### Golde r

Associate s Inc

. 20 0 Unio n Boulevard
, Suite 50 0 Lakewood
, C O US A 8022 8 Telephon e (303 ) 980-054 0 F a x (303 ) 985-208 0


## 37579 2

j'.'-Jli/Lyi'i * 

### SURFACE WATE R HUMA N HEALT H RIS K ASSESSMEN T CALIFORNI A GULC H SIT E p j [ £ LEADVILLE

, COLORAD O 3.0 7

Prepared For: 

### Asarco, Inc. 495 East 51st Avenue Denver, Colorado 80216-2098
Prepared By: Golder Associates Inc. 200 Union Blvd., Suite 500 Lakewood, Colorado 80228

Jun e 199 6 943-281 9

OFFICE S I N AUSTRALIA
, CANADA

, GERMANY

, HUNGARY
, ITALY
, SWEDEN

, UNITE D KINGDOM

, UNITE D STATE SJun e

1996____________________i____________________943-281 9 TABL E O F CONTENT S 1. 0 INTRODUCTION.................................................................................. 1 1. 1 Objective s an d Scope............................................................................. ! 2. 0 EXPOSUR E ASSESSMENT...................................................................... 2 2. 1 Potentia l Recepto r Populations................................................................. 2 

### 2. 2 Conceptua l Sit e Model........................................................................... 3 2. 3 Complet e Exposur e Pathways.................................................................

. 4 2. 4 Estimatin g Chemica l Intakes...................................................................

. 4 2. 5 Exposur e Assumptions........................................................................... 5 3. 0 DAT A ANALYSIS..................................:.............................................. 7 3. 1 Chemical s o f Concer n .......................................................................... . 7 4. 0 TOXICIT

Y ASSESSMENT......................................................................

. 8 5 . 0 RIS K CHARACTERIZATION................................................................... 9 5. 1 Hazar d Inde x fo r Noncarcinogenic Effects................................................

. 1 0 5. 2 Carcinogeni c Ris k

............................................................................. . 1 2 5. 4 Ris k Characterizatio n Result s
............................................................... . 1 4 6 . 0 UNCERTAINTIE

S AN D LIMITATIONS..................................................

. 1 5 6. 1 Dat a Evaluation................................................................................

. 16 6. 2 Exposur e Assessment.........................................................................

. 1 6 6. 3 Toxicit y Assessment..........................................................................

. 1 7 6. 4 Ris k Characterizatio n ......................................................................... . 1 7 7. 0 CONCLUSIONS.................................................................................

. 1 7 8. 0 REFERENCES...................................................................................

. 1 8Jun e

199 6 1

1 943-281 9 LIS T O F TABLES Tabl e 1 Leadvill e Surfac e Wate r Potentiall y Complet e Exposur e Pathway s Quantitativel y Evaluate d Tabl e 2 Genera l Assumption s fo r Bod y Weigh t Tabl e 3 Intak e Assumption s fo r Fis h Ingestio n Tabl e 4 Leadvill e Surfac e Wate r Fis h Tissu e Dat a Summar y Tabl e an d Exposur e 

### Poin t Concentrations 

### Tabl e 5 Lengths
, Weights
, an d Ag e Classe s o f Trou t Collecte d fo r Tissu e Sampl e Analysi s a t Stud y Locations o n th e Californi a Gulc h Sit e I n August
, 199 1 Tabl e 6 Chroni c an d Subchroni c Ora l RfD s an d Slop e Factor s fo r Chemical s o f 

### Concer n Tabl e 7 Surfac e Wate r Carcinogeni c Risk s an d Noncarcinogeni c Hazar d Inde x (H.I. ) Tabl e 8 Summar y o f Uncertaint y Factor s i n th e Surfac e Wate r Baselin e Ris k Assessmen t LIS

T O F FIGURE S Figur e 1 Zin c Concentration s an d Flo w i n Californi a Gulc h Figur e 2 Predicte d Zin c Concentration s i n th e Arkansa s Rive r Belo w Californi a Gulc h LIS

T O F APPENDICE S Appendi x A Interpretatio n O f ASSES S Outpu t

Golde r Associate sJun e

1996___________________1____________________943-281 9 

### 1. 0 INTRODUCTIO

N T h e followin g Huma n Healt h Ris k Assessmen t (RA ) fo r surfac e water has bee n prepare d i n suppor t o f th e Surfac e Wate r Remedial Investigatio n (RI ) Report (Asarco
, 1996a ) t o evaluat e potentia l healt h risk s fro m metal s i n surfac e water i n an d aroun d Leadville
, Colorado

. Thi s R A wa s performe d usin g dat a collecte d fro m th e stream s and river s i n and

nea r Californi a Gulc h sit e durin g the summe r o f 1991

. The result s presente d i n thi s R A addres s potentia l healt h risk s associate d wit h surfac e water , specificall y th e ingestio n o f locall y caugh t fish

. Al l potentia l exposure s fro m multipl e source s wil l b e evaluate d separatel y h i a sitewid e baselin e RA

. Th e exposur e parameters use d i n thi s R A ma y chang e i n th e sitewid e baselin e RA

. This R A evaluate s onl y a singl e sourc e contribution

. 

### 1. 1 Objective s an d Scop e The primar y objectiv e o f thi s R A wa s t o evaluat e potentia l healt h risk s du e t o exposur e t o surfac e wate r usin g recentl y collecte d data

. Wher e possible , site-specifi c dat a wer e used

. Thi s approac h i s consisten t wit h guidanc e provide d b y th e EP A Ris k Assessmen t Counci l whic h stresse s th e us e o f site-specifi c dat a t o evaluat e potentia l healt h risk s (EPA

, 1992a , b)

. Anothe r objectiv e o f th e R A was t o follo w th e Ris k Assessmen t Council' s guidanc e fo r ris k characterizatio n limitin g discussio n o f informatio n t o ris k assessment , an d not includin g discussion s o f ris k management

. Whil e th e Reasonabl e Maximu m Exposur e (RME ) scenari o use d i n thi s evaluatio n i s designe d t o b e a measur e o f "high-end " exposur e
an d i s use d b y ris k manager s i n makin g remedial decisions , th e averag e o r centra l tendenc y risk s informatio n i s necessar y t o mak e ris k managemen t decision s (EPA

, 1992c)

. Conservativ e assumption s wer e use d onl y whe n site-specifi c dat a wer e lackin g or incomplete

. Th e scop e o f thi s R A wa s limite d t o th e evaluatio n o f potentia l healt h risk s associate d wit h surfac e water historicall y affecte d b y mining

. Th e approac h use d wa s based o n EP A
Golde r Associate s

### Jun e

1996

__________________ 2

_____________________ 943-281 9 guidanc e fo r th e evaluatio n o f huma n healt h risk s a t Superfun d sites

. This R A i s consistent wit h EP A guidanc e provide d i n th e followin g documents : Exposur e Factor s Handboo k (EPA

, 1989a)
, Ris k Assessmen t Guidanc e fo r Superfund
, Volum e I : Huma n Healt h Evaluatio n Manual (EPA

, 1989b)
, an d th e Integrate d Ris k Informatio n Syste m (IRIS ) (EPA

, 1992d)
, a compute r databas e containin g up-to-dat e healt h ris k an d regulator y informatio n fo r numerou s chemicals

. EP A caution s tha t thes e document s ar e intende d t o provid e onl y guidanc e i n conductin g healt h ris k assessments , an d tha t considerabl e professiona l judgmen t mus t b e use d i n thei r applicatio n (EPA

, 1989b)

. 

### 2 . 0 EXPOSUR E ASSESSMEN

T Th e objectiv e o f thi s exposur e assessmen t wa s t o identify :



### * • population s tha t ma y b e expose d t o surfac e water-relate d chemical s (potentia l receptors) ; * • pathway s b y whic h exposure s ma y occu r (conceptua l sit e model) ; * • th e rout e o f intak e an d intak e paramete r value s fo r ingestion ; and , * the frequency
, magnitude , an d duratio n o f thes e potentia l huma n exposures

. 

### 2. 1 Potentia l Recepto r Population s Population s i n th e Leadvill e are a wer e evaluate d t o asses s th e likelihoo d an d exten t o f 

### potentia l exposur e t o chemical s o f concern . Population s tha t ma y b e particularl y sensitiv e t o chemica l exposure s includ e infant s an d children , th e elderly , pregnan t an d nursin g
women , an d peopl e wit h chroni c illnesses

. Sensitiv e recepto r location s ma y includ e hospitals , convalescent homes , schools , an d day-car e centers

. Childre n are sensitiv e 

### recepto r population s becaus e the y ar e no t full y develope d physicall y an d thei r natural

Golde r Associate sJun e

1996___________________3_____

_ 943-281

9 biochemica l defense s ma y no t b e adequat e for preventin g or reducin g adverse effect s due t o chemica l exposures

. 

### 2. 2 Conceptua l Sit e Mode l A Conceptua l Sit e Mode l (CSM)
, showin g al l potentiall y complet e exposur e pathway s fo r a sourc e i s presente d i n Figur e 1

. Significan t exposur e pathway s ar e represente d wit h a soli d circle ; a n ope n circl e represent s thos e pathway s considere d t o b e insignifican t relativ e t o other exposur e pathways

. EP A guidanc e define s a n insignifican t pathwa y a s on e that ha s a n exposur e estimate d t o b e tw o o r mor e order s o f magnitud e les s tha n b y other pathway s (o f th e sam e receptor)
, o r on e wit h a ver y smal l likelihoo d o f exposur e b y tha t pathwa y (EPA

, 1989b)

. Ingestio n o f sedimen t b y th e chose n receptor s wa s considere d highl y unlikely , an d wa s considere d a n incomplet e pathway

. Exposur e pathway s associate d wit h groundwate r and vegetabl e ingestio n are labele d a s "no t evaluated " on th e CS M becaus e thes e medi a wil l b e considere d i n another R A a s par t o f th e Hydrogeologi c R I Repor t (Asarco
, 1996b)

. Swimming
, wading , and surfac e wate r ingestio n ar e considere d unlikel y du e t o the temperature s o f th e surfac e waters

. Fo r thi s reason , an d th e fac t tha t metal s ar e no t absorbe d wel l acros s th e skin , derma l contac t wit h surfac e wate r wa s no t considere d a significan t exposur e pathwa y (EPA

, 1991a)

. Although recreationa l users , suc h a s kayaker s
ma y occasionall y inges t surfac e water , th e short-ter m natur e o f thes e exposure s woul d constitut e insignifican t risk

. Human Receptors 

### Base d on th e evaluatio n o f potentiall y complet e pathways , th e huma n receptors associate d wit h th e exposur e point s selecte d are :

Golde r Associate sJun e

1996____________________4____________________943-281 9



### + Adul t Recreational Use r

» Chil d Th e Adul t Recreational Use r an d Chil d wer e selecte d t o represent peopl e wh o might routinel y fis h i n th e stream s an d river s nea r th e Californi a Gulch an d wh o ma y ea t fish

. 

### 2. 3 Complet e Exposur e Pathway s The fina l componen t o f a complet e exposur e pathwa y i s a n intak e rout e int o the body

. Tabl e 1 summarize s the pathway s tha t wer e evaluate d i n thi s RA

. A s show n i n the CS M (Figur e 1)
, th e onl y complet e exposur e pathwa y considere d quantitativel y fo r thi s R A wa s 

### ingestio n o f fish

. Thi s exposur e wil l b e evaluate d fo r th e tw o receptors : th e Adul t Recreationa l User
, an d th e Child

. 2. 4 Estimatin g Chemical Intake s Th e nex t ste p i n th e exposur e assessmen t wa s t o quantif y th e magnitude , frequency
, and duratio n o f chemica l intake s b y recepto r populations

. This ste p wa s conducte d i n tw o stages : (1 ) estimatio n o f exposur e poin t concentrations , an d (2 ) estimatio n o f chemica l intake fo r eac h exposur e pathwa y unde r consideration

. Chemica l intake s wer e calculate d usin g guidanc e i n Ris k Assessmen t Guidanc e fo r Superfun d (EPA

, 1989b)
, Exposur e Factor s Handboo k (EPA

, 1989c)
, Assessin g Huma n Healt h Risk s fro m Chemicall y Contaminate d Fis h an d Shellfis h (EPA

, 1989d)
, othe r EP A document s an d scientifi c journa l articles , site-specifi c information
, an d professiona l judgmen t regardin g likel y exposur e conditions

. Chemica l intake s wer e estimate d usin g average an d RM E estimates


### o f chemica l concentration s i n fis h fillets
, reasonabl e estimate s o f exposur e parameter s such

a s bod y weight , ingestio n rates , an d other assumption s regardin g frequenc y an d duratio n o f exposure

. Th e intak e factor s use d t o quantif y chemica l intake s ar e presente d i n th e Surfac e Wate r R I Report (Asarco
, 1996a)

. Golde r

Associate sJun e

1996___________________5____________________943-281 9 

### Exposur e point concentration s use d t o calculat e potentia l risk s fro m th e ingestio n o f fis h

wer e obtaine d b y calculatin g th e averag e and 9 5 percen t uppe r confidenc e limi t (UCL ) on 

### th e mea n fo r eac h chemica l o f concer n fro m availabl e analytica l dat a fro m recen t sit e 

### investigations

. Dat a collectio n an d analysi s ar e describe d i n th e Surfac e Wate r RI Repor t (Asarco
, 1996a)

.
2. 5 Exposur e Assumption s The exten t o f potentia l intak e throug h the variou s exposur e pathway s wa s based o n EP A guidance , site-specifi c information
, an d professiona l judgment

. I t i s no t possibl e t o estimat e th e exac t leve l o f exposur e fo r specifi c individual s du e t o uncertainties i n behavior pattern s an d incomplet e knowledg e o f exposur e variabl e values

. A primar y objectiv e o f thi s R A wa s t o us e site-specifi c dat a wher e possibl e i n orde r t o no t underestimat e potentia l 

### huma n exposures

. Childre n wer e identifie d a s a sensitiv e recepto r populatio n i n Leadville

. Therefore
, exposur e variable s wer e calculate d incorporatin g yout h a s a factor

. Becaus e certai n exposur e parameters var y ove r tun e (e.g.
, ingestio n rates , bod y weights)
, time-weighte d 

### average bod y weight s wer e calculate d fo r th e Adul t Recreationa l Use r an d th e Chil d receptor s (Tabl e 2)

. Th e dat a use d t o determin e th e exposur e frequenc y wer e take n fro m th e Metal s Samplin g
an d Analysis Result s an d Demographic s Result s (Asarco
, 1992)

. Th e surve y result s indicate d tha t th e majorit y (65. 2 percent ) o f childre n i n Leadvill e neve r ea t locall y caugh t fish

. Anothe r 24. 3 percent ea t locall y caugh t fis h les s tha n onc e pe r month

. Therefore
, fo r a n averag e exposur e fo r children , a frequenc y o f si x locall y caugh t fis h meal s pe r yea r
wa s use d for th e RA

. Th e surve y result s als o indicate d tha t onl y 2. 8 percent o f th e childre n ea t locall y caugh t fis h tw o o r mor e time s pe r week

. Fo r a RM E scenari o fo r 

### children , a frequenc y o f one locall y caugh t fis h mea l per wee k wa s use d and wa s Golde r Associate sJun e

1996___________________6____________________943-281 9 considere d conservativ e i n ligh t o f th e surve y results

. Thi s numbe r represent s th e inclusio n o f th e 97t h percentil e o f al l respondents

. For adults , the surve y indicate d tha t 7 1 persons , o r approximatel y 4 percen t o f 

### respondents , eat locall y caugh t fis h mor e frequentl y tha n twic e pe r week

. Base d o n thi s result , a frequenc y o f thre e fis h meal s pe r wee k wa s use d for th e RM E scenario

. Th e surve y result s als o indicate d tha t approximatel y 5 0 percen t o f respondent s d o not ea t locall y caugh t fis h an d tha t 3 0 percen t ea t locall y caught fis h les s tha n onc e pe r month

. Fo r thi s RA
, a frequenc y o f on e locall y caugh t fis h mea l pe r wee k wa s use d fo r average 

### exposures

. The ingestio n rat e fo r adult s wa s assume d t o b e 15 0 gram s (1/ 3 o f a pound ) pe r mea l (EPA

, 1989d)

. I n th e Exposur e Factor s Handboo k (EPA

, 1989a)
, a stud y conducte d b y N P D Research
, Inc

. present s tota l fis h consumptio n b y ag e range . T o determin e ingestio n rate s fo r children , a weighte d averag e wa s use d t o conver t th e ag e range s presente d i n th e stud y t o thos e use d i n thi s RA

. Fro m thes e data , fo r bot h the mea n an d uppe r 95t h percentile , the weigh t o f fis h consumptio n b y childre n ( 0 t o 6 year s o f age ) wa s foun d t o b e 5 4 percen t o f tha t consume d b y adult s ( 7 t o 3 0 year s o f age)

. Thi s facto r wa s applie d t o th e ingestio n rat e fo r adult s t o deriv e a fis h ingestio n rat e o f 8 1 gram s pe r mea l fo r children

. Fo r carcinogeni c ingestio n exposur e durations , i t wa s assume d that th e Adul t Recreationa l Use r woul d b e expose d for 3 year s for th e average scenari o and 2 4 year s for th e RM E scenario

. Th e assumptio n wa s mad e that th e chil d recepto r woul d b e expose d 6 year s fo r bot h th e average an d RM E scenarios

. Additio n o f thes e exposur e durations fo r th e average scenari o equal s nin e year s ( 6 year s fo r childre n and 3 year s fo r the adult)
, and equal s thirt y year s fo r the RM E scenari o ( 6 year s fo r childre n and 2 4 year s fo r the adult)

. Thes e duration s relat e t o th e national media n an d uppe r boun d estimate s o f 9 an d 3 0 years , respectively , spen t i n on e residenc e (EPA

, 1989b)

. Golde r Associate sJun e

1996___________________7______________________943-281 9 Th e equatio n an d specifi c variable s use d t o estimat e intake o f chemical s vi a fis h ingestio n
are summarized i n Tabl e 3

. Intak e facto r calculation s are documente d i n Appendi x A

. 

### 3 . 0 DAT A ANALYSI S A n earl y ste p o f th e R A wa s t o revie w recen t water qualit y chemica l dat a collecte d a t th e site

. Th e objectiv e o f dat a analysi s wa s t o identif y chemical s o f concer n i n surfac e water

. Onl y validate d dat a use d i n th e quantitativ e evaluatio n o f risks

. I n orde r t o quantif y averag e and RM E concentrations , a valu e o f one hal f the detectio n limi t wa s use d whe n th e sampl e wa s reporte d a s undetected

. This i s consistent wit h EP A guidanc e (EPA

, 1989b ) an d th e Surfac e Water
, Be d Materia l an d Aquati c Ecosyste m Dat a Collectio n Progra m Work Pla n (Asarco
, 1991)

. Averag e analyt e concentration s wer e use d i n th e calculation s o f ris k for averag e exposure , and th e 9 5 percent uppe r confidenc e limit s (UCL ) o f th e arithmeti c mea n analyt e concentration s wer e use d i n th e calculation s o f th e RM E scenario

. Fis h tissu e dat a ar e presente d i n Tabl e 4

. 

### 3. 1 Chemical s o f Concer n Analytica l dat a wer e obtaine d a s par t o f the Surfac e Water
, Be d Materia l and Aquati c Ecosyste m Dat a Collectio n Progra m Wor k Pla n (Asarco
, 1991 ) an d wer e evaluate d t o identif y chemical s o f concern . Th e dat a fo r thi s progra m wer e collecte d i n th e summe r o f 1991

. Fis h caugh t i n th e progra m wer e filleted
, an d onl y th e edibl e portion s o f th e fis h

wer e analyzed

. Fis h tissu e analyse s wer e limite d t o th e followin g metals : arsenic , cadmium, chromium , copper , lead , mercur y an d zinc ; th e location s o f th e samplin g station s fo r th e collectio n o f fis h ar e show n h i Figur e 4. 1 o f Asarco
, 1991

. Fis h caugh t

wer e representativ e o f th e predominant species foun d i n th e area . Tabl e 5 show s th e type , 

### size , an d approximat e ag e o f th e fis h sample d accordin g t o location

. (Aquatic s Assoc.
, 1993)

. Golde r

Associate sJun e

1996___________________8

___________________ 943-281

9 Chemical s o f concer n fo r surfac e wate r wer e selecte d fro m th e metal s detecte d i n th e fis h tissue

. Cadmiu m wa s no t detecte d i n an y o f th e sample d fis h tissue

. Si x metal s wer e quantitativel y evaluate d fo r potentia l noncarcinogeni c hazard s an d carcinogeni c risks

. 

### Becaus e th e fina l numbe r o f chemical s o f concer n wa s low , i t wa s considere d unnecessar y t o perfor m a concentration-toxicit

y screen
. The chemical s o f concer n wer e arsenic , chromium , copper , lead , mercury , and zinc

. Lea d wa s no t quantitativel y evaluate d i n thi s surfac e wate r RA

. Th e potentia l healt h impact s fro m the exposur e t o lea d wil l b e quantifie d i n a sit e wide , multi-media , baselin e ris k assessmen t usin g the mos t curren t EP A Integrate d Exposur e Uptake-Biokinetic (IEUBK ) lead model available

. Thi s model account s fo r lea d exposur e fro m man y source s
an d predict s bloo d lead level s wit h th e inpu t o f eithe r EP A defaul t values , site-specifi c 

### values , o r a combination o f both

. 

### 4 . 0 TOXICIT Y ASSESSMEN

T Thi s sectio n describe s procedur e involve d i n performin g th e toxicit y assessmen t fo r chemical s o f concer n i n surfac e wate r a t th e Leadvill e site

. The purpos e o f th e toxicit y assessmen t wa s t o evaluat e th e toxicit y o f chemical s o f concer n
an d t o estimat e th e dose-respons e relationshi p fo r eac h o f thes e chemicals

. Chemical s o f



### concer n i n Leadvill e wer e identifie d b y the applicatio n o f EP A guidanc e and professiona l judgment

. Th e informatio n obtaine d i n th e toxicit y assessmen t wa s combined wit h estimate d contaminan t intake s calculate d a s par t o f the exposur e assessment t o estimat e the potentia l exces s lifetim e cance r risk s an d potentia l noncarcinogeni c healt h hazard s (EPA

, 1989b)

. 

### T h e Referenc e Dose (RfD ) an d Slop e Facto r (SF ) values use d in thi s ris k assessmen t wer e obtaine d fro m th e foli o whi g sources : Golde r Associate sJun e

1996___________________9___________________943-281 9

> • EPA' s Integrate d Ris k Informatio n Syste m (IRIS ) (EPA

, 1992d ) on-lin e databas e system ; and , * EPA' s Healt h Effect s Assessmen t Summar y Table s (EPA

, 1992e)

. Chemical s wit h hig h SF s an d lo w RfD s exhibi t highe r toxicities

. Tabl e 6 summarize s toxicit y value s use d i n thi s ris k assessmen t fo r th e chemica l o f concern . 

### 5 . 0 RIS K CHARACTERIZATIO

N Ris k characterizatio n wa s th e fina l ste p o f th e ris k assessmen t process

. I n thi s step , th e toxicit y factor s (RfD s an d SFs ) fo r th e chemical s o f concer n wer e applie d h i conjunctio n wit h estimate d chemica l intake s t o predic t noncarcinogeni c and carcinogeni c healt h risk s t o expose d individuals

. T h e potentia l fo r noncarcinogeni c effect s wa s characterize d b y comparin g estimate d 

### chemica l intake s wit h chemical-specifi c RfDs

. Thi s measur e i s know n a s the hazar d quotient (H.Q. ) fo r a singl e chemica l o r th e hazar d inde x (H.I. ) fo r multipl e chemicals

. Potentia l carcinogeni c effect s are characterize d i n term s o f th e incremental or exces s probabilit y that an individua l wil l develo p cance r h i hi s or her lifetim e due t o th e modele d exposure

. Exces s cance r ris k i s estimate d fro m th e projecte d lifetim e intake s an d th e
cance r slop e factor
, whic h represent s a n upper-boun d estimat e o f th e dose-respons e relationship

. I n thi s RA
, subchroni c ( 2 week s t o 7 years ) H.I. s ar e th e appropriat e indicato r o f potentia l

non-cance r advers e effect s fo r th e average chil d exposur e ( 6 years)
, th e RM E chil d 

### exposur e ( 6 years)
, an d the average Adul t Recreationa l Use r exposur e ( 3 years)

. The chroni c H.I

. i s th e appropriat e indicato r fo r th e RM E Adul t Recreationa l Use r because th e exposur e duratio n i s 2 4 year s (whic h i s greater tha n th e 7 yea r cutof f between subchroni c
an d chroni c timespans)

. However
, whe n th e chil d an d adul t scenario s ar e summe d t o
Golde r Associate sJun e

1996_________________10___________________943-281 9 represen t continuou s exposur e o f one individua l ove r bot h age group s (i.e.
, birt h throug h 9 year s fo r average, o r birt h throug h 3 0 year s fo r RME)

, th e chroni c H.I. s ar e summe d a s the appropriat e indicator s o f non-cance r ris k fo r timespan s exceedin g 7 years
. 

### 5 . 1 Hazar d Inde x fo r Noncarcinogeni c Effect s Th e potentia l fo r advers e noncarcinogeni c effect s resultin g fro m exposur e t o a chemica l o f

concer n wa s evaluate d b y comparin g th e averag e dail y intak e o f th e chemica l (expresse d a s 

### mg/kg-day ) t o a referenc e dose (expresse d a s mg/kg-day)

. Th e resultin g rati o i s calle d a H.Q

. (EPA

, 1989b)

. Th e H.Q

. wa s calculate d as :

T T _ _ Chemica l Intak e (mg / kg-day ) Noncance r H.Q

. = —————————-—-——

— R f D (mg/kg-day) Use o f th e Rf D assume s a leve l o f intak e (th e RfD ) belo w whic h i t i s unlikel y tha t eve n sensitive individual s wil l experienc e adverse healt h effect s ove r a lifetim e o f exposure

. I f th e averag e dail y intak e exceed s th e Rf D (tha t is , i f th e H.Q

. exceed s 1.0)
, ther e ma y b e caus e fo r concer n fo r potentia l noncance r effects

. I t shoul d be noted , however , tha t th e leve l o f

concer n doe s no t increas e linearl y a s th e Rf D i s approache d o r exceeded

. Thi s i s becaus e al l RfD s ar e no t equall y accurat e an d ar e no t based o n th e sam e severit y o f toxi c effects

. Thus
, th e slope s o f th e dose-respons e curv e h i exces s o f th e Rf D ca n var y widel y dependin g o n th e substance

. Furthermore
, i t mus t b e emphasize d that th e H.Q

. doe s no t represen t a statistica l probabilit y o f a n effec t occurring

. 

### T o asses s th e overal l potentia l fo r advers e healt h effect s pose d b y exposur e t o multipl e chemicals , th e H.Q. s fo r eac h chemica l o f concer n associate d wit h a give n exposur e pathwa y
wer e summed

. Th e resultin g su m i s referre d t o b y EP A a s th e H.I

. Th e H.I

. approach
assume s tha t multipl e subthreshol d exposures t o severa l chemical s coul d resul t i n a n advers e healt h effect

. Th e H.I

. wa s calculate d as :
Golde r Associate sJun e

1996___________________11___________________943-281 9 H.I

. = E 1 /RfD 1 + E2/RFD 2 .. . + E/RfD j where : E j = Exposur e level (o r intake ) fo r toxican t i RfD j = Referenc e dos e fo r toxican t i Wher e a recepto r ma y b e subjec t t o multipl e exposur e pathway s (e.g.
, inhalatio n o f particulate s an d ingestio n o f soils)
, th e individua l H.I. s fro m al l relevan t pathway s ar e summe d t o obtai n th e tota l H.I

. fo r tha t receptor

. Fo r multipl e chemica l exposures , th e tota l H.I

. migh t excee d 1. 0 eve n i f n o singl e chemica l intak e exceed s it s RfD

. I f th e tota l H.I

. i s 

### les s tha n 1.0 , cumulativ e exposures t o th e chemical s o f concer n a t th e sit e i s judge d unlikel y t o resul t i n a n advers e effect

. I f th e su m i s greate r tha n 1.0 , a mor e detaile d an d critica l evaluatio n o f th e risks , includin g consideratio n o f specifi c target organ s affecte d an d mechanism s o f toxi c actio n o f th e chemical s o f concern , i s require d t o ascertai n i f th e cumulativ e exposur e woul d i n fac t b e likel y t o har m expose d individuals

. T h e assumptio n o f additiv e effect s reflecte d in th e cumulativ e H.I

. i s mos t properl y applie d t o substance s tha t induce th e sam e effec t b y th e sam e mechanism (EPA

, 1989b)

. Consequently
, applicatio n o f th e equatio n t o a mixture o f substance s tha t ar e no t expecte d t o induce th e sam e typ e o f effect s coul d overestimat e th e potentia l fo r advers e healt h effects

. The H.I

. provide s a roug h measur e o f potentia l toxicity , but i t i s conservativ e an d dependen t

o n th e qualit y o f th e experimenta l evidence

. Sinc e th e H.I

. doe s no t defin e dose-respons e relationships , it s numerica l valu e canno t b e construe d a s a direc t estimat e o f ris k (EPA

, 1989b)
, bu t onl y a s a leve l o f concern .

Golde r Associate sJun e

1996_________________12___________________943-281 9 5. 2 Carcinogeni c Ris k Carcinogeni c risk s ar e estimate d a s th e incrementa l probabilit y o f a n individua l developin g
cance r ove r a lifetim e a s a resul t o f exposur e t o a potentia l carcinogen

. Th e numerica l estimat e o f exces s lifetim e cance r ris k i s calculate d b y multiplyin g the chemica l intak e averaged ove r a lifetim e b y th e cance r slop e facto r (SF ) a s follows : 

### Ris k = Chemical Intak e (mg/kg-day ) x S F (mg/kg-day)" 1 Th e EP A slop e factor s ar e uppe r 95t h percentil e confidenc e limit s o f th e probabilit y o f respons e per uni t intak e o f chemica l ove r a lifetime

. Slop e factor s are base d on experimenta l anima l dat a an d epidemiologica l studie s whe n available

. Th e linearize d multistag e model , a linear nonthreshol d mathematica l mode l fo r low-dos e extrapolation , i s use d t o calculat e a numerica l slop e facto r value

. EP A states tha t carcinogeni c risk s estimate d usin g thi s approach ar e upper-boun d estimates

. Thi s mean s tha t th e actua l ris k i s likel y t o b e les s tha n th e predicte d ris k (EPA

, 1989b)

. EP A guidanc e t o evaluat e cance r ris k fro m simultaneou s exposur e t o severa l carcinogen s assume s tha t incrementa l cance r risk s are additive

. Th e concep t tha t cance r risk s are additiv e i s base d o n a numbe r o f assumptions

. I f thes e assumptions ar e incorrect , over - o r under

estimatio n o f th e actua l ris k coul d resul t (EPA

, 1989b)

. Th e total cance r ris k i s estimate d b y 

### summin g th e risk s estimate d for eac h chemica l o f concer n an d for eac h pathway

. EP A polic y mus t b e considere d i n order t o interpre t th e significanc e o f th e cance r ris k estimates

. I n th e Nationa l Oi l an d Hazardous Substances Pollutio n Contingenc y Pla n (NCP ) (4 0 CF R Par t 300)
, EP A states that : "Fo r know n or suspecte d carcinogens , acceptabl e exposur e level s ar e generall y concentratio n level s tha t represen t an exces s upper-boun d lifetim e cance r ris k t o a n individua l o f between 10 ^ an d 10" 6

. " Th e EP A furthe r states , i n th e preambl e t o th e NCP
, tha t th e 1 x 10" 6 ris k leve l shoul d b e use d a s a poin t o f departur e Golde r Associate sJun e

1996___________________13___________________943-281 9 

### fo r establishin g remediatio n goal s fo r contaminant s a t specifi c hazardou s wast e sites

. Curren t EP A guidance , however , state s tha t wher e th e cumulativ e sit e ris k t o a n individua l base d o n reasonabl e maximu m exposur e i s les s tha n 1 x 10" 4

, action i s generall y no t warrante d (EPA

, 1991b)

. A carcinogeni c ris k level o f 1 x 10 ^ wa s therefor e use d a s th e target ris k level fo r evaluatio n o f potentia l exposure s i n thi s ris k assessment

. Risk Quantification The potentia l for noncarcinogeni c healt h effect s due t o a chemica l o f concern , expresse d a s a H.Q.
, i s calculate d usin g th e followin g format : ( Chemica l Intak e

Dail y ) / Rf D Hazar d Concentratio n X Facto r = Intak e (mg/kg-day

) = Quotien t 

### (mg/y ) (y/kg

-

(mg/kg

day ) day

) Wher e y = specifi c amoun t (weigh t o r volume ) o f mediu m h i whic h th e chemica l i s 

### measured ; the unit s o f whic h are mediu m dependent

. For example , a chemica l i n soi l ma y b e reporte d h i mg/k g an d h i wate r i n mg/liter

. Averag e o r RM E concentration s o f eac h noncarcinogeni c chemica l o f concer n ar e multiplie d b y th e pathway-specifi c intak e factor s t o yiel d a n averag e o r RM E dail y intake

. Th e dail y intak e i s the n divide d b y th e Rf D t o obtai n th e H.Q

. fo r averag e o r reasonabl e maximu m exposures

. Individua l H.Q. s are summe d for al l chemical s i n an exposur e pathwa y t o provid e a pathway

specifi c H.I

. Pathway-specifi c indexe s ar e summe d t o obtai n th e tota l H.I

. fo r al l exposur e pathway s applicabl e t o a give n receptor

. H.I. s o f noncarcinogeni c risk s fo r eac h recepto r and pathwa y ar e summarize d i n the Surfac e Wate r RI Report (Asarco
, 1996a)

. H.I. s are calculate d for chroni c exposure s ( 9 or 3 0 years )
Golde r Associate sJun e

1996___________________14___________________943-281 9 

### for receptors a t eac h o f th e exposur e locations

. Ris k calculation s are presente d i n Appendix A

. The potentia l fo r carcinogeni c effects
, expresse d a s exces s cance r risk, ar e calculate d i n a simila r manner : ( Chemical Lifetim e

Lifetim e

) Slop e Facto r Exces s Concentratio n X Intak e = Dail y X (mg/kg-day)" 1 = Cance r (mg/y ) Facto r

Intak e Ris

k 

### (y/kg-day ) (mg/kg



### day ) Wher e y = specifi c amoun t (weight o r volume ) o f a mediu m i n whic h th e chemica l i s 

### measured ; th e unit s o f whic h ar e mediu m dependent

. Concentration s o f eac h potentia l carcinoge n are multiplie d b y pathway-specifi c intak e factor s 

### t o yiel d a lifetim e dail y intake

. Th e dail y intak e i s the n multiplie d b y th e slop e facto r t o obtai n a numerica l estimat e o f exces s cance r risk

. The cance r risk s ar e the n summe d fo r al l o f the chemical s evaluate d fo r eac h exposur e pathway

. T o determine th e tota l carcinogeni c ris k t o a give n receptor , th e cance r risk s fo r


### eac h exposur e pathwa y ar e summed

. Carcinogeni c risk s fo r averag e an d RM E condition s ar e presente d i n Tabl e 7

. Cancer ris k calculation s ar e show n i n Appendix A

. 5. 4 Ris k Characterizatio n Result s Result s o f thi s R A indicat e tha t n o noncarcinogeni c H.I. s exceeded th e EP A leve l o f concer n


### o f 1. 0 fo r the exposur e pathwa y evaluate d fo r surfac e wate r usin g averag e o r reasonabl e maximu m exposur e assumptions (Tabl e 7)

.

Golde r Associate sJun e

1996___________________15____________________943-281 9 

### F o r surfac e water , th e greates t H.I

. fo r a recepto r fo r averag e exposur e assumption s wa s 3.5 8 x 10" 1 

### an d represent s th e Adul t Recreationa l User

. Th e greates t H.I

. fo r RM E assumption s fo r surfac e wate r wa s als o fo r th e Adul t Recreationa l Use r (5.9 8 x 10" 1 )

. Summin g th e chroni c H.I. s acros s th e age s o f birt h t o 3 0 year s fo r RM E an d fro m birt h t o 9 year s fo r averag e exposur e resulte d i n a combine d H.I

. less tha n 1.0

. Fo r averag e exposure s th e chroni c H.I

. su m wa s 3.9 3 x 10" 1

, an d for RM E assumption s th e chroni c H.I. s su m wa s 9.8 2 x 10" 1

. EP A huma n healt h ris k assessmen t guidanc e states tha t i f a H.I

. greate r tha n 1. 0 i s obtained a s a resul t o f summin g severa l H.Q.'s
, the n i t i s appropriat e t o segregat e compound s b y effec t an d b y mechanis m o f action, an d t o derive separat e H.I. s fo r eac h effec t

o n specifi c target organ s o r mechanism s o f actio n (EPA

, 1989b)

. Base d o n th e exposur e 

### assumption s used , thi s wa s unnecessary
. N o estimate d carcinogeni c risk s exceede d the EP A acceptabl e ris k leve l o f 1 x 10" 4 for the exposur e pathwa y (fis h ingestion ) evaluate d fo r bot h receptor s considered

. Tota l carcinogeni c ris k estimate d fo r the Chil d an d Adul t Recreationa l User
, addin g acros s the age s o f birt h t o 3 0 year s o f age, fo r th e RM E scenari o wa s 3.1 3 x 10" 5 (Tabl e 5)

. Fo r th e averag e scenario , th e total carcinogeni c ris k wa s 2.2 9 x 10" 6

. Th e RM E scenari o fo r tota l cance r risk s acros s th e age s fro m birt h t o 3 0 year s i s use d a s th e "high-end " exposur e (EPA

, 1992f)

. Th e averag e exposur e scenari o show n i n Tabl e 7 describe s centra l tendenc y exposur e risk s t o ai d i n discussio n o f uncertaintie s an d t o pu t th e RM E scenari o int o perspective

. I n th e RM E cas e fo r surfac e water, th e risk s fro m ingestio n o f fis h di d no t exceed 1 x 10" 4 fo r eithe r receptor

. 

### 6 . 0 UNCERTAINTIES

AN D LIMITATION

S The EP A guidanc e fo r ris k assessmen t provides a systemati c mean s fo r organizing , analyzing , an d presentin g informatio n o n th e natur e an d magnitud e o f potentia l risk s t o publi c 

### healt h an d th e environmen t pose d b y chemica l exposures

. Despit e th e advanced stat e o f th e
curren t methodology , uncertaintie s an d limitation s ar e inheren t i n th e ris k assessmen t Golde r Associate sJun e

1996__________________16___________________943-281 9 process

. Th e qualit y o f availabl e data , incomplet e informatio n abou t existin g conditions an d futur e circumstances , a s wel l a s othe r factor s discusse d belo w contribut e t o thes e uncertaintie s an d limitations

. Th e followin g section s discus s source s o f uncertaintie s an d 

### limitations associate d wit h thi s ris k assessment

. Thes e uncertaintie s are als o summarize d h i Tabl e 8

. 

### 6. 1 Dat a Evaluatio n Dat a use d h i th e R A wer e collecte d durin g th e Surfac e Water
, Be d Materia l an d Aquati c Ecosyste m Dat a Collectio n Program fo r th e Californi a Gulc h Sit e stud y area . Th e dat a collecte d durin g the progra m ar e subjec t t o uncertaint y associate d wit h samplin g and analysis , an d thi s ma y ac t t o over - o r under-estimat e th e potentia l risks

. 

### 6. 2 Exposur e Assessmen t Th e exposur e assessment i s based o n site-specifi c dat a an d o n a serie s o f assumptions concernin g concentration s o f chemical s t o whic h human s ma y b e expose d (exposur e poin t concentrations ) a s wel l a s patterns o f behavio r leadin g t o exposur e o r intak e o f chemical s (exposur e scenarios)

. 

### The exposur e assessmen t relie d o n assumption s fo r potentia l huma n exposur e whe n site

specifi c analytica l dat a wer e incomplet e or unavailable

. Assumption s use d wer e base d upon :

* Site-specifi c informatio n

+ EP A Guidanc e (EP A 1989b ) an d th e Exposur e Factor s Handboo k (EP A 1989a )

* • Professiona l judgmen t

Golde r

Associate sJun e

1996___________________17___________________943-281 9 

### 6. 3 Toxicit y Assessmen t I n general , th e availabl e scientifi c informatio n i s insufficien t t o provid e a thoroug h understandin g o f al l the potentia l toxi c propertie s o f chemical s t o whic h human s ar e potentiall y exposed

. Consequently
,

varyin g degree s o f uncertaint y surroun d th e 

### assessment o f advers e healt h effect s i n expose d populations

. 6. 4 Ris k Characterizatio n Du e t o uncertaintie s h i eac h ste p o f th e ris k assessment process , uncertainties are ofte n 

### magnifie d i n the fina l ris k characterization

. The fina l quantitativ e estimates o f ris k ma y b e
on e o r severa l order s o f magnitud e differen t fro m th e potentia l ris k associate d wit h a give n exposure

. I n an attemp t t o minimiz e th e consequence s o f uncertainty , EP A guidanc e typicall y relies on us e o f conservativ e estimate s o f hazard s i n th e absenc e o f stron g scientifi c data

. Th e overal l resul t i s tha t ris k estimates presente d i n thi s repor t are muc h

mor e likel y t o overestimat e th e potentia l ris k rather than t o underestimat e it

. Th e assessmen t ha s bee n prepare d i n a manne r consisten t wit h tha t generall y use d i n th e consultin g communit y an d agenc y guidanc e a t th e tun e i t wa s prepared

. I t i s likel y that ris k assessmen t method s an d dat a identifyin g an d quantifyin g th e toxicit y o f chemical s wil l 

### improv e wit h time

. Thi s assessment wa s base d o n recentl y collecte d dat a usin g the curren t availabl e ris k assessment methodology

. 

### 7. 0 CONCLUSION S Th e result s o f thi s ris k assessmen t indicat e tha t fo r huma n exposur e t o metal s h i fis h fillets
, 

### th e noncarcinogeni c H.I. s d o no t excee d th e EP A leve l o f concer n o f 1.0

. Estimate d carcinogeni c risk s d o no t excee d th e EP A acceptabl e ris k leve l o f 1 x 10" 4 fo r th e exposur e pathwa y evaluate d fo r an y receptors (Tabl e 7)

. Additionally
, potentia l tota l cance r risk s fro m Golde r Associate sJun e

1996___________________18___________________943-281 9 birt h t o ag e 3 0 wer e 2.2 9 x 10" 6 (averag e scenario ) an d 3.1 3 x 10" 5 (RM E scenario ) an d d o
not exceed 1 x 10" 4 fo r exposur e t o surfac e wate r (fis h ingestion ) (Tabl e 7)

. I t shoul d b e restate d tha t th e RM E scenari o i n thi s ris k assessmen t use d a combinatio n o f site-specifi c dat a
an d conservativ e assumption s tha t represen t th e "high-end " exposur e an d mor e tha n likel y 

### overestimate s th e actua l total cance r ris k give n th e exposur e an d behavior pattern s assume d f o r thi s assessment

. I t seem s unlikel y tha t an y individua l wil l consum e locall y caugh t fis h one tim e pe r wee k



### ever y wee k o f th e yea r fro m birt h t o 6 year s o f ag e an d thre e time s pe r wee k thereafte r throug h ag e 30

. I n addition , i t i s unlikel y tha t an y individua l wil l b e expose d a s a chil d an d

a s a n adul t ove r a perio d o f 3 0 years
. Addin g th e risk s fo r thes e receptors , therefore
, present s ver y conservativ e estimate s o f risk

. Eve n usin g thi s ver y conservativ e (protective ) approach , potentia l cance r an d non-cance r risk s t o human s wh o consum e fis h affecte d b y site-relate d chemical s ar e belo w EP A benchmar k levels

. Fis h ingestio n i s the onl y (complet e
o r significant ) exposur e pathwa y fo r surfac e wate r a t th e Californi a Gulch Site

. 

### 8. 0 REFERENCE S Aquatic s Associates

. 1993

. Aquatic Samplin g Progra m Result s Californi a Gulch Site

. Leadville
, Colorado
, 1991

. January

. Asarco

. 1991

. Surfac e Water
, Be d Materia l an d Aquatic Ecosyste m Dat a Collectio n Progra m Wor k Plan
, Californi a Gulch Site
, Leadville
, Colorado

. Prepare d b y Woodward-Clyd e Consultants

. June

. Asarco

. 1992

. Metal s Samplin g an d Analysi s Result s an d Demographic s Results

. Transmitta l lette r t o Ke n Wangeru d fro m Glen n Anderso n o n Septembe r 15

. 

### Asarco

. 1996a

. Surfac e Wate r Remedial Investigatio n Report

. Prepare d b y Golde r Associate s Inc

. May

. Asarco

. 1996b

. Hydrogeologi c Remedia l Investigatio n Report

. Prepare d b y Golde r Associate s Inc

. May

.
Golde r

Associate sJun e

1996___________________19

____________________ 943-281

9 

### U.S

. Environmenta l Protectio n Agenc y (EPA)

. 1989a

. Exposur e Factor s Handbook

. Exposur e Assessmen t Grou p Offic e o f Healt h an d Environmenta l Assessment

. Washington
, D.C

. EPA/600/8-89/043

. U.S

. Environmenta l Protectio n Agenc y (EPA)

. 1989b

. Ris k Assessmen t Guidanc e fo r Superfund

. Volum e I : Huma n Healt h Evaluatio n Manual

. Interi m Final

. Offic e o f Emergenc y an d Remedia l Respons e EPA/600/8-89-/043

. U

. S

. Environmenta l Protectio n Agenc y (EPA)

. 1989c

. Phas e I I Remedia l Investigation
, Technica l Memorandum

. Draft

. Californi a Gulch
, Leadville
, Colorado

. Vols

. I-VI

. 53-8129.0/DEN63786.RI

. Prepare d b y CH 2 M Hill
, Blac k & Veatch
, ICF
, PRC
, an d Ecolog y an d Environment

. May

. U.S

. Environmenta l Protectio n Agenc y (EPA)

. 1989d

. Assessin g Huma n Healt h Risk s fro m Chemicall y Contaminate d Fis h an d Shellfish : A Guidanc e Manual

. 

### U.S

. Environmenta l Protectio n Agenc y (EPA)

. 1991a

. Preliminar y Huma n Healt h Baselin e Ris k Assessmen t fo r th e Californi a Gulch NP L Site
, Leadville
, Colorado

. Prepare d f o r th e U.S

. EP A Regio n VHI
, Denver

, Colorad o b y Ro y F

. Weston
, Inc.
, 

### Lakewood
, Colorado

. U.S

. Environmenta l Protectio n Agenc y (EPA)

. 1991b

. Ris k Assessmen t Guidanc e fo i 

### Superfund : Volum e I
- Huma n Healt h Evaluatio n Manual (Par t B
, Developmen t o f Risk-base d Preliminar y Remediatio n Goals)

. Interim

. 9285.7-0IB

. U.S

. Environmenta l Protectio n Agenc y (EPA)

. 1992a

. Guideline s fo r Exposur e Assessment

. 5 7 F R 22888-22938 , Ma y 29 , 1992

. U.S

. Environmenta l Protectio n Agenc y (EPA)

. 1992b

. Mem o fro m F

. Henr y Habicht
, Deput y Administrator
, EPA

. Guidanc e o n Ris k Characterizatio n fo r Ris k Manager s 

### an d Ris k Assessors

. Februar y 26 , 1992

. U.S

. Environmenta l Protectio n Agenc y (EPA)

. 1992c

. Mem o fro m Henr y L

. Longest
, Director

, Offic e o f Emergenc y an d Remedial Response

. Implementin g th e Deput y Administrator' s Ris k Characterizatio n Memorandum

. May

. U.S

. Environmental Protectio n Agenc y (EPA)

. 1992d

. Integrate d Ris k Informatio n Syste m (IRIS)

. On-lin e database

. 

### U.S

. Environmenta l Protectio n Agenc y (EPA)

. 1992e

. Healt h Effect s Assessmen t Summar y Table s (HEAST)

. Annua l FY-1992

. OHEA-ECAO-CIN-821

.

March

.

Golde r Associate sGolde r Associate s

### TABL E 1 LEADVILL E SURFAC E WATE R POTENTIALL Y COMPLET E EXPOSUR E PATHWAY S QUANTITATIVEL

Y EVALUATE D 

### Potentiall y Expose d Receptor Scenari

o Potentiall

y Complet e Exposur e Pathway s Chil d Curren t Fis h

ingestio n
Adul t Recreationa l Use r Curren

t Fis h

ingestio n

Source : Woodwar d Clyd e Consultants
, Draf t Surfac e Wate r R I Repor t

Colde r Associate sa TABL E 2 GENERA L ASSUMPTION

S FO R BOD Y WEIGH T Ag e Rang e 0- 3 3- 6 6- 9 9-1 2 12-1 5 15-1 8 18-3 0 

### Year

s i n Ag e Rang e 3 3 

### 3 3 3 

### 3 1 2 K g a 11. 6 17. 4 25. 0 36. 0 50. 6 61. 2 7 0
TIM E WEIGHTED AVERAG E BOD Y WEIGHT S Chil d (1- 6 years) " Adul t (7-3 0 years) c Years

i n Ag e 

### Rang e 

### 6 3/2 4 Bod

y Weigh t 1 6 25/5 7 Exposur e Factor s Handboo k (EP A 1989a)

. b RAG S (EP A 1989b)

. Represent s th e 50t h percentil e bod y weight s fo r childre n age s 1 t o 6 year s (no t a tru e weighte d average)

. c Averag e scenari o use d 7 t o 9 year s o f ag e an d RM E scenari o use d 7 t o 3 0 year s o f age . 

### Source : Woodwar d Clyd e Consultants
, Draf t Surfac e Wate r R I Repor t

Colde r Associate sTABL E 3 INTAK E ASSUMPTION S FO R FIS H INGESTIO N Intak e Facto r = I R x E F x E D x F I x M E x IQ^g/m g BWxA T Paramete r Averag e Reasonabl e Maximu m I R = Ingestio n rate , mg/day 1 Adul t ( > 6 ) 150,00 0

150,00 0 

### Chil d (0- 6 years ) 81,00 0

81,00 0 E F = Exposur e frequency
, days/years

2 Adul t 2

15

6 

### Chil d 6

5

2 E D = Exposur e duration , years 3 

### Adul t 3

24 Chil d 6

6 M E = Matri x effect 4 1. 0

1. 0 F I = Fractio n ingeste d fro m contaminate d sourc e 1. 0

1. 0 B W = Bod y weight , kg 5 Adul t (weighte d average ) 25 5 7 Chil d (weighte d average ) 1 6 1 6 A T = Averagin g time , days 6 Noncarcinogen s Adul t 1,095

( 3 years ) 8,76 0 (2 4 years ) Chil d 2,19 0

( 6 years ) 2,19 0 ( 6 years ) Carcinogens 25,55 0

(70 years ) 25,55 0 (70 years )

1 EPA

, 1989 a an d EPA. O 1989c

. (Se e tex t fo r farthe r explanation , Sectio n 7.5.2)

. 2 1 fis h meal/wee k fo r adul t average exposure , 3 fis h meals/wee k fo r adul t RM E scenario

. 6 fis h meals/yea r fo r chil d averag e exposure , 1 fis h meal/wee k fo r chil d RM E scenario

. (Asarc o 1992 ) 3 Se e text , Sectio n 7.5. 2 fo r explanation

. 4 Matri x effec t o f 1. 0 represent s a conservativ e assumptio n abou t th e amoun t o f metal s tha t ar e boun d t o th e medium' s matrix

. Th e highe r th e ME

, th e greate r amoun t o f metal s are potentiall y bioavailable

. M E o f one assume s al l metal s are 10 0 percen t bioavailabl e an d absorbed

. 5 EPA

, 1989a

. 6 Nin e year s ( 6 year s a s a chil d an d 3 year s a s a n adult ) an d 3 0 year s ( 6 year s a s a chil d an d 2 4 year s a s a n adult ) ar e year s spen t i n on e residence fo r th e nationa l median an d uppe r boun d estimates , respectivel y (EP A 1989b)

. Averagin g tim e i s th e produc t o f thes e tim e period s an d day s pe r year . (Se e text , Sectio n 7.5. 4 fo r furthe r explanation. ) Source : Woodwar d Clyd e Consultants
, Draf t Surfac e Wate r R I Repor t

Colde r Associate sTABL E 4 LEADVILL E SURFAC E WATE R FIS H TISSUE DAT A SUMMAR Y TABL E AN D EXPOSUR E POIN T CONCENTRATION

S (mg/kg) a •$

: ^§^mii§£§::. A-AR01F-01-91081 3 A-AR02F-01-91081 3 A-AR03F-01-91081 3 A-AR04F-01-91081 4 A-AR05F-01-91081 4 A-EF01F-01-91081 2 A-EF02F-01-91081 2 A-EF02F-01-91081 5 A-EM02F-01-91081 4 A-EM03F-01-91081 4 A-EM04F-01-91081 4 A-HC01F-01-91081 3 A-IC501F-01-91081 3 A-LF01F-01-91081 3 A-TC01F-O1-91081 4 Numbe r o f Record s Numbe r Detect s Minimu m Media n Maximu m Averag e 95 % UC L Standar d Deviatio n Studen t 0.0 5 SEM " :

Arsenic :
0. 1 0.0 2 0.0 1 0.0 1 0.0 1 0.0 2 0.0 2 0.0 6 0.0 2 0.0 2 0.0 1 0.0 2 0.0 1 0.0 4 0.0 1 1 5 9 0.0 2 0.0 2 0.1 0 0.0 3 0.0 4 0.0 2 1.76 1 0.0 1 : :;;/PL.

: : : : ; : : : :::Qual.

: : ; ; :

J J 0.0 2 U J 0.0 2 U J 0.0 2 U J J J J J J 0.0 2 U J J 0.0 2 U J J 0.0 2 U J • '

. Chromium •

.

: :. :

: : x : : : S i Result ; V V <. ; D L y- :

- v Qua! : :
.-. . .•:•• : '• : '•::•.•:•.-.•. • .• : • • • :••••. • • • — '••/

. -.. : . - 0. 4 0. 3 0. 3 0. 4 0. 2 0. 2 0. 2 0. 3 0. 3 0. 3 0. 2 0. 4 0. 3 0. 4 0.0 5 0. 1 U 1 5 1 4 0.2 0 0.3 0 0.4 0 0.2 8 0.3 3 0.1 0 1.76 1 0.0 3 -

/Coppe r "-.& :

- '•'••::•• • P$l^;||£f P 0. 6 0. 4 0. 5 0. 2 0. 3 0. 3 0. 4 0. 4 0. 4 0. 3 0. 4 0. 4 0. 4 0. 4 0. 3 1 5 1 5 0.2 0 0.4 0 0.6 0 0.3 8 0.4 2 0.0 9 1.76 1 0.0 2 L

: g : : : - K : : : Qioal.:::: :

: :::: :;: : ^Result;:::;?:;:;:^:';: ^

:

: : ; : J 0.2 J 0.2 J 0.2 J 0.2 J 0. 4 J 0.2 J 0. 2 J 0.2 J 0.2 J 0.2 J 0.2 J 0.2 J 0.2 J 0.2 J 0. 2 1 5 1 5 0.2 0 0.2 0 0.4 0 0.21 0.2 4 0.0 5 1.76 1 0.0 1 j-v"--::;- :

, :-; :' , ^••^iff^.;^-^^^^

0.0 9 0.1 2 0.0 1 0.0

2 U 0. 2 0.0 1 0.0

2 U 0.0 4 0.0 5 0.0 8 0.0 4 0.0 3 0. 1 0.0 7 0.0 1 0.0

2 U 0.0 4 0.1 1 1 5 1 2 0.0 3 0.0 8 0.2 0 0.0 7 0.0 9 0.0 5 1.76 1 0.0 1 ^':3^^/&--- : -^.&-~Jf*-

5. 9 8 8. 9 3. 5 5. 8 4. 7 4. 8 9.3 5. 5 4. 5 3.9 4 5. 1 5.3 5. 1 1 5 1 5 3.5 0 5.1 0 9.3 0 5.6 2 6.4 2 1.7 6 1.76 1 0.4 6

" Averag e and 95t h UC L concentration s use d fo r average and RM E scenario s respectively

. Standar d erro r o f th e mean . D L = Detectio n Limi t U = No t Detecte d J = Estimate d SOURCE : WOODWAR D

CLYD E CONSULTANTS

, DRAF T SURFAC E WATE R R I REPOR T Golde r Associate sTABLE S

LENGTHS

, WEIGHTS

, AN D AG E CLASSE S O F TROU T COLLECTED FO R TISSU E SAMPL E ANALYSI S A T STUD Y LOCATION S O N TH E CALIFORNI A GULC H SIT E I N AUGUST
, 1991 a Locatio n Eas t Fork Arkansa s Rive r EF- 1 EF- 2

Arkansa s Rive r AR- 1 AR- 2 AR- 3 AR- 4 AR- 5 Tennesse e Cree k TC- I
Lak e For k LF- 1 Halfmoo n Cree k HC- 1 Iow a Gulc h IG- 1 Sampl

e No

. A-EF01F-01-91081 2 A-EF01F-01-91081 2 A-EF02F-01-91081 2 A-EF02F-01-91081 2 A-EF02F-01-91081 5
A-AR01F-01-91081 3 A-AR01F-01-91081 3 A-AR02F-01-91081 3 A-AR02F-01-91081 3 A-AR03F-01-91081 3 A-AR03F-01-91081 3 A-AR04F-01-91081 4 A-AR04F-01-91081 4 A-AR05F-01-91081 4 A-AR05F-01-91081 4 A-TC01F-01-91081 4 A-TC01F-01-91081 4
A-LF01F-01-91081 3 A-LF01F-01-91081 3 A-HC01F-01-91081 3 A-HC01F-01-91081 3 A-IG01F-01-91081 3 A-IG01F-01-91081 3 Specie s

Brown b Brow n Brow n Brow n Brow n Brow n Brow n Brow n Brow n Brow n Brow n Brow n Brow n Brow n Brow n
Brow n Brow n Brow n Brow n Brow n Brow n Brook d Broo k Lengt h (mm )

22 0 25 5 27 4 24 0 33 2

29 5 26 5 23 5 20 0 18 0 12 9 40 1 26 4 34 0 23 0

28 0 30 4

40 6 27 1

25 0 28 0

21 3 20 1 Weigh t ( g )

11 5 17 5 21 5 15 5 35 5

18 0 17 5 7 5 7 5 6 5 2 5 61 0 21 5 43 5 13 5

21 0 26 5

65 0 19 7

17 0 20 0

12 0 9 5 A g e Clas s

c
5 +

— 2 + 2 + 1 + 3 + 4 + 2 +

—

3 +

5 +

3 + 2 + Colde r Associate sTABLE S (Concluded )
Locatio n Empir e Gulch EM- 2 EM- 3 EM- 4 Sampl

e No

. A-EM02F-01-91081 4 A-EM02F-01-91081 4 A-EM03F-01-91081 4 A-EM03F-01-91081 4 A-EM04F-01-91081 4 A-EM04F-01-91081 4 Specie s

Broo k Broo k Brow n Brow n Broo k Broo k Lengt h (mm )

21 2 21 2
22 2 24 6 23 1 19 7 Weigh t ( g )

12 0 12 0
110 12 5 12 0 8 0 A g e Clas s

—

.

- 4 + 3 +

a Fillet s wer e combine d for digestio n an d metal s analysi s a t eac h site , excep t a t sit e EF- 2 wher e fillet s fro m th e tw o smalle r fis h wer e combined , an d th e fille t fro m th e larges t fis h was,analyze d separately

. b Salmon trutta
c Ag e clas s coul d no t b e determine d sinc e th e scal e sampl e wa s regenerate d an d no t readable

. d Salvelinus fontinalis SOURCE : WOODWAR D CLYD E CONSULTANTS

, DRAF T SURFAC E WATE R R I REPOR T

Colde r Associate sTABL E 6 

### CHRONI C AN D SUBCHRONI C ORA L RfD s AN D SLOP E FACTOR S FO R CHEMICAL S O F CONCER N Toxicit y Compound Arseni c Chromium V I Coppe r Lea d Manganes e Silve r Zin c Sources : (EPA

, 1992d , EPA

,

a Valu e fro m Healt h Effect s b Verified
, availabl e o n IRI S

C \T

r *.~lfi<*A mrn:1nV>1 a

r\ n TT>T C Exposur e Rout e Ingestio n Ingestio n Ingestio n Ingestio n Ingestio n Ingestio n Ingestio n Subchroni

c R f D (mg/kg-day ) 3E-04 a 2E-02 a 3.7E-02 d N D N D f 5E-03 a 2E-01 a Chroni c R f D (mg/kg-day ) 3E-04 C 5E-03 b 3.7E-02 " N D e N D f 5E-03 b 3E-01 b
1992e ) Assessmen t Summar y Table s (HEAST)

, Marc h 1992

. Carcinogenicit

y Slop e Facto r (mg/kg-day)"

1 1.75 d N D N D N D N D N D N D EP A Weigh t o f Evidence Category 8 A N D D B 2 D D D

Valu e fro m HEAST

, Marc h 1992

. Converted fro m Drinkin g Wate r Standar d t o Rf D (mg/kg-day)

. e Ora l Rf D no t verifie d an d currentl y no t unde r discussion

. Th e EP A IEUB K mode l wil l b e use d i n th e sitewid e Baselin e R A t o evaluat e ora l exposure s t o lead

. f Withdraw n fro m IRI S 10-01-92

. 8 A = Huma n carcinogen B 2 = Probabl e huma n carcinogen D = No t classifiabl e a s t o huma n carcinogenicit y (EPA

, 1989b ) N D = Not determine d b y EP A SOURCE : WOODWAR D CLYD E CONSULTANTS

, DRAF T SURFAC E WATE R R I REPOR T

Golde r Associate sTABLE ?

SURFACE WATE R CARCINOGENI

C RISK S AN D NONCARCINOGENI

C HAZAR D INDE X (H.I. )
Receptor/Pathway Adul t Recreationa l Use r Ingestio n o f Fis h Clul d Ingestio n o f Fis h Tota l Cance r

Ris k 1.92E-0 6 3.74E-0 7 2.29E-0 6 Averag e

Exposur e Subchronic Chroni c H.I

. H.I

. 3.30E-0 1 3.58E-0 1 3.21E-0 2 3.48E-0 2 3.93E-0 1 Reasonabl

e Maximu m Exposur e Cancer Subchroni c Ris k H.I

. 2.70E-0 5 4.33E-0 6 3.56E-0 1 3.13E-0 5 Chroni

c H.I

. 5.98E-0 1 3.84E-0 1 9.82E-0 1 SOURCE : WOODWAR D CLYD E CONSULTANTS

, DRAF T SURFAC E WATE R R I REPOR T

Golde r Associate sTABLE S

SUMMAR Y O F UNCERTAINT Y FACTOR S I N TH E SURFAC E WATE R BASELIN E RIS K ASSESSMEN T
Uncertaint y Facto r Us e o f cance r potenc y factors

. Critica l toxicit y values derive d primaril y fro m anima l studies

. Critica l toxicit y values derive d primaril y fro m hig h doses , mos t exposures ar e a t lo w doses

. Critica l toxicit y values

. Not al l chemical s at the sit e hav e critica l toxicit y values

. Metal s analysi s fo r tota l metal s only

. Effec t o f absorption

. Exposur e assumptions

. Exposure s assume d constant

. Exposur e poin t concentrations

. Exposur e poin t concentrations

. Exposur e scenarios

. Metho d detectio n limits

. Sampling

. Risks/dose s withi n an exposur e rout e assume d t o b e additive

. Ris k characterization

. Effec t o f Uncertaint y Ma y overestimat e risks

. Ma y over - o r underestimat e risks

. Ma y over - o r underestimat e risks

. Ma y over - o r underestimat e risks

. Ma y underestimat e risks

. Ma y overestimat e risks

. Ma y over - o r underestimat e risks

. Ma y overestimat e risks

. May over - or underestimat e risks

. Ma y overestimat e risks

. Ma y overestimat e risks

. Ma y overestimat e risks

. Ma y underestimat e risks

. Ma y overestimat e risks

. Ma y over - o r underestimat e risks

. Ma y overestimat e risks

. Commen t Potencie s ar e uppe r 95t h percent confidenc e limit s derive d fro m th e linearize d model

. Considere d unlikel y t o underestimat e tru e risk

. Extrapolatio n fro m anima l t o human s ma y induc e erro r due t o difference s i n absorption , pharmacokinetics , targe t organs , enzymes , an d populatio n variability

. Assume s linea r a t lo w doses

. Tend s t o hav e conservativ e exposur e assumptions

. No t al l values represen t th e sam e degre e o f certainty

. Al l ar e subjec t t o chang e a s ne w evidenc e become s available

. Thes e chemica l ar e no t addresse d quantitatively

. Di d no t distinguis h betwee n valenc e o r speciation

. Assume d th e meta l wa s presen t i n it s mos t toxi c form
, especiall y arseni c and chromium

. Th e assumptio n tha t absorptio n i s equivalen t acros s specie s i s implici t i n the derivatio n o f the critica l toxicit y values

. Absorptio n ma y actuall y var y wit h specie s an d age . Assumption s regardin g fis h intake , populatio n characteristics , an d exposur e pattern s ma y no t characteriz e exposures

. Doe s no t accoun t fo r environmenta l fate
, transport , o r transfe r whic h ma y alte r concentration

. Us e o f 9 5 % UC L i n calculatin g RM E ma y no t accuratel y represen t exposur e levels

. Use d the arithmeti c mea n concentratio n t o evaluat e averag e exposure

. Ma y not accuratel y represen t exposur e levels

. Us e o f RM E a s upper-boun d estimat e ma y no t accuratel y represen t exposures

. Fo r som e chemicals , th e merno d detectio n limi t i s abov e a concentratio n whic h might b e o f concern . Sampling biase d toward area s o f know n o r suspecte d elevate d metal s concentrations

. Doe s not accoun t for synergis m or antagonism

. Combinin g conservativ e assumption s at eac h ste p o f ris k assessmen t ma y lea d t o highl y conservativ e ris k estimates

. SOURCE : WOODWAR D CLYD E CONSULTANTS

, DRAF T SURFAC E WATE R R I REPOR T

Golde r Associate sGoldeMssociate sr 

## 3

100000

- V C D



### ~ 1000 0 

## c 

## o ^_ l 

### < o 100 0
c 0 

# 2 10 0 0 

### O


## o 1 0 N 1 1 1

/T\

. T 

### o --Vj l -!^ x 

## "thl/
m

.. . ._... _ __ . _ . _ — _ 

# \
, A \ A 

# T ...._. . 

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### £ • <

. _ . . ... _


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### t

_ Q ) 5 C D C D " O b

.

- i - p ~ a o 7' c b c o < b c b < 3 r S

CUCHT/PWWEC

T

_ . 

### ASARC O .4 ^ SURFAC E WATE R HUMA N HEALT H iBf C RIS K ASSESSMEN T V^A

s -..._ . .... .

_... . 

# J»*^N L 5*0*

- ^

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n

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# X

^

, 

### O t

- § ; O ^ C U 1 * • ? * < C D C O f U r o c o 2 5 

# ^ h ^

_ .. _ _ .

^ 10.0 0 Dissolve d Zin c 

## 9.0 0

— A
— CQ- 6 Flo w 

### 8.0 0 _.._.—-_ — 7.0 0 6.0 0 ^

- 5.0 0 S 

## 4.0 0 o n 3.0 0 

## 2.0 0 1.0 0 

# nn n > z c o 

# « ? f C O C O O 3 C O

.

m u 

### ZIN C CONCENTRATION S AN D FLO W 

### •olde r I

N CALIFORNI A GULC H SOCiaie s D«nv«r

, Cokxad o DRAW N A M CHECKE D

REVIEWE D° A T E JUN E 199 6 SCM £ N/ A R L E NO

. 2819A21 4

JO B N 943-281 9 DW C NO -/«EV.NO

. FWUR E
- j

## 60

0 54 0 48 0 42 0 36 0

o 30 0 Q 

## 24 0 18 0 12 0 

## 6 0 0 

# C G 6 Zin c Contribution s a t AR 3 Minimu m 2.5 % (14. 5 ug/L ) Maximu m 98.3 % (265. 2 ug/L ) 

# Averag e 26.8 % (26. 0

1 2 0 ug/ L Aquati c Lif e Referenc e



### Apr-9 1 Jul-9 1 Apr-9 2 May-9 2 May-9 2 May-9 2 May-9 2 Jun-9 2 Jun-9 2 Jun-9 2 Aug-9 2 

# A R 2 Contributio n 1

00 0 ug/ L CG 6 Zin c
CUEWT/PROJEC T 

### ASARC O 

### SURFAC E WATE R HUMA N HEALT H RIS K ASSESSMEN T 

### Golde r Denver

, Colorad o TTTI. E 

### PREDICTE D ZIN C CONCENTRATION S 

### I N TH E ARKANSA S RIVE R BELO W CALIFORNI A GULCH DRAW N CHECKE D REVIEWE D A T E JUN E 199 6 SCAl £ FIL E

NO

. OR19A21 3 J O B

N 943-281 9 D W C NO - / REV

- N O

- FWUR E

### iERPRE

f AlIQTlC) ! ASSES S OUTPU T

Golde r Associate sAppendi x A Junel996

____________________ A^

_____________________ 943-281

9 APPENDI X A

- INTERPRETATIO

N O F ASSES S OUTPU T 

### ASSES S provide s th e cance r ris k an d hazar d inde x calculation s fo r al l exposur e pathways 

### evaluate d a t a site

. Al l informatio n needed t o verif y calculation s i s provided

. Dat a are organized an d reporte d i n categorie s liste d below :

* • Chemical List ;

> • Receptor/Pathwa y Summary ; * • Pathwa y Summary ; * • Intak e Factors ; and ,


### > • Medi a Concentrations

. 

### Number s i n ASSES S ar e writte n i n scientifi c notation

. Th e numbe r followin g th e E i s a powe r o f 10 ; s o 1.61E-0 2 i s 0.0161

. 

### 1 . 0 CHEMICA L LIS T Tabl e A- l list s th e EP A toxicit y value s fo r eac h chemical

. Whe n available , value s ar e liste d for bot h ora l and inhalatio n exposur e route s for eithe r subchroni c or chroni c exposur e duration s (referenc e doses o r RfDs ) o r fo r carcinogeni c ris k (slop e factor s o r SF)

. Thes e value s ar e obtaine d usin g th e hierarch y recommende d b y EPA' s Ris k Assessmen t Guidanc e fo r Superfun d site s (EPA

, 1989 , 1991)

. Th e firs t an d secon d source s i n thi s hierarch y are 

### ( 1 ) IRI S (Integrate d Ris k Informatio n System)
, a n on-lin e compute r databas e o f chemica l ris k informatio n (EPA

, 1992a)
, an d (2 ) HEAS T (Healt h Effect s Assessmen t Summar y Tables ) (EPA

, 1992b)
, EP A table s whic h ar e periodicall y up-dated

. Toxicit y value s (RfD s an d SFs ) 

### d o no t ye t exis t fo r man y chemicals

. Fo r ris k assessmen t purposes , whe n thi s i s true , a

Golde r Associate sJun e

1996__________________A-2___________________943-281 9 chemica l ma y b e discusse d qualitativel y i n th e tex t o f th e report bu t wil l no t b e reporte d quantitativel y i n ASSESS

. RfD s ma y b e derive d fo r either subchroni c o r chroni c exposure s an d ar e use d t o calculat e subchroni c o r chroni c hazar d quotients , respectively

. A subchroni c Rf D ma y no t exis t fo r a particula r chemica l eve n thoug h a chroni c Rf D exists

. 

### 2. 0 RECEPTOR/PATHWA

Y SUMMAR Y Tabl e A- 2 list s eac h recepto r an d the potentia l healt h risk s associate d wit h chemica l exposur e fro m al l pathway s quantitated

. Th e potentia l advers e healt h risk s ar e divide d int o tw o exposur e scenarios : averag e exposur e an d reasonabl e maximu m exposur e (RME)

. For eac h exposur e scenario , potentia l healt h impact s ar e segregate d int o tw o categories : cance r ris k

an d a hazar d inde x fo r bot h subchroni c an d chroni c scenario

. Th e value s show n o n thi s shee t sho w th e total carcinogeni c risk s an d noncarcinogeni c hazard s associate d wit h averag e an d RM E scenari o fo r eac h recepto r listed

. RfD s are use d wit h a leve l o f exposur e durin g a specifi c tim e perio d an d expresse d a s a rati o


### o r hazar d quotient

. Accordin g t o th e EP A (EP A 1989 , 1991)
, generally , th e greate r th e valu e o f th e hazar d quotien t (or hazar d index)
, th e greate r th e leve l o f concer n for healt h 

### impacts

. Anothe r are a o f EP A guidanc e states tha t becaus e H.I

. i s no t a probabilit y function
, a n increase d valu e doe s no t indicat e a degre e o f risk

. Th e hazar d inde x i s th e su m o f a numbe r o f hazar d quotient s fo r a particula r pathway

. A hazar d inde x o f on e mean s th e 

### estimate d chemica l intak e equal s the referenc e dose

. Whe n thi s occurs, a mor e detaile d evaluatio n o f th e sit e i s indicated

. Whe n th e H.I

. i s les s tha n one , furthe r evaluatio n i s generall y no t warranted , an d th e exposur e i s expecte d t o b e safe

. 

### A chemical' s slop e facto r i s multiplie d b y th e lifetim e dail y average intak e o f tha t chemica l i n
a certai n medium t o estimat e th e incrementa l probabilit y (or risk ) o f an individua l developin g Golde r Associate sJun e

1996__________________A-3

___________________ 943-281

9

cance r durin g a lifetime

. Whe n a recepto r potentiall y i s expose d t o a variet y o f chemical s (i n
a give n medium ) possessin g slop e factors
, al l o f the product s ar e summe d t o yiel d the tota l



### cance r ris k fo r thos e chemical s fo r tha t specifi c exposur e pathway

. This ris k numbe r i s acceptabl e i f i t i s les s tha n IE- 4 o r 10" 4 o r 1 i n 10,000

. 

### Recepto r Detai l Repor t This repor t i s include d i n th e Receptor/Pathwa y Summar y Tabl e (Tabl e A-2 ) becaus e i t 

### detail s the carcinogeni c ris k an d the noncarcinogeni c hazar d fo r eac h o f the receptor' s exposur e pathway(s ) fo r bot h the averag e and RM E exposur e scenarios

. Tota l carcinogeni c risk s an d noncarcinogeni c hazard s fo r eac h recepto r ar e als o given

. Eac h recepto r ma y hav e


### a numbe r o f exposur e pathways

. A n exposur e pathwa y i s a rout e tha t a chemica l ma y tak e t o
reac h a populatio n o r receptor

. Eac h pathwa y i s categorize d a s on e o f th e following :

* Inhalation ;

> 

### Derma l contac t wit h solids ; * Derma l contac t wit h water ;

> • Ingestiono f solids ; and , * Ingestio n o f water

. 

### 3 . 0 PATHWA Y SUMMAR Y Tabl e A- 2 als o provide s th e sam e basi c informatio n a s th e Recepto r Detai l Repor t describe d above

. The differenc e betwee n the tw o i s tha t the Recepto r Detai l Repor t includes al l receptors whil e the Pathwa y Summar y Repor t i s receptor-specific
, providin g informatio n o n onl y on e recepto r pe r page

.

Golde r

Associate sJun e

1996_______________A-4___________________943-281 9 

### Pathwa y Detai l Repor t Table s A-3a throug h A-3d compris e th e majorit y o f th e ASSES S report

. Fo r bot h averag e
an d RM E exposur e scenarios , carcinogeni c ris k an d noncarcinogeni c hazard s ar e liste d fo r
eac h recepto r exposur e rout e an d chemical

. Tota l carcinogeni c risk s an d noncarcinogeni c hazard s ar e als o provided

. Thi s report i s especiall y helpfu l i n determinin g whic h chemical(s ) i s (are ) drivin g th e overal l risk s or hazard s for a particula r exposur e route

. Othe r value s provide d i n thi s repor t includ e th e concentratio n o f eac h chemica l i n th e medium , th e intak e facto r fo r tha t exposur e route, an d th e dail y intak e o f th e chemica l bein g evaluated

. This 

### dail y intak e o f a n individua l chemica l i s eithe r multiplie d b y it s slop e facto r o r divide d b y it s 

### Rf D fo r a given exposur e rout e (ora l o r inhalation)

. Unti l othe r informatio n i s availabl e fro m EPA

, ora l RfD s an d SF s ar e use d fo r assessin g the potentia l healt h impact s o f derma l exposure

. 

### 4 . 0 INTAK E FACTOR S Tabl e A-4 a and A-4b represent , i n equatio n format
, th e metho d o f calculatin g th e intak e factor s tha t appea r i n the pathwa y detail repor t explaine d above

. Eac h o f the parameter s tha t goe s int o a n intak e facto r equatio n i s define d for bot h th e averag e an d RM E scenarios

. Thes e parameter s ar e mor e full y describe d i n the Exposur e Assessmen t sectio n o f thi s report

. 

### 5. 0 MEDI A CONCENTRATION

S Tabl e A- 5 describ e th e chemica l concentration s fo r th e averag e an d RM E scenario s fo r a 

### give n medium

. I n som e cases , a higher concentration ma y b e use d t o evaluat e short-ter m risks

. Fo r example , particulat e concentration s i n ai r ma y b e highe r durin g a shor t constructio n projec t tha n th e long-ter m (2 5 year ) averag e migh t be

. I n mos t cases , th e sam e concentration s wil l b e use d for subchroni c an d chroni c scenario

. Thes e figure s are describe d i n the Dat a Summar y an d Selectio n o f Chemical s o f Concern sectio n o f thi s report

. Golde r Associate sJun e

1996__________________A-5___________________943-281 9 

### 6. 0 REFERENCE S Environmenta l Protectio n Agenc y (EPA)

. 1989

. Ris k Assessmen t Guidanc e fo r Superfund

. 

### Volum e I : Huma n Healt h Evaluatio n Manual

. Interi m final

. Offic e o f Emergenc y an d Remedial Response

. Washington
, D.C

. EPA/540/1-89/002

. 

### Environmenta l Protectio n Agenc y (EPA)

. 1991

. Ris k Assessmen t Guidanc e fo r Superfund : Volum e I
- Huma n Healt h Evaluatio n Manua l (Par t B
, Development o f Risk-base d Preliminar y Remediatio n Goals)

. Interim

. 9285.7-01B

. 

### Environmenta l Protectio n Agenc y (EPA)

. 1992a

. Integrate d Ris k Informatio n Syste m (IRIS)

. On-lin e database

. Environmenta l Protectio n Agenc y (EPA)

. 1992b

. Healt h Effect s Assessmen t Summar y Table s (HEAST)

. Annua l FY-1992

. OHEA-ECAO-CIN-821

.

March

.

Goide r Associate s

### Tabl e A- l Chemica l List

——— — Inhalatio n —————————————

— ——— — Non-Inhalatio n

————————— — Slop e Subchroni c

Chroni c Slop e Subchroni c

Chroni c Facto r RF O RF D Facto r

RF D RF D Chemica l (mg/kg/day )

- 1 mg/kg/da y mg/kg/da y (nig/kg/day)- !

mg/kg/da y mg/kg/da y
Arseni c 1.50E+0 1 1.75E+0 0 3.00E-0 4

3.00E-0 4 Cadmiu m (food ) 1.00E-0 3 Chromiu m II I 2.00E-0 5 2.00E-0 6

1.00E+0 0

1.00E+0 0 Chromiu m V I 4.10E+0 1 5.70E-0 6

5.70E-0 7

2.00E-0 2

5.00E-0 3

c °PP e r 3.70E-0 2 3.70E-0 2 Mercur y 8.60E-0 5 8.60E-0 5

3.00E-0 4

3.00E-0 4 zin c 2.00E-0 1 3.00E-0 1
Februar y 2 , 199 3 18:1 0Recepto r

/ Pathwa y ADUL T RECREATIONA L USE R

- - Ingestio n o f Fis h
CHIL D RECREATIONA L USE R

- - Ingestio n o f Fis h 

### Tabl

e A- 2 Receptor/Pathwa y Summar y Averag e Exposur e Cance r Subchroni c Chroni c Ris k H.I

. H.I

. Reasonabl

e Maximu n Exposur e Cance r Subchroni c Chroni c Ris k H.I

.

H.I

. 1.92E-0 6 3.30E-0 1 3.58E-0 1 2.70E-0 5 5.55E-0 1 5.98E-0 1 1.92E-0 6 3.30E-0 1 3.58E-0 1 2.70E-0 5 5.55E-0 1 5.98E-0 1 3.74E-0 7 3.21E-0 2 3.48E-0 2 4.33E-0 6 3.56E-0 1 3.84E-0 1 3.74E-0 7 3.21E-0 2 3.48E-0 2 4.33E-0 6 3.56E-0 1 3.84E-0 1

Februar y 2 , 199 3 18:1 0Tabl e A-3 a ADUL T RECREATIONA

L USE R 

### Ingestio n o f Fis h Averag e Exposur e

| Carcinogeni c

Ris k i Chemica l Arseni c

i | Hazar d Inde x - - Subchroni c i Chemica l Arseni c Chromiu m V I Coppe r Mercur y Zin c

i | Hazar d Inde x - - Chroni c i Chemica l Arseni c Chromiu m V I Coppe r Mercur y Zin c I

1 I Chemica l Concentratio n (nig/kg ) 3.00E-0 2

I i I Chemica l Concentratio n (mg/kg ) 3.00E-0 2 2.80E-0 1 3.80E-0 1 7.00E-0 2 5.62E+0 0

~ 1 I I Chemica l Concentratio n (mg/kg ) 3.00E-0 2 2.80E-0 1 3.80E-0 1 7.00E-02 5.62E+0 0 Ingestio n Intak e Facto r (kg/kg/day ) 3.66E-0 5

Ingestio n Intak e Facto r (kg/kg/day ) 8.55E-0 4 8.55E-0 4 8.55E-0 4 8.55E-0 4 8.55E-0 4

Ingestio n Intak e Facto r (kg/kg/day ) 8.55E-0 4 8.55E-0 4 8.55E-0 4 8.55E-0 4 8.55E-0 4 Dail y

Intak e (mg/kg/day ) 1.10E-0 6

Dail y Intak e (mg/kg/day ) 2.56E-0 5 2.39E-0 4 3.25E-0 4 5.98E-0 5 4.80E-0 3

O a i l y Intak e (mg/kg/day ) 2.56E-0 5 2.39E-0 4 3.25E-0 4 5.98E-0 5 4.80E-0 3 Slop e

Facto r

. (mg/kg/day )
- 1 1.75E+0 0

Subchroni c R F D (mg/kg/day ) 3.00E-0 4 2.00E-0 2 3.70E-0 2 3.00E-0 4 2.00E-0 1

Chroni c R F D (mg/kg/day ) 3.00E-0 4 5.00E-0 3 3.70E-0 2 3.00E-0 4 3.00E-0 1 Carcinogeni c

Ris k 1.92E-0 6

Hazar d Quotien t 8.55E-0 2 1.20E-0 2 8.78E-0 3 1.99E-0 1 2.40E-0 2

Hazar d Quo t i en t 8.55E-0 2 4.79E-0 2 8.78E-0 3 1.99E-0 1 1.60E-0 2 Tota l

Ris k 1.92E-0 6

Hazar d Inde x

3.30E-0 1

Hazar d Inde x

3.58E-0 1Tabl e A-3 b ADUL T RECREATIONA

L USE R 

### Ingestio n o f Fis h 

### Reasonabl e Maximum Exposur e

1 | Carcinogeni c

Ris k i Chemica l Arseni c

i | Hazar d Inde x - - Subchroni c i Chemica l Arseni c Chromiu m V I Coppe r Mercur y Zin c

| Hazar d Inde x - - Chroni c i Chemica l Arseni c Chromiu m V I Coppe r Mercury Zin c 

## 1 Chemica l

Concentratio n (mg/kg ) 4.00E-0 2 I 1 I Chemica l Concentratio n (mg/kg ) 4.00E-0 2 3.30E-0 1 4.20E-0 1 9.00E-0 2 6.42E+0 0
I I I Chemica l Concentratio n (mg/kg ) 4.00E-0 2 3.30E-0 1 4.20E-0 1 9.00E-02 6.42E+0 0 Ingestio n Intak e Facto r (kg/kg/day ) 3.86E-0 4

Ingestio n Intak e Facto r (kg/kg/day ) 1.12E-0 3 1.12E-0 3 1.12E-0 3 1.12E-0 3 1.12E-0 3

Ingestio n Intak e Facto r (kg/kg/day ) 1.12E-0 3 1.12E-0 3 1.12E-0 3 1.12E-0 3 1.12E-0 3 Dail

y Intak e (mg/kg/day ) 1.54E-0 5

4 Dail y Intak e (mg/kg/day ) 4.50E-0 5 3.71E-0 4 4.72E-0 4 1.01E-0 4 7.22E-0 3

Dail y Intak e (mg/kg/day ) 4.50E-0 5 3.71E-0 4 4.72E-0 4 1.01E-0 4 7.22E-0 3 Slop e

Facto r (nig/kg/day)- ! 1.75E+0 0

Subchroni c R F D (mg/kg/day ) 3.00E-0 4 2.00E-0 2 3.70E-0 2 3.00E-0 4 2.00E-0 1

Chroni c R F D (mg/kg/day ) 3.00E-0 4 5.00E-0 3 3.70E-0 2 3.00E-0 4 3.00E-0 1 Carcinogeni c

Ris k 2.70E-0 5

Hazar d Quotien t 1.50E-0 1 1.86E-0 2 1.28E-0 2 3.37E-0 1 3.61E-0 2

Hazar d Quotien t 1.50E-0 1 7.42E-0 2 1.28E-0 2 3.37E-0 1 2.41E-0 2 Tota l

Ris k 2.70E-0 5

Hazar d Inde x

5.55E-0 1

Hazar d Inde x

5.98E-0 1

### Tabl e A-3 c CHIL D RECREATIONA

L USE R Ingestio n o f Fis h 

### Averag e Exposur e

1 | Carcinogeni c

Ris k i Chemica l Arseni c

i | Hazar d Inde x - - Subchroni c i Chemica l Arseni c Chromiu m V I Coppe r Mercur y Zin c

i | Hazar d Inde x - - Chroni c i Chemica l Arseni c Chromiu m V I Coppe r Mercur y Zin c 

## 1 Chemica l

Concentratio n Cmg/kg ) 3.00E-02

\ \ 1 Chemica l Concentratio n (mg/kg ) 3.00E-0 2 2.80E-0 1 3.80E-0 1 7.00E-02 5.62E+0 0

1 1 I Chemica l Concentratio n (ing/kg ) 3.0uE-0 2 2.80E-0 1 3.80E-0 1 7.00E-0 2 5.62E+0 0 Inges t

io n Intak e Facto r (kg/kg/day ) 7.13E-0 6

Ingestio n Intak e Facto r (kg/kg/day ) 8.32E-0 5 8.32E-0 5 8.32E-0 5 8.32E-0 5 8.32E-0 5

Ingestio n Intak e Facto r (kg/kg/day ) 8.32E-0 5 8.32E-0 5 8.32E-0 5 8.32E-0 5 8.32E-0 5 O a i

l y Intak e (mg/kg/day )
2

. HE-0 7

Dail y Intak e (ing/kg/day ) 2.50E-0 6 2.33E-0 5 3.16E-0 5 5.83E-0 6 4.68E-0 4

Dail y Intak e (mg/kg/day ) 2.50E-0 6 2.33E-O S 3.16E-0 5 5.83E-0 6 4.68E-0 4 Slop e

Facto r

. (mg/kg/day )
- 1 1.75E+0 0

Subchroni c R F D (mg/kg/day ) 3.00E-0 4 2.00E-02 3.70E-0 2 3.00E-0 4 2.00E-0 1

~ Chroni c R F O (mg/kg/day ) 3.00E-0 4 5.00E-0 3 3.70E-02 3.00E-0 4 3.00E-0 1 Carcinogeni c

Ris k 3.74E-0 7

Hazar d Quotien t 8.32E-0 3 1.17E-0 3 8.55E-0 4 1.94E-0 2 2.34E-0 3

Hazar d Quotien t 8.32E-0 3 4.66E-0 3 8.55E-0 4 1.94E-0 2 1.56E-0 3 Tota l

Ris k 3.74E-0 7

Hazar d Inde x

3.21E-0 2

Hazar d Inde x

3.48E-0 2

### Tabl e A-3 d CHIL D RECREATIONA

L USE R 

### Ingestio n o f Fis h 

### Reasonabl e Maximu m Exposur e

1 | Carcinogeni c

Ris k i Chemica l Arseni c

i | Hazar d Inde x - - Subchroni c i Chemica l Arseni c Chromiu m V I Coppe r Mercur y Zin c

i | Hazar d Inde x - • Chroni c i Chemica l Arseni c Chromiu m V I Coppe r Mercur y Zin c 1

1 I Chemica l Concentratio n (mg/kg ) 4.00E-0 2

1 1 Chemica l Concentratio n (mg/kg ) 4.00E-0 2 3.30E-0 1 4.20E-0 1 9.00E-0 2 6.42E+0 0

1 1 I Chemica l Concentratio n (mg/kg ) 4.00E-0 2 3.30E-0 1 4.20E-0 1 9.00E-0 2 6.42E+0 0 Ingestio n Intak e Facto r (kg/kg/day ) 6.18E-0 5

Ingestio n Intak e Facto r C kg/kg/day ) 7.21E-0 4 7.21E-0 4 7.21E-0 4 7.21E-0 4 7.21E-0 4

Ingestio n Intak e Facto r (kg/kg/day ) 7.21E-0 4 7.21E-0 4 7.21E-0 4 7.21E-0 4 7.21E-0 4 Daily

Intak e (mg/kg/day ) 2.47E-0 6

Oafl y Intak e (mg/kg/day ) 2.88E-0 5 2.38E-0 4 3.03E-0 4 6.49E-0 5 4.63E-0 3

Dail y Intak e (mg/kg/day ) 2.88E-0 5 2.38E-0 4 3.03E-0 4 6.49E-0 5 4.63E-0 3 Slop e

Facto r .(mg/kg / day )
- 1 1.75E+0 0

Subchroni c R F D (mg/kg/day ) 3.00E-0 4 2.00E-0 2 3.70E-0 2 3.00E-0 4 2.00E-0 1

Chroni c R F D (mg/kg/day ) 3.00E-0 4 5.00E-0 3 3.70E-0 2 3.00E-0 4 3.00E-0 1 Carcinogeni c

Tota l Ris k Ris k 4.33E-0 6 4.33E-0 6

Hazar d Hazar d Quotien t Inde x 9.62E-0 2 1.19E-0 2 8.19E-0 3 2.16E-0 1 2.32E-0 2 3.56E-0 1

Hazar d Hazar d Quotien t Inde x 9.62E-0 2 4.76E-0 2 8.19E-0 3 2.16E-0 1 1.54E-0 2 3.84E-0 1

### Tabl e A-4 a Intak e Factor : SURFAC E WATE R Description : Adul t Recreationa l Use r - Fis h Inges t io n Abbreviation : AUF G Pathwa y Type : Inges t io n o f Soi l

Intak e Facto r ( I R x E F x E D x H E x F I x C F x S S ) ( B U x A T ) Februar y 2, 19 9 18: 1

Parameters : Carcinogeni c • Abbreviatio n IR EF E D M E F I C F S S B W A T Descriptio n Inges t io n Rate(mg/day ) Exposur e Freq.(dys/yr ) Exposur e Duration(yrs ) Matri x Effec t Fractio n Contaminate d Conversio n Facto r (kg/mg ) Site-specifi c Facto r Bod y Weigh t (kg ) Averagin g Tim e (dys ) A v e 15000 0 5 2 3 1 1 .00000 1 1 2 5 2555 0 RM E
15000 0 15 6 2 4 1 1 .00000 1 1 5 7 2555 0 Non

- Carcinogeni c A v e 15000 0 5 2 3 1 1 .00000 1 1 2 5 109 5 R M E
15000 0 156 2 4 1 1 .00000 1 1 5 7 876 0 Intak e Facto r Calculations : Carcinogenic : Averag e Exposur e ( 1.50E+0 5 x 5.20E+0 1 x 3.00E+0 0 x 1 x 1 x 1.00E-0 6 x 1 ) 3.66E-0 5 = (

2.50E+0 1 x 2.56E+0 4 ) Carcinogenic : Reasonabl e Maximu m Exposur e ( 1.50E+0 5 x 1.56E+0 2 x 2.40E+0 1 x 1 x 1 x 1.00E-0 6 x 1 ) 3.86E-0 4 = (

5.70E+0 1 x 2.56E+0 4 ) Non-Carcinogenic :

Averag e Exposur e ( 1.50E+0 5 x 5.20E+0 1 x 3.00E+0 0 x 1 x 1 x 1.00E-0 6 x 1 ) 8.55E-0 4 = (

2.50E+0 1 x 1.10E+0 3 ) Non-Carcinogenic :

Reasonabl e Maximu m Exposur e

< 1.50E+0 5 x 1.56E+0 2 x 2.40E+0 1 x 1 x 1 x 1.00E-0 6 x 1 ) 1.12E-0 3 = (

5.70E+0 1 x 8.76E+0 3 )

### Tabl e A-4 b Intak e Factor : SURFAC E WATE R Description : Chil d Recreationa l Use r - Fis h Inges t io n Abbreviation : CUF G Pathwa y Type : Inges t io n o f Soi l

Intak e Facto r ( I R x E F x E D x M E x F I x C F x S S ) ( B W x A T ) Februar y 2 , 19 9 18: 1

Parameters : Carcinogeni c Abbreviatio n ! R EF E D M E F I C F S S 8 U A T Descriptio n Inges t io n Rate(mg/day ) Exposur e Freq.(dys/yr ) Exposur e Duration(yrs ) Matri x Effec t Fractio n Contaminate d Conversio n Facto r (kg/mg ) Site-specifi c Facto r Bod y Weigh t (kg ) Averagin g Tim e <dys ) A v e 8100 0 6 6 1 1 .00000 1 1 1 6 2555 0 R M E
8100 0 5 2 6 1 1 .00000 1 1 1 6 2555 0 Non-Carcinogeni c A v e '8100 0 6 6 1 1 .00000 1 1 1 6 219 0 R M E
8100 0 5 2 6 1 1 .00000 1 1 1 6 219 0 Intak e Facto r Calculations : Carcinogenic : Averag e Exposur e ( 8.10E+0 4 x 6.00E+0 0 x 6.00E+0 0 x 1 x 1 x 1.00E-0 6 x 1 ) 7.13E-0 6 = (

1.60E+0 1 x 2.56E+0 4 ) Carcinogenic : Reasonabl e Maximu m Exposur e ( 8.10E+0 4 x 5.20E+0 1 x 6.00E+0 0 x 1 x 1 x 1.00E-0 6 x 1 } 6.18E-0 5 = (

1.60E+0 1 x 2.56E+0 4 ) Non-Carcinogenic :

Averag e Exposur e ( 8.10E+0 4 x 6.00E+0 0 x 6.00E+0 0 x 1 x 1 x 1.00E-0 6 x 1 ) 8.32E-0 5 = (

1.60E+0 1 x 2.19E+0 3 ) Non-Carcinogenic :

Reasonabl e Maximu m Exposur e ( 8.TOE+0 4 x 5.20E+0 1 x 6.00E+0 0 x 1 x 1 x l.OOE-0 6 x 1 ) 7.21E-0 4 = (

1.60E+0 1 x 2.19E+0 3 )

### Tabl e A- 5 Medi a Chemica l Concentrations :

SURFAC E

WATE R Februar y 2 , 19 9 18: 1 Median : Fis h Abbreviation : FIS H Mediu m Type : Soi I Subchroni c Chronic/Carcinogeni c Chemica l Averag e

(mg/kg ) R.H.E

. (mg/kg ) Arseni c Cadmiu m (food ) Chromiu m II I Chromiu m V I Coppe r Mercur y Zin c 3.00E-0 2 4.00E-0 2 2.80E-0 1 3.30E-0 1 3.80E-0 1 4.20E-0 1 7.00E-0 2 9.00E-02 5.62E+0 0 6.42E+0 0 Averag e

(mg/kg ) R.M.E

. (mg/kg ) 3.00E-0 2 4.00E-0 2 2.80E-0 1 3.30E-0 1 3.80E-0 1 4.20E-0 1 7.00E-0 2 9.00E-0 2 5.62E+0 0 6.42E+0 0