Background

The National Ambient Air Quality Standards (NAAQS) for ozone and fine particulate matter smaller than 10 microns (PM10) continue to be exceeded in several areas in the South Coast Air Basin, although a decrease in peak levels of these pollutants has been observed in recent years. The Basin is required to meet the federal health standard for PM10 by the year 2006.

PM10 is a complex mixture of pollutants derived from both natural and combustion sources that have significantly different size fractions. This pollutant mixture is associated with increased human morbidity and mortality, and is also responsible for significant visibility degradation in the Basin.

Fugitive dust from natural sources in desert environments, and road dust in urban areas, accounts for 40-50 percent of ambient PM10 and constitute a major fraction of coarse mode particles. These two components of PM10 are targeted for future control measures. Although there is a growing body of scientific evidence to support the theory that fine particles are probably more toxic than the coarse particles, no evidence exists to support the corollary that coarse particles are relatively safe.

Often control regulations targeting various fractions of PM10 (size and/or chemical species) are developed to meet NAAQS achievement deadlines. Since these regulations are not necessarily based on the toxicity profile of those specific fractions of PM10, the regulated community questions the efficacy of these regulations to provide true health benefits. Hence, to prioritize the components of PM10 targeted for controls, and to ensure that maximum health benefits are derived from each pollutant fraction targeted for control, it is necessary to determine the relative roles of coarse (natural sources) and fine (combustion sources) particles in causing adverse health effects.

The District has been awarded $375,000 from the U.S. Environmental Protection Agency's (EPA) 105 Grant program to conduct the following activities:

$350,000 for health effects studies to determine the impact of air pollution on public health and to estimate benefits derived from reducing ambient levels of PM10 and ozone in the South Coast Basin;

$25,000 for public information projects, related to these health effects studies, to be coordinated by the Coalition for Clean Air.

From the health effects studies portion of this 105 Grant, staff recommends funding the research project described below in the amount of $204,186. The purpose of this study shall be to determine whether the coarse particles derived from desert dust storms are as toxic as fine particles originated mostly from combustion sources. AQMD and EPA staff are presently working together to identify and select an additional health study to be funded by the remaining $145,964 available in this category. In addition, AQMD, EPA and the Coalition for Clean Air staff are working together to finalize the work plan for public information and out-reach projects to be funded by the grant support of $25,000 received under the latter category.

Proposal

Staff has reviewed a proposal from the California Public Health Foundation (CPHF) and the Office of Environmental Health and Hazard Assessments (OEHHA) investigators to conduct a two phase health study in the Coachella Valley region. This region has been designated as a serious non-attainment area for PM10. Desert dust dominates the coarse fraction of PM10, while secondary and combustion-source particles transported from the Los Angeles Basin contribute to the fine fraction of PM10 in this region. The main objective of the study is to determine whether the coarse particles (natural desert dust) are as toxic as fine particles generated from combustion sources.

In Phase I, which is retrospective in nature, investigators will analyze data collected from August 1989 through December 1994. In this analysis, the relationship between measured levels of PM10 and calculated levels of particulate matter smaller than 2.5 microns (PM2.5) (from airport visibility data) with health indices of the local population (based on emergency department visits and hospital admissions from the three hospitals in the region) will be determined. Daily monitoring in phase II will assist with validating the PM2.5 levels calculated in phase I of the study. The results will be useful in identifying those fraction(s) of PM10 that must either be targeted for control or be avoided, depending on its toxic profile as observed in this phase of the study.

In phase II, investigators will conduct data analyses similar to those conducted in Phase I, with data collected from 1995 through 1998. However, in Phase II the ambient data will be based on daily monitoring of PM10, PM2.5, and ozone levels for a period of three years beginning in the summer or fall of 1995. This duration of three years may be reduced if the results of Phase I indicate that adequate statistical significance is achievable with a shorter follow-up period. The results of Phase II will be used to develop District's future control and regulatory policies.

Data analyses conducted during both phases would involve controlling for weather and time-series regression techniques which have proven to be appropriate statistical methodologies for such studies. The analyses will also determine the role of co-pollutants, such as ozone, carbon monoxide and nitrogen dioxide, that are routinely monitored in the study area.

The proposal has been peer reviewed by two experts in the field of air pollution epidemiology and statistical methods (Drs. Arden Pope from Brigham Young University in Utah and Suresh Moolgavkar from Fred Hutchinson Cancer Research Center in Washington) and EPA Region IX staff. All evaluators have recommended approval of this proposal.

Staff proposes to set up an advisory panel comprised of these reviewers to oversee the progress of the study, assist in successful completion of this study, and review and comment on the reports (progress and final) submitted by the investigators.

Sole-Source Justification

Section II, Step C(3) of the Consultant Selection Policy identifies four provisions under which a sole-source award may be justified: (1) cost to prepare documents exceeds the cost for consultants, (2) delay would result in the endangerment of public health, (3) services are only available from sole-source, (4) other circumstances exist identifying sole-source as in the best interests of the AQMD.

This request for a sole-source award is being made under provision #4. The information obtained from this study will be crucial for the AQMD to target control measures against those PM10 fractions that pose maximum health threat to the public health. In other words, better public health protection will be achieved at a lower cost by prioritizing the PM10 fraction(s) for control based on their relative toxic roles than on their contributory role to violate the Federal and/or State Standards. The information will also help in developing future AQMPs, SIPs and FIPs for the Coachella Valley, which is designated as a serious non-attainment area for PM10.

The ambient profile of PM10 in the Coachella Valley differs significantly from the rest of the AQMD and eastern United States, both in terms of size fractions and chemical species. Thus, the use of results from health effects studies conducted in the eastern United States to develop control strategies for Coachella Valley becomes questionable. Hence, this site-specific study design was developed by the investigators to account for these differences.

The EPA staff are of the opinion that, "this study will fill an important knowledge gap and address nagging questions about the importance of certain PM source categories". Also, U.S. EPA, Region IX, is providing the fiscal support needed to fund this and other health effects studies to address the PM10 related issues which are specific to the District.

Thus, it is in the AQMD best interests to join the California Public Health Foundation and the Office of Environmental Health and Hazard Assessments (OEHHA) in this effort. This will also ensure a cost savings of 31 percent in labor costs (in-kind support of investigators time) and the proposed 19.5 percent of indirect costs is far lower than the typically observed 30-60 percent (New York University, California Institute of Technology).

Financial Terms

The total cost of the proposed project is $297,726. Cofunders include OEHHA $93,540 (in-kind) and the EPA, through the AQMD, in the amount of $204,186 (direct). With recognition and appropriation of the EPA 105 grant, sufficient funds are available in the Fiscal Year 1995-96 Technology Advancement budget to fund this project.

This recommendation was approved by the Technology Committee on September 13, 1995 and was approved for full Board authorization.

THEREFORE IT IS RECOMMENDED THAT YOUR BOARD

--Recognize $375,000 in revenue based on the award of a cooperative agreement with EPA.

--Appropriate $375,000 from the undesignated fund balance to the Technology Advancement, Services and Supplies Major Object, Professional and Special Services Account.

--Authorize the Chairman to execute an agreement with California Public Health Foundation, in an amount not to exceed $205,000 to conduct an epidemiological study to determine the relative toxic roles of coarse and fine particles on the local population health indices.

--Authorize the Chairman to execute an agreement with the Coalition for Clean Air, in an amount not to exceed $25,000 for public information projects subject to submittal of a work-plan satisfactory to the AQMD and the EPA staff.

Respectfully,

James M. Lents, Ph.D.

Executive Officer

ACL:ARA:SP