BOARD MEETING DATE: October 1, 2010
AGENDA NO. 16

PROPOSAL:

Execute Contract for Sources, Composition, Variability and Toxicological Characteristics of Ultrafine Particles in Southern California

SYNOPSIS:

The University of Southern California has submitted a proposal to study sources and toxicity of ultrafine particles in Southern California. This proposed study will be a complement to a study funded by the U.S. EPA characterizing coarse particles in Southern California. This action is to fund the study “Sources, Composition, Variability and Toxicological Characteristics of Ultrafine Particles in Southern California” in an amount not to exceed $470,969 from the Clean Fuels Fund.

COMMITTEE:

Technology, September 24, 2010, Recommended for Approval

RECOMMENDED ACTION:

Authorize the Chairman to execute a contract with the University of Southern California for the study “Sources, Composition, Variability and Toxicological Characteristics of Ultrafine Particles in Southern California” in an amount not to exceed $470,969 from the Clean Fuels Fund (Fund 31).
 

Barry R. Wallerstein, D.Env.
Executive Officer

Background

Current regulatory efforts are focused on reduction of ambient levels of particulate mass for PM₁₀ and PM_2.5. However, recent studies have demonstrated that ultrafine particles (UFP), generally defined as smaller than approximately 0.1-0.2 nanometers in diameter, may be more toxic on a per mass basis. Studies that show individual particles penetrating cellular membranes and causing cell damage, suggest that particle number rather than particle mass may be a more health-relevant metric of ambient particle exposure. Also, recent studies have indicated that, while vehicle emissions controls have substantially reduced the mass of particle emissions from motor vehicles, the ambient levels expressed as the number of ultrafine particles per unit of air volume has increased near roadway sources.

The majority of ambient particles in terms of particle count are ultrafine particles; but, due to their small size, only a small fraction of ambient particulate matter mass is in the ultrafine size range. Unlike PM_2.5, there are little data regarding the spatial differences and chemical composition of ultrafine particulates. Since these characteristics may be important in evaluating the health effects of ultrafine particles relative to coarse particulate matter (particles sized 2.5 - 10 micrometers in diameter, or PM_{2.5 – 10}) and PM_2.5, the proposed additional measurements will provide insights into the source, composition and health effects of these ultrafine particles.

Proposal

The objective of the proposal is to provide information on ultrafine particle sources, spatial and seasonal characteristics, and toxicity in Southern California.

The proposed project will make use of samples that have already been collected by the University of Southern California over an approximate 15-month cycle at 10 locations in the Los Angeles Basin reflecting different source and receptor locations, including near freeways. The samples were collected in conjunction with a U.S. EPA funded project characterizing the chemical composition and toxicity of course particulate matter (PM_{2.5 – 10}). Seven of these locations are also sampling sites for the U.S. EPA’s Multi- Ethnic Study of Atherosclerosis Air Pollution Study (MESA Air). MESA Air is a multi-year study funded by U.S. EPA that is looking into the health effects of PM_2.5. Thus, the results of the proposed study can be used to compare the composition, sources, and toxicity of UFP with those of PM_2.5 and PM_{2.5 – 10}. These results will be important in forming the scientific basis for air quality policies to reduce emissions and improve public health.

Benefits to AQMD

The results of this project will provide information to help understand the linkage between sources, chemical composition, and the toxicity of ultrafine particulates, which will provide a strong scientific basis on which to develop cost-effective strategies to protect the public from sources of toxic ultrafine particulate matter. The data will help determine if there is scientific foundation for reducing emissions of ultrafine particulate matter from a subset of sources, including motor vehicles.

Additionally, data on ultrafine particle characteristics will be an invaluable resource to the ongoing and planned particulate matter exposure and health studies in the Los Angeles Basin, including major research programs such as the Southern California Particle Center (SCPC) and MESA Air investigations, by developing additional information on ultrafine particle exposures and health effects.

Sole Source Justification

Section VIII.B.2. of the Procurement Policy and Procedure identifies four major provisions under which a sole source aware may be justified. This request for a sole source award is made under provision B.2.d. Other circumstances exist which in the determination of the Executive Officer require such waiver in the best interest of the AQMD. Specifically, clause B.2.d.(1): Projects including cost sharing by multiple sponsors. This project will be leveraged with other ongoing major research efforts in collaboration with the SCPC, funded by the U.S. EPA.

Resource Impacts

Total cost for this project is $470,969 over a 30-month period.

Funds are available from the Clean Fuels Fund (Fund 31), established as a special revenue fund resulting from the state-mandated Clean Fuels Program. The Clean Fuels Program, under Health and Safety Code Sections 40448.5 and 40512 and Vehicle Code Section 9250.11, establishes mechanisms to collect revenues from mobile sources to support projects to increase the utilization of clean fuels, including the development of the necessary advanced enabling technologies.

Funds collected from motor vehicles are restricted by statute to be used for projects and program activities related to mobile sources that support the objectives of the Clean Fuels Program. This project is related to the Clean Fuels Program because ultrafine particulates are directly emitted by fuel combustion and formed in the atmosphere from gaseous precursors emitted from motor vehicles and other sources. This project will help understand the benefits to be derived from switching to alternate technologies, including clean fuel technologies, to reduce emissions. AQMD is required to consider health effects when determining which clean fuels projects to fund. Previous studies have shown that reducing motor vehicle particulate mass can result in an increase in ultrafine particle number emissions. This study will provide information regarding which sources are more important in producing exposures to ultrafine particles, and that can be used to quantify the benefits of using alternate and advanced technology to reduce ultrafine particles derived from motor vehicle emissions and from other emissions sources.