa t du e to th e wide rang

e o f emission rate s associate

dwit hdifferen t technologie s an

dvintage s o f

D Ginstallations , th

e proximity o f

man y small engines an

d turbine s to affecte dpopulations , an dth e likelihoo dtha

t these source s wil l hav

e their highest utilizatio n unde

r pea k electrica l loa dcondition s tha

t typicall y coincide wit hpoo r ai r quality . Emission s standards ar e a n essentia l componen

t o f th e effor t to ensur e tha t th e benefit s o f

D Gar e not compromisedb y environmenta l an dhuma n healt h cost s associate dwit hth e usag e o f olde r an ddirtie r D Gtechnologies . I ncomment

s submitte dto th

e Departmen

t i nOctober, 200 3 MASSPIR Gsupporte d severa l provision s o f

th e propose drule : • th e standards proposedfo r non-emergenc

y engine s an

dturbines , • th e standards proposedfo r small emergenc

y engines , an

d • th e inclusio n o f

CO 2 i n th e pollutant s to be regulated . W e urgedthe Departmen

t to address : • th e omissio n o f

C O standards fo r

emergenc y turbines , • th e omissio n o f

mandator

y review s o f

the standards fo r

emergenc

y generators , an d • th e omissio n o f

provision s tha

t credit simultaneou s emission reductions. 1 

### Finally , w e questionedwh y th e Departmen

t propose ddifferen t

standards fo r

small an d larg e emergenc

y engines , an

dwh y th e Departmen

t di dno t propos e a

n ammoni astandar

d fo r non-emergenc

y engines .

1 Comment

s o f MASSPIR Gan

dCLFon th

e Draf t Emission Standard

s fo r Stationar y Engine s an

d Combustion Turbine s a

t 31 0 CM R7.20 . SubmittedOctobe r 10 , 2003 .

### I . Th e RA PMode l Rul e provide

s astrong an

d appropriat

e foundation fo rstat

e emissio n standards . W e ar e please dthat , i n severa

l importan

t areas , th e Department' s proposedamendment s follo w th e model rul e develope

di nth e stakeholde

r workgrou

p ledb y th

e Regulator

y Assistance Projec t

(the "Mode l Rule") . I nthese areas , th e propose damendment

s maintain th

e positiv e feature s o f

th e Department' s earlie

r proposal . Th

e Mode l Rul e incorporatedbroa

dparticipatio n b y ai

r regulators , environmenta l group s an

dengin e an d turbine manufacturers ; an dparticipant s i nth

e proces s relie do

n aconsiderable amoun

t o f data, develope

db y independen

t consultants , regardin g th e curren t an dexpecte dfutur e capabilitie s o f

differen t engin e an dturbin e technologies . A s aresult , i t provide s asoli d foundatio n fo r

stat e emission standards . I nparticular , MASSPIR Gsupport s th e emission standard

s propose dfo r non-emergenc

y engine s an

dturbine s (Table s 2 an

d3 i nproposed31 0 CMR7.26(43)) , wit hon e caveat . Th e standard

s propose dfo r non-emergenc

y engine s an

dturbine s ar

e bot h aggressiv

e an d reasonable , an

dthe y wil l no t impos e undu

e burden s o n eithe

r generato r manufacturer s o r customer s installin g D Gsystems . I n fact , given tha t Massachusett

s i s classifie da

s anon attainmen t are afo r ozone , th

e Departmen

t shouldfollo w severa

l othe r states an dadop t mor e stringen t NO x

### standards . Californi aha s establishedaNO x

### standar dfo r small generator s o f 0. 5 lbs/MW hthrough200 6 droppin g to 0.0 7 lbs/MWhi n2007 . Ai r regulators i nTexa

s hav e establishe

dagenera

l permi t withaNO x

### limi t

o f 0.1 4 lbs/MW h i n200 5 fo r th e Eas t Texa s non-attainmen

t are a(se e char t below) . Whil e curren

t diese l fuele dengine s wil l hav

e troubl e meeting th

e propose dNO x 

### standards , othe

r reciprocatin g engine s wil l be abl e to mee t them . Lean-bur

n engine s fuele db y natura

l ga s ca n achiev e th e propose d200 4 NO x

### standar

dtoda y wit hSC

R controls , an

dwithreasonabl

e R& D efforts , these unit s wil l be abl e to mee t th e proposed 200 8 an d201 2 standards . Rich-bur n engine s fuele db y natura l ga s ca n als o currentl y mee t th e propose d200 4 NO x

### standar

db y usin g athree-wa

y catalyst , an

dthese unit s to o shouldb e abl

e to mee t th e 200 8 an d201 2 standards . I t

i s wort hnotin g tha

t diesel-fuele d engines wil l continue to be th e technology o f

choic e fo r

emergenc

y generation , an

di nth e nea r t o mediumterm , th

e emergenc

y generation marke

t i s likel y to remain a

s larg e o r large r tha n the marke

t fo r othe r type s o f onsit e generation . I t

shouldals o be notedthat , given pas t advances i nemission controls , th e "technolog y forcing " natur e o f thi s regulatio n an

dth e mor e stringen t D Gstandards bein g adopte di nothe r states , i t i s not inconceivable tha

t diese l engines coul dmee

t these standards a

t som e point i nthe future . Th e assertio n tha t th e Department' s propose

dstandards fo r

non-emergenc

y generators ar

e reasonabl e i s supporte

db y tw o facts . First , thes e standards ar e consisten

t wit hthe standard s developedfo r

th e Mode l rule , an

da s noted , th

e Mode l rul e i s the produc t o f intensiv e stakeholde

r negotiation s an

dthir dpart

y research . Second, th

e proposed standard s ar e mor e lenien t tha n th e D Gstandards adopte

di nsevera

l othe r states . Th

e char t belo w compare s th

e Department' s proposedNO x

### standard s fo r non-emergency engine s wit hth

e standards i nth

e Mode l rule , the standard s adopte di nCalifornia , th

e standardize

dD Gpermit

adopte di n Eas t Texas an dthe permit

unde r consideratio n i n Connecticut . ' •

2

### MASSPIRGalso find s th e Department' s propose

dstandard

s fo r small emergenc

y engines an dfo r emergenc y turbine s t

o be sufficien t

t o protect th e environmen

t an dhuma n health , given th e operating limitation s on these generators . B y adopting th e US EP A non-roa d standard s fo r small emergenc

y engines , th

e Departmen

t i s adopting aggressiv

e emissio n standard s tha t als o minimiz e th

e administrativ e burde

n o n th e Departmen

t an dth e regulator y burde n o n engin

e manufacturers . Becaus e these ar e standards fo r

whic h engin e manufacturers ar

e alread y planning , the

y allo w fo r

efficien t product developmen

t an dwil l impos e ver

y small (i f

any ) additiona

l cost s on these companies . W e als o fin dth

e NO x

### standar

dfo r emergenc

y turbine s t

o be appropriate . A s discusse

di nth e section o

n CombinedHea

t an dPower, w e urg e th

e Departmen

t t o adop t additiona

l provision s o f

th e RA P Mode l Rule . II . There ar

e compellin

g healt h reason s limiting th

e operatio

n o f olde rdiesel fire d distributed generation. A recen t pape r examining th

e scientifi c literatur

e o n th e healt h effect s o f

diese l exhaus t foun dstrong evidence tha t acut e an dsub-chronic exposur

e to moderat

e level s o f

diese l exhaus t resul t i nver y significant

non-cance

r healt h effect s an

dma y als o lea dto cancer. ( A copy o f

thi s pape r i s attache dto thi s testimony. ) Th

e pape r focuse s o

n studie s o f short - an dmedium-ter

mexposur

e since tha

t i s th e typ e o f exposur e most likel y t o occu r fro mincrease

dus e o f diese l generation . Les s seriou s effect s o f exposur e include coughing , wheezing , an

dey e an dnose irritatio n an

dexacerbation o f

existin g allergies . I n addition , a

n inflammator

y an dimmunological response a t th e cellula r level , i nbot

h th e respirator y an dcardiovascula

r systems , i s consistentl

y observe dwit hshort-ter

mexposur

e t o diese l exhaust . Peopl e withlun g an

dhear t disease suffe r

eve n mor e seriou s risk s fro mexposur e to diese l exhaust . A large bod

y o f epidemiologica

l wor k document

s a n association betwee

n exposur e t o fin e particulat

e matte r an dacut e illnes s an

dmortality i npeople wit hhear t an dlun g disease . Tw o fact s sugges t tha t diese l exhaus t play s asignifican t

rol e i nthes

e observe dhealt h effects . First , fin e particulate s fro mdiese l engine s makes u

p a significant

portio n o f

ambien t fin e particulat

e matte r i nman y o f th e urba n area s studied . Second, althoug

h ther e ar e association s wit hsevera l pollutants , th

e strongest

associatio

n i s betwee n fin e particulate s an

ddail y healt

h effects , an

dove r 9 0 percen t o f th e particulat

e matte r b y mas s i n most

D E i s fin e particulat

e matter . Wor

k i s ongoin g to understan

dth e mechanism

s underlyin g thi s association an dth e specifi c particle s a

t cause , an dmuc h o f thi s wor k i s focusedo

n the cellula

r inflammatory/immunological response . Th e existin g dat

ao n th e carcinogenicit

y o f diese l exhaus t i s inadequat

e to determin

e whethe r acut e an dsub-chronic exposur

e leads to cancer. Ther

e i s strong evidence tha

t chroni c exposur

e leads to cancer, an

dbase do n thi s evidence th

e U S EP A ha s liste ddiese

l exhaus t a s aprobable carcinoge

n an dth e Californi aAi r

Resources Boar

dha s liste di t a s a know n carcinogen . However , bot h agencie s hav

e state dtha t ther e i s n o know n threshold fo r the carcinogenic effect s o f diese l exhaus t an dtha t shorter-ter

mexposure s ma

y lea dto cancer . Diese

l exhaus t contain s anumbe

r o f know n mutagens-an

dcarcinogens , includin g aldehydes , benzene , 1,3-butadiene , an dpolycycli c aromatic hydrocarbon s (PAHs) , whic h provid e aplausible mechanismfo r anon-threshold , mutagenic mod e o f action . 3

### III . Th e DEP' s rul e shoul d provide credit

s fo rCH Papplications . A s notedb y th

e Department, th

e RA P Mode l Rul e allow s credits fo r combinedhea

t an d powe r ("CHP" ) wher

e wast e hea t fro mthe engin

e i s pu t t o productiv e therma

l use , suc h a s heatin g o

r cooling . Th

e Departmen

t question s thi s provision , stating it s concer n tha t suc haprovisio n woul dallo w installatio n o f a"dirtier, " non-state-of-th e art , engin

e o r combustion turbine , relativ e t o wha t woul dbe allowe dabsen t th e CH P credit provisio n o f th e RAP Model Rule . MASSPIRGunderstand s thi s concer n o f th e Department , an

d agree s tha t i f includin g th

e CH P provisio n le dt

o ane t increase i n emission s fro mth e sources subject

to th e propose dregulations , i t

woul dnot

be appropriat

e to includ e i t

i n th e fina l rule . Further, MASSPIRGunderstands tha t administratio n o f

th e RAP model rul e provisio n coul dincrease th e administrativ e burde

n on th e Departmen

t i n ensuring tha t th e provision s o f

th e propose dregulation s wer

e being me

t i n amonitorable , verifiabl e manner . However , MASSPIRGbelieve s tha t the Department' s concerns ca n be full y addresse

d wit haslight

modificatio n o f

th e RA P Mode l Rule' s provisions , an dencourages th

e Departmen

t to tak e thi s ste p becaus e i t i s essentia

l to provide eve

n modes t financia l incentive s fo r

mor e efficien t

use s o f energy an

dfo r th e replacemen

t o f ol dboilers , whic h typicall y hav

e ver y hig hemission rates . The importanc e o f the financial incentiv e associate dwit hcreditin g CH

P application s i s magnifie db y th e fac t tha t th e most economic opportunitie s fo r CH P installation s - larg e industria l site s - hav

e generally mad e suc hinvestment

s already . Th

e remainin g (smaller

) commercia

l an dindustrial opportunitie s fo r

installatio n o f

CH P fac e a t bes t amargina

l cost , benefi t calculu s whe

n i t comes to cogeneratio

n investments . Importantly , credits fo r

cogeneration woul db e full y alignedwit hth e Department' s pollutio n prevention philosoph y an dcomplementar

y to it s existin g initiative s to rewar d generation efficiency , includin g th e migratio n o f

electricit y secto r rate-base demission contro l programs to emission standards base don emission s pe

r uni t o f electrica l outpu t (i.e. , "output-based " standards) , rathe r tha n hea t input (31 0 CM R7.29) , an

dthe administratio n o f

th e state' s NO x

### allowanc e tradin g progra mthrougha

n output-based allocatio n (31 0 CMR7.28) . I t woul dals o recogniz e tha t th e benefit s o f

cogeneration a

t th e smal l engin

e leve l ar e conceptually identical to th e benefit s provide db y larg e CH P facilities , whic har

e grante dcredit fo r coincident

stea mus e i n th e NO x

### allowanc e tradin g program . Credit

fo r CH P application s i n th

e proposedregulation s woul dals o be consisten t withothe

r stat e an dfedera l effort s to emphasiz

e pollutio n preventio n rathe r tha n onl y pollutio n reductio n (including , fo r example , EPA' s output-base dstandar dfo r it s Ne w Sourc

e Performanc e Standards regulatio n fo r large electri c utilit y stea

m generators (4 0 CF

R60 , Subpar

t Da) , Connecticut

an dNe w Jerse y regiona l NO x

### progra

m allocation s tha

t us e aformo f

output-basedstandards , EPA' s guidance documents o n output-base

dmethods to assis

t states i n designing rate-base dan dallowanc e allocatio n program s (includin g guideline s fo r specifi c allocatio n credit fo r CH P applications) , an

d federa l legislativ e proposal s fo r multi-pollutan t

regulation s using output-based standards) . Incorporatin g incentive s t o improv e efficienc y i n ever y aspec t o f emission contro l requirements , includin g economic incentive s fo r th e expansio

n o f CHP , i s criticall y importan

t i n ligh t o f th e dauntin g C0 2

### reduction s neede dto addres s globa

l climate change . Unlike othe r pollutants , th

e onl y wa y t o reduce C0 2

### emissions.i s b y 4

### switchin g fuel s or increasing th

e efficienc y o f

energ y conversion . Thus , th

e U S need s to enhanc e it s us e o f CH P considerabl

y an dquickly . Th e focu s o n pollutio n preventio n an defficienc y ha

s bee n incorporatedi n othe

r states ' D Gemission standar

drules , a s othe r states hav

e considere

di t importan t to include a steam-us e credi t fo r CH P applications . Fo

r example , th

e Californi arule , th

e Eas t Texa s D Gpermit , an

dth e draf t Connecticu

t permi t al l include provision s fo r emission reduction s du

e t o CHP . The draf

t Connecticu

t rul e als o include s provision s to credit reduce dflaring . MASSPIRGstrongly urge s th e Departmen

t to adop t aCH P provisio n simila

r t o th e on e i nth e Model rule . Th

e participant s i ntha

t proces s spen

t considerabl

e time developing a methodo f

calculatin g emission s displacedb y th e use o f byproduct

heat, an dwe fin dthi s methodt o be soun dan dappropriat

e fo r thi s purpose . However , MASSPIRGrecognize s th e Department' s concern , an dagree s tha t provision s fo r

credits shouldguar

dagains t gaming th e credits , an

destablishing amechanismtha t fail s to achiev

e actua l emission s reductions . Th e RA P Mode l Rul e include s specifi c mechanisms fo r ensurin g tha t emission s reduction s ar

e rea l beyon dth e time o f certification . Fo

r example , th

e Rul e include s thresholdrequirements fo r aCH P installation' s eligibilit y fo r credits a s wel l a s aca p on histori c emission rate s tha t ca n be use di nretrofi t

case s (se e Sectio n VI I o f th e Rule) . MASSPIRGbelieve s tha t th e RA P Mode l Rul e provide s a

n appropriat

e approac h to determining credit s fo r

CH P installations . Nevertheless , i f

the Departmen

t i s uncomfortabl e wit hth e prospec t o f "fre e ridership," i t shouldno t abando n th e creditin g o f

CH P altogethe

r - instead , i t

shouldconside

r othe r option s fo r

reducin g thi s likelihood , an dfo r makin g th

e credit provision s mor

e verifiabl e an denforceable . First , the Departmen t coul drequir

e that , fo r bot hne w facilitie s an d existin g facilities , th

e displacedemission s be calculatedusing emission rate s o f ne w ga s firedboiler s (rathe

r tha n th e dua l approac h proposedi nth

e Model Rule) . Thi s approac h woul dguar

dagainst givin g "to o much " credit i n situation s where , du

e to economics , a

n olde r boiler wa s goin g to be replacedanyway . Furthermore , th e Departmen

t coul dmak

e obtainin g th

e credi t dependen

t o n thre e factors : (1 ) demonstration o n a n annua l basi s tha

t th e facilit y owne

r ha s no t installe danew , separat

e boiler , (2 ) demonstration tha t th e ol d boiler ha s bee n removed , an

d(3 ) demonstration tha

t th e facilit y owne

r continue s t

o hav e stea mdeman dtha t i s me t b y th e CH P applicatio n a

t aleve l tha

t i s roughl y equivalen

t t o historica l use . These three requirements woul dg o alon g wa y t o makin g th

e emission reduction s verifiabl e an

denforceable , an

dth e administrativ e burde

n to th e Departmen

t o f administering suc

h aprovisio n coul dbe transferre dto th e facilit y b y demonstration requirements writte n into th e operating permi t

o r certificate . Whil e thes

e reducedprovision s fo r

administratio n o f

aCH P credi t (relativ e to th

e RA P Mode l Rule ) coul daddres s th e Department' s substantive concerns an dadministrativ e burdens , wha

t remain s unsatisfactor

y i s tha t ther e ar e likel y t o be som e situation s wher

e onl y th e provisio n o f

credit s ca

n mak e th e replacemen

t o f aboiler economic ; an

dtha t i n th e absenc e o f the credit

a n ol dboiler

wil l not be replaced . I nthi s case, th e emission s reduction woul dbe undervaluedunde r amechanismtha

t onl y provide s acredit

base do n th e emissio n rat e o f ane w gas-fire dboiler . Before adopting suc h areduce

dcredit 5

### mechanism , th e Departmen

t shoulddiscus s withinterestedpartie s alternativ e mechanism

s fo r addressin

g thi s situation . IV . Th e Departmen t shoul dprovid e credit s fo r concurren t

emissio n reduction s achieve db y reduce dflarin g o f wast e gases . Whil e flarin g i s necessar

y t o reduce th

e impacts o f

certain pollutants , i t

waste s valuable energ y tha t shouldbe put

t o use . Given tha

t flarin g i s require di nMassachusett s fo r man y facilities , owner

s o f engine s an

dturbine s a

t suc h facilitie s shouldbe allowe dt o ne t avoidedemission s fro mflarin g against their emission s fo r

complianc e purposes . Th e Mode l Rule allow s operators eithe r to measur

e emission s fro madisplacedflar e t o calculat e avoidedemission s or

to us e default emission rate s define di nth e rule . W e believ e tha

t thi s i s asoun

dapproac h to calculatin g emission s avoidedb y reducedflaring . V . Th e Departmen

tshould considerestablishing mor e stringen

tNO x

### standards fo rnon-emergenc

y engine s an d turbines (Tables 2 an

d 3 in propose

d 31 0 CM R 7.26(43) ) The Departmen

t shouldconside

r establishing emission s standard s fo r NO x 

### , mor

e stringen t tha n th e RA PMode l Rule , along th

e line s o f th e standar dadopte di n Californi a an dthe genera

l permit adopte di n Eas t Texas (se e char t below) . NO x

### Emissio n Standard s fo rDistribute d Generation i n Non-Attainmen tAreas 0. 7

2004 200 5 200 6 200 7 200 8 200 9 201 0 201 1 201 2 

### VI . Th e Departmen

tshould explain wh

y a n ammoni

astandard ha

s no tbee n propose d fo rnon-emergenc

y engines . Undoubtedly , som

e engine s wil l comply wit hth e propose demission standards using selective catalyti c reductio n (SCR) systems ; thu s th e risk o f ammoni asli p wil l be present . Despit e ou r reques t i nour Octobe r comments , th

e Departmen

t ha s not explaine dit s approac h o n thi s issue . We urge th

e Departmen

t to addres s thi s issu

e and , absen

t a compellin g rationale , to expan dth e proposedammoni astandar dto apply to bot

h turbine s an dengines .

6

### VII . Th e Departmen tshould adop

tacarbon monoxid

e (CO ) standard fo rsmall emergenc y turbines (310 CM R7.26(42 ) Tabl e 1) . Becaus e emission s o f

C O ca n ris e a s combustion processes ar e manage dto minimiz e NO x

### emissions , i t

i s importan

t to regulat e bot ho f these pollutant s t

o preven t aNO x 

### standar dfro mresultin g i nunintendedincreases i n CO emissions . W e believ e tha

t aC O standar do f 0. 5 lb/MW hwoul dlimi t CO emission s fro msmall turbine s appropriately whil e stil l allowin g these unit s to mee t th e NO x

### standar

dcomfortably . VIII . Larg e engine

s (outpu to f ove r1 MW ) use

d a s emergenc

y generator

s should eithermee

tamor e rigorou s NO x

### standar

d tha n smalle rengine

s o rb e held t o th e sam e standar

d a s small engines . MASSPIRGi s trouble db y th e larg e emergenc

y engin e standar dcontainedi n th

e propose drule . These standard

s ar e mor e lenien t tha n th e Tier 2 non-roa dstandards (propose dfo r small emergenc

y engines ) fo r

NO x

### ye t mor e stringen t fo r CO. 2

### Th

e proposa l o f tw o standards i s puzzling , given tha t (a ) i t woul db e simple r t o apply th

e federa l non-roa dstandard

s t o al l emergenc

y engine s an

d(b ) NO x

### i s aparticularl y problemati c pollutant

i nth e Northeast . A s th

e Departmen

t i s wel l aware , emergenc

y engine s ar

e most likel y to b

e use do n ho t summe r days , period s whe

n the ris k o f exceedin g the ambien

t ozon e standar di s ver y high . W e firml y believ e tha

t larg e engine s (outpu

t o f ove r 1 MW ) use

da s emergenc

y generator s shouldeithe

r mee t amor e rigorou s NO x

### standar

dtha n smalle r engine s or

be hel dt o th e sam e standar da s small engines . Absen

t acompellin g rationale , MASSPIRG urge s th e Departmen

t t o appl y th e EP A non-roa

dstandard

s t o al l emergenc

y engines . IX . W

e urg e th e Departmen

tt o include provision

s fo rmandator

y revie w o f th e standards applicable t

o emergenc

y generators . The propose

drul e include s arequiremen t fo r revie w o f

th e standard

s applicabl e t

o non emergenc y generator

s (i n201 0 an

di n 201 7 an

dever y fiv e year

s thereafter) . Broadening thi s review requiremen

t to appl y to th e emergenc

y generato

r standard s woul dad

dlittl e additiona l wor k fo r th e Department, an

di t woul densur

e tha t Massachusett

s citizen s benefi t fro man y relevan t advances i n technology i nth e coming years . Periodi c review o f emission standards i s important , becaus e Massachusett

s citizen s wil l liv e wit hne w powe r plants - bot

h larg e an dsmall - fo r

man y years . X . MASSPIR G strongl y support

s th e inclusion o

f a n emissio n standard fo rC0 2 

### . The Commonwealt

h o f Massachusetts , through it s ai r emission s regulator

y program , ha

s assume dacritical nationa

l rol e b y regulatin g C0 2

### emissions . Th e promulgatio n o f

31 0 CMR7.2 9 se t th e Commonwealt

h on thi s path , an

dthese regulation s ar

e the logical nex

t ste p down tha

t path . B y regulatin g C0 2 

### , th e Departmen

t i s effectivel y fulfillin g th e environmenta

l an dpubli c healt

h protectio n mandat

e o f it s enabling legislatio n an d

2Th e Department' s propose

dNO x standards ar

e 18. 3 lbs/MW hfo r

engines betwee

n on e an dtw o M Wi n size an d16. 3 lbs/MWhfo r

unit s tw o M Wan

dlarger . Th

e 2006 Tier

2 non-roa dstandar dfo r NO x an d NMOC s combinedi s 14. 1 lbs/MWh . Th e Department' s propose

dC O standard

s ar e 5. 0 an d1. 5 respectively , an

dth e 200 6 Tier

2 C O standar

di s 7. 7 lbs/MWh . 

### 7

### responding to th e challenge o f

th e Climat e Actio n Pla

n o f th e Ne w EnglandGovernor

s an dEaster n Canadia

n Premiers . XI . Summar

y MASSPIRGsupports th

e Department' s promulgatio n o f thes e emission standards . W e als o suppor

t man y o f th e specifi c provision s i nth e Department' s proposedstandards . However , w

e strongly urge th

e Departmen

t to revisi t it s omission o f

severa l importan

t component

s o f th e emission regulations . These omitte dcomponent s are : provision s fo r th e creditin g o f

concurren

t emission reduction s fro mCH P an dreduce dflaring , C O standards fo r

emergenc

y turbines , an

daprovisio n fo r

reviewin g th

e emissio n standard

s fo r emergenc

y generators . We urg e the Departmen t to hol dlarg e emergency engines to a standar da t least a s stringen t a s the standar

dfo r smal l ones . Finally , w e question why a n ammoni astandar

dha s not bee n proposedfo r

non-emergenc

y engines .

8

### Healt h Risk s o f Exhaus t fro m Diesel-Fuele d Electri c Generator s Geof f Keith , Synaps e Energ yEconomics , Jun e 21 , 200 4 2 2 Pear l St. , Cambridg e MA , 02452 , www.synapse-energy.co m

Executiv e Summar y Thi s pape rexamine s th e scientifi cliteratur e o n th e healt h effect s o f diese l exhaus t ("DE") , t o she d ligh t o n th e potentia l healt h risk s o f operatin g urba n diese l generator s mor e intensively . W e focu s o n studie s o f short - an d medium-ter m exposur e ("acute " an d "sub-chronic " exposure) , tha t is , exposur e fo rperiod s o f severa l hour s t o severa l weeks . W e focu s o n thes e studie s becaus e thi s i s th e typ e o f exposur e tha t woul d resul t fro m increase d us e o f diese l generator s an d becaus e th e mechanism s triggere d b ychroni c exposure , an d th e resultin g healt h effects , mayb e differen t tha n thos e triggere d b y shorter-ter m exposures . Ther e i s stron g evidenc e tha t acut e an d sub-chroni cexposur e t o moderat e level s o f D E result s i n non-cance rhealt h effects . D E als o contain s know n mutagen s an d carcinogens , an d thes e chemical s represen t a plausibl e mechanis m fo rcance rresultin g fro m acut e an d sub-chroni cexposure . However , ther e i s considerabl e uncertaint y aroun d th e potentia l fo rcance rfro m non-chroni cexposure . D E als o contribute s t o urba n smog , whic h pose s healt h risk s t o asthmatic s an d othe rsubgroups . However , smo g i s a regiona l problem , cause d bypollutio n fro m man ydifferen t sources , an d diese l generator s ar e a relativel ysmal l sourc e o f smo g precursors . Thu s w e d o no t addres s th e healt h effect s o f smo g here . I n a numbe ro f laboratorytests , health yhuman s hav e bee n expose d t o moderat e level s o f DE , i n th e rang e o f 10 0 t o 30 0 ug/m 3

### o f diese l particulat e matte r("DPM") . (DP M i s commonl yuse d a s a surrogat e measur e o f whol e DE. ) Consistentl yobserve d symptom s includ e coughing , wheezin g an d ey e an d nos e irritation . Dizziness , nause a an d othe r neurologica l symptom s ca n resul t fro m exposur e t o highe rconcentrations . D E ha s als o bee n show n t o exacerbat e existin g allergies . I n additio n t o thes e symptoms , exposur e t o D E result s i n wel l documente d inflammatoryan d immunologica l response s a t th e cellula r leve l i n bot h th e respiratoryan d cardiovascula rsystems . Aconsiderabl e bod yo f anima l researc h provide s additiona l informatio n abou t thi s inflammation/immun e response . Exposur e t o D E ma ypos e muc h mor e seriou s risks , however , t o peopl e wit h lun g an d heart disease . Epidemiologica l studie s hav e establishe d a clea rlin k betwee n exposur e t o urba n fin e particulat e matte ran d dail yillnes s an d mortalit yfro m lun g an d heart disease . Wor k

i s ongoin g t o understan d th e mechanism s underlyin g thi s associatio n an d th e specifi cparticle s at cause , bu t i t appear s tha t th e cellula rresponse s t o particulat e exposur e includ e mechanism s tha t ca n caus e acut e respiratoryan d cardia cdistres s an d death . Tw o fact s sugges t tha t D E play s a significan t rol e i n th e dynamic . First , diese l particulat e matte rmake s u p a significan t portio n o f ambien t fin e particulat e matte ri n man yo f th e urba n area s studied . Second , althoug h ther e ar e association s wit h severa l pollutants , th e stronges t associatio n i s betwee n fin e particulate s an d dail yhealt h effects , an d ove r9 0 percen t o f th e particulat e matte rb ymas s i n mos t D E i s fin e particulat e matter .

### Th e researc h o n D E exposur e an d cance rha s yielde d les s certai n conclusions . Ther e i s

reasonabl ystron g epidemiologica l evidenc e tha t chroni cexposur e t o D E (usuall ystudie d i n a n occupationa l setting ) lead s t o lun g cancer . Chroni cexposur e t o hig h concentration s ha s als o bee n show n t o produc e lun g tumor s i n rats . Base d largel yo n th e epidemiologica l data , th e U S EP Aha s labele d D E a "probable " carcinogen , an d th e Californi a Ai rResource s Boar d ha s labele d i t a "known " carcinoge n an d establishe d a uni t ris k numbe rfo rchroni cexposure . However , thes e finding s ma ytel l u s littl e abou t whethe rshorter-ter m an d mor e periodi cexposur e t o D E ca n caus e cancer . Th e stronges t evidenc e tha t short-ter m exposur e coul d lea d t o cance rlie s i n th e know n carcinogen s an d mutagen s withi n DE . Thes e chemical s includ e benzene , formaldehyde , acetaldehyde , acrolei n an d PAHs . Importantly , ther e i s n o know n threshol d fo rth e carcinogenicit yo f som e o f thes e chemical s (e.g. , benzene) . However , mor e wor k need s t o b e don e t o determin e whethe rthes e chemical s produc e cance ri n th e cas e o f inhalatio n exposur e t o DE . Currently , th e weigh t o f evidenc e suggest s tha t longe r exposur e period s ar e mor e likel yt o lea d t o cance rtha n shorte rones , bu t tha t th e potentia l fo rcance rresultin g fro m shorter-ter m exposure , vi a a non-threshold , mutageni c mod e o f action , canno t b e rule d out . Th e ris k o f acut e illnes s an d mortalit yt o peopl e wit h heart an d lun g diseas e appear s t o b e th e mos t seriou s healt h ris k pose d b ya n urba n diese l generator . Th e curren t short ter m ambien t ai rqualit ystandar d fo rPM 2 5 

### i s 6 5 ug/m 3 

### . Base d o n dat a fro m th e U S EP A an d othe rsource s regardin g ambien t concentration s o f DP M a t urba n location s an d i n occupationa l settings , i t i s reasonabl e t o assum e tha t a diese l generato ri n a n urba n setting , operatin g fo ra perio d o f severa l hours , coul d creat e localize d concentration s o f PM 2 5 

### abov e 6 5 ug/m 3 

### .

2

### I . Introductio n

Mos t urba n area s i n th e U S ar e hom e t o many , smal l diesel-fuele d electri cgenerators . Unlik e larg e powe rplants , thes e unit s ar e ofte n locate d i n densel ypopulate d areas , an d the yd o no t hav e tal l smokestack s t o dispers e thei rai remissions . Historically , thes e generator s hav e bee n operate d a t verylo wutilizatio n rates , wit h mos t o f the m operate d a s "emergenc ygenerators, " tha t is , operate d onl ydurin g powe routages . However , wit h th e deregulatio n o f th e electri cindustryi n som e region s o f th e country , ther e ha s bee n pressur e t o allo wfacilitie s wit h diese l generator s t o operat e th e unit s durin g period s o f hig h prices . Utilize d i n thi s way , diese l generator s migh t operat e fo rentir e afternoon s o n man ysumme rdays , whe n .electricit ydeman d an d price s ar e high . Thi s pape rexamine s th e scientifi cliteratur e o n th e healt h effect s o f diese l exhaus t ("DE") , t o she d ligh t o n th e potentia l healt h risk s o f operatin g urba n diese l generator s mor e intensively . W e focu s o n studie s o f short - an d medium-ter m exposur e ("acute " an d "sub-chronic " exposure) , tha t is , exposur e fo rperiod s o f severa l hour s t o severa l weeks . W e focu s o n thes e studie s becaus e thi s i s th e typ e o f exposur e tha t woul d resul t fro m increase d us e o f diese l generator s an d becaus e th e mechanism s triggere d b ychroni c exposure , an d th e resultin g healt h effects , ma yb e differen t tha n thos e triggere d b y shorter-ter m exposures . Section s I I an d II I belo wprovid e brie f backgroun d o n diese l electri cgenerator s an d thei r emission s Sectio n I V examine s th e non-cance rhealt h effect s o f exposur e t o DE , an d Sectio n V examine s th e researc h o n cance ran d exposur e t o DE . II . Diesel-fuele d electri c generator s Ther e ar e a larg e numbe ro f diesel-fuele d generator s i n mos t urba n area s o f th e US . Unlik e larg e powe rplants , th e exac t numbe ran d locatio n o f diese l generator s i s no t wel l known . Onl yrecentl yha s ther e bee n interes t i n developin g detaile d inventorie s o f thes e units . I n 2003 , th e Northeas t State s fo rCoordinate d Ai rUs e Managemen t (NESCAUM ) release d a n initia l assessmen t o f th e populatio n o f diesel-fuele d generator s i n th e Northeast. 1 

### Thi s assessmen t i s base d o n dat a fro m Powe rSystem s Researc h (PSR ) an d review s o f stat e permi t data . PS R estimate s th e numbe ro f engin e generator s i n th e Northeas t usin g a databas e o n U S engin e sales , import s an d export s an d telephon e survey s o f engin e owners . NESCAU M staf f compare d th e estimat e generate d b yPS R t o permi t informatio n availabl e fro m stat e environmenta l agencies . (Th e assessmen t covere d Connecticut , Maine , Massachusetts , Ne wHampshire , Ne wYork , Pennsylvania , Rhod e Islan d an d Vermont. ) A s see n i n Tabl e 1 , th e numbe ro f generator s estimate d b yPS R exceede d th e numbe r indicate d i n permi t record s considerably . NESCAU M note s tha t thi s i s probabl ydu e t o severa l factors : th e permi t informatio n reviewe d fo rman ystate s wa s incomplete , man y engine s fal l belo wth e siz e threshold s o f permittin g requirements , som e engine s tha t shoul d hav e permit s d o no t hav e them , an d ther e i s likel yt o b e som e rang e o f erro ri n th e PS R estimates . Not e tha t th e PS R estimate s ar e fa ri n exces s o f th e permi t record s i n th e smalle rsiz e ranges , whil e th e tw o source s ar e mor e consisten t fo rth e large rsize d engines . Thi s i s becaus e operatin g permit s ar e no t typicall yrequire d fo rth e smalles t engines , whil e permit s ar e require d an d reportin g requirement s ar e stric t fo rth e larges t ones . Thus , th e tw o source s leav e muc h mor e uncertaint yaroun d th e numbe ro f smal l generator s i n th e Northeast .

### Tabl e 1 . Dat a fro m th e NESCAU M Assessmen t o f StationaryDiese l Engine s Siz e (kW) PS REstimate s Permi t Record s 25-5 0 1,768 15 6 50-100 7,28 0 52 3 100-25 0 11,55 7 2,729 250-500 7,15 6 2,43 6 500-75 0 1,65 9 1,772 750-1000 1,50 7 1,33 5 1000-150 0 1,357 1,29 0 1500 + 1,39 4 1,14

5 Tota l 33,67 8 11,38 6 Th e NESCAU M assessmen t indicate s tha t roughl y7 5 percen t o f th e diese l generatin g capacit yi n th e Northeas t i s designate d fo remergenc yuse . A s noted , emergenc y generator s ar e limite d t o severa l hundre d hour s o f operatio n pe ryear . However , thi s leave s roughl y25-percen t o f th e capacit ytha t i s no t permitte d a s emergenc ycapacit y an d thu s mayb e operatin g a considerabl e amoun t durin g period s o f pea k electricit y demand . Th e emissio n rat e o f a diese l generato ri s primaril ya functio n o f tw o factors : th e typ e o f uni t (emergency , peakin g o rbaseload ) an d th e ag e o f th e unit . Generally , emergenc y unit s hav e th e highes t emissio n rate s an d baseloa d unit s hav e th e lowest . Thi s i s becaus e ai rregulators hav e historicall ythough t i n term s o f tota l annua l emissions . Unit s subjec t t o stric t operatin g limitation s ca n hav e substantiall yhighe remissio n rate s an d stil l hav e tota l annua l emission s simila rt o unit s tha t operat e more . Regardin g age , olde r generator s o f al l type s ten d t o hav e highe remissio n rate s tha n newe rones , becaus e regulator s requir e lowe remissio n rate s fo rne wunit s ove rtime , a s technolog yevolves . Thus , th e lowest-emittin g diese l generator s ar e likel yt o b e newe runit s permitte d fo r non-emergenc yuse , an d th e highes t emittin g one s ar e likel yt o b e ol d emergenc y generators . Typica l emissio n rate s fo remergenc ygenerator s ar e show n i n Tabl e 3 below . III . Diese l exhaus t Diese l exhaus t i s a mi xo f gases , vapor s an d smal l particles . Th e specifi crati o o f gase s an d vapor s t o particle s depend s o n th e typ e o f engine , th e fue l an d lubricant s use d an d o n operatin g conditions . Th e gas/vapo rportio n o f D E consist s primaril yo f typica l combustio n products : wate rvapor , oxygen , carbo n dioxid e (C0 2 

### ) , an d nitroge n oxide s (NO x 

### ) , bu t i t als o include s smalle rquantitie s o f man ytoxi csubstances . EP Aha s liste d ove r4 0 substance s foun d i n D E a s hazardou s ai rpollutants , an d th e Internationa l Agenc yfo rResearc h o n Cance r(IARC ) ha s liste d 1 5 o f the m a s carcinogen s o r probabl e carcinogens . Th e particulat e matte ri n D E consist s primaril yo f unburne d carbon , an d th e vas t majorit yo f i t fall s int o th e categoryo f fin e particulat e matter . Gases and vapors Th e toxi cgase s prevalen t i n D E include: carbo n monoxid e (CO) , sulfu roxide s (SO x 

### ) an d volatil e organi ccompound s suc h a s alkenes , aldehydes , aromati chydrocarbon s an d polycycli caromati chydrocarbon s (PAHs) . Lo wmolecula rweigh t compound s mak e u p a majorit yo f th e gas-phas e organi c compound s i n diese l exhaust , wit h acetaldehyde , formaldehyd e an d aceton e accountin g fo rmor e tha n half . Alkane s mak e u p a smalle rfractio n o f thes e compounds . Th e 4

### majorit yo f th e highe rmolecula rweigh t compound s consist s o f branche d an d cycli c

hydrocarbons . Fro m a toxicologica l perspective , th e mos t dangerou s organi ccompound s i n diese l exhaus t ar e th e aldehydes , benzene , 1,3-butadiene , an d polycycli caromati c hydrocarbon s (PAHs) . Tabl e 2 list s th e mos t importan t ai rpollutant s an d toxi cchemical s i n D E an d summarize s thei rhealt h effects . Tabl e 2 . Importan t Constituent s o f D E an d Thei rKnow n Healt h Effect s D E Componen t Atmospheri c Reactio n Product s Biologica l Impac t Carbo n dioxid e Majo rcontributo rt o globa l warmin g Carbo n monoxid e Highl ytoxi ct o human s Oxide s o f nitroge n Nitri cacid , ozon e Nitroge n dioxid e i s a respiratorytrac t irritan t an d majo r ozon e precursor . Nitri caci d contribute s t o aci d rain . Sulfu rdioxid e Sulfuri caci d Respirator ytrac t irritation ; contributo rt o aci d rai n Alkane s (#C18 ) Aldehydes , alky l nitrates , Respiratorytrac t irritation . Reactio n product s ar e ozon e precursor s (i n th e presenc e o f NOx) . Alkene s (#C4 ) (e.g. , 1,3-butadiene ) Aldehydes , ketone s Respiratorytrac t irritation . Som e alkene s ar e mutageni c an d carcinogenic . Reactio n product s ar e ozon e precursor s (i n th e presenc e o f NOx) . Formaldehyd e Carbo n monoxide , hydroperoxy l radical s Formaldehyd e i s a probabl e huma n carcinoge n an d a n ozon e precurso r (i n th e presenc e o f NOx) . Highe raldehyde s (e.g. , acetaldehyde , acrolein ) Peroxyacy l nitrate s Respiratorytrac t an d ey e irritation ; cause s plan t damage . Monocycli caromati c compound s (e.g. , benzene , toluene ) Hydroxylate d an d hydroxylated-nitr o derivatives a Benzen e i s toxi can d carcinogeni ci n humans . Som e reactio n product s ar e mutageni ci n bacteria . PAH s (< 4 rings ) (e.g. , Nitro-PAH s ( 4 rings ) Som e o f thes e PAH s an d nitre - PAH s ar e know n phenanthrene , fluoranthene ) mutagen s an d carcinogens . Nitro-PAH s ( 2 an d 3 rings ) (e.g. , nitronaphthalenes ) Quinone s an d hydroxylatednitr o derivative s Som e reactio n product s ar e mutageni ci n bacteria . Elementa l carbo n non e Nucle i adsor b organi ccompounds ; siz e permit s transpor t dee p int o th e lung s (alveoli) Inorgani csulfat e an d nitrat e non e Respiratorytrac t irritatio n Hydrocarbon s (C14 - C35 ) Littl e information ; possibl yaldehydes , ketones , an d alky l nitrate s Unknow n PAH s (> 4 rings ) (e.g. , pyrene , benzofalpyrene ) Nitro-PAH s ($ 4 rings) a Nitro-PA H lactone s Large rPAH s ar e majo rcontributor s o f carcinogen s i n combustio n emissions . Man ynitro-PAH s ar e poten t mutagen s an d carcinogens . Nitro-PAH s ($ 3 rings ) (e.g. , nitropyrenes ) Hydroxylated-nitr o derivative s Man ynitro-PAH s ar e poten t mutagen s an d carcinogens . Som e reactio n product s ar e mutageni ci n bacteria . Source: USEPA, Health

Assessment

Document

for Diesel Engine Exhaust (p. 2-87,91). 

### Particulate

Matter Ai rregulator s divid e particulat e ai rpollutio n int o severa l categorie s base d o n it s size , a s measure d i n microns . ( Amicro n i s abou t on e sevent h th e widt h o f a huma n hair. ) Th e larges t particle s fal l int o th e categoryo f PM 1 0 

### , particle s wit h a diamete ro f te n micron s o r less . Fin e particulates , o rPM 2 

### . 5 

### , ar e th e subse t o f PM 1 0

### havin g a diamete ro f 2. 5 micron s o rless . Th e recentl ycoine d ter m "ultrafin e particulates " refer s t o th e subse t o f PM2.5 havin g a diamete ro f on e micro n o rless . I n general , smalle rparticle s pos e greate rhealt h 

### 5

### threats , becaus e the yremai n suspende d i n th e ai rlonge rtha n large rparticle s an d ar e

mor e likel yt o travel pas t filterin g system s i n huma n airways int o th e lung . Diese l particulat e matte r(DPM ) usuall yrange s fro m 1 0 t o 3 5 percen t o f tota l PM 2 5 

### i n U S cities . Typicall yove r9 0 percen t o f th e P M emitte d bydiese l engine s fall s int o th e PM 2 5 

### category . Diese l fin e particle s ar e o f particula rconcer n fro m a huma n healt h perspective , because , a s th e particle s ar e forme d i n th e combustio n process , the ybecom e coate d wit h th e gas - an d vapor-phas e toxin s discusse d above . Th e toxin s typicall yrang e fro m 2 0 t o 4 0 percen t o f th e tota l particl e weight . Diese l engine s emi t particulate s at rate s significantl ygreate r(a s muc h a s 2 0 time s greater ) tha n gasolin e engines . Thi s i s primaril ybecaus e diese l fue l i s les s volatil e tha n gasoline , an d i t i s stil l largel yi n liqui d for m whe n injecte d int o th e cylinde rfo r combustion . Gasoline , i n contrast , i s injecte d primaril yi n gaseou s form . Th e liquid/ga s mixtur e o f diese l fue l burn s les s completel ytha n gasoline . Hydroge n i s strippe d fro m th e diese l hydrocarbons , an d th e remainin g carbo n tend s t o aggregat e int o particles . A numbe ro f factor s determin e th e amoun t o f particulat e emissio n fro m a give n diese l engine , includin g th e conditio n o f th e fue l injectors , th e desig n o f th e combustio n chamber , th e sea l o f th e pisto n ring s an d th e presenc e o f lubricatin g oil s a t combustion . Th e U S ha s ha d ambien t ai rqualit ystandard s fo rPM 1 0

### sinc e th e 1970s . State s striv e t o achiev e thes e ai rqualit ystandard s by , amon g othe rthings , requirin g engin e operator s t o obtai n operatin g permits , whic h includ e emissio n rat e limits . (Ambien t ai rstandard s fo r PM 2 5 

### wer e promulgate d muc h mor e recentl ys o operatin g permit s hav e onl yrecentl y begu n limitin g PM 2 5 

### . ) A s engin e technolog yha s advance d ove rtime , th e emissio n limit s facin g ne wengine s hav e becom e mor e stringent , howeve rthes e mor e stringen t requirement s hav e bee n applie d onl yt o ne wengines . Mos t existin g engine s hav e bee n "grandfathered " unde rthei rorigina l permi t limits . Becaus e man yelectri cgenset s ar e operate d a smal l numbe ro f hour s pe ryear , thes e engine s ten d t o remai n i n operatio n fo rlonge rperiod s tha n truc k engines . Thi s ha s lef t th e U S wit h a n existin g flee t o f relativel yold , high-emittin g electri cgensets . Tabl e 3 show s emissio n rate s typica l o f today' s emergenc ygenerator s i n th e U S Thes e emissio n rates , fro m th e U S EPA , represen t thos e o f a n emergenc ygenerato ri n th e rang e o f 1 0 t o 3 0 year s old . Th e emissio n rate s ar e show n i n term s o f pound s emitte d pe rMegawatt-hou ro f electricit yproduced . Not e tha t th e vas t majorit yo f th e particulat e matte remitte d i s PM 2 5 

### . Tabl e 3 . Typica l Emissio n Rate s fo ra n Emergenc yGenerato r Pollutan t Emissio n Rat e (Ib/MWh ) NO x 3 0 

## so 2 3 C 0 2 161 0 PM 1 0 0.5 7 P M 2 5 0.5 0 Formaldehyd e 0.000 8 Acetaldehyd e 0.000 3 Acrolei n 0.000 1 Benzen e 0.007 8 PA H 0.002 1 

### NO x

### emission s contribut e t o urba n smog ; S0 2 

### i s th e primarycaus e o f aci d rain ; an d C0 2 

### i s th e primarycaus e o f climat e change . Particulat e matte ran d th e toxi cpollutant s ar e th e sourc e o f th e majo rloca l healt h effect s discusse d below . 

### 6

### Exposure to diesel generator

exhaust I f diese l generator s bega n operatin g durin g period s o f hig h electricit yprices, i n additio n t o durin g powe routages , thi s woul d probabl yresul t i n operatio n fo rfou rt o si xhou r period s o n veryho t summe rafternoons . Thi s typ e o f operatio n woul d resul t i n short-ter m exposur e t o D E fo rpeopl e wh o live d o rworke d nea rth e generator . I t woul d probabl yno t resul t i n chroni cexposur e fo rthes e people . Ther e hav e bee n fe wdetaile d studie s o f th e concentration s o f D E likel yt o resul t fro m th e operatio n o f urba n diese l generators , an d mor e wor k need s t o b e don e i n thi s area . I n particular , wor k

i s neede d t o characteriz e bette rth e concentration s tha t ca n resul t whe n tal l building s slo wth e dispersio n o f pollutant s fro m urba n sources . However , estimate s an d measurement s hav e bee n mad e o f D E concentration s i n differen t place s an d ove r variou s tim e periods , an d a thes e dat a provid e a basi s fo restimatin g D E concentration s nea rurba n diese l generators . Modelin g studie s performe d durin g th e 1980 s estimate d annua l averag e DP M concentration s o f 2 t o 1 3 microgram s pe rcubi cmete r(pg/m 3 

### ) i n urba n an d suburba n areas , wit h dail ymaximu m value s o f 2 2 pg/m 3 

### . 2 

### Thes e studie s too k measurement s o f tota l PM 1 0

### i n urba n an d suburba n area s an d use d model s t o attribut e tha t PM 1 0

### t o differen t sources . DP M wa s estimate d t o constitut e 7 t o 3 6 percen t o f tota l ambien t PM 1 0 

### o n average . I n studie s performe d durin g th e 1990s , annua l averag e DP M concentration s wer e lowe r- i n th e rang e o f 1. 2 t o 4. 5 pg/m 3 

### . Th e declin e fro m th e 1980 s probabl y reflect s declinin g concentrations , bu t ma yals o reflec t change s i n modelin g tool s an d methods . I n specifi clocation s DP M concentration s ca n reac h muc h highe rlevels , particularl yi n partiall yenclose d space s an d wher e tal l building s slo wdispersion . Fo r example , DP M concentration s o f 46. 7 pg/m 3

### wer e reporte d a t a Ne wYor k Cit ybu s stop . Tabl e 4 summarize s thes e dat a an d concentration s fro m severa l occupationa l setting s cite d byEPA . Regardin g th e occupationa l data , EP Anotes , tha t concentration s a t site s wit h stationaryengine s ar e usuall yhighe rtha n a t site s wit h mobil e engines . Tabl e 4 als o show s th e curren t ambien t ai rqualit ystandar d fo rPM 1 0

### an d PM 2 5 

### . However , not e tha t DP M i s onl yon e portio n o f tota l PM , s o th e DP M concentration s i n thi s tabl e ar e no t directl ycomparabl e t o th e P M standards . (A s thes e number s imply , th e P M standard s ar e commonl yexceede d i n larg e citie s an d ca n b e exceede d b yquit e a bi t i n occupationa l settings. ) Tabl e 4 . Compariso n o f DP M Concentration s

Locatio n Typ e DP M concentratio n (pg/m" 5 ) Urba n an d suburba n annua l averag e 1. 2 t o 4. 5 Urba n an d suburba n dail ymaximu m 2 2 NY C bu s sto p dail ymaximu m 4 7

Occupatio n Minin g dail ymaximu m 7-1,28 0 Railroa d dail ymaximu m 39-19 1 Firefightin g dail ymaximu m 4-74 8 Publi cTransi t dail ymaximu m 7-9 8 Mechanic s an d Dockworker s dail ymaximu m 5-6 5 Ai rqualit ystandard s P M concentratio n (ug/nT 3 ) PM 1 0 annua l averag e 15 0 PM 1 0 dail yaverag e ? ? P M 2 5 annua l averag e 1 5 P M 2 5 dail yaverag e 6 5 Source: US EPA, Health

Assessment

Document

for Diesel Engine Exhaust (p. 2-124,125). 

### 7

### Base d o n th e availabl e dat a o n DP M concentration s i n variou s areas , i t i s reasonabl e t o

assum e tha t a diese l generato ri n a n urba n setting , operatin g fo ra perio d o f severa l hours , coul d creat e localize d concentration s o f PM 2 

### . 5 wel l abov e th e dail yaverag e standar d (6 5 pg/m 3 

### ) . IV . Non-Cance r Healt h Effect s Scientist s asses s th e healt h effect s o f ai rpollutant s usin g thre e type s o f studies : animal , huma n an d epidemiologica l studies . Al l thre e stud ytype s hav e bee n use d t o asses s th e non-cance reffect s o f exposur e t o DE . I n anima l studies , researcher s hav e expose d variou s specie s t o elevate d concentration s o f D E unde rcontrolle d condition s an d measure d th e response . The yhav e als o performe d a rang e o f othe rexperiment s i n vitr o

- i n huma n an d anima l cel l cultures . I n huma n chambe rstudies , volunteer s hav e bee n expose d t o moderat e level s o f D E an d undergon e variou s test s before , durin g an d afte r exposure . Description s o f non-scientifi cexposur e incident s als o she d ligh t o n th e huma n healt h effects . Ther e ar e severa l type s o f epidemiologica l studies . I n "time-series " studies , researcher s mak e statistica l comparison s o f dat a o n dail ypollutio n level s an d rate s o f illnes s an d deat h i n a give n area . I n "cohort " studies , researcher s loo k fo rpattern s o f diseas e i n selecte d groups , suc h a s peopl e i n differen t location s o roccupations . I n "prospective " cohort studies , researcher s follo wa grou p o rgroup s ove rtim e an d examin e pattern s o f disease . Review s o f th e literatur e o n th e non-cance rhealt h effect s o f D E hav e bee n publishe d b y th e U S EPA, 3

### th e Healt h Effect s Institute 4

### an d th e Californi a Environmenta l Protectio n Agency. 5 

### Thes e review s ar e mor e exhaustiv e an d mor e technica l tha n thi s one . Also , not e tha t th e focu s her e i s o n th e effect s o f acut e an d sub-chroni cexposure , becaus e thi s typ e o f exposur e bette rapproximate s exposur e t o diesel-fuele d electri cgenerators . Ther e i s stron g evidenc e fo rhealt h effect s fro m long-ter m exposur e t o DE , whic h i s no t discusse d here . Ther e ar e a rang e o f healt h effect s fro m short-ter m exposur e t o DE . Thes e effect s includ e transien t symptom s suc h a s ey e irritation , coughing , wheezing , dizzines s an d nausea . At th e cellula rlevel , transien t effect s includ e inflammatio n an d immunologica l responses . Ther e i s als o substantia l epidemiologica l evidenc e fo rmor e seriou s short ter m healt h effects , includin g hospitalizatio n an d death , i n sensitiv e population s expose d t o fin e particulates . The non-cancer

animal data Anima l studie s generall yexamin e th e effect s o f D E o n lun g function , respiratorytissues , and/o rinflammatio n an d immunologica l response s a t th e cellula rlevel . A t a larg e scale , th e respons e o f laboratoryanimals ' airways t o particulate s i s fairl ywel l understood , an d huma n airways ar e assume d t o operat e i n generall ysimila rways . Readil ysolubl e particle s ar e ofte n dissolve d an d cleare d i n mucu s an d othe rfluids . Les s solubl e particle s - lik e DP M - ar e targete d b ycell s o f th e immun e system , calle d macrophages . Airwa yepithelia l cell s an d activate d macrophage s releas e mediator s (cytokines , growt h factor s an d proteases ) tha t caus e inflammatio n an d ca n caus e cel l injuryan d cel l proliferation. 6 

### I n general , advers e effect s o n lun g functio n fro m acut e exposur e ar e onl ysee n i n th e contex t o f extremel yhig h concentration s - abov e severa l mg/m 3 

### . Lun g functio n i s 8

### typicall ymeasure d b yairwa yresistance , expiratoryvolum e an d othe rindices . However ,

ther e i s substantia l evidenc e tha t acut e exposur e t o concentration s les s tha n thi s resul t i n inflammatio n an d immunologica l response s a t th e cellula rlevel . Pepelk o expose d youn g rat s t o 6 t o 7 mg/m 3

### DP M fo reigh t day s an d measure d arteria l bloo d gases , bloo d pH , bod yweigh t changes , lun g volume s an d severa l othe rindices . Th e onl ysignifican t difference s wer e i n weigh t gai n an d bloo d p H - bot h lowe ri n th e expose d grou p tha n th e contro l group. 7

### Weiste ret . al . expose d youn g guine a pig s t o 6. 3 mg/m 3

### fo r2 8 day s an d teste d th e animal s durin g exposure . Increase d pulmonaryflo w resistanc e wa s observe d (3 5 percent) , bu t ther e wa s n o chang e i n severa l othe r measure s o f lun g function. 8

### Pepelk o et . al . expose d cat s t o 6. 4 mg/m 3

### DP M fo r2 8 days , an d observe d onl ymodes t change s i n lun g functio n (decrease d expiratoryflo wrat e a t 10-percen t vita l capacity) . O n histologica l examination , th e lun g tissu e appeare d charcoa l gre ywit h blac k spots , an d macrophag e aggregate s wer e foun d i n th e alveoli. 9 

### Thes e finding s demonstrat e remarkabl yrobus t lun g functio n i n th e fac e o f concentrate d particulat e exposure . I n contras t t o studie s o f lun g function , studie s o f th e cellula rrespons e t o D E hav e consistentl yfoun d evidenc e o f a n immunologica l response . Whit e an d Gar g expose d rat s t o 6 mg/m 3

### DPM , fo rtim e period s rangin g fro m si xhour s t o 63 day s an d examine d immunologica l markers. 1 0

### Afte rsi xhours , ther e wa s evidenc e o f macrophag e activity , an d afte r2 4 hour s ther e wa s upregulatio n o f certai n immun e cells . Afte rsevera l week s ther e wer e change s i n th e size , conten t an d shap e o f macrophages , thickenin g o f th e septa l wal l adjacen t t o thes e cell s an d th e appearanc e o f othe rinflammatorycells . Boutillie ret . al . foun d a n inflammatio n respons e bu t n o chang e i n standar d lun g functio n i n rat s expose d t o 4 0 mg/m 3

### o f urba n particulate s fo rfou rhours. 1 1 

### Severa l studie s o f guine a pig s expose d fo rshort period s foun d increase d airwa yresistanc e typica l o f allergi cstimulation. 12,1 3 

### Th e U S EP Aconclude s fro m th e availabl e literatur e that , wit h acut e an d sub-chroni c exposures , healt h effect s relate d t o lun g function , whe n found , ar e mil d an d resul t fro m hig h DP M concentrations . Th e agenc yals o conclude s tha t ther e i s ampl e evidenc e o f othe rpathophysiologia l effect s fro m short-ter m exposur e t o lowe rlevel s o f DE . Thes e effect s include: accumulatio n o f DP M i n pulmonarytissues , a n inflammatoryresponse , macrophag e aggregatio n an d accumulation , immun e cel l proliferatio n an d thickenin g o f alveola rwall s adjacen t t o macrophag e aggregates. 1 4

### Whil e uncertaintie s remai n aroun d thes e dynamics , particularl ywit h respec t t o th e dose-respons e relationship , th e effect s ar e generall yconsisten t wit h thos e observe d i n th e huma n exposur e dat a an d th e association s foun d b yepidemiologica l researchers . The human exposure

data Experiment s i n whic h human s ar e expose d t o D E us e moderat e concentration s o f D E (compare d t o th e anima l studies) , i n th e rang e o f 10 0 t o 30 0 ug/m 3 

### . Th e mos t commo n an d consisten t effect s o f exposur e t o D E ar e ey e irritation , coughing an d complain t o f a n unpleasan t smell . Thes e symptom s ar e reporte d consistentl yi n studie s exposin g volunteer s t o concentration s o f 20 0 pg/m 3

### an d greater . Subject s hav e als o reporte d dizziness , lightheadedness an d nause a wit h exposur e t o highe rconcentrations . Severa l studie s examinin g healt h effect s ove rth e cours e o f a Workshift i n diesel-relate d occupation s hav e reporte d al l o f thes e symptoms . Gambl e et . al . performe d a case contro l stud yexaminin g worker s durin g a shif t i n a diese l bu s garag e wit h DP M level s i n th e rang e o f 25 0 pg/m 3 

### . Expose d worker s reporte d increase d incidenc e o f burnin g eyes , 

### 9

### headaches , labore d breathing , nause a an d wheez e compare d t o th e contro l grou p (wit h

a simila rworkshif t bu t n o D E exposure). 1 5 

### Description s o f severa l incident s support thes e findings , bu t exposur e wa s no t measure d i n thes e cases . Severa l report s o f miner s expose d t o hig h concentration s o f D E describ e complaint s o f nos e an d ey e irritation , headaches , lightheadednes s an d nausea. 1 6 

### Notably , Wad e et . al . describ e railroa d worker s wh o develope d persisten t neurological symptoms , an d asthma-lik e respiratorysymptoms , workin g fo rlon g period s nea rdiese l locomotives. 1 7 

### A n inflammatio n respons e a t th e cellula rleve l i s als o a commo n findin g i n huma n exposur e studies , an d a s i n th e anima l studies , thi s respons e i s ofte n foun d i n subject s i n whic h th e standar d indice s o f lun g functio n ar e unchanged . Severa l studie s b yRudel l et . al . consistentl yfoun d cellula rmarker s o f inflammatio n i n fluid s take n fro m volunteers ' airway s afte rcontrolle d exposur e t o dilute d DE. 18,1 9 

### Nordenhal l et . al . expose d 1 5 subject s t o dilute d D E (DP M = 30 0 pg/m 3 

### ) , an d foun d significantl yelevate d marker s o f inflammatio n (neutrophile s an d solubl e proteins). 2 0

### Salv i et . al . expose d huma n volunteer s t o th e sam e concentratio n o f DP M fo ron e hou rwit h intermitten t exercise . Subject s exhibite d " a well-define d an d marke d systemi can d pulmonaryinflammatio n response.. . whic h i s underestimate d b ystandar d lun g functio n measurements." 2 1 

### Th e observe d respons e wa s characterize d b yincrease s i n neutrophil s an d lymphocyte s a s wel l a s histamin e an d fibronecti n i n bronchia l fluids . Th e Healt h Effect s Institut e (HEI ) recentl ypublishe d tw o huma n chambe rstudies , i n whic h bot h health yan d asthmati csubject s wer e expose d t o D E a t concentration s varyin g fro m 2 3 t o 31 1 pg/m 3

### o f DPM . I n on e o f thes e studie s (Gon g et . al. ) ther e wa s verylittl e differenc e i n th e response s o f th e health yan d asthmati csubjects, 2 2 

### an d i n th e othe r(Holgat e et . al.) , th e health ysubject s showe d a greate rinflammatio n respons e tha n th e asthmati csubjects. 2 3

### However , i n bot h HE I studies , th e health ysubject s presente d clea rinflammatio n responses . Th e researcher s i n th e latte rstud ystat e tha t "modes t concentration s o f diese l exhaus t [10 0 pg/m 3 

### ] hav e clear-cu t inflammatory effect s o n th e airway s o f nonasthmati csubjects." 2 4

### Th e consisten t findin g o f a marke d inflammatio n respons e a t th e cellula rleve l wit h littl e measurabl e chang e i n lun g functio n suggest s tha t thi s inflammatio n respons e wa s probabl yals o presen t i n studie s wher e onl yth e standar d indice s o f lun g functio n wer e measured . Recen t researc h ha s als o show n tha t th e inflammatio n respons e t o D E involve s th e cardiovascula rsyste m a s wel l a s th e respiratorysystem . Th e Holgat e stud ycite d i n th e previou s paragrap h als o foun d tha t exposur e t o D E resulte d i n parasympatheti c stimulatio n o f heart rat e variabilit yi n bot h th e health yan d asthmati csubjects . Anothe r recen t HE I stud yexamine d health ysubject s expose d t o concentrate d ambien t particulate s fro m Lo s Angeles . Th e subject s expose d t o particulate s showe d mea n increase s fibrinogen , i n a bloo d inflammatio n parameter , whil e th e contro l grou p di d not. 2 5 

### Th e cardiovascula reffect s o f DP M ar e discusse d furthe ri n th e sectio n o n non cance repidemiologica l researc h below . Th e evidenc e fo ra n allergi crespons e t o D E exposur e i s als o persuasive . Diaz-Sanche z et . al . hav e publishe d a numbe ro f studie s o n thi s topic , consistentl ydocumentin g increase d level s o f certai n mediator s involve d i n allergi cresponse s (e.g. , Ig E an d cytokine ) wit h exposur e t o DE. 2 6

### I n on e study , subject s produce d antigen-specifi c protein s a t a rat e 16-time s greate ri n th e presenc e o f bot h D E an d a n allergen tha n i n th e presenc e o f th e allerge n alone. 27,2 8



### 1 0

### Severa l studie s o f childre n livin g o rattendin g schoo l nea rmajo rroadway s support th e

evidenc e fo rman yo f th e healt h effect s describe d above . On e stud yfoun d th e incidenc e o f cough , wheeze , runny-nos e an d docto rdiagnose d asthm a t o b e highe ramon g childre n livin g withi n 10 0 meter s o f heavil ytravele d road s tha n amon g othe rchildren. 2 9 

### Th e associatio n wit h asthm a i s interesting , give n th e negativ e finding s i n th e HE I studie s cite d above . Brunkree f et . al . performe d tw o studie s comparin g respiratorysymptom s t o proximit yt o traffic. 30,3 1 

### Th e tw o studie s togethe rfoun d association s betwee n proximit yt o truc k traffi can d a rang e o f effect s (lun g functio n decrements , choug h an d wheeze , bronchiti can d allergi csymptoms) , althoug h som e symptom s wer e foun d i n onl yon e o f thes e studies . Th e U S EP Aprovide s a n exhaustiv e revie wo f th e anima l an d huma n exposur e dat a i n it s 200 2 Healt h Assessmen t Documen t fo rDiese l Engin e Exhaust . Base d o n thi s review , th e agenc yconclude s tha t D E probabl ycontribute s t o airwa yinflammatio n an d diseas e throug h th e releas e o f proinflammatorymediator s an d it s tendenc yt o exacerbat e th e effect s o f othe rairborn e irritants. 3 2 

### Regardin g change s i n lun g function , EP Aconclude s tha t "reversibl e change s i n pulmonaryfunction " ca n occu ri n human s i n relatio n t o D E exposure , thoug h i t i s no t possibl e a t thi s tim e t o relat e thes e change s t o specifi c exposur e levels . The non-cancer

epidemiological

data Ove rth e pas t 1 5 years , epidemiologist s hav e uncovere d a n associatio n betwee n ambien t level s o f particulat e matte ran d dail ymorbidit y(illness ) an d mortality , particularl y i n peopl e wit h lun g an d heart disease . Wor k i s ongoin g t o understan d th e mechanism s underlyin g thi s associatio n an d th e specifi cparticulate s a t cause , bu t tw o fact s sugges t tha t D E play s a significan t rol e i n th e dynamic . First , diese l particulat e matte rmake s u p a significan t portio n o f tota l particulat e matte ri n man yo f th e urba n area s studied . Second , th e stronges t associatio n i s betwee n D E an d fin e particulates , an d ove r9 0 percen t o f th e particulat e matte rbymas s i n mos t D E i s fin e particulat e matter . Som e o f th e mos t ofte n cite d epidemiologica l wor k o n fin e particulate s i s know n a s th e "Si xCities " work . Th e firs t Si xCitie s study , publishe d i n 1993 , wa s a prospectiv e cohort stud yfollowin g 8,11 1 adult s i n th e Easter n U S fo r1 5 t o 1 7 years . Afte rcontrollin g fo r potentia l confoundin g factors , th e stud yreporte d a significan t associatio n betwee n long ter m mortalit yrate s an d thre e differen t measure s o f particulat e matte r(PM 1 0 

### , PM 2 

### . 5 

### , an d sulfates) . Thi s study , an d anothe rfindin g a simila rlin k betwee n cance ran d long-ter m exposur e t o particulates , wa s heavil ycite d i n th e proceeding s tha t resulte d i n ne w ambien t fin e particulat e standard s i n 1997 , an d intens e debat e ove rth e wor k resulte d i n reconstructio n an d reanalysi s o f bot h studie s byothe rresearchers . Bot h reanalyse s replicate d an d confirmed th e finding s o f th e origina l studies. 3 3 

### Later , a time-serie s stud ywa s publishe d whic h focuse d o n dail ymortalit yi n th e sam e si x cities. 3 4

### Afte rcontrollin g fo rtim e trend s an d weather , th e stud yfoun d tha t a 1 0 pg/m 3 

### (microgra m pe rcubi cmeter ) increas e i n th e 2-da ymea n concentratio n o f PM 2 5

### wa s associate d wit h a 3.3-percen t increas e i n dail ymortalit ydu e t o lun g diseas e an d a 2.1 - percen t increas e i n mortalit yfro m heart disease . Moreover , th e stud yfoun d tha t fin e particle s wer e mor e closel yassociate d wit h mortalit ytha n cours e particulates , a fac t whic h implicate s combustion-base d pollutio n mor e tha n suspende d dus t an d soil-base d particles . Thi s stud yto o wa s reconstructe d an d reanalyze d byothe rresearchers , wh o confirme d th e finding s o f th e origina l study. 3 5



### 1 1

### Othe rtime-serie s studie s hav e show n a lin k betwee n fin e particulate s an d dail ymortalit y i n a numbe ro f differen t urba n areas , includin g London, 3 6

### Ohio, 3 7

### Philadelphia , Sant a C|ara, 3 9 

### Lo s Angeles, 40,41,4 2 

### Utah 4 3

### an d Alabama. 4 4

### Studie s hav e demonstrate d a n associatio n betwee n particulate s an d acut e illnes s (a s measure d b yhospitalization , hospita l visit s o rothe rmedica l intervention ) i n severa l citie s i n Ne wYork 4 5 

### an d i n Ontario 4 6

### an d Utah. 4 7

### Mor e recently , Zariobett i et . al . foun d a n associatio n betwee n particulat e level s an d hospita l admission s fo rheart an d lun g diseas e i n te n U S cities. 4 8 

### Peter s et . al . documen t a n associatio n betwee n hear t attack s an d PM 2 5

### i n th e greate r Bosto n area 4 9 

### an d a n associatio n betwee n intervention s fro m implante d cardia c defibrillator s an d severa l pollutant s (N0 2 

### , CO , an d PM 2 5 

### ) i n easter n Massachusetts . Mos t o f thes e studie s contro l fo rseason , temperatur e an d humidit yan d othe rpollutants . Notably , severa l time-serie s studie s hav e foun d association s betwee n dail ymortalit yan d S0 2 

### , bu t no t PM 1 0

### o rTS P ("tota l suspended particulates") . Moolgavkar 5 0

### report s suc h finding s i n severa l area s o f th e US , an d Le e et . al. 5 1 

### report suc h finding s i n dat a fro m seve n Korea n cities . Thes e finding s ar e consisten t wit h th e stronge rlin k t o fin e particle s tha n coars e particles , a s S0 2 

### ga s i s a precurso ro f sulfat e particles , on e o f th e mos t prevalen t fin e particles . Le e conclude s tha t "ther e ma yb e collinearit yproblem s wher e TS P an d S0 2 

### ar e include d i n th e sam e mode l or.. . TS P ma yfunctio n les s tha n S0 2 

### a s a surrogat e fo rfin e particle s i n th e ambien t ai ro f Korea. " Severa l meta-analyse s hav e bee n performed , whic h revie wth e epidemiologica l dat a o n fin e particulates , an d thes e studie s support th e association s wit h dail ymortalit yan d morbidity. 52,5 3

### I n addition , th e U S EP Aconclude d tha t a clea rassociatio n exist s i n it s 199 6 revie wo f th e P M ai rqualit ystandards, 5 4

### an d th e Californi a Offic e o f Environmenta l Healt h Hazar d Assessmen t (OEHHA ) cam e t o th e sam e conclusio n i n it s 199 8 Ris k Assessmen t fo rDiese l Exhaust. 5 5 

### Othe rwor k ha s specificall yinvestigate d potentia l confoundin g factor s i n th e epidemiologica l literatur e (e.g. , weathe ran d gaseou s pollutants ) an d foun d i t unlikel ytha t th e associatio n i s attributabl e t o confounding. 56,5 7 

### I n 2000 , th e Healt h Effect s Institut e (HEI ) release d th e Nationa l Mortality , Morbidit yan d Ai rPollutio n Study , a two-part stud ydesigne d specificall yt o resolv e som e o f th e uncertaintie s i n th e epidemiologica l literature. 5 8

### Th e firs t part addresse d methodologica l issue s i n th e studies , an d th e secon d part i s a large-scal e stud yo f dat a i n 9 0 U S cities . I n th e latte rpaper , Same t et . al . use d th e sam e statistica l technique s t o examin e dat a i n al l cities , providin g bot h analytica l consistenc yan d a leve l o f statistica l powe rno t foun d i n previou s studies . Th e result s ar e "generall yconsisten t wit h a n averag e approximat e 0.5-percen t increas e i n overal l mortalit yfo revery1 0 pg/m 3

### PM 1 0

### measure d th e da y befor e death. " Th e effec t wa s slightl ygreate rfo rdeath s du e t o heart an d lun g diseas e tha n fo rtota l deaths . Asubse t o f thes e dat a wer e publishe d i n th e Ne wEnglan d Journa l o f Medicine. 5 9 

### Recen t wor k

ha s focuse d o n understandin g th e healt h effect s o f differen t type s o f urba n PM . Lade n et . al . compare d mortalit ydat a t o ambien t level s o f thre e differen t kind s o f fin e particles. 6 0

### Th e author s identifie d differen t particl e type s derivin g fro m soi l an d crusta l material , moto rvehicl e exhaus t an d coa l combustion . Elevate d level s o f th e vehicle - an d coal-base d particle s wer e foun d t o b e associate d wit h increase d cardiovascula ran d pulmonarymortality , bu t a simila rassociatio n wa s no t foun d fo rth e soil-base d particles . Th e associatio n wa s stronges t fo rth e moto rvehicl e particles . Recen t researc h ha s als o focuse d o n gainin g a bette runderstandin g o f fin e particulates ' effect s o n peopl e wit h heart disease , a n associatio n mor e puzzlin g tha n th e on e betwee n particulate s an d lun g disease . Pop e et . al . foun d change s i n hear t rat e 

### 1 2

### variabilit ydurin g period s o f hig h particulat e pollution , an d Broo k et . al . foun d brachia l arteryconstrictio n i n huma n volunteer s simultaneousl yexpose d t o PM 2 5

### an d ozone . Dockerysummarize s th e epidemiologi cliteratur e o n particulat e exposur e an d cardiovascula reffects. 6 2 

### Researc h o n th e mechanism s behin d th e mortality/morbidit yrespons e i s focusin g o n th e cellula rinflammatio n response . Muc h o f th e anima l dat a implicate s thi s mechanism , an d th e mechanis m i s consisten t wit h th e observe d associatio n betwee n bot h lun g an d hear t disease . A s discusse d above , Salv i et . al . examine d inflammatoryresponse s i n th e airway s an d bloo d vessel s o f huma n volunteer s expose d t o PM 1 0 

### , an d foun d a marke d systemi cinflammatio n response. 6 3

### Nemma ret . al . hav e performe d severa l studie s examinin g th e effec t o f particulat e exposur e o n thrombu s developmen t i n bloo d vessels . ( Athrombu s i s a bloo d clo t tha t form s i n a n injure d bloo d vessel , an d vessel s blocke d b y suc h clot s ar e th e mos t commo n caus e of heart attacks. ) I n on e study , Nemma ret . al . foun d tha t particle s deposite d i n th e trache a o f hamster s enhance d thrombu s developmen t b yfacilitatin g bloo d platele t activation. 6 4

### Asecon d stud yconfirme d thes e findings , demonstratin g bot h a pulmonaryinflammatio n respons e an d bloo d platele t activation. 6 5 

### Summary

of non-cancer

effects Th e anima l an d huma n experimenta l dat a o n th e non-cance rhealt h effect s o f D E is , i n th e word s o f th e U S EPA , "extensiv e an d compelling." 6 6

### Healt h effect s o f acut e an d sub chroni cexposur e includ e transien t respiratorysymptom s a s wel l a s immunologica l an d inflammatio n responses . Th e epidemiologica l evidenc e fo rfin e particulat e matter' s rol e i n mortalit yan d morbidit yi s substantial . Ongoin g laboratoryresearc h i s focuse d o n biologi cmechanism s tha t plausibl yexplai n thi s association , includin g th e inflammatio n respons e identifie d i n th e anima l an d huma n studies . Base d o n th e availabl e data , i t i s reasonabl e t o assum e tha t DP M i s a t leas t a t harmfu l t o human s a s ambien t urba n PM2.5 . 

### Th e U S EP Aha s mad e quantitativ e assessment s o f saf e level s o f bot h PM2.5 an d DPM , althoug h thes e assessment s ar e quit e different . I n 200 2 EP Aestablishe d a chronic , non cance rreferenc e concentratio n (RfC ) fo rdiese l exhaus t o f 5 ug/m 3

### DPM . Achroni cRf C i s define d a s "a n estimat e (wit h uncertaint yspanning perhap s a n orde ro f magnitude ) o f a continuou s inhalatio n exposur e t o th e huma n populatio n (includin g sensitiv e subgroups ) tha t i s likel yt o b e withou t a n appreciabl e ris k o f deleteriou s non-cance r effect s durin g a lifetime. " I n othe rwords , EP Aconclude s tha t breathin g u p t o 5 pg/m 3

### o f DP M al l th e tim e fo ra n entir e lif e wil l no t resul t i n advers e non-cance rhealt h effects . I n additio n t o th e diese l exhaus t RfC , EP Aestablishe d a n ambien t ai rqualit ystandar d fo rPM 2 5 

### i n 1997 . Thi s standar d i s a n annua l averag e o f 1 5 pg/m 3

### an d a 24-hou raverag e o f 6 5 pg/m 3 

### . Thi s standar d i s base d o n th e healt h effect s - bot h cance ran d non-cance r

- identifie d i n EPA' s revie wo f th e scientifi cliterature , documente d i n th e 199 6 P M Criteri a Document 6 7

### an d th e 199 6 P M Staf f Paper 6 8

### I n contras t t o th e D E RfC , th e ambien t PM 2 5 

### standar d i s designe d t o protec t th e publi cfro m bot h acut e an d chroni c exposur e risks . (Th e Rf C i s no t applicabl e t o short-ter m exposures. ) Thus , th e standar d relevan t t o short-ter m exposure s i s 1 5 pg/m 3 

### . However , considerin g th e definitio n o f th e Rf C ("wit h uncertaint yspannin g perhap s a n orde ro f magnitude") , th e level s o f th e Rf C an d th e PM 2 5 

### standar d ar e ver ysimilar . A s discusse d i n Sectio n III , i t i s reasonabl e t o assum e tha t a n urba n diese l generato rcoul d creat e PM2.5 concentration s i n exces s o f th e 24-hou raverag e PM 2 5 

### standard . 

### 1 3

### V . Cance r ris k

Take n together , th e toxicological , anima l an d epidemiologica l researc h provide s stron g evidenc e tha t D E i s carcinogenic . (Huma n chambe rstudie s ar e no t use d t o evaluat e cance rendpoints. ) Th e toxicologica l wor k focuse s o n th e exposur e o f tissu e an d cell s t o D E extracts . Th e anima l researc h include s chroni can d acut e exposur e studie s o f laboratoryanimals , an d th e epidemiologica l dat a focuse s o n occupationa l setting s wher e chroni cexposur e t o D E i s common . The mutagenicity

of DE constituents D E contain s bot h know n carcinogen s an d know n mutagens . Th e ter m "mutagen " refer s t o th e abilit yo f a chemica l t o induc e geneti calteration s (gen e mutations , deletion s etc.) . Al l cancer s involv e geneti calterations , bu t no t al l geneti calteration s resul t i n cancer . I n 197 8 Huising h et . al . firs t foun d extract s o f D E t o b e mutageni ci n salmonell a bacteria. 6 9 

### Thi s findin g triggere d a considerabl e amoun t o f research , primaril ybioassays i n whic h bacteri a an d mammalia n cell s wer e expose d t o concentrate d diese l extract s i n vitro . Thi s wor k

ha s foun d D E extract s t o b e mutageni ci n bot h salmonell a an d E . col i bacteri a an d i n severa l mammalia n cel l lines . Claxto n et . al . reviewe d th e literatur e o n D E mutagenicit yi n 1983; 7 0

### th e IAR C reviewe d i t i n 1989; 7 1 

### an d th e U S EP Areviewe d i t i n 2002. 7 2 

### Notably , a t leas t thre e studie s sugges t tha t th e nitro-PAH s i n D E (nitrate d polynuclea raromati ccompounds ) ar e responsibl e fo rmos t o f it s mutageni ceffects. 73,74,7 5 

### Th e 198 9 IAR C pape rfocuse s o n th e nitro-PAHs . I n additio n t o gen e mutations , extract s o f D E hav e als o bee n show n t o caus e structura l chromosom e aberration s an d increase s i n DN Aadduct s i n animals . Bon d et . al . compare d lun g DN Aadduc t formatio n rats , mice , hamster s an d monkeys . Afte r1 2 week s o f exposur e t o hig h concentration s o f diese l particulat e matter , mic e an d hamster s showe d n o increas e i n DN Aadduct s i n periphera l lun g tissues , whil e adduct s wer e increase d i n rat s an d monkey s b y6 0 t o 8 0 percent. 7 6

### Shirname-Mor e reviewe d th e anima l researc h o n DN Aadduct s i n 1995. 7 7 

### Ther e i s als o epidemiologica l evidenc e tha t D E cause s DN Aadduct s i n humans . Bot h Nielso n et . al . an d Hemmink i et . al . foun d elevate d DN Aadduct s i n garag e worker s expose d t o DE, 78,7 9 

### an d Ho u et . al . foun d elevate d adduct s i n expose d bu s mechanics. 8 0 

### Th e U S EP Aconclude s that , "compare d wit h th e database s o f mos t othe rtoxicants , th e basi ctoxicologica l databas e fo rD E i s substantial." 8 1 

### Th e fac t tha t component s o f D E ar e carcinogeni can d mutageni cstrongl ysuggest s tha t inhalatio n o f D E ca n lea d t o cancer , bu t i t doe s no t prov e it . Thus , on e importan t goa l o f researc h o n D E i s t o determine whethe rth e carcinogen s an d mutagen s i n D E ar e bioavailabl e an d ar e take n u p b yth e bod yi n way s tha t caus e cancer . The animal research Inhalatio n exposur e t o hig h concentration s o f D E (4-1 0 mg/m 3 

### ) ha s produce d lun g tumor s i n rat s wit h som e consistency . Sub-chroni cinhalatio n exposur e ha s als o produce d cance ri n rats , bu t wit h les s consistency . Evidenc e fro m ra t studie s i n whic h D E extract s wer e instille d i n th e trachea , painte d o n ski n an d injecte d subcutaneousl y suppor t th e finding s o f th e inhalatio n studies . Th e numbe ro f studie s i s large , however , an d man ystudie s di d no t produc e a significan t cance rresponse . Interpretin g thi s bod yo f wor k bring s u p comple xissues , particularl ywit h respec t t o th e mechanis m an d th e dose/respons e relationship . Despit e th e uncertainty , th e U S EP Aan d th e Californi a 

### 1 4

### OEHH Ahav e bot h conclude d tha t chroni cexposur e t o hig h concentration s ca n lea d t o

cance ri n rats . EPA 8 2 

### provide s a n exhaustiv e revie wo f th e rat data , an d th e Californi a OEHH Aprovide s a mor e concis e one. 8 3 

### Th e studie s o f mic e d o no t provid e a clea rpictur e o f th e cance rrespons e t o DE . Pepelk o et . al. 8 4

### an d Heinric h et . al. 8 5

### produce d significantl yincrease d incidenc e o f lun g tumor s i n mic e wit h inhalatio n o f DE . Tw o othe rstudie s le d b yHeinric h (o n th e sam e mous e species ) produce d conflictin g results. 86,8 7

### Stil l othe rstudie s di d no t produc e statisticall ysignifican t cance rresponse s i n mice , an d a t leas t on e o f thes e studie s replicate d th e condition s unde rwhic h tumor s wer e produce d i n rats . Non e of th e fou rextan t hamste rstudie s report s a significan t cance rrespons e t o DE , an d othe rwor k

ha s als o show n hamster s t o b e relativel yinsensitiv e t o lun g tumors . Asmal l amoun t o f wor k

o n cat s an d monkey s i s inconclusive . Thus , th e bul k

o f th e anima l evidenc e fo rcarcinogenicit ycome s fro m th e ra t data , wit h th e dat a o n mic e providin g supporting , bu t equivocal , evidence . Importan t question s remai n abou t th e mechanis m an d th e dose/respons e relationshi p i n th e roden t cance r response . First , rat s hav e als o bee n show n t o develo p tumor s fro m hig h concentration s o f particulate s withou t th e adsorbe d organic s foun d i n D E (e.g. , carbo n black). 8 8

### Thes e finding s hav e give n ris e t o a "lung-burden " theor yo f th e cance rmechanism . Thi s i s th e ide a tha t hig h concentration s o f particulat e matte roverwhel m th e rodent' s lun g clearin g capacit yan d th e resultin g particulat e burde n damage s tissues , leadin g t o a cel l proliferatio n (cancerous ) response . However , othe rwor k

indicate s tha t whol e D E (includin g th e organi cmutagens ) i s mor e carcinogeni ctha n DP M strippe d o f th e organics . Rittinghause n et . al . instille d 1 5 m g o f whol e D E i n th e trache a o f rat s an d foun d a 17-percen t incidenc e o f tumor s compare d t o a 2-percen t incidenc e i n rat s instille d wit h extracte d DP M (n o organics). 8 9 

### Iwa i et . al . als o foun d tha t whol e D E wa s mor e carcinogeni ctha n DP M strippe d o f it s organic s ( a 31 - percen t tumo rrat e versu s 1 4 percen t o n a lun g burde n basis) . Studie s b yGimme ret . al . specificall yimplicat e th e PAH s i n DE . I n thi s work , D E extract s wer e separate d int o PAH-lade n an d PAH-fre e fractions , an d th e extract s wer e implante d i n rat' s lungs . Th e fractio n wit h PAH s produce d a 25-percen t tumo rrate , an d th e fractio n withou t PAH s produce d n o tumors.(cite ) Thes e studie s an d other s sugges t tha t whol e D E i s likel yt o b e mor e carcinogeni ctha n a n equa l amoun t o f particulat e matte rwithou t th e organi c mutagens . Further , b yshowin g tha t th e organic s i n D E ca n b e bot h bioavailabl e an d carcinogeni ci n rodents , thi s wor k leave s ope n th e possibilit yo f mutageni cactivit ya t muc h lowe rconcentrations . Mor e wor k explorin g thi s possibilit yi s needed . Recently , a thir d hypothesi s ha s emerge d regardin g th e carcinogenicit ymechanis m i n rodents . Macrophage s an d lymphati ccell s i n severa l roden t specie s produc e elevate d level s o f oxidan t reactant s whe n challenge d b yforeig n particles . Unde rcertai n circumstance s thes e oxidan t reactant s ca n initiat e a proces s tha t ca n damag e DNA. 9 0 

### Ongoin g researc h i s focuse d o n determinin g whethe rthi s proces s ca n translat e fin e particulat e exposur e int o lun g tumor s i n rodents . Thus , whil e th e evidenc e fo ra cance rrespons e i n rat s i s sufficient , th e mechanis m i s uncertain , an d thi s add s t o th e uncertaint yabou t th e dose/respons e relationships . Th e "particle-burden " theor yand , t o a lesse rextent , th e "oxidan t reactant " theoryimpl ya dose/respons e relationship . Tha t is , mor e particle s i n th e lun g increas e th e ris k o f cancer . I n contrast , th e organic s i n DE , whic h ar e carcinogeni ca t hig h concentrations , ma yals o b e carcinogeni ca t lo wconcentrations . Notably , whil e D E constituent s lik e 

### 1 5

### benzen e ar e know n carcinogens , threshold s hav e no t bee n identifie d fo rthei r

carcinogeni ceffects . Th e trut h abou t th e cance rmechanis m i n rat s ma yno t b e simple . I t seem s probabl e tha t mor e tha n on e mechanis m exists , an d mor e tha n on e ma yb e involve d i n an ygive n cance rresponse . The epidemiological

data Th e evidenc e fro m epidemiologica l studie s i s considere d strongl ysupportiv e o f a findin g tha t D E i s "causall yrelated " t o lun g cancer , althoug h ther e ar e considerabl e uncertaintie s withi n thi s bod yo f work . Th e literatur e consist s primaril yo f thre e stud y types : population-base d case-contro l studie s o f lun g cance ran d cohort an d case-contro l studie s o f worker s i n selecte d industries . Thes e studie s generall yfocu s o n th e risk s o f chroni cexposur e t o DE ; thu s w e provid e a verybrie f revie wo f thi s work . Th e genera l population-based , case-contro l studie s revie wth e occupationa l historyo f cance rpatient s an d compar e thes e dat a t o tha t o f a contro l group . A s a whole , thes e studies , al l o f whic h contro l fo rcigarett e smoking , hav e consistentl yfoun d increase d incidenc e o f cance ri n truc k drivers , railroa d workers , heavyequipmen t operator s an d fo r self-reporte d diese l exposur e i n general. 9 1 

### Th e occupationa l studie s identifyworker s i n position s likel yt o b e chronicall yexpose d an d determine whethe rther e i s increase d lun g cance rwithi n thi s grou p relativ e t o th e genera l population . Thes e studies , no t al l o f whic h contro l fo rsmoking , hav e consistentl y identifie d statisticall ysignifican t elevation s i n lun g cance rrates . Importan t studie s includ e examination s o f truc k drivers , garag e mechanic s an d railroa d workers. 9 2 

### Amon g th e mos t influentia l studie s hav e bee n th e studie s o f railroa d worker s performe d b y Garshi k et . al. 93,9 4

### an d th e studie s o f truc k driver s performe d bySteenlan d et . al. 95,9 6 

### Althoug h thes e studie s identif yconsistentl yelevate d incidenc e o f cance ramon g expose d populations , ther e ar e significan t uncertaintie s associate d wit h th e findings . First , fe wo f th e studie s measure d th e exposur e o f th e workers ; rathe rthe y reconstructe d exposur e retrospectively . Second , i n man yo f th e studie s ther e i s insufficien t contro l fo rpotentia l confoundin g factors , suc h a s smoking . Despit e thes e uncertainties , severa l meta-studie s o f th e epidemiologica l literatur e hav e conclude d tha t ther e i s a n associatio n betwee n chroni cexposur e t o D E an d lun g cancer . I n 199 5 th e Healt h Effect s Institut e reviewe d ove r3 0 studie s an d foun d a wea k bu t relativel yconsisten t associatio n betwee n exposur e an d lun g cancer. 9 7

### HE I conclude d tha t occupationa l exposur e t o D E fro m divers e source s increase s th e rat e o f lun g cance r b y2 0 t o 4 0 percen t i n expose d worker s generally , an d t o a greate rexten t amon g worker s wit h prolonge d exposure . HE I als o foun d tha t th e result s ar e no t explicabl e b y confoundin g cause d b ycigarett e smokin g o rothe rknow n source s o f bias . I n 199 8 th e Californi a OEHH Aals o reviewe d 3 0 studie s an d foun d tha t al l bu t fiv e o f the m reporte d a t leas t on e positiv e associatio n betwee n diesel-relate d occupation s o rexposur e an d lun g cancer , althoug h som e wer e no t statisticall ysignificant. 9 8 

### The California

ARB's interpretation

of the data I n 1998 , afte ra n exhaustiv e revie wo f th e availabl e data , th e Californi a AR B conclude d tha t diese l exhaus t i s a know n carcinoge n an d issue d a uni t ris k numbe rfo rchroni c exposure . Th e AR B base d thi s findin g o n th e weigh t o f evidenc e foun d i n th e epidemiological , anima l an d toxicologica l literatur e combined . Regardin g th e epidemiologica l work , th e AR B note d tha t mor e tha n 3 0 studie s ar e consisten t wit h a n 

### 1 6associatio n betwee n diese l exhaus t an d lun g cancer . Ake yfacto ri n th e ARB' s

assessmen t o f thes e dat a wa s th e meta-analysi s o f th e epidemiologica l literatur e performe d b yth e Californi a OEHH A(discusse d above) , whic h foun d tha t "statisticall y significan t poole d estimate s o f relativ e ris k persiste d throug h numerou s subse t an d sensitivit yanalyses." 9 9 Th e AR B viewe d th e anima l an d toxicologica l dat a a s consisten t wit h th e epidemiologica l dat a an d supportiv e o f a causa l association . I n particular , th e AR B cite d th e ra t studie s an d th e wor k showin g tha t constituent s o f diese l exhaus t ar e mutageni can d carcinogenic . Base d o n th e epidemiologica l data , th e AR B establishe d a lifetim e ris k figur e o f 3 x10~ 4 pe rug/m 3 , o r30 0 additiona l cance rdeath s pe rmillio n peopl e pe rpg/m 3 . Thi s figur e represent s th e additiona l cance rris k fro m chroni cexposur e t o diese l exhaus t ove ra 70 - yea rlifetime . Base d o n estimate d averag e level s o f D E i n th e stat e (average d ove rbot h indoo ran d outdoo rareas ) o f 1.5 4 pg/m 3 , thi s represent s roughl y45 0 cance rcase s pe r millio n Californian s du e t o DE . However , thi s assessmen t o f chroni cris k ma yhav e littl e relevanc e t o th e risk s fro m acut e an d sub-chroni cexposure . Regardin g shorte rter m exposures , th e AR B note d onl ytha t tha t the yha d no t identifie d a threshol d fo rth e carcinogeni ceffect s o f DE . EPA's interpretation

of the cancer data EP Arelease d it s comprehensiv e Healt h Assessmen t Documen t fo rDiese l Engin e Exhaus t ir i Ma yo f 2002 . Base d o n th e bod yo f evidenc e fro m human , anima l an d othe r studies , thi s assessmen t conclude s tha t diese l exhaus t i s "likel yt o b e carcinogeni ct o human s b yinhalatio n an d tha t thi s hazar d applie s to . environmenta l exposur e conditions. " EP Abase s thi s decisio n o n th e followin g evidence : • Stron g bu t les s tha n sufficien t epidemiologi cevidenc e fo ra causa l associatio n betwee n D E exposur e an d increase d ris k o f lun g cance ramon g worker s i n differen t occupations ; • Evidenc e o f carcinogenicit yo f DP M i n rat s an d mic e b ynoninhalatio n route s o f exposur e (intratrachea l instillation , lun g implantation , ski n painting , an d subcutaneou s injection) ; an d • Extensiv e supportin g dat a includin g th e demonstrate d mutageni cand/o r chromosoma l effect s o f D E an d it s organi cconstituents , suggestiv e evidenc e fo r th e loca l an d systemi cbioavailabilit yo f th e organic s fro m DE , an d knowledg e o f th e know n mutageni cand/o rcarcinogeni cactivit yo f a numbe ro f individua l organi ccompound s presen t o n th e particle s (e.g. , PA H an d derivatives ) an d i n th e D E gase s (e.g. , benzene , 1, 3 butadiene , an d aldehydes). 1 0 0 Th e agenc ynote s tha t th e evidenc e fo ra hazar d i s strengthene d b yth e fac t tha t concentration s o f diese l exhaus t commonl yfoun d i n th e environmen t ar e clos e to , i f no t overlapping , th e occupationa l exposure s examine d i n thes e studies . Du e t o th e hig h concentration s use d i n th e ra t inhalatio n studies , EP Adoe s no t fin d thes e dat a predictiv e o f a huma n hazar d a t lowe renvironmenta l responses . EP Adoe s no t deriv e a cance runi t ris k estimat e i n th e Healt h Assessmen t Document , bu t the yd o provid e a detaile d discussio n o f th e availabl e dat a o n th e dose-respons e relationshi p o f th e cance rendpoin t an d th e uncertaintie s i n thos e data. 1 0 1 EP Adoe s no t stat e whethe rit s findin g tha t D E is . a probabl e carcinoge n applie s t o bot h chroni cand . acut e exposures , an d thi s i s consisten t wit h th e uncertaint yaroun d th e mechanism s o f th e cance rrespons e an d th e dose/respons e relationships . Base d o n th e 

### 1 7existin g literature , EP Aconclude s tha t ther e ma yno t b e a threshol d fo rcance reffects .

Charle s Ri s o f EP Awrites , "i n th e absenc e o f a mor e complet e understandin g o f ho w diese l exhaus t ma ycaus e advers e healt h effect s i n human s an d laborator yanimals , relate d assumption s (i.e. , th e presenc e o f a biologica l threshol d fo rchroni crespirator y effect s base d o n cumulativ e dosag e an d th e absenc e o f a threshol d fo rlun g cance r stemmin g fro m subtl e an d irreversibl e effects ) ar e considere d reasonabl e an d prudent." 1 0 2 Regardin g th e issue s o f mechanis m an d threshold , EP Awrites : Th e particl e overloa d hypothesi s appear s sufficien t t o accoun t fo rDE-induce d lun g cance ri n rats . However , ther e i s als o biologica l plausibilit yfo rlun g cance rinduction i n human s at concentration s insufficien t t o induc e lun g particl e overloa d a s see n i n rats . Th e uptak e o f particle s b yepithelia l cell s a t ambien t o roccupationa l exposur e levels , DNAdamag e resultin g fro m oxygen-fre e radical s generate d fro m organi cmolecules , an d th e gradua l i n sit u extractio n an d activatio n o f procarcinogen s associate d wit h th e diese l particle s ma ypla ya rol e i n thi s respons e an d provid e a basi s fo rth e plausibility . Th e slowe rparticl e clearanc e rate s i n human s (u p t o a yea ro rmore ) ma yresul t i n greate r extractio n o f organics . Thi s i s supporte d b yreport s o f increase d DN Aadduct s i n human s occupationall yexpose d t o D E a t concentration s unlikel yt o induc e lun g particl e overload. 1 0 3 VI . Conclusion s Ther e i s stron g evidenc e tha t acut e an d sub-chroni cexposur e t o moderat e level s o f D E result s i n non-cance rhealt h effects . D E als o contain s know n mutagen s an d carcinogens , an d thes e chemical s represen t a plausibl e mechanis m fo rcance rresultin g fro m acut e an d sub-chroni cexposure . However , ther e i s considerabl e uncertaint y aroun d th e potentia l fo rcance rfro m non-chroni cexposure . D E als o contribute s t o urba n smog , whic h pose s healt h risk s t o asthmatic s an d othe rsubgroups . However , smo g i s a regiona l problem , cause d b ypollutio n fro m man ydifferen t sources , an d diese l generator s ar e a relativel ysmal l sourc e o f smo g precursors . Thu s w e d o no t addres s th e healt h effect s o f smo g here . I n a numbe ro f laborator ytests , health yhuman s hav e bee n expose d t o moderat e level s o f DE , i n th e rang e o f 10 0 t o 30 0 pg/m 3o f diese l particulat e matte r("DPM") . (DP M i s commonl yuse d a s a surrogat e measur e o f whol e DE. ) Consistentl yobserve d symptom s includ e coughing , wheezin g an d ey e an d nos e irritation . Dizziness , nause a an d othe r neurologica l symptom s ca n resul t fro m exposur e t o highe rconcentrations . D E ha s als o bee n show n t o exacerbat e existin g allergies . I n additio n t o thes e symptoms , exposur e t o D E result s i n wel l documente d inflammator yan d immunologica l response s a t th e cellula r leve l i n bot h th e respirator yan d cardiovascula rsystems . Aconsiderabl e bod yo f anima l researc h provide s additiona l informatio n abou t thi s inflammation/immun e response . Exposur e t o D E ma ypos e muc h mor e seriou s risks , however , t o peopl e wit h lun g an d hear t disease . Epidemiologica l studie s hav e establishe d a clea rlin k betwee n exposur e t o urba n fin e particulat e matte ran d dail yillnes s an d mortalit yfro m lun g an d hear t disease . Wor k

i s ongoin g t o understan d th e mechanism s underlyin g thi s associatio n an d th e specifi cparticle s a t cause , bu t i t appear s tha t th e cellula rresponse s t o particulat e exposur e includ e mechanism s tha t ca n caus e acut e respirator yan d cardia cdistres s an d death . Tw o fact s sugges t tha t D E play s a significan t rol e i n th e dynamic . First , diese l particulat e matte rmake s u p a significan t portio n o f ambien t fin e particulat e matte ri n man yo f th e urba n area s studied . Second , althoug h ther e ar e association s wit h severa l pollutants , th e stronges t associatio n i s betwee n fin e particulate s an d dail yhealt h effects , 

### 1 8

### an d ove r9 0 percen t o f th e particulat e matte rb ymas s i n mos t D E i s fin e particulat e

matter . Th e researc h o n D E exposur e an d cance rha s yielde d les s certai n conclusions . Ther e i s reasonabl ystron g epidemiologica l evidenc e tha t chroni cexposur e t o D E (usuall ystudie d i n a n occupationa l setting ) lead s t o lun g cancer . Chroni cexposur e t o hig h concentration s ha s als o bee n show n t o produc e lun g tumor s i n rats . Base d largel yo n th e epidemiologica l data , th e U S EP Aha s labele d D E a "probable " carcinogen , an d th e Californi a Ai rResource s Boar d ha s labele d i t a "known " carcinoge n an d establishe d a uni t ris k numbe rfo rchroni cexposure . However , thes e finding s ma ytel l u s littl e abou t whethe rshorter-ter m an d mor e periodi cexposur e t o D E ca n caus e cancer . Th e stronges t evidenc e tha t short-ter m exposur e coul d lea d t o cance rlie s i n th e know n carcinogen s an d mutagen s withi n DE . Thes e chemical s includ e benzene , formaldehyde , acetaldehyde , acrolei n an d PAHs . Importantly , ther e i s n o know n threshol d fo rth e carcinogenicit yo f som e o f thes e chemical s (e.g. , benzene) . However , mor e wor k need s t o b e don e t o determin e whethe rthes e chemical s produc e cance ri n th e cas e o f inhalatio n exposur e t o DE . Currently , th e weigh t o f evidenc e suggest s tha t longe r exposur e period s ar e mor e likel yt o lea d t o cance rtha n shorte rones , bu t tha t th e potentia l fo rcance rresultin g fro m shorter-ter m exposure , vi a a non-threshold , mutageni c mod e o f action , canno t b e rule d out.

1 Northeas t State s fo rCoordinate d Ai rUs e Management . 2003 . StationaryDiese l Engine s i n th e Northeast : A n Initia l Assessmen t o f th e Regiona l Population , Contro l Technolog yOption s an d Ai rQualit yPolic yIssue s (www.nescaum.org) . 2 U S Environmenta l Protectio n Agency . 2002 . Healt h assessmen t documen t fo rdiese l engin e exhaust . Prepare d b yth e Nationa l Cente rfo rEnvironmenta l Assessment , Washington , DC , fo rth e Offic e o f Transportatio n an d Ai rQuality ; EPA/600/8-90/057F , p . 2-124,125 . 3U S Environmenta l Protectio n Agenc y(EPA) . 2002 . 4Healt h Effect s Institut e (HEI) . 1995 . Diese l exhaust : a critica l analysi s o f emissions , exposure , an d healt h effects : a specia l report o f th e Institute' s Diese l Workin g Group . Cambridge , MA : Healt h Effect s Institute . 5 Californi a Environmenta l Protectio n Agency , Offic e o f Environmenta l Healt h Hazar d Assessment . 1998 . Healt h Assessmen t Documen t fo rDiese l Engin e Exhaust , Par t B : Healt h Ris k

Assessmen t fo rDiese l Exhaust . 6Thi s descriptio n i s base d o n U S EPA , 2002 . Sectio n 5.2.2 . 7Pepelko , WE . 1982 . Effect s o f 2 8 day s exposur e t o diese l engin e emission s i n rats . Environ . Res . 27:16 - 23 . 8Wiester , MJ , e t al . 1980 . Altere d functio n an d histolog yi n guine a pig s afte rinhalatio n o f diese l exhaust . Environ . Res . 22:285-297 . 9 Pepelko , WE , e t al . 1980 . Pulmonaryfunctio n an d patholog yi n cat s expose d 2 8 day s t o diese l exhaust . J Enviro n Patho l Toxico l 4:449-458 . 1 0White , HJ ; Garg , BD . 1981 . Earl ypulmonaryrespons e o f th e ra t lun g t o inhalatio n o f hig h concentratio n o f diese l particles . J App l Toxico l 1:104-110 . 1 1 Bouthillier , L . 1998 . Acut e effect s o f inhale d urba n particle s an d ozone . America n Journa l o f Pathology , 153(6) : 1873-1884 . 1 2 Kobayashi , T ; Ito , T . 1995 . Diese l exhaust particulate s induc e nasa l mucosa l hyperresponsivenes s t o inhale d histamin e aerosol . Funda m App l Toxico l 27:195-202 . 1 3Kobayashi , T , etal . 1997 . Short-ter m exposur e t o diese l exhaus t induce s nasa l mucosa l hyperresponsivenes s t o histamin e i n guine a pigs . Funda m App l Toxico l 38:166-172 . 1 4U S EPA , 2002 , Sectio n 5 . 1 5 Gamble , J , e t al . 1987 . Epidemiological-environmenta l stud yo f diese l bu s garag e workers : acut e effect s o f N0 2 an d respirabl e particulat e o n th e respiratorysystem . Enviro n Re s 42:201-214 . 

### 1 91 6Kahn , G , e t al . 1988 . Acut e overexposur e t o diese l exhaust : report o f 1 3 cases . A m J Iri d Me d 13:405 -

406 . 1 7Wade , JF , e t al . 1993 . Diese l asthma : reactiv e airway s diseas e followin g overexposur e t o locomotiv e exhaust . J Occu p Me d 35:149-154 . 1 8Rudell , B , e t al . 1990 . Controlle d diese l exhaust exposur e i n a n exposur e chamber : pulmonaryeffect s investigate d wit h bronchoalveola rlavage . J Aeroso l Sc i 21(suppl . 1):S411-S414 . 1 9 Rudell , B , e t al . 1996 . Effect s o n symptom s an d lun g functio n i n human s experimentall yexpose d t o diese l exhaust . Occu p Enviro n Me d 53:658-662 . 2 0Nordenhall , C , e t al . 2000 . Airwa yinflammatio n followin g exposur e t o diese l exhaust : a stud yo f tim e kinetic s usin g induce d sputum . Eu rRespi rJ 15:1046-1051 . 2 1 Salvi , Sundeep , et . al . 1999 . Acut e inflammatoryResponse s i n th e Airway s an d Periphera l Bloo d Afte r Short Ter m Exposur e t o Diese l Exhaus t i n Health yHuma n Volunteers . America n Journa l o f Respiratoryan d Critica l Car e Medicin e 159:702-709 . 2 2 Gong , H Jr . 2003 . Controlle d Exposure s o f Healt h an d Asthmati cVolunteer s t o Concentrate d Ambien t Particle s i n Metropolita n Lo s Angeles . Researc h Report 11 8 o f th e Healt h Effect s Institute . 2 3Holgate , ST , e t al . 2003 . Healt h effect s o f acut e exposur e t o ai rpollution : Par t I , Health yan d asthmati c subject s expose d t o diese l exhaust . Researc h Repor t 11 2 o f th e Healt h Effect s Institute . 2 4Holgate , ST , e t al . 2003 . p p 1 . 2 5 Holgate , ST , e t al . 2003 . Healt h effect s o f acut e exposur e t o ai rpollution : Par t II , Health ysubject s expose d t o concentrate d ambien t particulate s expose d t o diese l exhaust . Researc h Report 11 2 o f th e Healt h Effect s Institute . 2 6Diaz-Sanchez , D , e t al . 1996 . Enhance d nasa l cytokin e productio n i n huma n being s afte ri n viv o challeng e wit h diese l exhaus t particles . J Allerg yCli n Immuno l 98:114-123 . 2 7Diaz-Sanchez , D , e t al . 1997 . Combine d diese l exhaus t particulat e an d ragwee d allerge n challeng e markedl yenhance s huma n i n viv o nasa l ragweed-specifi cIg E an d skew s cytokin e productio n t o a Thelpe r cel l 2-typ e pattern . J Immuno l 158:2406-2413 . 2 8Diaz-Sanchez , D , e t al . 1999 . Nasa l challeng e wit h diese l exhaust particle s ca n induce sensitizatio n t o a neoallerge n i n th e huma n mucosa . J Allerg yCli n Immuno l 104(6) : 11.83-1188 . 2 9 va n Vliet , P , e t al . 1997 . Moto rvehicl e exhaus t an d chroni crespiratorysymptom s i n childre n livin g nea r freeways . Enviro n Re s 74(2) : 122-132 . 3 0Brunekreef , B , e t al . 1997 . Ai rpollutio n fro m truc k traffi can d lun g functio n i n childre n living nea r motorways . Epidemiolog y8(3):298-303 . 3 1 Brunekreef , B , e t al . 2000 . Traffi crelate d ai rpollutio n an d it s effec t o n respiratoryhealt h o f childre n livin g nea rmotorways . Presente d at : P M 2000 : Particulat e matte ran d health-th e scientifi cbasi s fo rregulatory decision-making . Sponsore d b yth e Ai ran d Wast e Managemen t Association , January24-28 , 2000 . 3 2 U S EPA . 2002 . p . 5-14. 3 3Healt h Effect s Institute . 2000 . Th e Nationa l Morbidity , Mortalit yan d Ai rPollutio n Study . Healt h Effect s Institute , Reanalysi s o f th e Harvar d Si xCitie s Stud yan d th e America n Cance rSociet yStud yo f Particulat e Ai rPollutio n an d Morbidity . 3 4Schwart z J , et . al . 1996 . I s dail ymortalit yassociate d specificall ywit h fin e particles ? Journa l o f th e Ai r an d Wast e Managemen t Associatio n 46:927-939 . 3 5 Klem m RJ , et . al . 2000 . I s dail ymortalit yassociate d specificall ywit h fin e particles ? Dat a reconstruction an d replicatio n o f analysis . Journa l o f th e Ai ran d Wast e Managemen t Associatio n 50:1215-1222 . 3 6Schwart z J . an d Marcu s A . 1990 . Mortalit yan d ai rpollutio n i n London : Atime-serie s analysis . A m J Epidemio l 131:185-94 . 3 7Schwart z J . an d DockeryDW . 1992 . Particulat e ai rpollutio n an d dail ymortalit yi n Steubenville , Ohio . A m J Epidemio l 135:12-20. 3 8Schwart z J . an d DockeryDW . 1991 . Increase d mortalit yi n Philadelphi a associate d wit h dail yai rpollutio n concentrations . A m Re vRespi rDi s 145:600-4 . 3 9 Fairley , D . 1999 . Dail ymortalit yan d ai rpollutio n i n Sant a Clar a County , California : 1989-1996 . Environmenta l Healt h Perspective s 107(8):637-41 . 4 0Shumwa yRH , e t al . 1988 . Modelin g mortalit yfluctuation s i n Lo s Angele s a s function s o f pollutio n an d weathe reffects . Enviro n Re s 45:224-41 . 

### 2 04 1 Kinne yPL , an d Ozkayna k H . 1991 . Association s o f dail ymortalit yan d ai rpollutio n i n Lo s Angele s County . Enviro n Re s 54:99-120 . 4 2 Ostr o B . 1995 . Fin e particulat e ai rpollutio n an d mortalit yi n tw o Souther n Californi a counties . Enviro n Re s 70:98-104 . 4 3Pop e CAIII , e t al . 1992 . Dail ymortalit yan d PM1 0 pollutio n i n Uta h Valley . Arc h Enviro n Healt h 42:211-7 . 4 4Schwart z J . 1993 . Ai rpollutio n an d dail ymortalit yi n Birmingham , AL . A m J Epidemio l 137:1136-47 . 4 5 Thursto n GP , e t al . 1992 . Amulti-yea rstud yo f ai rpollutio n an d respiratoryhospita l admission s i n three Ne wYor k

Stat e metropolita n areas : Result s fo r198 8 an d 198 9 summer . J Expo s Ana l Enviro n Epidemio l 2:429-50 . 4 6Burnet t RT , e t al . 1995 . Association s betwee n ambien t particulat e sulphat e an d admission s t o Ontari o hospital s fo rcardia can d respiratorydiseases . A m J Epidemio l 142:15-22 . 4 7Pop e C AIII . 1991 . Respiratoryhospita l admission s associate d wit h PM1 0 pollutio n i n Utah , Sal t Lak e an d Cach e Valleys . Arc h Enviro n Healt h 46:90-7 . 4 8Zanobett i A , e t al . 2000 . Airborn e particle s ar e a ris k facto rfo rhospita l admission s fo rheart an d lun g disease . Environmenta l Healt h Perspective s 108(11):A520-1 . 4 9 Peter s A , e t al . 2001 . Increase d particulat e ai rpollutio n an d th e triggerin g o f myocardia l infarction . Circulatio n 103:2810-2815 . 5 0Moolgavkar , SH . 2000 . Ai rpollutio n an d dail ymortalit yi n three U S counties . Enviro n Healt h Perspec t 108:521-525 . 5 1 Le e JT , e t al . 2000 . Ai rpollutio n an d dail ymortalit yi n seve n majo rcitie s o f Korea , 1991-1997 . Enviro n Re s 84(3):247-25 4 5 2 Rosales-Castill o JA , et . al . 2001 . Acut e effect s o f ai rpollutio n o n health : evidenc e fro m epidemiologica l studies . Salu d Public a Mexic o 43(6):544-55 . 5 3Stieb DM , et . al . 1999 . Meta-analysi s o f time-serie s studie s o f ai rpollutio n an d mortality : effect s o f gase s an d particle s an d th e influenc e o f caus e o f death , ag e an d season . Journa l o f th e Ai ran d Wast e Managemen t Associatio n 52(4)470-84 . 5 4U S EPA . 1996 . Revie wo f Nationa l Ambien t Ai rQualit yStandard s fo rParticulat e Matter : Policy Assessmen t o f scientifi can d technica l information . OAQP S Staf f Paper . EPA-452/R-96-013 . Washingto n DC . 5 5 Californi a Environmenta l Protectio n Agency , Offic e o f Environmenta l Healt h Hazar d Assessment . Healt h Assessmen t Documen t fo rDiese l Engin e Exhaust , Part B : Healt h Ris k Assessmen t fo rDiese l Exhaust , Ma y 1998 . 5 6Samet , J , et . al . 1988 . Doe s weathe rconfoun d o rmodif yth e associatio n o f particulat e ai rpollutio n wit h mortality ? A n analysi s o f th e Philadelphi a data , 1973-1980 . Environmenta l Research , Apri l 1998 , p p 9-19 . 5 7Schwart z J . 2004 . I s th e associatio n o f airborn e particle s wit h dail ydeath s confounde d b ygaseou s ai r pollutants ? A n approac h t o contro l b ymatching . Environmenta l Healt h Perspectives , Apri l 2004 , p p 557-61 . 5 8Samet , J , e t al . 2000a . Th e Nationa l Morbidity , Mortalit yan d Ai rPollutio n Study . Healt h Effect s Institut e researc h report 94 , HEI , Boston , Massachusetts . 5 9 Same t J , et . al . 2000b . Fin e Particulat e Ai rPollutio n an d Mortalit yi n 2 0 U S Cities , 1987-1994 . Th e Ne w Englan d Journa l o f Medicin e 343(24) : 1742-1749 . 6 0Laden , F , et . al . 2000 . Associatio n o f fin e particulat e matte rfro m differen t source s wit h dail ymortalit yi n si xU S cities . Environmenta l Healt h Perspective s 108(10):941-7 . 6 1 Pop e C . 1999 . Heart rat e variabilit yassociate d wit h particulat e ai rpollution . America n Heart Journa l 138:890-899 . 6 2 Dockery , DW . 2001 . Epidemiologi cevidenc e o f cardiovascula reffect s o f particulat e ai rpollution . Environmenta l Healt h Perspective s 109 , Suppl . 4:483-6 . 6 3Salvi , S . e t al . 1999 . 6 4Nemma rA , e t al . 2002 . Ultrafin e particle s affec t experimenta l thrombosi s i n a n i n viv o hamste rmodel . A m J Respi rCri t Car e Me d 166:998-1004 . 6 5 Nemmar , A . 2003 . Diese l exhaus t particle s i n lun g acutel yenhanc e experimenta l periphera l thrombosis . Circulatio n 107:1202-1208 . 6 6U S EPA . 2002 . p . 6-1 . 

### 2 16 7U S EPA . 1996a . Ai rqualit ycriteria fo rparticulat e matter . Researc h Triangl e Park , NC : Nationa l Cente r

fo rEnvironmenta l Assessment-RT P Office ; repor t nos . EPA/600/P-95/001aF-cF . 3v . 6 8U S EPA . 1996b . Revie wo f th e nationa l ambien t ai rqualit ystandard s fo rparticulat e matter : polic y assessmen t o f scientifi can d technica l information . OAQP S staf f paper . Researc h Triangl e Park , NC : Offic e o f Ai rQualit yPlannin g an d Standards ; report no . EPA/452/R-96-013 . Availabl e from : NTIS , Springfield , VA ; PB9 7 115406REB . 6 9 Huisingh , J , e t al . 1978 . Applicatio n o f bioassa yt o th e characterizatio n o f diese l particl e emissions . In : Applicatio n o f short-ter m bioassay s i n th e fractionatio n an d analysi s o f comple xenvironmenta l mixtures : [proceeding s o f a symposium ; February ; Williamsburg , VA] . (Hollaender , A ; Probstein , F ; Welch , BL , eds . Environmenta l scienc e research : v . 15. ) Waters , MD ; Nesnow , S ; Huisingh , JL ; e t al. , eds . Ne wYork : Plenu m Press ; pp . 383-418 . 7 0Claxton , LD . 1983 . Characterizatio n o f automotiv e emission s bybacteria l mutagenesi s bioassay : a review . Enviro n Mutage n 5:609-631 . 7 1 Internationa l Agenc yfo rResearc h o n Cancer . 1989 . Diese l an d gasolin e engin e exhaust s an d som e nitroarenes . (IAR C monograph s o n th e evaluatio n o f carcinogeni crisk s t o humans : v . 46) . Lyon , France : Worl d Healt h Organization ; pp . 41-185 . 7 2 U S EPA . 2002 . Sectio n 4 . 7 3Liberti , A , e t al . 1984 . Determinatio n o f nitrated-polyaromati chydrocarbon s (nitro-PAHs ) i n environmental sample s byhig h resolutio n chromatographi ctechniques . J Hig h Resolu t Chromatog rCommu n 7:389-397 . 7 4Schuetzle , D an d Frazier , JA . 1986 . Factor s influencin g th e emissio n o f vapo ran d particulat e phas e component s fro m diese l engines . In : Carcinogeni can d mutageni ceffect s o f diese l engin e exhaust : proceeding s o f th e internationa l satellit e symposiu m o n toxicologica l effect s o f emission s fro m diese l engines ; July ; Tsukub a Scienc e City , Japan . (Development s i n toxicolog yan d environmenta l science : v . 13. ) Ishinishi , N ; Koizumi , A ; McClellan , RO ; e t al. , eds . Amsterdam : Elsevie rScienc e Publisher s BV ; pp . 41-63 . 7 5 Schuetzle , D an d Perez , JM . 1983 . Factor s influencin g th e emission s o f nitrated-polynuclea raromati c hydrocarbon s (nitro-PAH ) fro m diese l engines . J Ai rPollu t Contro l Asso c33:751-755 . 7 6Bon d JA , e t al . 1990 . Th e rol e o f DN Aadduct s i n diese l exhaust-induce d pulmonarycarcinogenesis . In : Mendelsohn , ML , Albertin i RJ , editors . Mutatio n an d th e environmen t Part C : Somati can d heritabl e mutation , adduction , an d epidemiology . Ne wYork : Wiley-Liss , Inc ; 1990b . pp . 259-69 . 7 7Shirname-More , L . 1995 . Genotoxicityo f diese l emissions . Part I : Mutagenicit yan d othe rgeneti ceffects . Diese l exhaust : a critica l analysi s o f emissions , exposure , an d healt h effects . Aspecia l report o f th e Institute' s Diese l Workin g Group . Cambridge , MA : Healt h Effect s Institute , pp . 222-242 . 7 8Nielsen , P S an d Autrup , H . 1994 . Diese l exhaust-relate d DN Aadduct s i n garag e workers . Cli n Che m 40:1456-1458 . 7 9 Hemminki , K , e t al . 1994 . DN Aadduct s amon g personne l servicin g an d loadin g diese l vehicles . Carcinogenesi s 15:767-769 . 8 0Hou , S , e t al . 1995 . Relationshi p betwee n hprt mutan t frequency , aromati cDN Aadduct s an d genotype s fo rGSTM 1 an d NAT 2 i n bu s maintenanc e workers . Carcinogensi s 16:1913-1917 . 8 1 U S EPA . 2002 . p . 6-31 . 8 2 U S EPA . 2002 . Sectio n 7 . 8 3Californi a Environmenta l Protectio n Agency , OEHHA . Healt h Assessmen t Documen t fo rDiese l Engin e Exhaust , Par

t B : Healt h Ris k

Assessmen t fo rDiese l Exhaust , May1998 , p 1-5 . 8 4Pepelko , W.E . an d W.B . Peirano. Healt h effect s o f exposur e t o diese l engin e emissions : Asummaryo f anima l studie s conducte d b yth e U S Environmenta l Protectio n Agency' s Healt h Effect s Researc h Laboratorie s a t Cincinnati , OH . Journa l o f th e America n Colleg e o f Toxicolog yVol . 2 , No . 4 , pp . 253-306 , 1983 . 8 5 Heinrich , U . 1986a . Chroni ceffect s o n th e respiratorytrac t o f hamsters , mic e an d rat s afte rlong-ter m inhalatio n o f hig h concentration s o f filtere d an d unfiltere d diese l engin e emissions . J . App l Toxico l 6(6):383 - 395 . 8 6Heinric h U . 1986b . Compariso n o f chroni cinhalatio n effect s i n rodent s afte rlong-ter m exposur e t o eithe r coa l ove n flu e ga s mixe d wit h pyrolize d pitc h o rdiese l engin e exhaust . De vToxico l Enviro n Sc i 13:441-57 . 8 7Heinric h U . 1995 . Chroni cinhalatio n exposur e o f Wista rrat s an d tw o differen t strain s o f mic e t o diese l engin e exhaust , carbo n black , an d titaniu m dioxide . Inha l Toxico l 7:533-56 . 

### 2 2Driscoll , KE , e t al . 1996 . Pulmonaryinflammatory , chemokine , an d mutageni cresponse s i n rat s afte r sub-chroni cinhalatio n o f carbo n black . Toxico l App l Pharmaco l 136:372-380 . 8 9 Rittinghausen , S , e t al . 1997 . Pulmonarycysti ckeratinizin g squamou s cel l lesion s afte r inhalation/instillatio n o f differen t particles . Expe rToxico l Patho l 49:433-446 . 9 0See : U S EPA . 2002 . p . 7-131 . 9 1 Californi a EPA . 1998 . p . 1-7 . 9 2 Californi a EPA . 1998 . p . 1-7 . 9 3Garshic k

E , e t al . 1987 . Acase-contro l stud yo f lun g cance ran d diese l exhaus t exposur e i n railroa d workers . A m Re vRespi rDi s 135:1242-8 . 9 4Garshic k

E , e t al . 1988 . Aretrospectiv e cohor t stud yo f lun g cance ran d diese l exhaus t exposur e i n railroa d workers . A m Re vRespi rDi s 137:820-5 . 9 5 Steenlan d NK , e t al . 1990 . Case-contro l stud yo f lun g cance ran d truc k drivin g i n th e Teamster s Union . America n Journa l o f Publi cHealt h 80:670-674 . 9 6Steenlan d K , e t al . 1992 . Exposure s t o diese l exhaus t i n th e truckin g industryan d possibl e relationship s wit h lun g cancer . America n Journa l o f Industria l Medicin e 21:887-890 . 9 7Cohen A J an d Higgin s MWP . 1995 . Healt h effect s o f diese l exhaust : Epidemiology , Diese l Exhaust : A Critica l Analysi s o f Emissions , Exposur e an d Healt h Effects . ASpecia l Repor t t o th e Institute' s Diese l Workin g Group , Healt h Effect s Institute , Cambridg e MA . 9 8Californi a EPA . 1998 . p . C- 1 - C-29 . 9 9 Californi a EPA . 1998 . p . 1-8 . 1 0 0U S EPA . 2002 . p . 7-142 . 1 0 1 U S EPA . 2002 . 1 0 2 Ris , Charles , 2002 , p . 36 . 1 0 3U S EPA . 2002 . p . 7-137 .



### 2 3

# MICROPOWE R A T TH E CROSSROAD S Publi c Healt h an d th e Futur e o f Distributed Generatio n

MASSPIRG Educatio n Fun d

# MICROPOWE R

A TTH E CROSSROAD S Publi c Healt h an d th e Future o f Distribute d Generatio n

Bra d Heavne r Fran k Gork e MASSPIR G Educatio n Fun d

# ACKNOWLEDGMENT S Th e MASSPIR GEducatio n Fun dgratefull y acknowledge s Set hKapla n o f

th e Con servatio n La w Foundatio n an dTod dCampbel l o f th e Coalitio n fo r

Clean Ai r

fo r pro vidin g assistanc e i n th e developmen t an ddraftin g o f

thi s report . Thank s t o Mar a Thermos , Elle n Montgomery , an dMariann e Zuge l fo r researc h assistance . Thank s als o t o Michae l Perri , Kati e McCormack , andRo b Sargent fo r editoria l guidance . Thank s t o Harrie t

Eckstei n fo r

layou t design . Cove r photograph s courtes y o f (clockwis e fro muppe r

left) : Pau l Gipe , Hig hFrequenc y Activ e Aurora l Research , Nationa l Renewabl e Energ y Laboratory , an dCapston e Microturbines . Thi s repor t

wa s mad e possibl e b y th e generou s suppor t o f th e Pe w Charitabl e Trust s unde r thei r Nationa l Distribute dGeneratio n Emission s Campaign . Th e author s alon e bea

r responsibilit y for

an y factua l errors . Th e recommendation s ar e thos e o f th e MASSPIR GEducatio n Fund . Th e view s expressedi n thi s repor t ar e thos e o f th e author s an dd o no t necessarily reflec t

th e view s o f

ou r funders . © 200 3 MASSPIR GEducatio n Fun d Th e MASSPIR GEducatio n Fun di s a501(c)(3 ) organizatio n workin g o n environmen ta l protection , consume r rights , andgoo dgovernmen t i n Massachusetts . Fo r additiona l copie s o f

thi s report , sen

d$1 0 (includin g shipping ) to : MASSPIR G 2 9 Templ e Plac e Boston , M A 0211 1 Fo r mor e informatio n abou t th e MASSPIR GEducatio n Fund , pleas e cal l 617-292 - 480 0 o r visi t th e MASSPIR Gweb site a t www.masspirg.org.

# TABL E O F CONTENT S

Executiv e Summar y 4 Wha t I s Distribute d Generation ? 7 Th e Cleanes t Micropowe r Technologie s 1 1 Sola rPhotovoltaic s 1 1 Win d 1 2 Fue l Cell s 1 4 Combine d Hea t an d Powe r1 6 Th e Dirties t Micropowe r Technologie s 1 8 Diese l Generator s 1 8 Othe rFossi l Fue l Interna l Combustio n Engine s 2 2 Improvin g Engine s fo rEmergenc yan d Portabl e Us e 2 3 Ne wMicropowe rTechnologie s 2 5 Alternativ e Fue l Reciprocatin g Engine s 2 5 Turbine s 2 5 Microturbine s 2 5 Stirlin g Engine s 2 6 Polic y Recommendation s 2 8 Appendi x A : Alternativ e Fuel s 3 0 Appendi x B : Glossar y 3 1 Note s 3 3

# EXECUTIV E SUMMAR Y 

# T h e debate over

Massachusetts ' en erg y futur e ha

s focuse dincrease d attentio n o n micropower , th e gen eratio n o f

electrica l energ y b y home owner s an dbusinesse s nea r th e plac e i t

i s useda s a n alternativ e o r

supplemen t

t o th e statewid e powe r

grid . Micropower , als o know n a s distribute d generatio n (DG) , i s agrowin g secto r o f th e energ y marke t

tha t hold s great

prom is e fo r locall y controlle dpower genera tion. 1 Havin g facilitie s widel y disperse d increase s reliability , an dsom e o f thes e technologie s ar

e amon g th e mos t

envi ronmentall y friendl y electricit y generat in g technologie s eve r invented . Bu t continue drelianc e o n othe r type s o f micropower , technologie s tha t ar e highl y polluting , pose s athrea t t o publi c health . Currently , micropowe r i s no t subjec t t o th e sam

e ai r pollutio n control s a

s cen tra l power

plants , andth e mos t

prevalen t for mo f micropowe r

currentl y i n opera tio n i s als o th e mos t

pollutin g for m- die se l engines . Thes e generator s hav e bee n installe doutsid e many publi c building s an dadvertise dfo r

hom e us e a

s asolutio n t o th e "energ y crisis. " A s micropowe r

ha s grown , polic y mak ers hav e come t o realiz e tha t limit s o n emission s frommicropowe r facilitie s ar

e neede dt o avoi dth e cumulativ e effect s o f many smal l bu t

very dirt y generators . An d state s increasingl y recogniz e tha t the y ca n increas e energ y generatio n flexibility an d realiz e majo r

environmenta l improve ment s b y encouragin g th e cleanes t form s o f micropower . Th e Massachusett s Departmen t o f Environmenta l Protectio n (DEP ) i s plan nin g t o set

ai r pollutio n standard s fo r micropowe r

technologies . The y ar

e seekin g t o establis h atechnology-neutra l stan dar dfo r al l application s tha t

work s t o reduc e environmenta l emission s andpro tec t publi c health . Th e DE P shoul dse t stric t standard s tha t full y protec t

huma n health andth e environment , an dshoul dphas e the mi n over tim e t o allo w manufacturer s t o pre pare fo r change . Ne w standard s shoul d encourag e clea

n technologie s suc h a

s so lar an dwind , allo w developin g technolo gie s suc h a

s fue l cell s andmicroturbine s t o graduall y decreas e emissions , andpro hibi t o r dramaticall y reduc e us e o f th e mos t pollutin g technologies . Du e t o se ver e environmenta l an dpubli c healt h impact s fromth e growin g use o f diese l generators , emission s standard s mus t b e se t a t level s tha t

limi t diese l application s t o emergenc y situation s an donl y whe n generator s ar

e operate di n conjunctio n wit hemission-contro l measures . Micropowe r

i s a t acrossroads . Ne w stan dard s shoul dpromot e clea n technologies , no t allo w dirt y technologie s t o proliferat e andpollut e the air . An dstandard s needt o establis h unifor mtreatmen t o f th e variou s micropowe r

technologie s an

dapplications . W e hav e produce dthi s repor t t o poin t th e way t o aclea

r futur e direction . A s w e wor k t o promot e th e highes t possibl e leve l o f efficienc y i n ou r

use o f energy , w e mus t simultaneousl y suppor t sustain able , reliable , versatil e technologie s tha t ca n brin g efficien t

energ y generatio n right t o th e sourc e o f

use whil e reducin g harmfu l ai r

pollution . 

### Polic yRecommendation s Principle s T o ensur e tha t publi c health i s protecte d an dne w technologie s tha t reduc e pollu tio n ar e encouraged , distribute dgenera tio n polic y shoul db e base do n th e followin g principles : o Micropowe r

mus t b e a s clea n a s o r cleaner than th e cleanes t

centra l 4 Micropowe ra t th e Crossroad spowe r plan t technolog y currentl y i n widespreaduse . o Stat e rule s an dincentive s mus t promot e th e cleanes t

energ y industr y fo r th e futur e o f

iMassachusetts . o Regulation s shoul dbe a s simpl e a

s possibl e s o manufacturer s ca n anticipat e change s an dcompl y wit h ne w technolog y requirements . Primar y Recommendation s Stat e agencie s ca

n hel p mov e micropowe r i nth e righ t

direction . T o protec t th e healt h o f th e peopl e o f

Massachusett s and th e ai r qualit y o f

th e stat e whil e helpin g t o assur e reliabl e loca l powe r

generation , w e recommen dth e followin g immediat e polic y actions : o Se t stringen t

emission s standard s fo r al l micropowe r

unit s operate di n Massachusetts . Us e output-base d standard s t o encourag e greate r efficienc y o f

performance . o Conduc t

acomprehensiv e inventor y o f existin g micropowe r

an dothe r on-sit e generation . o Streamlin e th e permittin g proces s fo r clea n unit s tha t

mee t o r bea t new , stringen t standards . o Ensure aggressiv e enforcemen t o f standard s an destablis h significan t penaltie s fo r

violation . Additiona l Recommendation s I naddition , man y othe r specifi c policie s coul dadvanc e clean micropowe r whil e curbin g th e use o f

dirt y micro-power . W e recommen dtha t

stat e agencies : Establish standards and

rides for jnicropower

operation:

• Requir e tha t

al l micropowe r

unit s operate di n Massachusett s receiv e certificatio n o r

permit s a

s aconditio n fo r bein g connecte dt o th e electri c 

### grid . • Requir e tha t

transmissio n gri d operator s draw o n clean , efficien t micropowe r

befor e similarl y price d dirt y generatio n facilities . • Requir e emission s contro l measure s fo r diese l generator s usedfo r emer genc y back-u p powe r

supply . • Requir e tha t

al l ne w residentia l an d commercia l constructio n b e "solar ready " wit hth e basi c infrastructur e t o eas e futur e installatio n o f

photo voltai c panels . Providefunding for

clean micropowei~.

• Requir e forma l consideratio n o f clea n micropowe r

a s apotentia l leas t cos t alternativ e t o transmissio n an d distributio n upgrade s an damean s o f avoidin g th e cos t

o f futur e environ menta l regulation . • Expan dfundin g fo r

clea n micro powe r technolog y advancement . • Expan dth e availabilit y o f financial incentives , includin g financing assistance , buy-dow n programs , ta x credits , an dgrants , fo r

th e installa tio n o f clea n micropower . • Provid e incentive s fo r developer s t o includ e clean micropowe r a t ne w residentia l o r

commercia l construc tion projects . • Provid e incentive s fo r th e trade-i n andupgrad e o f

pollutin g micropowe r installations . Clear hurdles to the implementation of clean micropower:

• Streamlin e th e permittin g an dutilit y interconnectio n proces s for clea n micropowe r

installations . • Develo p incentiv e tariff s an dreduce d standb y an dexi t

fee s for clea n micropowe r

installations .

Micropower

a t th e Crossroads 5Th e adoptio n o f thes e recommenda tion s wil l promot e avita l distribute d generatio n syste mtha t reduce s th e negativ e publi c health impact s associate d

wit hdiese l an dothe r

dirt y micropowe r technologies .

6 Micropowe ra t th e Crossroad s

# WHA TI S MICROPOWER ? 

# F o r more tha n acentur y th e standard formul afo r

generatin g an ddistrib utin g electricit y has been simple . Buil dahug e powe r

plan t an dru n powe r line s t o populatio n center s wher e indus tr y andpeopl e nee dth e electricity . Con nec t th e individua l hom e o r busines s t o th e electrica l gri dan dpowe r up . Primaril y usin g fossi l fuels , thes e fa cilitie s have grow n i n scale an dquantit y a s ou r deman dfo r

electrica l powe r

ha s increased . Man y o f

thes e gian t

powe r plant s have been majo r polluter s a

s the y have worke dt o provid e acheap , reliabl e electricit y sourc e fo r

consumers . Despit e advance s i n technology , thes e larg e cen tra l powe r

plant s continu e t o dominat e ou r energ y systemi n size , environmen ta l consequences , an dconvenience . Th e dominanc e o f

thi s mode l has fa cilitate dth e proliferatio n o f electricall y powere ddevice s t o th e poin t wher e mos t o f u s neve r thin k abou t ho w powe r

i s gen erated . W e jus t

plu g ou r

compute r

int o th e wal l outle t

an dge t t o work . I nsom e case s i t has bee n advantageou s t o develo p localize dpowe r generatin g capacity . Geographicall y isolate dfacilitie s an dsom e larg e factorie s hav e been usin g loca l powe r

generatio n fo r

years , fre quentl y deployin g man y o f th e technolo gie s tha t cause environmenta l harm . Bu t i t wa s arare occurrenc e whe n a n indi vidua l woul dnee do r

wan t independen t loca l power

generatio n fo r

ahom e o r smal l business . Deregulatio n o f

th e electri c powe r productio n industr y an dth e recen t tur moi l i n energ y market s has starte dt o chang e al l that . Wit hgrowin g concern s abou t th e reliabilit y o f

traditiona l power source s du

e t o increase s i n powe r plan t dow n time , mor e an dmor e consumer s ar e questionin g th e conventiona l mode l o f centra l powe r

plants . The y ar

e look in g fo r mor e reliabl e energ y sources , searchin g fo r greate r contro l over

powe r costs , andseekin g alternative s t o powe r source s tha t

degrad e th e environmen t

and undermin e publi c health . Th e combinatio n o f

advancin g tech nolog y an dwidesprea dconcern s abou t larg e centra l powe r

plant s ha

s made lo calize dpower

generatio n a

n ide awhos e tim e ha s come . Instea do f

concentratin g powe r source s at

larg e plants , micro powe r system s locat e powe r source s close r t o th e consume r

- i n a n offic e building , aneighborhood , afactory , o r a home. - Fo r many , smal l powe r

generatio n unit s locate dnea

r th e poin t

o f use hav e bee n asafet y an dreliabilit y measur e t o suppl y back-u p power

durin g blackouts . Other s hav e suggeste dtha t i n ligh t o f escalatin g energ y cost s durin g pea k de man dperiods , micropowe r ca n b e use d a s acheape

r alternativ e powe r

sourc e o r asourc e o f

profi t b y sellin g th e distrib ute dpowe r

int o th e grid . I ngrid-congeste darea s wher e trans missio n lin e upgrade s woul dotherwis e be needed , micropowe r

ha s th e potentia l t o significantl y reduc e cost s fo r power . Transmissio n an ddistributio n costs ca n reac h $1.5 0 fo r

ever y $1.0 0 spen

t o n elec tricit y generation. 3 I n addition , societ y ca n benefi t throug h enhance dreliabilit y an ddecrease dnee dfo r infrastructure . Estimate s o f

th e monetary valu e o f

thes e benefit s rang e a

s hig ha s 2. 8 (t/kWh . Thi s Tabl e 1 : Th e Economi cBenefit s o f Decentralize d Powe r(C/kWh) 4 Benefi t Saving s Substatio n deferra l 0.16-0. 6 Transmissio n syste m losses 0.2-0. 3 Transmissio n wheelin g 0.28-0.7 1 Distributio n benefit s 0.067-0.1 7 Enhance d reliabilit y 1. 0 Tota l 1.7-2. 8 Micropowe rat th e Crossroad si s asubstantia l saving s fro mcurren t gen eratin g an ddistributio n costs , whic har e no w typicall y 4- 9 c/kWh . Growin g interes t

i n loca l contro l o f electrica l power

generatio n i s bot h a

n opportunit y fo r

an dathrea t

t o Massa chusett s residents . Th e centra l powe r plan t syste mhas evolve dsom e cleaner technologies , bu t

older , dirtie r

micro powe r technologie s ar

e stil l predominant . W e canno t

allo w th e proliferatio n o f lo calize dpowe r

generatio n t o undermin e pollutio n standards . Th e affordabilit y o f

meetin g stricte r emission s standard s was documente di n a200 2 stud y b y Energ y Nexu s Grou p analyzin g th e economi c feasibilit y o f complyin g wit hpropose dne w standard s fo r micropowe r

i nCalifornia . Th e study foun dtha t

wit hth e amoun t

o f technol og y advancement

expecte dunde r

norma l marke t forces , nearl y al l o f

th e cleanes t technologie s wil l mee t th e standard s i n 2003 , mos t

o f th e ne w technologie s wil l mee t th e standard s i n 2007 , an dal l bu t th e dirties t

technologie s wil l mee t th e standard s i n2012 . Th e study determine d th e cos t o f addin g emission s contro l equipmen t

t o fossi l fuel-base dmicro power t o b e onl y abou t

1 c/kWh. 5 A s publi c agencie s consider regulation s addressin g micropowe r technologies , w e hav e th e opportunit y t o promot e cost effectiv e renewabl e energ y source s tha t are significantl y les s harmfu l t o ou r health . Bu t

i f th e growin g deman dfo r micropowe r

result s i n th e proliferatio n o f pollutin g technologies , w e fac e th e prospec t o f highe r level s o f

localize d emission s tha t

plac e ou r

respirator y health a t significan t

risk . Wha t follow s i s a

n overvie w o f

th e pollutio n andpubli c healt h impact s o f man y o f th e technologie s currentl y avail abl e t o thos e intereste di nth e deploymen t o f micropower . W e hav e groupe dth e variou s technologie s int o thre e catego rie s base do n thei r

curren t environmen ta l performance . Ne w regulation s shoul d b e performance-based , s o tha t emergin g technologie s have equa l opportunit y t o mee t emission s standard s i n th e future . Clea n Micropowe r

- Th e cleanes t distribute dgeneratio n technologies , primaril y usin g renewabl e fue l sources . Thes e includ e solar , wind , an dfue l cells . Thes e form s o f power generatio n have minima l negativ e publi c health impacts . I n addition , 

### Figur e 1 : Emission

s fro m Micropowe

rTechnologies 6 25 5 2 0

o 1 5 E 1 0

Diese l Natura l Ga s Natura l Ga

s Microturbin e Engin e Engin e Engin e

(lea n burn ) (ric h burn ) Fue l Cel l NO x 

# •

C O 

### E D SO x PMI O 

### H UH C

Sola r Win d 8 Micropower

a t th e Crossroad sFigur e 2 : Carbo n Dioxid e Emission s fro m Micropowe r Technologies 7 1,800- I 1,600 - 1,40 0 •MIAI, 1,200 - 1,00 0 - t o C 80 0 - o (/ ) 600 - E Ll J 40 0 - 200 - Diese l Natura l Ga s

Engin e Engin e

(lea n burn ) Natura l Ga s

Engin e (ric h burn ) Microturbin e Fue l Cel l Sola r Win d high-efficienc y combine dhea t an d powe r system s ca

n significantl y reduc e negativ e impacts . Dirt y Micropowe r

- Th e dirties t an dbest-know n technologies , usin g fossi l fue l sources . Diese l generatio n i s th e mos t

prevalent

technology , bu t ther e ar e als o gasolin e an dnatura l ga s engine s tha t

ar e excessivel

y polluting . Thes e form s o f powe r generatio n undermin e publi c health an dcaus e disease . Ne w Micropowe r

Emergin g technologie s have th e potentia l t o delive r cleaner power . Option s such a s alternativ e fuel s an dmicro turbine s hol dpromis e fo r th e future . Th e health impact s o f

thes e form s o f powe r generatio n vary . On-sit e power

generatio n i n itsel f

i s n o panace afo r

th e problem s plaguin g th e energ y market . I f

th e rus h t o micropowe r i s arus h t o th e mos t

availabl e an dleas t expensiv e technology , the n som e o f th e problem s - includin g increase dpollution , inefficien t

energ y production , cost s tie d t o non-renewabl e fuels , andgrowin g pub li c health problem s - wil l b e perpetuated . Th e technolog y i s availabl e t o avoi d thos e pitfall s andt o promot e efficien t and increasingl y cost-effectiv e micropowe r tha t ca n benefi t th e environment , th e re liabilit y o f

th e electricit y system , andpub li c health . Som

e o f th e potential advantage s o f clea n micropowe r

include :

• Powe r doesn' t have t o trave l lon g distance s over

th e grid , reducin g energ y los s an dth e nee dt o buil d new powe r

lines.

• Win dan dsolar

technologie s ar

e fuele db y renewabl e energ y sources . • Generatio n at

poin t o f use allow s fo r th e utilizatio n o f

wast e hea t fo r othe r energ y needs . • Loca l generatio n ca

n enhanc e th e reliabilit y o f

th e electricit y systemb y reducin g th e burde n o n th e grid . • Fewer large , central-statio n powe r plant s wil l b e neede da

s micropowe r increases . • Th e potentia l fo r

large-scal e black out s i s reduced . • Loca l contro l o f

energ y source s allow s increase dresponsivenes s t o loca l concerns . • Powe r source s ca

n b e buil t t o appro priat e scal

e fo r local consumption .

Micropowe ra

t th e Crossroad s 9Th e vas t majorit y o f

micropowe r

unit s currentl y operatin g i nMassachusett s ar e diese l generators . Diese l generator s re leas e a s muc h a s 363 time s mor e smog formin g pollutant s than th e mos t efficien t natura l ga

s powe r plan t technologies. 8 Thes e pollutant s hav e bee n show n t o increas e th e ris k

o f seriou s healt h problem s rangin g fro mheadache s an d

nause at o asthmacomplication s an dlun g cancer. 7 Th e opportunit y t o en dthi s threa t t o publi c health i s a t

han di f w e use emis sio n standard s an dpolic y incentive s fo r distribute dgeneratio n t o pus h newe r technologie s t o th e forefront .

1 0 Micropowe r

a t th e Crossroads

# TH E CLEANES TMICROPOWE R TECHNOLOGIE S 

# S olar

an dwin dtechnologie s hav e bee n prove n effectiv e fo r loca l power generatio n throughou t th e country . Wit hfree fuel , advance dtech nology , an dincentive s provide db y th e state , thes e technologie s ar e becomin g more cos t

effectiv e andcos t

competitive. 1 0 Recentl y th e powe r

industr y has mad

e substantial advance s i nfue l cel l technolo gie s an di n usin g combine dheat an d powe r system s t o increas e energ y effi ciency . Publi c agencies , smal l an dlarg e businesses , an dindividua l homeowner s ar e takin g advantag e o f

thes e advance ment s t o instal l localize dan dindepen den t powe r generatio n capacity . Thes e clea

n technologie s ar

e no t with ou t thei r environmenta l impact , bu t the y substantiall y reduc e th e environmenta l impact s o f

electricit y generation . 

## Sola r Photovoltaic s Man y peopl e mistakenl y believ e tha t so lar powe r ca n onl y b e harnesse deffec tivel y i nth e Souther n an dSouthwestern states , bu t

sola r P V i s avaluabl e resourc e fo r Massachusett s a

s well . Th e state' s so la r potentia l i s excellent , an dsola r power generatio n peaks a

t th e sam

e time tha t energ y deman dpeak s - i n th e heat o f summe r afternoons . Photovoltai c technolog y convert s sun ligh t directl y int o electricit y withou t us in g an y movin g parts . Th e basi c buildin g bloc k i s th e photovoltai c cell , whic hi s mad e o f semiconducto r

materials . Cell s ca n b e connecte dtogethe r t o for mmod ules , an dmodule s ca

n be connecte dt o for marrays . A fe w P V cell s wil l powe r a hand-hel dcalculator , whil e intercon necte darray s ca

n provid e electricit y fo r aremot e villag e o r

serve a s apowe r

plan t fo r

acity . P V i s atrul y uniqu e technolog y wit hman y advantages . Accordin g t o th e U.S . Departmen t

o f Energy , "i t

i s eas y t o foresee PV' s 2 1 s t

century preeminence."' ' Althoug hP V panel s onl y generat e electricit y whe n th e su

n i s shining , con nectio n wit hth e gri dmake s i t possibl e t o depen do n PV , bot hfro mth e con sumer an dth e state plannin g perspec tives . O n ho t

days , whe n electricit y consumptio n i s a

t it s peak, P V panel s fee d exces s electricit y int o th e grid . I n th e evenin g whe n th e sun i s dow n an delec tricit y deman di s lower , customer s draw electricity fromth e grid . Recen t improve ment s i n "ne t

metering " - i n whic hth e electricit y mete r

run s backwar dwhe n powe r i s beingfe dint o the gri d-hav e mad e thi s muc hmor e practical for consumers . 

### Advantage s o f Photovoltai c Technologie s

• Simplicit y - Wit hn o movin g parts , operatio n an dmaintenanc e cost s ar e minimal . • Versatilit y - P V ca

n connec t

t o th e existin g infrastructur e o f th e utilit y gri dan dserve a

s a n alternativ e powe r sourc e durin g pea

k period s o f powe r deman do r

i t ca n operate remotel y (of f

th e utilit y power-lin e grid) . Man y P V systems ar e easily transported . P V ca

n als o be scaled accordin g t o th e amoun t o f powe r needed . • Reliabilit y - Firs t

develope dfo r

U.S . man-mad e satellite s i n th e 1950 s - where lo w maintenanc e was a n absolute necessit

y - an dno w wit h ove r 4 0 year s o f

technica l advance ment s improvin g performance , P V ha s very hig honlin e availability. 1 2 Micropowe ra t th e Crossroad s• Pea k Outpu t - P V power

outpu t peaks whe n deman dpeaks . • Quie t - P V system s mak

e n o noise .

• Sustainability - P V share s th e tw o advantage s commo n t o al l renewabl e energ y sources : i t

has alo w environ menta l impac t

(i t i s nonpolluting ) an dth e fue l i s free . Sola r P V ha s zero operatin g emissions . Therefore , sola

r P V i s exemp t

fro mal l ai r qualit y permittin g requirements . 

## Win d Win dturbine s are a

n excellen t

loca l powe r generatio n optio n fo r

man y Mas sachusett s resident s an dbusinesses . A win dturbin e consist s o f arotor , a

n elec trica l generator , aspeedcontro l system , an datower . Whe n th e win dblow s an d spin s th e propeller s o f

th e turbine , whic h ar e aki n t o airplan e propelle r blades , th e kineti c energ y o f

th e win di s converte d t o mechanica

l power , whic hi ntur n drive s th e electrica l generato r

an dproduce s a

n electrica l current .

PV I N CAMBRIDG E ravestar , aCambridg e rea l estate developer tha t own s an doperate s shoppin g centers , installe da2 0 k Wphotovoltai c array i n 199 9 a s par t o f a$1 3 millio n redevelopmen t projec t at th e Porte r

Squar e Shoppin g Cente r

i n Cambridge . Th e Porte r

Squar e projec t

include dth e renovatio n o f an existin g stri p mal l wit ha

n additio n tha t

house s apharmac y an dhealth-fitnes s center . Th e 2 0 k Wphotovoltai c array , consistin g o f 8 0 AS E 30 0 DGF/5 0 modules , wa s installe do n to p o f

th e existin g structure . Th e annual energ y productio n of22,00 0 kW ho f energ y i s applie dt o sit e lightin g an dcommo n areas . Thi s lead s t o annua l saving s o f approximatel y $2,200 . Th e syste mals o offset s approximatel y 31,00 0 pound s o f C02 , 16 0 pound s o f

S02 , an d5 0 pound s o f NO x each year. 1 3 Th e pane l location ,

alon g th e sout

h front wit h a3 5 degre e tilt, make s th e systemmor e visibl e from th e stree t an dparkin g ar ea s i norde r

t o increas e it s educationa l value . Th e shoppin g cente r als o ha s a n educationa l kios k i nth e commo n area . Usin g atouc hscreen , visi tor s ca n findvaluabl e in formatio n abou t

ho w th e systemworks , ho w muc h energ y i s produced , an d othe r photovoltai c facts. 1 4

Micropowe ra t th e Crossroad sMos t people , ar

e familia r

wit hthes e turbine s whe n the y are groupe dtogethe r i n awin dfar man doperate lik e acon ventiona l powe r

plant , feedin g electric it y t o th e utilit y grid . Bu t smal l turbine s ca n b e installe dan doperate dindividu all y t o satisf

y th e electrica l need s o f a hom e o r business , jus t

a s the y were o n farm s fo r

hundred s o f

years . Individua l turbine s var y i n size , rang in g fro mabou t

3 0 fee t hig hwit hpropel ler s betwee n 8 an d25 fee t i n lengt h t o 4 0 storie s hig hwit hpropeller s over 30 0 fee t i n length. 1 3 Singl e home-size dwin dturbine s i n th e 10-5 0 k Wrang e ar e becomin g mor e popular i n man y places . Sinc e the y don' t nee da s muc h win da

s th e large r

turbines , the y ca n b e effectiv e i n mor e areas . 

### Advantage s o f Win d Technologie s

• Simplicit y - Operatio n an dmainte nanc e cost s ar

e minimal . Moder n win dturbine s requir e maintenanc e checks onl y onc e ever

y six months. 1 6

• Versatilit y - Win dturbine s ca n connec t t o th e existin g infrastructur e o f th e utilit y gri do r

ca n operate remotel y (of f

th e utilit y powe r

lin e grid) . • Reliabilit y - Win dpower i s th e fastes t growin g energ y sourc e world wid e an dit s prove n reliabilit y has muc h t o d o wit hit s success. 1 7 Smal l win dsystem s ar

e designe dt o operate fo r at leas t 3 0 years. 1 8

• Sustainabilit y - Wind-generate d power share s th e tw o advantage s commo n t o al l renewabl e energ y sources : i t

ha s alo w environmenta l impac t (i t i s nonpolluting ) an dth e fue l i s free . • Quie t - Moder n win dturbine s ar e muc h quiete r

tha n combustio n turbines . WIN D POWE R I N HUL L



# T h e tow n o f

Hul l recentl y turne dt o win dpower , embracin g it s pas t

whil e movin g forwar dint o aclean fu ture . Th e town , 2 0 mile s south eas t o f Bosto n o n apeninsul a betwee n th e Adanti c Ocean an d Bosto n Harbor , installe da66 0 k WVestas V-4 7 win dturbin e i n 200 1 o n asite tha t

was hom e t o awindmil l lon g ago . Th e 150 - foo t whit e tower , wit h90-foo t blades , i s no w th e larges t win d turbin e o n th e Eas t

Coast. 1 9 Th e turbin e supplie s enoug h energ y t o power

th e town' s 1,00

0 streetlight s an d1 4 traffi c lights . Thi s alon e save

s th e loca l taxpay ers $60,00 0 ayear. 2 0 Th e turbin e produce s ap proximatel y 1.

5 millio n kW hpe r year , th e equivalen t

o f supplyin g power t o 200-25 0 homes. 2 1 Th e tow n i s on e o f

1 8 recipi ent s o f th e U.S . EPA' s Environ menta l Meri t

Awar di n 2002 . Hul l was selecte dfromapoo l o f 9 0 nomination s tha t

year . Thi s award , whic hhas bee n give n ou t sinc e 1970 , honor s specifi c indi vidual s o r

communitie s tha t demonstrat e astron g commit men t t o

Micropowe ra t th e Crossroad s 1 3Win dtechnologie s have man y o f th e sam e advantage s a

s sola r photovoltai c technologies . Lik e sola r PV , win dha s zero operatin g emissions . Win dturbine s ar e therefor e exemp t

fromal l ai r

qualit y permittin g requirements . 

## Fue l Cell s Wher e sola

r photovoltaic s o r

win dtur bine s ar e no t feasible , fue l cel l technolo gie s ar e agoo dloca l powe r

generatio n option , especially whe n operate di n com bine dhea

t an dpower

applications . (Se

e belo w fo r

mor e abou t

combine dheat

an d power. ) Althoug hthe y no w us e fossi l fu el s t o creat

e hydrogen , fue l cell s emi t fa r les s pollutant s tha n diese l an dmos t othe r fossi l fue l generators . Emission s from curren t cell s ar e primaril y C0 2 an dwa ter . Wit hfurthe r

developmen t

the y wil l be abl e t o utiliz e renewabl e energ y t o produc e thei r

hydroge n fuel . Throug hth e chemica l reactio n o f combinin g hydroge n an doxyge n t o make water , fue l cell s conver t chemica l energ y int o electricit y an dheat withou t combus tion . The y operate similarl y t o batteries . Bot hbatterie s andfue l cell s utiliz e a n electrolyt e separate db y a n anod e an da cathod e t o generat e adirec t electrica l current , an dbot h ca

n b e combine dint o group s t o increas e powe r output . Batterie s store thei r

fuel , the n periodi call y ru n dow n an drequir e recharging . Fue l cells , o n th e othe r hand , ar

e fe da continuou s suppl y o f

fuel . Th e varyin g type s o f fue l cell s al l rel y o n hydroge n a s thei r fuel , bu t the y ca n ge t i t fromavari et y o f sources . Fou r differen t

type s o f fue l cell s - th e Phosphori c Aci dFue l Cel l (PAFC) , th e Molte n Carbonat e Fue l Cel l (MCFC) , th e Proto n Exchang e Membran e (PEM) , an dth e Soli dOxid e Fue l Cel l (SOFC ) - have been o r

ar e operatin g i n 1 6 coun tries , an dsevera

l mor e type s ar

e bein g develope dan dtested . Fue l cell s ar

e bein g develope dfo r

us e i nbot hvehicle s an dstationar y applica tions . Thes e application s includ e powe r fo r individua l facilitie s sucha s hospitals , offic e buildings , an dschools ; primar y powe r source s fo r

remot e village s an d campgrounds ; utilit y power plants ; an d power source s fo r

temporar y need s such a s constructio n sites . A s distribute delec trica l generatio n become s mor e wide spread , fue l cell s coul dserve a s primar y powe r an dtherma l energ y source s fo r virtuall y anything . Mos t fue l cell s are name dfo r thei r electrolyte , andthe y each have differen t properties , capabilities , fue l require ments , an demissions . Fo r example , th e PAF C tha t

i s commerciall y availabl e to da y i s offere di n th e 20 0 k Wsize , thoug h i t i s technicall y abl e t o operat e i n th e rang e o f 5 0 k Wt o 1 1 MW . Th e PAFC s i noperatio n toda y us e eithe r natura l gas o r propane , bu t

coul dals o b e fuele db y methane , alcohols , landfil l gas , o r anaero bi c digester

gases . Because o f

th e lo w emission s o f

fue l cells , Massachusett s ha s grante da

n ex emptio n t o PAFC s usin g natura l ga s from al l ai r qualit y permittin g requirement s i n th e state . I n th e future , renewabl e energ y sources ma

y b e widely use

d t o generat

e the hydroge

n neede d t o powerfuel cells . Sunlin e Transi tha

s ane w hydrogen gen eration facilit

y powere d by win d an

d so larenergy 

## Advantage

s o f Fue l Cel l Technologie

s

• Lo w emission s - Fue l cell s emi t fewe r pollutant s tha n any othe r fossi l fuel-base dmicropowe r technology . • Quiet-Fue l cell s ar

e quiet . • Versatilit y - Fue l cell s ar e modula r

i n design ; so the y ca

n b e stacke dt o increas e power

output . • Simplicit y - Wit hfe w movin g parts , fue l cell s ar

e low-maintenance . 1 4 Micropowe ra t th e Crossroad sCAP E CO D FUE L CEL L 

# C ap e Co dwil l soo

n b e hom e t o afue l cel l o f

the lates t commercia

l technolog y a

t th e Coas t Guar dAi r Statio n i n Bourne . Th e 25 0 k WDirec t

Fuel Cel l i s expecte

dt o b e installe db y Fal l 2 002. 2 3 

### Th e fue l cel l wil l operat

e o n natura

l gas . Th e energ

y producedwil l b

e use dt o hea t wate r fo r statio n personne

l bot h i nthe barrack

s an dthe gal ley ; Facility manager

s hope tha

t exces s hea t fro mthe fue l cel l wil l b

e use d t o hea t the buildin g i n th e future . Th e initia l reductio n i n utilit y bill s i s projecte dt o b

e $50,00 0 per year. 2

4 

### Th e fue l cel l i s projecte dto b e 70 % efficient , generating 23 0 k Wfo r the first tw o years . I n tw o year

s th e plant' s stac

k i s schedule

dfo r replace ment i norde r t o tak e advantag

e o f newe r technology . Afte r

tha t upgrad e the plan t i s expecte dt o generat

e 30 0 k Wor more . Sinc e the mission o f

the ai r statio n i s searc

h an drescue , i t

is particularly importan t

t o hav e powe r durin g heav

y storms . Th e Coas

t Guar ddetermine dthat

the fue l cel l woul db

e the most

dependabl

e powe r source fo r tha t purpose . I t

wil l help suppor

t fou r H6 0 Jayhaw

k helicopters an

dfou r H2 5 Falcon jets. 2 5 

### Th e mos t

significant

featur e o f tfl e Bourn

e facility i s th

e us e o f amol ten carbonat

e fue l cell . Molte n carbonat e fue l cell s ar

e acuttin g edg

e fue l cel l technolog y becaus

e they hav

e bee n develope

dt o capitalize o n energ

y efficienc y an

dessentiall

y operat e with ou t generatin g pollution . Th e Bourne plant i s amon g the first fe w o f thes e cell s t o be installe di nth

e Unite dStates. 2 6 

### Thi s projec t

i s mad e possibl e b y the join t effor t an dfinancial backing o f

bot h governmen

t an dprivat e business . Th e U.S . Departmen

t o f Energ y Technolog

y Lab , the Massachusett

s Renewabl

e En ergy Trust , an

dKeyspa n Inc. , anatural ga s supplier , mad

e i t possibl e fo r PP L Spectru man dFue l Cel l Energy t o cre at e thi s plant .

Phot o b yFue i Cel l Energy



### Flexibility - Fuel cell s ca

n us e differ en t fue l sources sinc

e the y onl y nee

d hydroge n an doxygen . Reliabilit y - Fuel cells ar

e online a greate r percentag

e o f the time tha

n large powe

r plants . Micropowe ra t th e Crossroad s 1 5CH P A TMALDE N MILL S

Phot o b yMaide n Mill s 

# M aide n Mills , i nLawrence , i s no strange r to the mediaspotlight . Th e mil l first receive dattentio n i n 199

5 when afire destroyedthree o f it s buildings . CE O Aaro n Feuerstei n gaine dnationa l acclai mwhe n h e decide dt o rebuil dthe compan

y whil e keeping hi s employees o n the payroll . No w Maide n Mills , manufacture r o f Polartec fabric , i s bac

k i n the news . Th e compan

y wa s presente dwit ha200

0 Energy Sta

r CombinedHea

t & Powe r Certificate , sponsore

db y the U.S . EP

A an dthe U.S . Departmen

t o f Energy . Th e awar

di s give n t o leader s wh o increase electri c generation efficiency wit hthe us

e o f combine dhea

t an d powe r programs . Whe n Maide n Mill s bega

n operatin g it s ne

w CH P facility i n1999 , then-Secretar y o f Energy Bil l Richardson wa

s on handt o dedicat

e th e fa cility , along wit hothe

r dignitaries . Richardson said , "Th e cogeneration powe r syste mw e dedi - — » . cate

dtoda y wil l produc e energ

y fo r th e factor

y 'fc* 1 

### '^"*' ] whil e virtuall y eliminatin g sulfu r dioxide emis 5 

### sions , reducin g nitrou s oxid e emissions b y 7

5 percent , an

dcuttin g carbon dioxide emissions by 2 5 percent . Thi s wil l mak

e Maide n Mill s a model o f energ y efficienc y andenvironmenta l responsibility." 2 8 

### Maide n Mill s installe dtw o 4. 3 M Wturbines , manufacturedb y Sola r Tur bines , whic hus

e fiber cerami c combustion liners . Th e liner s wer e specifically develope dto decreas

e NO x emissions b

y a t least anothe r 40% . Th e tw o tur bine s combine t o produce enoug h energ y t o suppl y 4,00 0 homes wit hpower. 29 

### Th e facility a

t Maiden Mill s provide s electricit y fo r th e plant . Th e mil l maintain s it s connection t o th e Massachusett s Ga s & Electri c gri da

s abacku p energ y sourc e i ncas e o f turbin e failure . Th e cogeneration syste

mwa s develope

di n partnershi

p wit hth e Depart ment o f Energy . 

## Combine d Hea t an d Powe r Combinedhea

t an dpowe r (CHP ) i s no t aspecifi c generatin g technolog y bu t rathe r a n applicatio n o f

technologie s to mee t end-use r need s fo r heating o r

cool in g a s wel l a s mechanica

l an delectrica

l power . Recen t technolog y development s - particularl y i n turbine s andmicro turbine s - hav e mad e small-scal

e CH P system s mor e cost-effectiv e an

dreliable . Whe n properl y designed , fossi l fuel base dgenerator s ca

n dramaticall y in creas e thei r

efficienc y throug h modificatio n int o CH P systems . I nCH P systems , the hea t tha t i s nor mall y release

da s wast e hea t i s instea d recovere dan duse dt o hea t water, room s an dbuilding s and/or

driv e motor s fo r

air conditioning or

refrigeration . CH P system s 1 6 Micropowe ra t th e Crossroad sca

n als o us e wast e heat t o provid e stea

m t o generat

e mor e electricity , lik e "cogen eration " a

t larg e powe r

plants . Combine d hea t an dpower

system s ca

n b e employe d i nmany commercia l an dindustria l facili tie s where ther e i s arelativel y constan t therma l need . Recoverin g an dreusin g wast e heat i n thi s manne r

ca n mak e generator s mor e tha n 80 % efficient , mor e tha n doubl e th e 33 % average efficienc y o f conventiona l electricit y generatin g systems. 2 7 Th e in creasedefficienc y saves th e extrafue l tha t otherwis e woul db e necessar y t o operate heatin g systems - ofte n replacin g old , in efficien t anddirt y boilers . Increase dfue l efficienc y translate s di rectl y int o reduce demission s o f green hous e gase

s an dothe r

pollutants . NOx , whic hform s smog , an dC02 , th e princi pa l globa l warmin g pollutant , ar e signifi cantl y reduced . Combine dhea t an d powe r system s als o reduc e S0 2 emis sions , precursor s t o aci drain , an dparticu lat e matter , acaus e o f chroni c lun g disease . Because i t

i s stil l base

do n burnin g fos si l fuels , CH P i s no t

sustainabl e energ y productio n o n th e leve l o f win dan dso lar . Bu t a s lon g a s fossi l fuel s ar

e use dt o driv e generators , CH P shoul db e widel y encourage da

s avery goo dimprovemen t ove r les s efficien t

technologies . 

### Advantage s o f CH P System s

• Efficienc y - Increase s efficienc y o f fue l use b y capturin g wast e heat fo r heating , coolin g an dothe r on-site energ y requirements . • Flexibilit y - Can b e designe dt o delive r multipl e energ y services . • Reliabilit y - Advance dtechnolog y andlocal contro l enhanc e servic e delivery . • Improve dEnvironmenta l Perfor manc e - Produce s lowe r emission s than conventiona l separat e systems . 

### Key

Recommendations

for Clean Micropower Electricit y generatio n ha s alway s hadseriou s negativ e impact s o n ai r quality . W e no w hav e th e opportunity , however , t o generate ou r

powe r wit hminima l envi ronmenta l consequences . Stat e agencie s mus t d o al l the y ca

n t o encourag e th e widescal e implementatio n o f clea n tech nologies , a

s the y simultaneousl y encour ag e energ y users t o consume energ y a s efficientl y a

s practical . Recommende d polic y action s includ e th e following . • Requir e forma l consideratio n o f clean micropowe r

a s apotentia l leas t cos t alternativ e t o transmissio n an d distributio n upgrade s an damean s o f avoidin g th e cos t

o f futur e environmenta l regulation . • Incorporat e efficienc y i n emission s standards t o credi t

the efficienc y advantages o f

combine dhea

t and power . • Expan dth e availabilit y o f financial incentives , includin g buy-dow n programs , ta

x credits , an dgrants , fo r th e installatio n o f

clea n form s o f micropower . • Develo p incentiv e tariff s an dreduce d standb y an dexi t

fee s fo r clea n micropowe r

installations . • Streamlin e th e permittin g an dutilit y interconnectio n proces s fo r clean micropowe r

installations . • Expan dfundin g fo r

clea n micro powe r technolog y advancement . • Provid e incentive s fo r developer s t o includ e clea

n micropowe r

a t ne w residentia l o r

commercia l constructio n projects . • Establis hrequirement s tha t al l ne w residentia l an dcommercia l constructio n b e "solar-ready " wit h th e basi c infrastructur e t o eas e futur e installatio n o f

photovoltai c panels .

Micropowe ra t th e Crossroad s 1 7

# TH E DIRTIES TMICROPOWE R TECHNOLOGIE S 

# T h e interna l combustio n engin e (ICE) , th e traditiona l technolog y use di n vehicles , i s als o th e pre dominan t

technolog y fo r

portabl e an d stationary generators . Als o calle drecip rocatin g engines , ICE s ca n us e avariet y o f fuels , includin g diesel , gasoline , natu ra l gas , an dpropane . Diese l i s th e mos t commo n fue l fo r

ICE s use da

s micro power . 

## Diese l Generator s Althoug hther e ar

e no w man y competi tiv e technologie s availabl e fo r micro power , diesel generator s have historicall y dominate dth e micropowe r market . Thi s for mo f micropowe r

has als o been th e mos t cos t effectiv e fo r

consumers , largel y becaus e th e publi c healt han denviron mental costs o f

burnin g diesel fue l ar

e no t accounte dfo r

i n th e cos t

o f generation . Th e diese l generato r

i s als o th e mos t pollutin g for mo f

micropower . Man y peopl e ar e familia r

wit hth e blac k

plume s o f smok e release db y diesel - truck s and buses . Diese l generator s ar e n o different . Th e harmfu l healtheffect s o f diese l ex haus t hav e been studie dan dwel l docu mente dfo r

decades . Becaus e man y diesel generator s ar

e locate di n dens e urba n settings , thi s technolog y significantl y increase s th e public' s exposur e t o cancer causin g pollutants . 

### Quantifyin g th e Proble m Diese l generator s ar e widel y use d throughou t

Massachusetts , providin g powe r fo r everythin g fro mbusinesse s t o agricultura l equipmen t

t o homes . Diese l generator s ar

e foun di n th e basement s o f offic e building s o r

powerin g light s use d durin g freewa y construction . However , n o accurate inventorie s o f diesel genera tor s have been made . Th e DE P maintain s adatabas e tha t include s electri c generator s calle dth e Stationar y Sourc e Emissio n Inventor y Syste m(SSEIS) . Facilitie s tha t bur n mor e tha n 1 0 millio n Btu/h r o f energ y mus t registe r wit hthi s system , coverin g onl y th e larges t

distribute dresources . Th e SSEI S databas e contain s record s o f 76 0 fossi l fuel-base dmicropowe r unit s i nMassachusetts . 77 % o f thes e ar e pow ere db y diesel . (Se

e Tabl e 2. ) Estimate s basedo n datafromothe r state s indicat e tha t

thi s i s likel y t o vastl y understat e th e prevalenc e o f diese l gen erator s i n Massachusetts . Th e California . Ai r Resource s Boar d(CARB ) ha s mad e th e bes t attemp t amon g stat

e ai r qualit y agencie s t o quantif y diese l generato r ownership . CAR B estimate s tha t ther e Tabl e 2 : Fossi l Fuel-Base d Micropowe rUnit s Registere d i n Massachusetts 1 Fue l Numbe ro f

Generator s Emission s (tons/yr ) Fue l Numbe ro f

Generator s NO x ; S0 2 P M 1 0 ' C O VO C Diesel/Oi l 58 3 40 7 5 3 2 4 17 5 20 8 Natura l Gas 15 9 62 1 1 2 4 5 32 2 12 5 Kerosene/Je t Fue l 4 < 1 < 1 < 1 < 1 < 1 Propan e 9 < 1 < 1 < 1 1 < 1 Gasolin e 5 1 < 1 < 1 2 8 1 Tota l 76 0 1,03 0 6 5 6 9 52 6 33 4 1 8 Micropowe ra t th e Crossroad sar

e atota l o f

65,38 2 diesel generator s i n California . Assumin g a

n equa l numbe r o f diesel generator s per

capitai nMassachu setts , thi s equate s t o 5,63 8 diese l genera tor s i n th e state . (Se

e Tabl e 3. ) I f al l generator s i n th e stat e emi t pol lutant s a t th e sam e average rat e a

s th e actual average emission s o f th e genera tor s i n th e SSEI S database , 5,000 diese l generator s i n Massachusett s woul demi t 3,50 0 ton s o f

NOx , 46 0 ton s o f

S02 , 20 0 ton s o f PM10 , 1,50

0 ton s o f

CO , an d 1,80 0 ton s o f VOCs . Whil e thi s i s aroug h estimate o f

statewid e emission s base do n a n incomplet e database , thes e number s ar e larg e enoug h t o indicat e tha t diese l generator s ar

e asignifican t

sourc e o f

pol lutio n tha t

deman dregulator y attention . Diesel generators ar

e use di navariet

y o f ways , wit hthre e genera

l categorie s o f

use : Emergenc y standb y generator s - Ofte n referre dt o a

s "back-up generators " o r BUGs , thes e ar

e generator s tha t

op erate o n atemporar y basi s a s back-u p powe r supplie s i nth e event

o f power out ages . Prim e generator s - Generator s use d o n aregular

basi s t o supplemen t

energ y fro mth e power

grid . Portabl e generator s - Generator s tha t ar e move dfromlocatio n t o locatio n t o provid e powe r

(moto r vehicle s anden gine s usedt o prope l equipmen t directl y ar e no t considere dportabl e generators) . Th e mor e hour s adiese l engin e op erates , th e mor e pollutant s i t release s int o th e ai r

w e breathe . Fo r

example , emergenc y back-u p generator s i n nor ma l operatio n ar

e generall y use donl y 25-5 0 hour s ayea

r whil e prim e engine s operat e anywhere fro m100 t o several thousan dhour s pe r

year . Hence , al thoug hther e ar

e fa r mor e emergenc y generator s i n Massachusetts , prim e en gine s ar e alarge r

sourc e o f

diese l pollu tio n i nth e stat

e due t o thei r

longe r hour s o f operation . Currently , diese l generator s ar e regu late ddifferentl y dependin g o n ho w the y ar e used . Th e resul t

ha s been confusin g Tabl e 3 : Estimate d Diese l Generator s

- i n Massachusetts 3 1 Diese l Generator s Numbe r i n b y Typ e o f Us e Massachusett s Emergenc yStand-b y 2,12 6 Generator s Prim e Generator s 33 1 Portabl e Generator s 3,18 0 TOTA L 5,63 8

an dinconsisten t

standard s fo r

no t onl y diese l generator s bu t

fo r al l micropower . Thi s need s t o b e improve db y develop in g standard s tha t

ar e base do n environ menta l an dpubli c health impacts . 

### Emission s Diese l generator s ar

e asignifican t

sourc e o f ai r pollutio n i n th e stat

e o f Massachu sett s an dnationwide. 3 2A s diese l fue l burns , ove r

fort y identifie dtoxi c ai r con taminant s ar

e release dint o th e ai r w e breathe . Th e primar y pollutan t i s nitro ge n oxides , whic hca

n cause lun g func tio n deterioratio n an dothe r seriou s human healt h effects . Additiona l pollut ant s includ e carbo n monoxide , carbo n dioxide , sulfu r

oxides , an dvolatil e organi c compounds . Se

e Tabl e 5 fo r

adescriptio n o f th e health andenvironmenta l effect s o f thes e pollutants . Emission s fro mdiese l generator s ca n hav e alarg e impac t

o n ambien t

ai r qual it y a t time s o f heavy use . Thi s ca

n be a Tabl e 4 . Estimate d NO x Emission s fro m Diese l Generator s i n Metr o Bosto n Durin g Pea k Use 3 4 Estimate d Numbe r o f ; Diese l Generator s Estimate d

Capacit y o f Diese l Generator s (MW ) : NO x " .

Emissio n :Ra'te|^>:v ; ;v " (Ibs/MWh ) NO x

Emission s • J (tons/day ) 1,23 7 40 8 21. 8 2. 7 Micropowe r a t th e Crossroad s 1 9Tabl e 5 : Descriptio n o f Emission s

Nam e o f Pollutan t Abbrevia tio n Sourc e an d Environmenta l Impact s Healt h Impact s Carbo n Monoxid e C O C O i s produce d b yburnin g organi cmatte r suc h as fossi l fuels , woo d an d charcoal . Moto rvehicle s produc e 67 % o f th e man mad e C O tha t i s release d int o th e atmo sphere . Fatigue , angina , reduce d visua l perceptio n an d dexterity , deat h i n close d space . Carbo n Dioxid e 

## co 2 C 0 2 i s produce d b yburnin g organi cmatte r suc h a s fossi l fuels , woo d an d charcoal . C0 2 i s a greenhous e gas . Majo rcontributo rt o globa l warming , whic h has bee n linke d t o a n increas e i n th e sprea d o f disease . Nitroge n Oxide s NO x Oxide s o f nitroge n are th e chemical s respon sibl e fo rgivin g smo g it s brow n appearance . NO xcontribute s t o th e formatio n o f ozone , productio n o f particulat e matte rpollution , an d aci d rain . Irritate s lun g tissue , cause s bronchiti s an d pneumonia , ha s bee n linke d t o a decreas e i n lun g functio n growth . Particulat e Matte r P M Particulat e matte rconsist s o f soo t an d dus t particle s tha t ar e smalle rtha n th e diamete r o f a huma n hair . Electricit ygeneration , trans portatio n an d industr ygenerat e roughl y equivalen t proportion s o f PM . Penetrate s dee p int o th e lung s an d i s associate d wit h numerou s respirator yan d cardia cproblem s an d cancer . Sulfu r Oxide s SOx Oxide s o f sulfu rar e produce d b yth e burnin g o f fossi l fuels . Larg e emitter s o f SO xinclud e moto rvehicles , refinerie s an d powe rplants . SO xcontribute s significantl yt o aci d rain . Reduce s respirator yvol ume , increase s breathin g an d nasa l airwa yresistance . Volatil e Organi c Compound s VOC/UH C VOC s ar e a clas s o f reactiv e organi cgase s tha t contribut e t o th e formatio n o f ozon e an d smog . Moto rvehicles, refinerie s an d powe rplant s ar e th e primar ysourc e o f VOCs . Level s o f VOC s ar e ofte n determine d b y measurin g unburne d hydrocarbon s (U.HC) . Coughing , fatigu e an d nausea ; contribute s t o th e inflammatio n o f lun g tissu e an d reduce d lun g capacity . Ai r Toxic s Ai rtoxic s lik e benzene , toluene , an d formal dehyd e ar e forme d fro m fossi l fue l process in g an d combustion . Th e U.S . EP Aha s identifie d 18 8 chemical s a s hazardou s ai r pollutants . Cancer , reproductiv e disorders , developmenta l disorders .

majo r facto r influencin g attainmen t wit h ai r qualit y standards . Ho t summe r

days , whe n ai r

problem s ar

e a t thei r worst , ar

e th e mos t

likel y time tha t

micropowe r

wil l be i n operatio n t o boos t a n electricit y loa d tha t i s heightene db y th e heav y use o f airconditioning . I n othe r words , diese l generator s pu t

ou t thei r highes t level s o f pollutio n exactl y whe n ai r qualit y i s th e mos t sensitiv e t o increase s i n pollution . Sinc e ther e has no t bee n any require men t fo r registerin g mos t

diese l genera tor s o r an y statewid e inventor y o f diese l generators , i t

i s no t possibl e t o measur

e thi s impac t

wit hprecision . However , estimate s ca

n giv e u s agoo dpictur e o f ho w bi g aproble mthi s i s likel y t o be . Assumin g th e sam

e numbe r

o f diesel gen erator s pe r

capit ai n Massachusett s a s hav e bee n counte di n California , an d 2 0 Micropowe ra

t th e Crossroad sFigur e 3 : Potentia l Cance r Ris k fro m Activitie s Usin g Diese l Fuele d Engine s I I Idlin g Schoo l Buse

s EmergencyStandb yEngin e

Truc k Sto p Lo wVolum e Freewa

y _ Distributio n Cente r Prim e Engin e Hig h Volum e Freeway 0 10 0 20 0 30 0 40 0 50 0 60 0 70 0 80 0 Potentia l Exces s Cancer s (Chance s pe rmillio n base d o n 70-yea rexposure ) 90 0

assumin g tha t

th e averag e size o f

thes e generator s i s 3 3 0 kW, 3 3 20 % o f thes e gen erator s operatin g fo r

thre e hour s o n ada

y o f tigh t electricit y supplie s i n Bosto n woul demi t

2. 7 ton s o f

NOx . (Se

e Tabl e 4. ) Thi s amoun t

o f pollutio n coul dpus h th e cit y int o non-complianc e wit hclea n ai r standards . 

### Healt h Impact s Th e extende dus e o f

diesel generator s ca

n resul t i n seriou s huma n health implica tions , especiall y sinc e mos t non-agricul tura l diese l generator s ar e locate di n densely populate durba n areas . Wher e larg e number s o f

peopl e are , so to o ar

e thes e under-regulated , high-emittin g engine s tha t

spe w smog-formin g chemi cals , fine particles , an dknow n cancercausin g agents . Thi s ca n create significan t

healt h risk s fo r entir e neighborhoods . Peopl e livin g withi n 10-2 0 averag e cit y block s o f adie sel generato r

operatin g onl y 10

0 hour s pe r yea r experienc e elevate dmortalit y risks. 3 5 

### Cance r Ris k I nrecen t years , a n increasin g numbe r

o f health organizations , a s wel l a s th e U.S . EPA an dstat

e environmenta l agencies , hav e recognize dth e cancer-causin g effect s o f diese l exhaus t

exposure. 3 6Ai r

pol lutio n contro l official s no w estimate tha t base do n alifetim e ris k

o f sevent y year s exposure , diese

l exhaus t ma y b e responsibl e fo r ove r 125,00 0 cance

r case s eac h yea r nationwide , includin g 2,90 0 i n Boston. 3 7 Th e cancer

ris k fro ma n emergenc y standb y engin e i s equivalen t t o tha t o f a n idlin g schoo l bus . Th e cance r ris k fro m prim e engine s (includin g non-agricul tura l engine s an dagricultura l engines ) i s mor e tha n tha t

o f alow-volum e freewa y o r tha t o f afacilit y tha t

ha s constan t

die sel truc k traffic . Bot hcurren t

diesel back u p generator s an dprim e engine s substantiall y surpas s th e acceptabl e risk leve l o f on e i n amillio n cance

r cases es tablishe db y th e U.S . EPA . Th e Californi aAi r

Resource s Boar d ha s estimate dtha t

aperson' s lifetim e can cer ris k increase s b y 50 % i f

he o r sh e live s Micropowe ra t th e Crossroad sPnot o D ynrg n Frequenc yActiv e Aurora l Researc n nea r asingl e one-megawatt diese l gen erato r tha t run s fo r a s littl e a s 25 0 hour s annually. 3 8 Anothe r

Californi astud y foun dth e cance

r risk i n five citie s t o be 70-14 0 time s highe r

tha n commonl y ac cepte dlevel s i n th e mos t affecte dneigh borhoods. 3 9 

### Non-Cance r Healt h Risk s Diese l exhaus t

i s als o know n t o caus e nu merou s non-cancer

respiratory problems . Diese l i s amajo r

sourc e o f

particulat e matte r (PM) , o r

soot , whic hca

n lodg e dee p i n th e lung s an dresul t i n th e exac erbatio n o f

asthma , respiratory infections , increase dsusceptibilit y t o allergens , chroni c obstructiv e lun g disease , pneu monia , andheart

disease . A recen t

study foun dtha t

eve n short-ter mexposur

e t o P M ma y in - creas e th e chanc e o f

heart attack s i n at ris k popula tions. 4 0 Diese l ex haus t als o con tains , nitroge n oxide s (NOx) . NO x i n th e presenc e o f sunligh t an d volatil e organi c compound s form s smog . Recently , th e US C Kec k

Schoo l o f

Medicin e foun di n along-ter mstudy tha t bot h NO x andP M ca n permanentl y reduc e th e lun g func tio n o f achil dlivin g i n Southern Cali forni ab y a

s muc h a s 10% . Diese l exhaus t wa s believe dt o b e asignifican t con tributor. 4 1 Man y othe r

toxi c substance s ar

e foun d i ndiese l exhaust . Mor e tha n 4 0 compo nent s o f diese l exhaus t

ar e liste da s haz ardou s ai r

pollutant s b y th e U.S . EPA. 4 2 

## Othe r Fossi l Fue l Interna l Combustio n Engine s Natura l Ga s Engine s Interna l combustio n engine s fuele db y natura l ga

s ar e cleaner tha n diesel gen erators , bu t

stil l have hig hemission s o f dangerou s ai r

pollutants . Natura l ga

s gen erator s have larg e reduction s i nNO x an d SO x compare dwit hdiese l generators , mediu mreduction s i nP M an dC02 , an d minima l reduction s i n C O an dVOCs . Natura l ga

s engine s ar

e offere dwit h tw o tunin g setting s - ric hburnin g (sto ichiometric ) o r

lea n burnin g (i n whic hth e air/fue l rati o i s increased) . However , th e choic e i s atrade-of

f o f lowerin g emission s o f on e pollutan t

whil e increasin g thos e o f another . Th e lo w emissio n tunin g wil l reduc e NO x an dhydrocarbo n emissions , bu t increas e C0 2 emissions . Al l othe r Tabl e 6 : Emission s o f Diese l an d Ga s Micropowe r an d Larg e Ne wPowe r Plant s (Ibs/MWh) 4 3 Generato r Typ e Efficienc y NO x C O 

## so 2 PM1 0 UH C 

## co 2 Diese l Engin e 38 % 21. 8 6. 2 0. 5 0. 8 1. 2 1,43 2 Natura l Ga

s Engin e (lea n burn ) 36 % 2. 2 5. 0 0.0 1 0.0 3 16. 5 1,10 8 Natura l Ga

s Engin e (ric h burn ) 29 % 0. 5 4. 0 0.0 1 0.0 3 0. 4 1,37 6 Combine d Cycl e Natura l Ga

s Powe rPlan t 5 1 % 0.0 6 0. 1 0.00 4 0.0 4 0.0 5 77 6 2 2 Micropowe ra t th e Crossroad semission s ar e simila r betwee n th e tw o tunings. 4 ' 1 Natura l ga

s generator s stil l contribut e significantl y t o th e sam e en vironmenta l andhealt

h impact s describe d i nTabl e 5 . 

### Engine s Usin g Othe rFossi l Fuel s ICE s ca n als o us e gasoline , propane , an d kerosene a

s fuel . Thoug h no t

a s commo n a s diese l an dnatura l ga

s generators , suc h generator s ar

e commerciall y available . Emission s level s fro mgasoline-fuele d ICE s fal l between thos e o f natura l ga

s an d diesel-fuele dgenerators . Gasolin e gen erator s ar e th e cheapest

generator s o n th e market , bu t

hav e areputatio n o f

hig h maintenanc e requirement s a s compare d t o generator s usin g an

y o f th e othe r

fossi l fuels . Propan e generator s emi t very simila r amount s o f

pollutant s a

s th e natura l ga

s generators. 4 5 

## Improvin g Engine s fo r Emergenc y an d Portabl e Us e Du e t o th e sever

e publi c health an den vironmenta l hazard s associatedwit hIC E generators , thei r

use shoul db e limite dt o emergenc y back-u p generatio n an dpor tabl e operations , an dthe n onl y whe n operate di n conjunctio n wit hemission contro l measures . Th e pollution-reducin g measure s tha t

ca n reduc e th e harmfu l impac t o f diese l generator s o n nearb y communitie s includ e fue l advancements , contro l technologies , improve defficiency , an dstringen t

operation s standards . • Fue l Advancement s - Th e U.S . EP A recentl y adopte dregulation s requirin g petroleu mproducer s t o distribut e low sulfu r diese l (1 5 pp msulfur

content ) nationall y b y 200 6 fo r

vehicl e use . Thi s rul e shoul dals o apply t o off-roa d diese l use . Massachusett s shoul d institut e thi s requiremen t o n it s own . Because mos t

advanceddiese l pollu tio n contro l device s ar

e sulfur sensitive , suc h step s t o requir e low-sulfu r

diese l ar e essentia

l t o achiev e furthe r

emission s reduction s fo r diese l engines . • After-Treatmen t

Technolog y / Emissio n Contro l - Particulat e trap s physicall y capture particulat e matte r i nafilter an dca n reduc e P M emis sion s b y 83%. 4 6Selectiv e catalyti c reductio n (SCR ) uses ammoni aa s a catalys t t o brea k dow n NOx . SC R systems have bee

n show n t o reduc e NO x b y 65 % t o 99%. 4 7 Nitroge n oxid e adsorber s have th e potentia l t o reduc e NO x b y 90% . Thi s technol og y involve s bot h achemical catalys t an dburnin g th e filter

clean . Eve n wit hthes e improvements , however , diese l an dothe r

fossi l fue l generator s ar e stil l dirtie r

tha n th e goo d micropowe r

technologie s discussed earlier . • Increase dEfficienc y - Th e efficienc y o f IC E generator s ca

n be improve d b y ensurin g prope r

installatio n an d sizing . Imprope r

installatio n ca

n accoun t fo r a25 % los s i n efficiency . Anothe r wa y t o improv e efficienc y i s t o captur e andreus e th e generator' s heat . Th e wast

e hea t produce db y th e generato r

ca n b e recovere dt o provid e energ y fo r

furthe r electricit y productio n o r

space andwate r heating . Thi s ca

n reduc e emission s b y 3 5 t o 50% . • Hour s o f

Us e - Reducin g th e operat in g hour s o f

IC E generator s wil l als o reduc e th e amoun t

o f pollutio n tha t i s release dint o th e ai r

w e breathe . 

### Key Recommendations

for Dirty Micropower Th e Massachusett s stat

e governmen t

ha s a n obligatio n t o protec t th e state' s ai r Micropowe r at th e Crossroad s 2 3quality . Sinc e th e mov e t o loca l power generatio n ha s partl y involve da n in creasedrelianc e o n th e mos t pollutin g form s o f

electricit y generation , stat e agencie s shoul dtak e step s t o discourag e th e us e o f

dirt y micropower . Thi s woul d includ e th e followin g measure's .

• Requir e tha t

al l micropowe r

unit s operate di n Massachusett s receiv e certificatio n o r

permit s a

s acondi tio n fo r bein g connecte dt o th e electri c grid . • Provid e incentive s fo r th e trade-i n an dupgrad e o f

pollutin g micropowe r installations . • Requir e tha t

transmissio n gri d operator s dra w o n clean , efficien t micropowe r

befor e similarl y price d dirt y installations . • Requir e ultr alow-sulfu r diesel fo r

al l diese l engine s i n Massachusetts , o n an doff-road . • Establis h aclea

r an dlimite ddefini tio n o f "emergenc y use. "

Manufacturers an d distributor s o f diese l generators use d th e "energ ycrisis " t o encourag e consumer s t o purchas e pollutin g hom e powe rsystems .

2 4 Micropowe ra t th e Crossroad s

# NE W MICROPOWE R TECHNOLOGIE S 

# N e w technologie s fo r

generatin g local powe r

are emergin g i nth e marketplace . Althoug hthe y ar e no t a s clean a

s th e renewabl e energ y sources , mos t

o f thes e alternative s ar

e distinc t improvement s over

curren t die se l generators . B y phasin g i n stringen t standard s regardles s o f

technology , stat

e official s wil l pus h manufacturer s t o im prov e thes e technologie s t o limi t harm fu l emissions . Som e o f thes e micropowe r

option s ca

n b e use di n combine dhea t an dpowe r applications . The y ar

e no t a s simpl e t o operate andmaintai n a s sustainabl e op tion s sucha

s win dan dsolar , bu t

the y ar e ofte n versatil e an dreliable . Mos t avail abl e technologie s utiliz e carbon-base d fuels . Whil e the y pollut e les s than diese l engines , the y stil l emi t

harmfu l gases . 

## Alternativ e Fue l Reciprocatin g Engine s Th e reciprocatin g engine , o r interna l combustio n engine , i s th e traditiona l en gin e usedi n vehicle s anddiese l genera tors , a s note dabov e i n th e "Dirties t Micropower " section . Thi s syste mdraw s ai r int o acylinder , compresse s th e ai r t o hea t it , the n inject s fuel , whic hignite s whe n mixe dwit hth e ho t air . Th e result in g explosio n move s th e piston . I t i s a n ope n system , meanin g tha t i t doe s no t reus e th e air

i t draw s in ; insteadi t

release s i t int o th e atmosphere a

s exhaus t hea t and gases . Stationary reciprocatin g engines , lik e th e diese l generator , ar

e typicall y 5 M W o r less , wit hth e 1-3. 5 M Wrang e bein g th e larges t

growin g segmen t

recently. 4 8 Whe n fuele db y traditiona l fossi l fuels , thes e engine s are th e mos t pol lutin g o f th e micropowe r

options . Whe n operate dwit halternativ e fuels , however ,

thei r emission s ca

n b e reduced . Se

e Ap pendi x A fo r

informatio n o n alternativ e fuels . 

## Turbine s A ga s turbin e differ s fro mth e recipro catin g engin e i n tha t

i t uses acontinuou s combustio n proces s rathe r tha n intermit ten t combustion . Lik e areciprocatin g en gine , th e basi c ga

s turbin e i s a

n ope n system , bu t

i t ca n be modifie dt o reus e it s exhaus t

heat . Exhaus t

treatmen t

tech nologie s ca

n reduc e NO x emission s sig nificantly , an dsom

e manufacturer s ar

e no w incorporatin g simila r technolog y int o th e combustio n proces s itself. 4 9 Ga s turbine s have traditionall y been manufacture dt o generat e severa l hun dre dmegawatt s fo r

use a s centra l power plants . No w som

e manufacturer s ar

e scal in g dow n thei r

unit s t o les s tha n 3 0 MW. 5 0Mos t

ne w turbine s ar

e fuele db y natura l gas . Some ca

n als o use othe r

pe troleu mfuel s o r

adual-fue l configuration . 

## Microturbine s Introduce dover

th e las t fe w years , th e microturbin e has arapidl y growin g mar ket . Basedo n th e sam

e technolog y a

s a je t engine , althoug hmuc hreduce di n size andimprove dwit hadvance dcomponent s an dsoftware , microturbine s ca n provid e powe r i n th e 2 5 k Wt o 500 k Wrange . Th e initiall y availabl e commercia l unit s generate power

rangin g from2 8 k Wt o 7 5 kW . Thes e smalle r

unit s ar e abou t th e size o f arefrigerator . Th e turbin e shaf

t o f amicroturbin e spin s a s fas t a s 100,00 0 rpm . Th e high frequenc y powe r

generate di s the n con verte dt o 60H z fo r

commo n use . Thi s Micropowe ra t th e Crossroad ssimpl e desig n lend s itsel f wel l t o th e low maintenanc e need s o f

distribute dgenera tion. 5 1 Microturbine s hav e th e potentia l t o operate o n avariet y o f fuels . Manufac turers , wit hsom

e suppor t

fro mfedera l andstat e agencies , ar

e workin g t o improv e microturbin e performance , includin g gen eratio n efficiency . Model s buil t t o dat e hav e lowe r

efficiency , an dthu s highe r C0 2 emissions , tha n traditiona l engines . I nadditio n t o thei r

smal l physical size an dflexibilit y regardin g fue l sources , microturbine s hav e onl y on e movin g par t and , therefore , lo w maintenanc e costs . The y ar e highl y suitabl e fo r

combine d heat an dpowe r

applications . Microturbines ' advancedfue l combus tio n technolog y result s i nlo w NO x emis sions , withou t

an y emissio n contro l technology , i n compariso n wit hgas-fire d centra l station plants . Earl y test s indicat e tha t thi s emission s performanc e wil l be maintaine dove r

extende doperatin g pe riods . Capston e Turbin e Corporatio n claim s tha t

curren t unit s emi t

NO x a t th e rat e o f 0.5 0 lbs/MWh , andproject s tha t performanc e improvement s wil l decreas e NO x emission s t o 0.1 4 lbs/MW hb y 200 5 an d0.05 lbs/MW hb y 2008 . 

## Stirlin g Engine s Stirlin g engine s ar

e powere db y th e ex pansio n o f

aga s tha t result s whe n th e ga

s i s heate dan dth e compressio n o f aga s tha t result s whe n th e ga

s i s cooled . I n thi s close dcycl e system , afixedamoun t o f ga s i s externall y heated , usuall y b y combus tion , anda

s i t expand s an dcontracts , i t move s th e pistons . Theoreticall y thes e engine s ca n us e an y hea t source . Currentl y systems ar e bein g develope dtha t

us e biomass , woodchip s an dsola r heat . Stirlin g engine s ar e physi cally smalle r

tha n conventiona l engine s an drelativel y quieter . Engine s rangin g from50 0 watt s t o 1 0 k War e eithe r avail abl e no w o r

unde r development . Emission s associate dwit hStirlin g en gine s vary accordin g t o th e hea t sourc e used . Th e Stirlin g engin e itsel f has n o emissions , s

o whe n i t

i s develope dt o us e sola r heat a s th e hea

t source , th e entir e syste mwil l b e emission-free . Whe n fossi l fuel s ar e burne dt o provid e th e hea t source , ther e ar e emissions . Sinc e th e combustio n take s plac e externally , i t

ca n b e monitore d t o bur n fuel s completel y andlimi t th e tem perature , reducin g emission s somewhat . 

### Potentia l Advantage s o f Emergin g Technologie s Technica l advancements , includin g im provement s i nfue l combustio n an demis sion s reductio n equipment , hav e th e potentia l t o significantl y reduc e th e en vironmenta l impact s o f

thes e micropowe r technologies . Federal , stat e an dmanufac turer-funde dresearch anddevelopmen t program s ar

e pursuin g suc h improve ments . Clea r

emission s standard s wil l provid e clea

r signal s regardin g technol og y performanc e targets , an dastron g incentive s polic y ca

n establis h attractiv e marke t advantage s fo r

th e cleanes t micropowe r

technologies . 

### Key Recommendations

for New Micropower Thes e technologie s alread y sho w th e promis e o f

bein g safe

r fo r publi c healt h than th e dirties t

micropower . Bu t

t o mak e sur e tha t the y mov e towar dth e cleanes t micropowe r

technologies , w e mus t en sur e tha t pollutio n standard s ar

e applie d acros s th e boar dt o al l developin g tech nologies , an dcomplemen t th e standard s wit hpolicie s tha t

provid e economi c an d othe r incentive s t o th e cleanes t micro powe r systems . Stat

e agencie s shoul dtake th e followin g actions . • Establis h priorit y fundin g fo r clean micropowe r

technolog y advancement . 2 6 Micropowe ra t th e Crossroad sStreamlin e th e permittin g proces s fo r clea n unit s tha t

mee t o r bea t ai r pollutio n standards . Requir e tha t

al l micropowe r

unit s operate di n Massachusett s receiv e certificatio n o r

permit s a

s a conditio n fo r bein g connecte dt o th e electri c grid . • Ensur e adequat

e enforcemen t

o f emission s standard s andestablis h significan t

penaltie s fo r

violation .

Micropowe ra t th e Crossroad s

# POLIC YRECOMMENDATION S 

# M icropowe r

i s here t o stay , and i s likel y t o expan drapidl y i n th e comin g years . Thi s i s bot h a n opportunit y an daris k for publi c healt

h i nMassachusetts . Clean micropowe r op tion s hav e th e potentia l t o greatl y reduc e dangerou s emission s fromelectricit y pro duction , bu t

th e mos t

commo n micro power technolog y - th e diesel generato r

- i s eve n mor e pollutin g than th e leadin g technologie s ofhrg e central power plants . Principle s T o ensur e tha t publi c health i s protecte d an dtha t ne w technologie s tha t reduc e pollutio n ar

e encouraged , micro-powe r polic y shoul dbe base

do n th e followin g principles : o Distribute dgeneratio n mus t be a s clean a s o r cleaner tha n th e cleanes t centra l powe r

plan t technolog y currentl y i n widespreaduse . Regula tion s shoul dtarge t

attainmen t

o f equivalen t

performanc e a

s soo n a s practical . o State rule s andincentive s mus t promot e th e cleanes t

energ y industr y fo r th e futur e o f

Massachusetts . o Regulation s shoul dbe a s simpl e a

s possibl e s o manufacturer s ca n anticipat e change s an dcompl y wit h ne w technolog y requirements . Primar y Recommendation s Stat e agencie s can hel p mov e micro powe r i n th e righ t

direction . T o protec t th e health o f

th e peopl e o f

Massachusett s an dth e ai r

qualit y o f

th e stat e whil e help in g t o assur

e reliabl e loca l powe r

genera tion , w e recommen dth e followin g o Set stringen t

emission s standard s fo r al l micropowe r

unit s operate di n A4assachusetts . Micropowe ra t th e Crossroad s o Conduc t acomprehensiv e inventor y o f existin g micropowe r

andothe r onsit e generation . o Streamlin e th e permittin g proces s fo r clean unit s tha t

mee t o r bea t ai r pollutio n standards . o Ensur e adequat

e enforcemen t

o f standard s an destablis h significan t penaltie s fo r

violation . Additiona l Recommendation s I naddition , many othe r specifi c policie s coul densur

e that th e move t o loca

l powe r generatio n lead

s t o air qualit y benefit s rather tha n adigression t o pollutin g technologies . W e recommen dtha

t stat e agencies : Establish standards and

rules for micropoiver

operation:

• Requir e tha t

al l micropowe r

unit s operate di n Massachusett s receiv e certificatio n o r

permit s a

s acondi tio n fo r bein g connecte dt o th e electri c grid . Thi s polic y establishe s achec k agains t th e operatio n o f excessively pollutin g micropowe r system s an dpreferre dtreatmen t fo r th e cleanes t

micropowe r options . • Requir e tha t

transmissio n gri d operator s draw o n clean , efficien t micropowe r

befor e similarl y price d dirt y installations . Ai r

pollutio n emis sion s shoul db

e consideredi ndecision s regardin g whic hgenerator s ar e used i ntime s o f

excess powe

r capacity . • Requir e emission s contro l measure s fo r diese l generator s usedfo r emer genc y back-u p powe r

supply . Back u p generator s wil l continu e t o be a majo r pollutio n proble mi f

the y ar e lef t ou t o f th e regulator y picture .• Requir e tha t al l ne w residentia l an d commercia l constructio n be "solar ready " wit hth e basi c infrastructur e t o eas e futur e installatio n o f

photo voltai c panels . Provide funding for

clean micropower:

• Requir e forma l consideratio n o f clea n micropowe r

a s apotentia l leas t cos t alternativ e t o transmissio n an d distributio n upgrade s an damean s o f avoidin g th e cos t

o f futur e environ menta l regulation . • Establis h priorit y fundin g fo r clea n micropowe r

technolog y advance ment . Stat

e researc h anddevelop men t program s ca

n targe t th e mos t promisin g clea

n micropowe r

tech nolog y options . Publi c mone y fo r th e developmen t

o f thes e technologie s woul db e agoo dinvestment

fo r th e long-ter mhealt

h o f th e stat e economy . • Expan dth e availabilit y o f financial incentives , includin g financin g assistance , buy-dow n programs , ta x credits , an dgrants , fo r

th e installa tio n o f clea n micropower . A s lon g a s consumer s ar

e expecte dt o shoulde r th e burde n o f

th e investmen t

cost s o f ne w technology , th e governmen t shoul dprovid e financial assistance . • Provid e incentive s fo r developer s t o includ e clea

n micropowe r

at new residentia l o r

commercia l construc tio n projects . Sinc e builder s don' t pa y th e ongoin g energ y cost s o f th e unit s the y build , the y ar e reluctan t

t o includ e energ y savin g measure s tha t wil l increas e th e initia l sal e pric e o f thei r buildings . • Provid e incentive s fo r th e trade-i n an dupgrad e o f

pollutin g micropowe r installations . Othe r

state s hav e show n thi s t o be acost-effectiv e approac h t o reducin g ai r pollution . Clear hurdles to the implementation of clean micropower:

• Streamlin e th e permittin g an dutilit y interconnectio n proces s fo r clea n micropowe r

installations . Micro powe r i s currentl y at

adisadvantag e compare dwit htraditiona l powe r generatio n du e t o a

n unnecessaril y complicate dinterconnectio n process . Eliminatin g thi s disadvantag e fo r clean micropowe r

woul dpromot e it s expansion . • Develo p incentiv e tariff s an dreduce d standb y an dexi t

fee s fo r clea n micropowe r

installations . Thi s woul d addres s financial disincentive s i n utilit y relationship s wit hmicropowe r operators . Th e adoptio n o f

thes e recommenda tion s wil l promot e avita l micropowe r systemtha t

reduce s th e negativ e publi c health impact s associate dwit hdiese l and othe r dirt y micropowe r

technologies .

Micropowe ra t th e Crossroad s 2 9

# APPENDI XA : ALTERNATIV E FUEL S 

# S everal non-traditiona l fuel s have bee n develope dtha t

ca n replac e pur e fossi l fuel s i n som e combus tio n engines , microturbines , Stirlin g en gines , an dfue l cells . Whil e som e o f thes e fuel s ma y hol dpromis e fo r reducin g emission s fro melectricit y generation , mos t o f the minvolv e level s o f

health ris k simila r t o thos e o f

traditiona l fuels . Biodiese l i s afue l tha t

i s made fro mveg etabl e oil s o r

animal fats . Thi s i s th e "bio " part , whic hca

n be usedalone , bu t

i s usu all y mixe dwit hconventiona l petroleu m diese l fue l at

arati o o f

20-30 % "bio " t o 70-80 % diesel. 5 2Th e fue l operate s i n a conventiona l combustio n engin e lik e a diese l generator . Compare dt o regular diesel , biodiese l ha

s reduce demission s o f CO , SO, , an dparticulat e matter , bu t has increase dN O an dsolubl e CO , emis sions . Propane , als o calle dLiquefie dPetro leu mGas (LPG) , i s forme da s aby-prod uc t o f processin g natura l ga

s an drefinin g crud e oil . Propan e usag e emit s n o aro mati c compounds , benzene o r particu lates . Engine s tha t

ar e optimize dfo r propan e hav e lowe r

CO , emission s tha n diese l generators . Propan e ca n be used a s asubstitut e fo r

diese l fue l i n interna l combustio n engines . Ethano l i s mad e fro mth e fermentatio n o f sugar s o r

starche s i n grains , agricul tura l feedstock s an dagroforestr y prod ucts . Ethano l i s mixe dwit hgasolin e i n differen t percentage s t o be useda s afuel . Methano l i s predominantl y mad e from stea mreformin g o f

natura l gas . I t

ca n als o b e made fro mfeedstock s o f coal o r bio mass , bu t

currentl y thes e ar

e no t a s eco nomical . Lik e ethanol , methano l i s mixe d wit hgasoline t o b e use

da s afuel . I n thes e gasolin e mixtures , bot h ar e referre dt o a

s gasoho l an dar

e designe dfo r

vehicl e use . Biomas s describe s many type s o f tech nologie s t o tur n agricultura l material s and wast e int o energy . Som

e ar e unacceptabl y harmfu l t o th e environmen t whil e other s provid e ane t

benefi t t o th e environment . Th e us e o f

biomas s i n fue l cells , micro turbine s andStirlin g engine s i s stil l be in g researched . P Serie s Fuel s ar

e blend s o f

methyl tetrahydrofura n (MTHF) , ethano l an d hydrocarbons . Currentl y MTH Fi s pro duce dfro mbiomas s o r petroleu mfeed stocks .

3 0 Micropowe ra t th e Crossroad s

# APPENDI XB : GLOSSAR Y

Back-u p generator s (BUGs ) Emergenc y powe r

generator s use dt o avoi dpotentia l powe r interruption s cause dby malfunctionin g powe r plants , natura l disasters , o r

deman doverload s o n th e electri c grid. 1 3 Britis h therma l uni t(Btu ) Th e standardmeasure o f heat energy , equal t o th e amoun t

o f energ y neede dt o rais e th e temperatur e o f on e poun do f wate r b y on e degre e Fahrenhei t at se a level . I t take s abou t

2,00 0 Btu s t o mak

e a po t o f coffee . Californi aAi rResource s Boar d (CARB ) Th e regulator y agency tha t ensure s California' s complianc e wit hth e Clea n Ai r Act . CAR B has don e mor e tha n any othe r stat e environmenta l agency t o in ventor y micropowe r

resource s andmea sur e thei r effects . Carbo n monoxid e (CO ) A n ai r pollutan t

produce db y burnin g or gani c matte r

suc h a s oil , natura l gas , fuel , woo dandcharcoal . Moto r vehicle s pro duc e 67 % o f

th e man-mad e C O tha t i s release dint o th e atmosphere . Carbo n dioxid e (C02 ) A greenhous e gas , produce db y burnin g organi c matte r

suc h a s oil , natura l gas , fuel , woo dan dcharcoal . Combine d hea tan d powe r(CHP ) A power generatio n syste mtha t use s wast e hea t t o hea t water , room s andbuild ings ; provide ai r

conditionin g o r

refrig eration ; o r

provid e stea

mt o generat e mor e electricity . Departmen to f

Environmenta l Protectio n (DEP ) Massachusetts ' regulatory agenc y tha t en sure s complianc e wit hth e Clea n Ai r Act . Distribute d generatio n (DG )

Energ y productio n tha t occur s nea

r th e plac e where i t

i s used . Thi s ter mi s used interchangeabl y wit h"micropower " throughou t

thi s report . Emergenc y standb y generator s Ofte n referre dt o a

s "back-u p genera tors " o r BUGS , thes e ar

e generator s tha t operat e o n atemporary basi s a s back-up powe r supplie s i n th e even t o f powe r outages . Fue l cel l A n energ y productio n technolog y tha t create s electricit y an dheat throug h th e chemical reactio n o f

combinin g hydro gen andoxyge n t o mak

e water . Kilowatt-hou r(kWh ) Th e mos t

commonly-use duni t

o f measur e tellin g th e amoun t

o f electricit y con sumedover

time , equa

l t o on e kilowat t o f electricit y supplie dfo r on e hour . A typica l househol dconsume s 50 0 kW h i n a n average month . Megawatt(MW ) On e thousan dkilowatt s (1,00 0 kW ) o r on e millio n watts . On e megawat t i s enoug h energ y t o power 1,00 0 averag e Massachusett s homes . Megawatt-hou r(MWh ) On e thousan dkilowatt-hours , o r a n amoun t o f electricit y tha t

woul dsuppl y th e monthl y powe r

need s o f

atypica l hom e havin g a

n electri c ho t

wate r sys tem . Microturbin e A new micropowe r

technolog y base

do n th e sam e technolog y a

s aje t engin e al thoug hmuc h reduce di n size an dim prove dwit hadvance dcomponent s an d software . Micropower a t th e CrossroadsNe t meterin g A syste mfo r

meterin g electricit y con sumptio n tha t

subtract s th e amoun t

o f powe r fe dbac k

int o th e gri db y a micropowe r

uni t fro mth e amoun t

tha t i s draw n fro mth e grid . Nitroge n oxide s (NOx ) Th e chemical s responsibl e fo r givin g smo g it s brow n appearance . NO x con tribute s t o th e formatio n o f ozone , pro ductio n o f

particulat e matte r

pollutio n an daci drain . Particulat e matte r(PM ) A n ai r pollutan t

mad e u p o f soo t an ddus t particle s tha t

ar e smaller tha n th e diam ete r o f ahuman hair . Pea kloa d o rpeak deman d Th e electri c loa dtha t

correspond s t o a maximu mleve l o f

electri c deman di n a specifie dtim e period . Pea k period s dur in g th e da

y usuall y occu r

i n th e mornin g hour s fro m6 t o 9 a.m . an ddurin g th e afternoon s fro m4 t o abou t 8 o r 9 p.m . Th e afternoo n pea

k deman dperiod s ar

e usuall y higher , an dthe y ar e highes t dur in g summe r

month s whe n air-condition in g us e i s th e highest . Photovoltai c (PV ) pane l Als o know n a

s asola r panel , PV s conver t sunligh t directl y int o electricit y usin g semiconducto r

technology . Prim e generator s Generator s use do n aregula r basi s t o supplemen t

energ y fro mth e powe r grid . Portabl e generator s Generator s tha t

ar e move dfro mlocatio n t o locatio n t o provid e power (moto r ve hicle s andengine s use dt o prope l equip men t ar e no t

considere dportabl e generators) . Sulfu roxid e (SOx ) A n ai r pollutan t

produce db y th e burn in g o f fossi l fuels . Larg e emitter s o f SO x includ e moto r

vehicles , refinerie s an d power plants . SO x contribute s signifi cantl y t o aci drain . Volatil e organi c compound s (VOCs ) A clas s o f

reactive organi c gase

s tha t con tribut e t o the formatio n o f ozon e an dsmog . Moto r vehicles , refinerie s andpower plant s ar e th e primary sourc e o f

VOCs . Win d turbin e A n energ y generatio n technolog y i n whic hth e kineti c energ y o f th e win di s converte dt o mechanical power , whic hi n tur n drive s th e electrica l generato r an d produce s a

n electrica l current .

3 2 Micropowe r

a t th e Crossroads

# NOTE S

1 . Throughou t

thi s report , th e term s "micropower " an d"distribute dgeneration " ar e use dsynonymously . 2 . Micropowe r

shoul dno t

b e confuse dwit hth e "peaker plants " tha t

ar e muc hi n th e new s recently . Althoug hbot har e smal l electricit y generatin g plants , peaker s ar e generator s operate db y utilitie s an dindependen t powe r producer s tha t

are usedonl y durin g pea k deman dtimes . The y ar e typicall y 50-10 0 MW . Micropowe r

unit s ar e normall y no t

operate db y utilities , andar

e typicall y i n th e 2 k Wt o 1 M W range , wit hsome a

s hig ha s 1 0 MW . 3 . Davi dMorris , Seein g th e Light : Regainin g Contro l o f

Ou r Electricit y Syste m(Minneapolis : Institut e fo r

Loca l Self-Reliance , 2001) , 54 . 4 . Ibid . 5. Energy Nexus Group, Performance and Cost Trajectories of

Clean Distributed

Generation Technologies, 29May 2002. 6 . Regulator y Assistanc e Project , Mode l Regulation s fo r

th e Outpu t

o f Specifie dAi r Emission s fro mSmaller-Scal e Electri c Genera tio n Resources : Mode l Rul e an dTechnica l Suppor t Documents , Novembe r 2001 , Appendi x B . 7 . Ibid . 8 . Ibid . 9 . Man y studie s hav e establishe dth e link s betwee n thes e pollutant s an dthei r healt heffects , includin g D. WDocker y e t al , "A n Associatio n betwee n Ai r

Pollutio n an dMortalit y i n Si x U.S . Cities, " Ne w Englan dJourna l o f jMedicine , 1993 . Fo r

agoo dovervie w o f

th e healt heffect s o f powe r plan t pollution , se

e Clea n Ai r

Tas k Force , Death , Diseas e & Dim ' Power , Octobe r 2000 . 10 . Se e Ne w Yor k

Shines , Ne w Yor k

Consume r Guid e t o Buyin g aSola r Electri c System , availabl e a

t www.nyshines.org/pvguide.pdf ; Californi aPubli c Interes t Researc h Group , Affordable , Reliabl e Renewables : Th e Pathwa y t o California' s Sustainabl e Energ y Future , Jul y 2001 ; an dCaliforni aPubli c Interes t Researc h Group , Predictabl y Unpredictable : Volatilit y i n Futur e Energ y Suppl y an dPric e from California' s Over-Dependenc e o n Natura l Gas , Septembe r

2001 , availabl e at

www.calpirg.org . 11 . U.S . Departmen t o f Energ y (DOE) , Offic e o f Utilit y Technologies , Renewabl e Energ y Technolog y Characterizations , Decembe r 1997 . 12 . PVha s a

n averag e availabilit y facto r o f 96% : Sacrament o Municipa l Utilit y District , Sus taine dOrderl y Developmen t o f PV , downloade d fro mwww.ttcorp.eom/upvg/4.5doc / 4.5mwsmd.htm , 4 Jun e 2001 . 13 . Sola r Boston , Porte r

Square Shoppin g Cente r Generate s Powe r

fro mth e Sun , down loade dfro mwM-w.solarboston.org/ portersquare.htm , 2 8 Ma y 2002 . 14 . Interstat e Renewabl e Energ y Council , Solar Powere dShoppin g Cente r Comin g t o Cam bridge , Massachusetts , excerp t fro mUtilit y Photovoltai c Grou p Memo , 2 6 Octobe r 2001 . 15 . U.S . DOE , Quic k

Fact s abou t

Win dEnergy , downloade dfro mwww.eren.doe.gov/wind / web.hunl , 1 5 Jul y 2001 . 16 . Danis h Win dTurbin e Manufacturer' s Association , Windpowe r FAQs , downloade d fro mwww.windpower.dk/faqs.html , 25 Ma y 2001 . 17 . Leste r

Brow n e t

al , State o f

th e Worl d200 1 (NY : W.W . Norton , 2001) , 94 . 18 . America n Win dEnerg y Association , Californi aElectricit y Crisi s Spur s Sale s o f Hom e Win dEnerg y System s (pres s release) , 1 3 Februar y 2001 . Win dturbine s hav e a n averag e availabilit y facto r

o f 98% : U.S . DOE , Office'o f Utilit y Technologies , Renewabl e Energ y Technolog y Characterizations , Decembe r 1997 . 19 . U.S . EPA , EPA Present s Environmenta l Meri t Award s t o Eightee n i n Massachusetts , downloade dfro mwww.epa.gov/region01/pr , 25 Jun e 2002 . 20 . Ibid . 21 . Massachusett s Energ y Consumer s Alliance , Win dPower , downloade dfro m www.massenergy.com/Wind.html , 2 Jul y 2002 . 22 . Sunline , Clea n Fuels , downloade dfro m www.sunline.org/clean_fuels , 3 1 Augus t 2001 . 23 . FuelCel l Energ y , PP LSpectru man d FuelCel l Energ y Inc . t o Suppl y Direc t Fue l Cel l Powe r Plan t t o Unite dState s Coas t Guar d Statio n (pres s release) , 1 8 Octobe r 2001 . Micropowe ra t th e Crossroad s 3 324 . Dav e Cleveland , U.S . Coas t Guar dCap e Co dAuxiliar y Office , personal communication , 1 1 Jul y 2 002. ' 25 . Dav e Cleveland , personal communication , 7 Augus t 2002 . 26 . U.S . Coas t

Guard , Fue l Cel l Installatio n at Ai r Statio n Cap e Co d(fac t sheet) , downloade d fro mwww.rdc.uscg.gov , 1 1 Jul y 2002 . 27 . U.S . Combine dHea t an dPowe r

Associa tion , Combine dHea t

an dPower : Distribute d Generatio n Application s tha t Sav e Power , Reduc e Costs , an dImprov e Energ y Security , downloade dfro mwww.nemw.org/uschpa/ papers.htm , 1 7 Augus t 2001 . 28 . U.S . Departmen t

o f Energy , Energ y Secretary Richardso n Join s Massachusett s Congressiona l Representative s t o Dedicat e Ne w Cogeneratio n Syste ma t Maide n Mills , 8 Novemhe r

1999 . 29 . U.S . Combine dHea t an dPowe r

Associa tion , 200 0 EnergySta r

Combine dHea t

an d Powe r Awards , 22 Jun e 2001 . 30 . Massachusett s DEP , "Stationar y Sourc e Emissio n Inventor y System " (spreadsheet) , 1 4 Marc h2001 . 31 . Extrapolatio n o f

Californi adatafro m Californi aAi r

Resource s Boar d(CARB) , Diese l Ris k Reductio n Plan , Appendix - II , Octobe r 2000 . Numbe r

o f non-agricultura l generator s translate dpe r

capita . Numbe r

o f agricultura l generator s translate db y rati o o f gros s state produc t o f farmin g secto r

(DOC , Burea u o f Economi c Data , Regiona l Account s Data , 2000) . 32 . State number s ar

e i n th e previou s section . A n estimate d371,00 0 ton s o f NO x an d16. 7 millio n ton s o f

C0 2 ar e emitte dfro mdiese l generator s nationwide : Virinde r Singh , Renew abl e Energ y Polic y Project , Blendin g Win dan d Solar int o th e Diese l Generato r Market , Winte r 2001 . 33 . 33 0 k Waverag e diese l generato r siz e estimat e fro manalysi s o f th e 200 1 Diese l an d Turbin e Worldwid e Annua l Powe r Generatio n Surve y b y Powe r

System s Research , 2001 . 34 . Numbe r

o f generator s i s th e pe r

capit a equivalen t

o f Californi adatafo r

non-agricul tura l prim e andemergenc y back-u p generator s fro mCARB , Diese l Ris k Reductio n Plan , Appendi x II , Octobe r

2000 . Estimate dcapacity i s base do n a

n averag e capacity o f

33 0 kW . NO x emissio n rat e fromRegulator) ' Assistanc e Project , Mode l Regulation s fo r th e Outpu t

o f Specifie d.Air Emission s fro mSmaller-Scal e Electri c Generatio n Resources : Mode l Rul e an d Technica l Suppor t

Documents , Novembe r 2001 , Appendi x B . 35 . Nanc y Ryan , Kat e Larsen , an dPete r Black , Environmenta l Defense , Smaller , Closer , Dirtier : Diese l Backu p Generator s i n California , Augus t 2002 . 36 . Ca l EPA , Chemical s Know n t o th e State t o Caus e Cance r

o r Reproductiv e Toxicity , revise d 1 Ma y 1997 . 37 . State an dTerritoria l Ai r Pollutio n Progra m Administrator s an dth e Associatio n o f Loca l Ai r Pollutio n Contro l Officials , "Cance r Ris k fro m Diese l Particulate : Nationa l an dMetropolita n Are aEstimate s fo r

th e Unite dStates, " 1 5 Marc h 2000 . 38 . CARB , Attachmen t t o Lette r

o n Emergenc y Generators : Ai r

Pollutio n Emission s fro m Electricit y Generation , 2 1 Februar y 2001 . Based o n 70-yea

r exposure . 39 . Se e not e 35 . 40 . A . Peter s e t

al , "Increase dParticulat e Ai r Pollutio n an dth e Triggerin g o f Myocardia l Infarction, " Circulatio n 103 (23) , 1 2 Jun e 2001 . At-ris k population s ar

e considere dt o b e children , athletes , peopl e wit hrespirator y disease , an dth e elderly . 41 . W.Jame s Gaudenna n e t al , Associatio n betwee n Ai r

Pollutio n an dLun g Functio n Growt hi n Souther n Californi aChildren , 2 Ma y 2000 . 42 . CAR B an dOffic e o f Environmenta l Healt h Hazar dAssessment , Propose dIdentificatio n o f Diese l Exhaus t

a s aToxi c Ai r

Contaminant , 2 2 Apri l 1998 . 43 . Se e not e 6 . Micropowe r

figure s represen t emission s fromunit s wit hn o emission s treat ment , whic hi s typica l o f mos t curren t micropowe r

facilities . 44 . Nathanae l Green e an dRoe l Hammerschlang , "Smal l an dClea n I s Beautiful : Explorin g th e Emission s o f Distribute dGenera tio n an dPollutio n Preventio n Policies, " Electricit y Journal , 2000 . 45 . Mar k

Delucchi , Propan e Educatio n an d Researc h Council , LP Gfo r Forklifts : A Fuelcycl e Analysi s o f

Emission s o f

Urba n Ai r Pollutant s an dGreenhous e Gase s (pres s release) , 1 7 September

1999 . 46 . CARB , Diese l Ris k Reductio n Plan , 3 4 Micropowe ra t th e Crossroad sr.

Appendi x II , Octobe

r 2000 . 47 . Unio n o f

ConcernedScientists , Rollin g Smokestacks : Cleanin g U p America' s Truck s an d Buses, Octobe

r 2000 . 48 . Set h Dunn , Worldwatc hInstitute , Micro power : Th e Nex t

Electrical Era , Jul y 2000 . 49 . Se e not e 5 . 50 . Se e not e 48 . 51 . Se e not e 5 . 52 . National Biodiese

l Board , Biodiese

l Frequently Aske

dQuestions , downloade

dfro m www.biodiesel.org/general/faq.htm , 2 2 August 2001 . 53 . Thanks t o th

e Californi aEnergy Commissio

n (www.energy.ca.gov/glossary ) fo r man y o f these definitions .

Micropowe ra t th e Crossroad s 3 5