1

COMMUNITIES FOR A BETTER ENVIRONMENT 

COMMUNITIES FOR CLEAN PORTS 

EAST YARD COMMUNITIES FOR ENVIORNMENTAL JUSTICE 

NATURAL RESOURCES DEFENSE COUNCIL 

June 30, 2011 

Philip M. Fine 

South Coast Air Quality Management District 

21865 Copley Dr. 

Diamond Bar, CA 91765 

(909) 396-2239 

pfine@aqmd.gov 

Dear Dr. Fine: 

On behalf of Communities for a Better Environment, Communities for Clean Ports, East 

Yard Communities for Environmental Justice, and the Natural Resources Defense Council, we 

submit these comments on the 2011 Air Monitoring Network Plan for the South Coast Air 

Quality Management District (“the District”). For the reasons described below, the Air 

Monitoring Network Plan fails to meet the requirements established in the Clean Air Act and 

applicable regulations. Specifically, the Air Monitoring Network Plan fails to adequately 

monitor near heavily trafficked highways, especially those with a large share of diesel trucks. As 

it relates to Particulate Matter less than 2.5 micrometers in diameter (“PM 2.5”), EPA’s 

monitoring regulations require placement of at least one monitor in a population-oriented area of 

expected maximum concentration. The comments and the appended materials indicate that the 

Air Monitoring Network Plan has failed to comply with this provision because it fails to include 

adequate monitoring near major roadways. In addition, section 107(a) of the Clean Air Act 

requires that the State demonstrate that its plan for attainment will reduce emissions to the levels 

needed to attain the NAAQS “within the entire geographic area comprising such State.” By not 

locating monitors in populated areas affected by the incremental concentrations of PM2.5 caused 

by emissions from heavily trafficked highways, the attainment demonstration and 

implementation plan will fail to demonstrate attainment within the geographic area of the state 

adjacent to such highways. 

Beyond conflicting with the provisions of the Clean Air Act and applicable monitoring 

regulations, the failure of the Air Monitoring Network Plan to adequately address the elevated 

levels of pollution near highways violates environmental justice principles. 

I. Introduction. 

 In its Charge for Developing Recommendations to Address the Air Quality Impacts of 

Goods Movement on Communities, EPA acknowledges the following: 
2

The environmental, public health, and quality of life impacts of goods movement on 

communities are more pronounced in areas with major transportation hubs and heavily 

trafficked roads. “Near roadway hotspots” – localized areas with elevated levels of air 

pollution – is an issue of longstanding concern to EPA and other environmental health 

agencies. This issue also is a matter of increasing concern to government transportation 

and planning agencies. Research shows that the many communities, including minority 

and/or low income communities, living near these transportation hubs and thoroughfares, 

already bear disproportionate environmental impacts because of their close proximity to 

multiple pollution sources.1

Despite this acknowledgement of the major impact roadways have on air quality in 

neighborhoods adjacent to heavily trafficked highways, the current monitoring network used to 

develop the last plan to meet the National Ambient Air Quality Standards (“NAAQS”) for 

PM2.5 in the South Coast Air Basin fails to monitor in these areas. This compromises the 

adequacy and lawfulness of the last plan, and any future plan based on demonstrating attainment 

in the air basin, given the large populations that reside near heavily trafficked highways and the 

high levels of pollution found near highways. The failure of the current monitoring network to 

measure population exposures to elevated concentrations of PM2.5 found in communities 

adjacent to major highways, and the resulting failure to develop an attainment strategy designed 

to eliminate NAAQS violations in these communities, allows serious health risks to be ignored in 

the South Coast Air Basin. 

EPA has identified highways carrying significant numbers of diesel vehicles as the 

highways that require attention because of their potential for emitting enough fine particles to 

cause NAAQS violations. In the rulemaking where EPA determined that new or expanded 

highway projects require a quantitative analysis to determine whether vehicle emissions are 

likely to cause new, more frequent, or more severe NAAQS violations for PM2.5, EPA 

concluded “that highway and transit projects that involve significant levels of diesel vehicle 

emissions have the potential to increase local PM2.5 concentrations.” 71 Fed.Reg. 12,468, 

12,472 (March 10, 2006). EPA drew this conclusion from 

... studies [that] provide strong evidence of elevated PM2.5 concentrations along 

roadways on a consistent basis from certain types of projects. Based on EPA's review of 

all studies, studies identified elevated PM2.5 concentrations of 8% to 60% for high-traffic 

roadways to 285% for major truck stops, compared to background concentrations. 

Variables identified in the studies as key predictors of PM2.5 concentrations include: 

Total traffic volume; volume of heavy-duty trucks; traffic congestion; and proximity to 

major facilities (within approximately 150 meters). Most studies showed elevation in 

                                                           

1

 EPA, Charge for Developing Recommendations to Address the Air Quality Impacts of Goods 

Movement on Communities, attached as Exhibit A.
3

PM2.5, black carbon, or other components \4\ associated with major facilities (e.g., truck 

routes, intermodal or bus terminals). 

Id. EPA concluded that the evidence of localized impacts from highways was sufficiently 

compelling that “it is essential that a quantitative PM2.5 or PM10 hot-spot analysis be performed 

for all projects of air quality concern.” Id. The Agency concluded that highways “that have a 

significant number of or significant increase in diesel vehicles” were presumptively “projects of 

air quality concern.” 71 Fed. Reg. at 12,470; 40 C.F.R. § 93.123(b)(i).

Although these criteria for identifying transportation facilities “of air quality concern” 

were developed for the purpose of identifying new or expanded transportation facilities that 

should be evaluated before approval for “hot spot” NAAQS violations, the criteria have equal 

applicability for identifying existing facilities that require evaluation as part of the SIP process. If 

a facility is known to emit pollutants at elevated levels that EPA has found to be associated with 

NAAQS violations, emissions from such a facility should be evaluated in the development of an 

attainment strategy to ensure that emissions will not cause or contribute to NAAQS violations on 

or after the statutory deadline for attainment. 

The conditions that EPA found to cause elevated near-highway exposures to PM2.5 occur 

on a number of highway links and terminals throughout the South Coast Air Basin where diesel 

vehicles are concentrated. These include diesel truck access to the first and second busiest ports 

in the nation, carrying freight to and from rail yards and transshipment terminals in Los Angeles, 

Riverside, and San Bernardino counties. Regional planners are also taking actions to 

accommodate massive increases in cargo throughout this region, which will place near highway 

residents, children attending schools near highway alignments, and others spending time in close 

proximity to highways at risk to severe adverse health impacts. The following map demonstrates 

the expansive and intricate network of freight facilities in the region. 

// 

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Los Angeles/Long Beach, California Map

***Copied from Global Trade Impacts: Addressing the Health, Social and Environmental 

Consequences of Moving International Freight (March 2011) available at 

http://hydra.usc.edu/scehsc/web/index.html. 

Many advocacy groups have been pressing EPA to address the failure of the 2007 South 

Coast PM2.5 SIP to demonstrate attainment of the 1997 NAAQS near highways, and to address 

the failure to account for the incremental concentrations of PM2.5 near highways in the 

determination of design values for the purpose of making nonattainment designations for the 

2006 NAAQS. But EPA has refused to consider the evidence of elevated near highway 

exposures when reviewing the adequacy of the SIP or making designations. Instead EPA urges 

advocates to focus on working with state and local governments to revise the air quality 

monitoring network to ensure that monitors are sited to measure highway impacts. For example, 

in the designation process for the 2006 24-hour PM2.5 NAAQS environmental groups requested 

that EPA model highway emissions using the techniques required by EPA’s Quantitative 

Guidance for assessing the impact of emissions on receptor locations in communities near 

highway. In response to these requests, EPA stated: 
5

 

The EPA does not believe that the designations process is the appropriate forum in which 

to address this potential localized hotspot issue. The designations process relies on air 

quality data from monitoring sites that already have been in existence and operational for 

at least three full years. The commenter’s issue is more directly associated with the 

design of the PM2.5 monitoring network established by each State. EPA’s network design 

criteria (40 CFR Part 58, Appendix D) emphasize that PM2.5 monitors are to be sited to 

represent community-wide air quality. This general approach follows from the studies on 

which the PM2.5 NAAQS were established and later revised. These studies evaluated the 

correlation of health effects to varying levels of communitywide fine particle 

concentrations. However, Appendix D also requires the State to establish at least one 

monitoring station in a population-oriented area of expected maximum concentration. 

Each State is required to develop a PM2.5 network design plan and make it available for 

public review prior to submitting it to EPA for approval. EPA believes that the 

commenter should work with the States in the network design process to explore the 

appropriateness of establishing new monitoring locations in the near-roadway zone.2

The undersigned organizations do not agree that highway scale modeling such as that 

required by EPA’s Guidance for Quantitative Hot Spot analysis of transportation facilities is an 

inappropriate tool for determining the design values in communities exposed to emissions from 

highways to ensure that control strategies are developed to eliminate NAAQS violations and the 

significant adverse health impacts associated with high levels of pollution near highways. 

However, these organizations are heeding EPA’s advice to work with the Air District to remedy 

the failure of the current monitoring network to provide reliable evidence of PM2.5 exposures 

experienced by communities adjacent to the major diesel traffic routes in the South Coast Air 

Basin. 

Specifically, the South Coast Air Monitoring Network Plan fails to monitor any of the 

transportation facilities identified by EPA as of “air quality concern.” EPA found that emissions 

from these types of facilities contribute to high levels of pollution near highways that are 

associated with violations of the NAAQS. Failure to monitor PM2.5 in the impact zone within 

150 meters of such facilities where EPA determined that incremental PM2.5 concentrations 

occur means that NAAQS violations caused by emissions from such facilities will not be 

remedied by the next SIP for PM2.5 unless EPA and the District apply highway scale modeling 

to identify such NAAQS violations and adopt control measures sufficient to eliminate such 

violations. Such modeling could be conducted without monitoring data under the authority of 

EPA’s 2007 Implementation rule: 

                                                           

2

 EPA, Public Comment Summary and Response Document on EPA’s Recommended Area 

Designations for the 2006 24-hour PM2.5 Designation Recommendations, EPA-HQ-OAR-2007-

0562, at 31, attached as Exhibit B.
6

[N]onattainment areas with potential hotspot issues (relatively high concentrations and/or 

gradients of primary PM2.5) should not rely exclusively on regional modeling. 

 * * * 

We describe an “unmonitored area analysis” which uses interpolated ambient data 

combined with gridded model outputs to examine whether potential violations of the 

NAAQS may occur in unmonitored areas. If potential violations are indicated, we 

recommend further analysis of the problem through additional local modeling. Options 

for State action to address such a situation could include imposition of reasonably 

available control technology to reduce emissions, or the deployment of an air quality 

monitor to further characterize the problem. 

72 Fed.Reg. 20, 586, 20,607 (April 25, 2007). But if the Air District does not commit to 

performing the kind of local scale modeling described by EPA in its “Guidance on the Use of 

Models and Other Analyses for Demonstrating Attainment of Air Quality Goals for the 8-Hour 

Ozone and PM2.5 NAAQS and Regional Haze,” then at least one roadside monitor that satisfies 

the requirements of 40 C.F.R. Part 58 must be included in the monitoring network. 

For this and other reasons, the Air Monitoring Plan fails to comply with the Clean Air 

Act and applicable regulations. 

I. Highway Emissions Cause the Highest Population Exposures to PM2.5 for South 

Coast Air Basin Residents. 

Dozens of studies have shown greatly increased pollutant levels and health impacts in 

close proximity to freeways, prompting the California Air Resources Board (“CARB”) to 

recommend in 2005 that local governments “[a]void siting new sensitive land uses within 500 

feet of a freeway, urban roads with 100,000 vehicles/day, or rural roads with 50,000 

vehicles/day.”3

 The rationale for that caution is summarized as follows: “In traffic-related 

studies, the additional non-cancer health risk attributable to proximity was seen within 1,000 feet 

and was strongest within 300 feet. California freeway studies show about a 70% drop off in 

particulate pollution levels at 500 feet.” Additionally: “we recommend that land use agencies 

track the current assessment efforts, and consider limitations on the siting of new sensitive land 

uses in areas immediately downwind of ports.” 

A) Air Pollution is Significantly Elevated Near Roadways. 

One recent study in the Los Angeles basin measured elevated air pollutants far 

downwind, up to 2,000 meters and up to 600 meters upwind of a major freeway.4

 The study, 

along Interstate10, documented high concentrations of ultra-fine particulates, polycyclic 

                                                           

3

 California Air Resources Board, Air Quality and Land Use Handbook: A Community Health 

Perspective, April 2005, http://www.arb.ca.gov/ch/handbook.pdf. 4

 Hu, S. et.al., A wide area of air pollutant impact downwind of a freeway during pre-sunrise 

hours, Atmospheric Environment 2009; 43:2541-2549.
7

aromatic hydrocarbons and nitric oxide at distances of 1,200 meters (roughly 4,000 feet) and 

farther downwind, especially during pre-sunrise hours when winds were low, humidity was high 

and there was a surface temperature inversion. Numerous other studies show elevated pollutant 

concentrations within up to 500 meters (1,600 feet) of freeways and busy roadways.5

 

II. Evidence Supporting Revision of NAAQS Demonstrates that Health Risks to be 

Prevented Are Associated with Exposure to Highway Emissions. 

EPA has argued that the annual NAAQS is to be applied to prevent regional scale 

exposures to PM2.5 because the data used to develop the standards were derived from studies 

that evaluate health risks associated with exposure to concentrations measured at the regional 

scale. But the last review of the NAAQS included studies showing adverse health effects 

associated with exposure to highway emissions. The need for the annual NAAQS relied, in part, 

of evidence showing adverse health effects linked to exposure to highway emissions. 

We summarize here some of the studies included in the last review, and others published 

more recently that affirm the evidence in earlier studies demonstrating that the adverse effects 

associated with exposure to fine particles from highways is not less than the effects linked to a 

broader mix of particles measured at the regional scale. 

A) Correlation Between Asthma and Attending School Near a Major Roadway. 

In California, over two percent of public schools (K-12) are within 150 meters of high 

traffic roads and a disproportionately large percentage of students attending these schools are 

economically disadvantaged and nonwhite.6

 A related study surveying over 1,000 elementary 

school students in Northern California found higher rates of asthma and bronchitis symptoms in 

children attending schools near busy roads and freeways.7

 A study of thirteen southern California 

communities found children exposed to traffic-related pollution in school were more likely to 

develop asthma, irrespective of residential exposure.8

 A study of almost 1,500 children in Dutch 

schools found a positive relationship between school proximity to freeways and asthma 

                                                           

5

 Commenter has attached two technical reports that provide evidence of high levels of pollution 

near highways. First, Commenter has attached a Draft Technical Report from Gregory Gould 

(attached as Exhibit C). Second, Commenter has attached a report from Pechan & Associates 

that summarizes much of the research on the high levels of pollution near highways (attached as 

Exhibit D). The SJVAPCD and EPA should review these documents prior to taking final action 

on the Air Monitoring Plan. 

6

 Green, R.S. et. al., Proximity of California Public Schools to Busy Roads, Environmental 

Health Perspectives 2004; 112(1): 61-66.

7

 Kim, J. et al., Traffic-related air pollution and respiratory health: East Bay Children’s 

Respiratory Health Study, American Journal of Respiratory and Critical Care Medicine 2004; 

170: 520-526.

8

 McConnell, R. et al., Childhood Incident Asthma and Traffic-Related Air Pollution at Home 

and School, Environmental Health Perspectives 2010; 118(7): 1021-1026. 
8

occurrence. Truck traffic intensity and pollutant levels measured in schools were significantly 

associated with chronic respiratory symptoms.9 

A recent nationwide study of almost 9,000 U.S. public schools asserts that children spend 

a significant amount of time at school, making exposure to pollution at school an important 

consideration; the study found that approximately one third of students were likely to be at an 

increased risk of acute and chronic respiratory disorders due to close proximity of their school to 

a freeway.10 Surveys among thousands of junior high school students in Jakarta also revealed a 

link between traffic levels and respiratory impacts including phlegm, persistent cough and 

asthma.11

B) Correlation Between Respiratory Disease and Living Near a Major Roadway. 

Proximity of residences to heavy traffic levels has been associated with respiratory 

impacts such as cough, wheeze, persistent cough, asthma and hospital admissions for asthma in 

many studies.12 The California Children’s Health Study, which began in 1992, found an 89 

percent increase in the likelihood of being diagnosed with asthma for those children living close 

to freeways versus those living farther away.13 Another report from the Children’s Health Study 

showed adverse health impacts of local traffic exposure on children independent of regional air 

quality, including decreased lung function that is unlikely to be regained and thus predisposes 

                                                           

9

 Speizer, F. E. and B. G. Ferris, Jr., Exposure to automobile exhaust. I. Prevalence of respiratory 

symptoms and disease, Archives of Environmental Health 1973; 26(6):313-8; Van Vliet, P.et al., 

Motor vehicle exhaust and chronic respiratory symptoms in children living near freeways, 

Environmental Research 1997; 74(2):122-32.

10 Appatova, A.S. et al., Proximal exposure of public schools and students to major roadways: a 

nationwide US survey, Journal of Environmental Planning and Management 2008; 51(5): 631-

646.

11 Duki, M.I.Z. et al.,. Effect of Air Pollution on Respiratory Health in Indonesia and its 

Economic Cost, Arch Environmental Health 2003; 58:135–143.

12 Nicolai, T. et al., Urban traffic and pollutant exposure related to respiratory outcomes and 

atopy in a large sample of children, Eur Respir J. 2003;21:956–963Brunekreef, B. et al., Air 

pollution from truck traffic and lung function in children living near motor-ways, Epidemiology

1997; 8(3): 298-303; Duhme, H. et al., The association between self-reported symptoms of 

asthma and allergic rhinitis and self-reported traffic density on street of residence in adolescents, 

Epidemiology 1996; 7(6): 578-582;Edwards, J. et al., Hospital admissions for asthma in 

preschool children: relationship to major roads in Birmingham, United Kingdom, Archives of 

Environmental Health 1994; 49(4): 223-227.

13 Gauderman, W.J. et al., Childhood Asthma and Exposure to Traffic and Nitrogen Dioxide. 

Epidemiology 2005; 16:737-743; This study was confirmed by a separate Southern CA study 

finding an 85% higher likelihood for an asthma diagnosis among children living with 75 meters 

of a major road. McConnell R, et al., Traffic, susceptibility, and childhood, Environ Health 

Perspectives 2006; 114(5):766-772.
9

those individuals to cardiovascular illness later in life.14 A recent review of California Health 

Interview Survey (CHIS) data revealed a three-fold increase in asthma related hospital visits 

among children living in high traffic density areas.15 A similar study based on CHIS data 

attributes a 92 percent increase in asthma symptoms among those living near the highest traffic 

densities, and suggests that impacts may be disproportionately worse among those in poverty due 

to heightened vulnerability.16 Those in poverty may also be disproportionately exposed to 

pollution due to older and poorer quality housing. A study in Washington state found that older 

homes, smaller homes, and homes with fewer renovations were more likely to have a higher 

infiltration fraction of PM 2.5.17 

Distance matters. A study of nearly 10,000 children in England found that wheezing 

illness, including asthma, was more likely with increasing proximity of a child's home to main 

roads, with the greatest risk being for children living within 90 meters of the road.18 A study in 

rural New York found that children living in neighborhoods with heavy truck traffic within 200 

meters of their homes had increased risks of asthma hospitalization.19 A Dutch study of over 

1,000 children found that asthma, wheeze, cough, and runny nose were significantly more 

common in children living within 100 meters of freeways; and that increasing density of truck 

traffic was associated with significantly higher asthma levels.20 Another Dutch study found that 

traffic-related pollution was associated with increased respiratory infections, as well as some 

measures of asthma and allergies among four year olds studied from birth.21

                                                           

14 Gauderman, W.J., et al., Effect of exposure to traffic on lung development from 10 to 18 years 

of age: a cohort study, Lancet 2007; 369(19561): 571-7.

15 Wilhelm et. al., Environmental Public Health Tracking of Childhood Asthma Using California 

Health Interview Survey, Traffic, and Outdoor Air Pollution Data, Environmental Health 

Perspectives 2008; 116(8):1254-1260.

16 Meng et. al., Are Frequent Asthma Symptoms Among Low-Income Individuals Related to 

Heavy Traffic Near Homes, Vulnerabilities, or Both?, AEP 2008; 18(5):343-350.

17 Hystad, P.U. et al., Modeling Residential Fine Particulate Matter Infiltration for Exposure 

Assessment, Journal of Exposure Science and Environmental Epidemiology 2009; 19:570-579. 

18 Venn et al., Living Near A Main Road and the Risk of Wheezing Illness in Children, American 

Journal of Respiratory and Critical Care Medicine 2001; 164:2177-2180.

19 Lin, et al., Childhood Asthma Hospitalization and Residential Exposure to State Route Traffic, 

Environmental Research, Section A 2002; 88:73-81;similarly, a San Diego study found increased 

medical visits in children living within 550 feet of heavy traffic. English P., et al., Examining 

Associations Between Childhood Asthma and Traffic Flow Using a Geographic Information 

System, Environmental Health Perspectives 1999; 107(9):761-767.

20 Van Vliet et al., Motor exhaust and chronic respiratory symptoms in children living near 

freeways, Environmental Research 1997; 74:12-132. 

21 Brauer, M. et al., Air pollution and development of asthma, allergy and infections in a birth 

cohort, Eur Respir J 2007; 29:879-888.
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C) Association Between Cancer and Living Near a Roadway. 

A comprehensive Southern California study of urban toxic air pollution shows that motor 

vehicles and other mobile sources of air pollution are the predominant source of cancer-causing 

air pollution, accounting for roughly 94% of the cancer risk from toxic air pollution, most of 

which is from diesel exhaust (84% of the cancer risk).22 CARB estimates an increased cancer 

risk of 100 in one million within 90 meters downwind of freeways carrying 10,000 trucks per 

day.23 A study in Denver showed that children living within 250 yards of streets or highways 

with 20,000 vehicles per day are six times more likely to develop all types of cancer and eight 

times more likely to contract leukemia.24 A Danish study of several thousand children concluded 

that a doubling of vehicle pollution increased the risk of lymphomas by 25 percent.25 An earlier 

English study found a cancer corridor within three miles of highways, airports, power plants, and 

other major polluters, showing greater risk of leukemia or other cancers within a few hundred 

yards from highways or other major pollution sources and decreasing risk of cancer with distance 

from these roadways and facilities.26

D) Association Between Reproductive Impacts and Exposure to Motor Vehicle 

Pollutants. 

Pre- and post-natal impacts on infants born to mothers with heavy traffic exposure have 

also been well documented. A Los Angeles study found that pregnant women living near heavy 

traffic areas with high levels of carbon monoxide were more likely to experience adverse birth 

outcomes such as low birth weights and preterm births.27 Another study found that pregnant 

women with high traffic exposure were three times as likely to have a child with certain heart 

defects as women breathing the cleanest air.28 A study of California children found an increased 

                                                           

22 South Coast Air Quality Management District. Multiple Air Toxics Exposure Study-III. 

September 2008, available at 

http://www.aqmd.gov/prdas/matesIII/MATESIIIFinalReportSept2008.html. 

23 CARB, 2005.

24 Pearson et al., Distance-weighted traffic density in proximity to a home is a risk factor for 

leukemia and other childhood cancers, Journal of Air and Waste Management Association 2000; 

50:175-180.

25 Raaschou-Nielsen, O.et al., Air Pollution from traffic at the residence of children with cancer, 

Am J Epidemiology 2001; 153:433-443.

26 Knox and Gilman, Hazard proximities of childhood cancers in Great Britain from 1953-1980, 

Journal of Epidemiology and Community Health 1997; 51:151-159.

27 Wilherm M. et al., Local variations in CO and particulate air pollution and adverse birth 

outcomes in Los Angeles County, California, USA, Environ Health Perspect. 2005; 113(9):212-

21.

28 Ritz B. et al., Ambient air pollution and risk of birth defects in Southern California. Am J 

Epidemiology 2002; 155:17-25.
11

risk of autism among children who lived within 300 meters of a freeway during the third 

trimester and shortly after birth.29 

E) Association Between Proximity to Busy Roadways and Other Health Impacts. 

A wide body of research also confirms other adverse health outcomes related to close 

proximity to busy roadways. Dutch researchers evaluating long term exposure to traffic have 

found that people who lived near a main road were almost twice as likely to die from heart or 

lung disease and 1.4 times as likely to die from any cause compared with those who lived in lesstrafficked areas.30 A Canadian study of 5,000 people showed that those living within 50 meters 

of a major road or within 100 meters of a highway had increased risks of mortality, with an 

“aging effect” (i.e. years of life lost) of roughly 2.5 years, which is similar to the “aging effect” 

of having chronic heart disease (3.1 year Rate of Advancement for mortality).31 Another 

Canadian study found that people residing within 150 meters of a highway or within 50 meters of 

a major road were more likely to die of coronary heart diseases. Furthermore, subjects who 

moved away from a road during the study period showed a decreased risk of death from coronary 

heart disease while those who moved closer to a road were more likely to die of coronary heart 

disease.32 

III. General Statutory and Regulatory Requirements. 

The statutory basis for monitoring air quality originates in §§110(a)(2) and 319 of the 

Clean Air Act. EPA’s monitoring regulations that define how states must implement these 

statutory mandates are located at 40 C.F.R. Part 58. 

A) Requirements for the EPA Regional Administrator. 

 When state or local agencies submit an air quality monitoring plan that proposes 

modifications or new monitoring sites, the EPA Regional Administrator is required to allow time 

for public comment. Following the time for public comment, the Administrator must either 

approve or disapprove the plan within 120 days.33 

                                                           

29 Volk, H., Residential Proximity to Freeways and Autism in the CHARGE Study. 

Environmental Health Perspectives 2010, doi: 10.1289/ehp.1002835, available at 

http://dx.doi.org. 

30 Hoek, et al., Association between mortality and indicators of traffic-related air pollution in the 

Netherlands: a cohort study, Lancet 2002; 360(9341):1203-9.

31 Finkelstein et al., Traffic Air Pollution and Mortality Rate Advancement Periods, Am J 

Epidemiology 2004; 160:173-177.

32 Gan, W. Q., Changes in Residential Proximity to Road Traffic and the Risk of Death from 

Coronary Heart Disease, Epidemiology 2010; 21(5):642-649. 

33 40 C.F.R. 58.10(a)(2).
12

B) Requirements for Monitoring Plans and Monitoring Agencies. 

 Part 58 requires that state or local agencies submit an annual monitoring network plan for 

“the establishment and maintenance of an air quality surveillance system that consists of a 

network of [State or Local Air Monitoring Systems (“SLAMS”)].”34 The monitoring plan is 

subject to EPA approval when it proposes modifications to the previous plan or any new 

monitoring sites. Here, the Air Monitoring Network Plan proposes modifications to the previous 

plan. The annual plan must be available for public inspection and comments 30 days prior to 

submission for approval to the EPA Regional Administrator, which is required by July 1 of each 

year.35 The monitoring plan must also include the method by which state or local agencies will 

provide for review of changes to a PM 2.5 monitoring network if those changes impact the 

location of a violating PM 2.5 monitor or the creation of or change to a community monitoring 

zone. The affected agency must provide time for public comment and include any received 

comments in the submitted plan.36

 The monitoring plan is required to include “a statement of purposes for each monitor and 

evidence that siting and operation of each monitor meets the requirements stated in appendices 

A, C, D, and E.”37 Appendix A addresses quality controls for monitoring sites to ensure correct 

monitoring results. Appendix C addresses required methods for monitoring criteria pollutants. 

Appendix D addresses criteria for assembling monitoring networks. Appendix E addresses 

specific criteria for the location of monitoring sites. 

C) Appendix D 

 Appendix D of Part 58 details “monitoring objectives and general criteria to be applied in 

establishing the required SLAMS ambient air quality monitoring stations and for choosing 

general locations for additional monitoring sites.”38 The three criteria for monitoring networks 

are as follows: “(a) Provide air pollution data to the general public in a timely manner... (b) 

Support compliance with ambient air quality standards and emissions strategy development... (c) 

Support for air pollution research studies...”39 

Monitoring networks must be designed with a variety of types of monitoring sites. 

“Monitoring sites must be capable of informing managers about many things including the peak 

air pollution levels, typical levels in populated areas, air pollution transported into and outside of 

                                                           

34 40 C.F.R. 58.10(a)(1).

35 40 C.F.R. 58.10(a)(2).

36 40 C.F.R. 58.10(c).

37 40 C.F.R. 58.10(a)(1).

38 40 C.F.R. 58, App. D(1).

39 40 C.F.R. 58, App. D(1.1).
13

a city or region, and air pollution levels near specific sources.”40 Appendix D of Part 58 list the 

following six type of sites. 

(a) Sites located to determine the highest concentrations expected to occur in the area 

covered by the network; (b) Sites located to measure typical concentrations in areas of 

high population density; (c) Sites located to determine the impact of significant sources 

or source categories on air quality; (d) Sites located to determine general background 

concentration levels; (e) Sites located to determine the extent of regional pollutant 

transport among populated areas, and in support of secondary standards; and (f) Sites 

located to measure air pollution impacts on visibility, vegetation damage, or other 

welfare-based impacts.41

PM 10 monitoring sites are not always required; their inclusion is dependent on 

population size and concentration.42 At least one PM 2.5 monitor must be located in a 

population-oriented area with expected maximum concentrations (based on previous assessments 

of PM 2.5 levels).43 Additionally, “the required [PM 2.5] monitoring stations or sites must be 

sited to represent community-wide air quality...These monitoring stations will typically be at 

neighborhood or urban-scale; however, in certain instances where population-oriented micro-or 

middle-scale PM 2.5 monitoring are determined by the Regional Administrator to represent 

many such locations throughout a metropolitan area, these smaller scales can be considered to 

represent community-wide air quality.”44 One suggested location for a middle-scale PM 2.5 

monitoring site is an area where “people moving through downtown areas, or living near major 

roadways, encounter particle concentration that would be adequately characterized by this spatial 

scale. Thus, measurements of this type would be appropriate for the evaluation of possible shortterm exposure public health effects of particulate matter pollution.”45

IV.The SCAQMD Must Place Monitors Near Heavily Trafficked Roadways. 

 Currently, the District has failed to comply with the requirements laid out in the Clean 

Air Act and 40 C.F.R. part 58. At its core, the Clean Air Act requires States (or local agencies) 

to ensure compliance with the NAAQS in the entire geographic area under its jurisdiction.46 The 

monitoring network plays a critical role in ensuring compliance with the NAAQS for all 

populations, including those residents near highways. EPA may not lawfully approve a 

monitoring network that does not include monitoring near highways because the plan fails to 

ensure attainment in the entire geographic area, including the large number of neighborhoods 

                                                           

40 40 C.F.R. 58, App. D(1.1.1). 

41 40 C.F.R. 58, App. D (1.1.1).

42 40 C.F.R. 58, App. D(4.6(a)).

43 40 C.F.R. 58, App. D(4.7.1(b)(1)).

44 40 C.F.R. 58, App. D(4.7.1(b)).

45 40 C.F.R. 58, App. D(4.7.1(c)(2)).

46 42 U.S.C. 7407(a).
14

adjacent to highways where fine particle concentrations have been shown to be significantly 

higher than levels measured at regional scale monitors located outside the known impact zone of 

transportation facilities. 

A) Large-Scale Regional Modeling Does Not Predict Impact of Reductions in Highway 

Emissions. 

The modeling analysis performed for the attainment demonstration in prior Air Quality 

Management Plans uses the CAMx model. This is a regional airshed model that aggregates 

emissions and estimates average ambient concentrations across a large scale grid that includes 

many square miles. For the purpose of comparing modeling results with monitoring station 

measurements, the average concentration over a large area is used. 

This approach may be suitable for the purpose of estimating concentrations of secondary 

species that are formed after primary pollutants are cooked in the chemical soup of the Air Basin, 

but this large scale averaging provides no useful information regarding the dispersion of primary 

pollutants emitted from large sources such as highways. 

 Unlike secondary particulate pollutants, which become particles downwind from their 

point of emission as gases, the elemental carbon and aerosol VOCs emitted from tailpipes, road 

dust, and tire and brake pad particles are emitted directly from highways to the atmosphere, and 

are most highly concentrated at the source. The regional grid modeling analysis performed by 

CAMx aggregates these emissions and averages them over large regions, rather than recognizing 

them as being most highly concentrated at the point of origin. EPA explained in its guidance 

regarding PM attainment demonstrations that “[d]ispersion models are better able to capture the 

influence of primary PM sources where large concentration gradients may exist. Grid models 

spread out the PM emissions to the size of the grid (typically 4 or 12 km). This makes it difficult 

to judge the benefits of control strategies that may affect primary PM sources.”47 The large-scale 

regional modeling analysis performed for the SCAQMD cannot, and does not, predict 

concentrations of the primary species in the near-highway environment. Given the limitations of 

this large scale tool for predicting the impact of primary PM emissions from sources on local 

ambient concentrations, the Monitoring Network must be augmented to include adequate nearhighway monitoring to protect the health of residents. 

B) The Failure to Monitor Near Highways Violates Applicable Regulations in Part 58. 

Currently, the failure to adequately monitor near highways violates EPA’s monitoring 

regulations. Specifically, the monitoring plan fails to provide the following types of sites: 

“(a) Sites located to determine the highest concentrations expected to occur in the area 

covered by the network”; 

                                                           

47 72 Fed. Reg. 20,607-08.
15

“(b) Sites located to measure typical concentrations in areas of high population density”; 

and 

 “(c) Sites located to determine the impact of significant sources or source categories on air 

quality”.48

Monitoring near highways provides information critical to meeting each of these criteria. 

Moreover, EPA’s monitoring regulations require that “[a]t least one PM2.5 monitor must be 

located in a population-oriented area with expected maximum concentrations.”49 As these 

comments and appended technical analysis demonstrate, there are currently many populationoriented areas of maximum concentrations that remain unmonitored. Specifically, the District 

has failed to place a monitor in close proximity (e.g. 25-100 meters) to a major roadway with 

significant truck traffic in an area of the South Coast Air Basin with high background particulate 

concentrations. Placing a monitor in those areas is necessary for the following reasons. 

1. Significant Populations in the Los Angeles region are Impacted by Major Roadways. 

Attached to these comments, we have provided a draft technical report that assesses the 

number of people in California that reside next to major roadways. Specific to the SCAQMD, 

we have found the following population numbers: 

Population within 100m, 300m, and 500m of roads with greater than 50,000 AADT in 

South Coast Air Basin Counties. 

Distance to Road (>50,000 AADTa)

State County 100m 300m 500m

California Los Angeles 329,906 3.47%b 1,248,158 13.11% 2,220,631 23.33%

California Orange 103,654 3.64% 385,325 13.54% 673,478 23.66%

California Riverside 17,572 1.14% 77,495 5.01% 154,118 9.97%

California San Bernardino 26,595 1.56% 103,088 6.03% 188,266 11.01%

aAnnual Average Daily Trips    b Percentage of county population

// 

// 

// 

// 

                                                           

48 40 C.F.R. 58, App. D (1.1.1 (a)-(c)).

49 40 C.F.R. 58, App. D (4.7.1(b)(1)).
16

Population within 100m, 300m, and 500m of roads with greater than 100,000 AADT in 

South Coast Air Basin Counties. 

Distance to Road (>100,000 AADTa)

State County 100m 300m 500m

California Los Angeles 225,445 2.37% 908,718 9.55% 1,639,205 17.22%

California Orange 60,877 2.14% 239,659 8.42% 421,817 14.82%

California Riverside 14,133 0.91% 64,088 4.15% 127,260 8.23%

California San Bernardino 17,408 1.02% 71,975 4.21% 134,411 7.86% aAnnual Average Daily Trips

b Percentage of county population

As demonstrated by this analysis, significant populations in several counties currently reside 

next to major roadways. With more than 1,284,440 people within 300 meters of a roadway 

greater than 100,000 AADT, this poses a large population exposed to pollution from highways 

that demands monitoring.50 For context, this area of unmonitored people in the Los Angeles 

region alone would be in the top ten for most populous cities in the nation. 

 Failure to monitor in these high population areas fails to meet the criteria of providing sites 

in places of high population density. 

2. Credible Scientific Evidence Demonstrates High Levels of Particulate Matter and Other 

Pollutants Near Major Roadways. 

The attached technical report demonstrates that concentrations of many pollutants, 

including PM2.5, near highways are significantly higher than background concentrations 

measured at regional scale monitors.51 The undersigned organizations contends that the 

submitted evidence in various studies confirms EPA’s findings in the conformity hot spot 

rulemaking that the incremental concentrations of PM2.5 observed near highways are higher 

than regional background levels. Combining these results with EPA’s conclusion that higher 

concentrations are linked to traffic levels and proximity to the roadway, it is clear that a 

monitoring plan that fails to include monitors within the impact zone of highways fails to satisfy 

numerous criteria in Part 58, including the requirement to site a monitor at the point of 

maximum expected location in the nonattainment area, and the requirement that the monitoring 

network be adequate to support a demonstration that the SIP will provide for attainment. 

                                                           

50 In prior comments, Environmental Defense Fund estimated approximately 1.5 million 

residents in the region next to road links with greater than 125,000 AADT. See Exhibit E 

(coalition letter with attachment H). Whatever the population number, it represents a significant 

number of people in close proximity to major roadways. 

51 Gould, Draft Report – Near Roadway Emissions: Measurement, Exposure, and Monitoring, at 

5-8 (Exhibit C); see also Pechan Report (Exhibit D).
17

 

District and EPA review this material because it supports the need for monitoring near 

major roadways. Monitoring near roadways will ensure the entire geographic area has the 

benefits of the Clean Air Act protections, and it will ensure the SCAQMD addresses 

environmental justice concerns. Because roadways pose high concentrations of air pollutants 

and most likely the unmonitored areas near roadways are an area of maximum concentration, the 

Monitoring Guidelines compel placement of monitors near roadways. 

V. Failing to Monitor Near Highways Violates Environmental Justice Requirements. 

EPA has acknowledged many times the threat that highways pose to the health of 

residents. In fact, EPA has noted that decreases in diesel particulate matter and nitrogen oxides, 

two common pollutants near highways, lead to “tremendous health benefits.”52 As EPA noted in 

a 2010 response on air quality and environmental justice, “the explosive growth in commerce in 

the late 1990’s through the early part of this decade exacerbated the air quality issues in goods 

movement communities.”53 EPA also acknowledges that “minority, low income, and indigenous 

populations have borne a disproportionate share of the cumulative air toxics health impacts from 

goods movement.”54 EPA claims to have set a goal of “targeting issues associated with goods 

movement and environmental justice,”55 but the Agency could fail to live up to this mandate by 

sitting idly by through years of Monitoring Plans that fail to monitor near highway 

concentrations of pollutants. A pervasive example of a current flaw of addressing air pollution in 

environmental justice communities is EPA’s approach that fails to monitor levels of PM 2.5 near 

highways in the South Coast Air Basin. This approach violates several provisions of federal law 

and regulatory policy.56 

The attached report demonstrates that many of the communities residing near major 

roadways in the South Coast Air Basin tend to be communities of color. Moreover, in many 

counties, the odds ratio of living near a highway are much higher if a resident is black or latino 

compared to white populations. 

Here, the District has chosen to site monitors away from major roadways, which has the 

purpose and effect of denying the benefits of attainment by excluding large populations of 

communities of color from compliance with the Clean Air Act attainment provisions and the 

                                                           

52 EPA, Response to the National Environmental Justice Advisory Council Report: Reducing Air 

Emissions Associated with Goods Movement: Working Toward Environmental Justice 3 (2010), 

available at http://www.epa.gov/compliance/ej/resources/publications/nejac/epa-resp-nejacgoods-movement-2009.pdf.

53 Id. at 11.

54 Id. at 13.

55 Id. at 3.

56 See, e.g., 42 U.S.C. § 7410(a)(2)(E)(i)(requiring that states provide necessary assurances that 

SIPS are not prohibited by federal law). 
18

monitoring regulations. Failing to adequately monitor near highways substantially impairs the 

ability of the District to ensure communities of color along major roadways are not denied the 

benefits that flow from lawful monitoring to ensure compliance with the NAAQS. Because the 

District, through the Air Monitoring Network Plan, has failed to protect near highway residents, 

the policy violates environmental justice principles in addition to federal law. 

VI.Commenters Propose the Following Locations As Sites for Future Monitoring. 

In a prior effort to determine appropriate locations to place monitors in the region, we 

identified several locations. Specifically, we identified three specific categories of places that 

should have a monitor: 1) locations near the I-710 because it has the highest diesel truck traffic 

share in the air basin; 2) locations near major interchanges where traffic density is expected to be 

greatest; and 3) locations near freeways in the inland empire where regional concentrations of 

PM2.5 are high. 

I-710 Locations 

1) The SCAQMD should place two monitors in Commerce near the I-710 to measure 

upwind concentrations and downwind concentrations. If SCAQMD decides it can only 

place a monitor in one of these locations, it should choose the downwind location. Here 

is a list of locations to consider: 

a. Triggs St and Duncan Ave Commerce CA. 90040 [downwind of the I-710] 

b. Connor and Leonis St. Commerce CA. 90040 [upwind of the I-710] 

c. S Ford Blvd & S Mines St., Los Angeles, CA 90022 [Ford Boulevard Elementary School 

is located near this intersection and may be a good location for a monitor] 

d. White Ave & E. Neece St., Long Beach, CA 90805 

Locations Near Major Interchanges 

1) East Los Angeles Interchange which has the highest aggregate VMT in the South Coast 

Air Basin [Soto Street Elementary School is located in close proximity to this interchange 

and may be a good location for a monitor] 

2) I-10 and I-405 Interchange [This location should be chosen to provide a reference point 

for monitoring where two primarily commuter traffic roads intersect] 

Inland Empire Locations Near Major Freeways and Goods Movement Hubs 

1) Klamath River Dr. Riverside CA 91761 [Near the Highway 60 and many major 

distribution centers in the inland empire] 

2) Cisco St and Atchison St Colton, CA 92324 [Near the I-215/I-10 interchange close to 

significant goods movement activities] 

Monitors should be located within the proximity to roadways discussed by the siting guidance in 

Part 58, Appendix E. 
19

 (a) Since emissions associated with the operation of motor vehicles contribute to 

urban area particulate matter ambient levels, spacing from roadway criteria are necessary 

for ensuring national consistency in PM sampler siting. (b) The intent is to locate 

localized hot-spot sites in areas of highest concentrations whether it be from mobile or 

multiple stationary sources. If the area is primarily affected by mobile sources and the 

maximum concentration area(s) is judged to be a traffic corridor or street canyon 

location, then the monitors should be located near roadways with the highest traffic 

volume and at separation distances most likely to produce the highest concentrations. For 

the microscale traffic corridor site, the location must be between 5 and 15 meters from 

the major roadway. 

71 Fed.Reg. 61,235, 61,325. Satisfying these criteria is especially important for the purpose of 

being able to show that populations living near highways will be fully protected. Given the 

gradient of concentrations near highways, attainment must be demonstrated for those living 

closest to highways to ensure that all exposed populations are protected. 

VII. EPA’s Final Decision on the Monitoring Plan Must Be Published in the Federal 

Register. 

 Given the importance of the Air Monitoring Network Plan to promoting compliance with 

the Clean Air Act and applicable regulations, we request that EPA’s ultimate decision to approve 

or disapprove this Air Monitoring Network Plan be published in the Federal Register. This will 

allow the public an opportunity to review the responses to the significant comments and 

technical analysis attached to these comments. 

VIII. Conclusion. 

The undersigned organizations respectfully request that the District revise their 

monitoring network to include near-roadway monitoring. Specifically, the District should site 

PM 2.5 monitors in areas close to major highways in population-oriented areas that have high 

truck shares. Also, since these comments are forwarded to EPA, if the District fails to address 

these comments, we respectfully request that EPA disapprove the Monitoring Plan and request 

that the agency 

Sincerely, 

Adriano Martinez 

Staff Attorney 

Natural Resources Defense Council 

[Signatories Continued on Next Page] 

Bob Yuhnke 

Consultant for NRDC 

Robert E. Yuhnke & Associates 
20

Maya Golden-Krasner 

Attorney 

Communities for a Better Environment 

Giselle Fong 

Executive Director 

Communities for Clean Ports 

Jocelyn Vivar 

Policy Director 

East Yard Communities for Environmental Justice 

Enclosures 

CC: Jared Blumenfeld, Region IX Administrator 

Deborah Jordan, Director Air Division, Region IX