South Coast Air Quality Management District

Execute Contract to Co-Sponsor Study of Children’s Pollutant Exposures During School Bus Commutes

SYNOPSIS:

CARB is in the process of initiating an interagency agreement with CE-CERT to conduct a study to characterize school bus commute exposures to diesel particles and other air pollutants experienced by children while riding on school buses, waiting at bus stops, or waiting near idling buses. The study is intended to focus on diesel buses, but also includes natural gas buses as well. Additional testing is needed to study exposures from buses equipped with particulate traps. This action is to execute a contract with CE-CERT to conduct the additional testing for an amount not to exceed $59,000. CARB’s portion of the study is $450,000.

COMMITTEE:

Technology, April 27, 2001, Recommended for Approval

RECOMMENDED ACTION:

Authorize the Chairman to execute a contract with CE-CERT for pollutant testing inside school buses retrofitted with particulate traps in an amount not to exceed $59,000 from the Clean Fuels Fund.

Barry R. Wallerstein, D.Env.
Executive Officer

Background

Previous research by CARB showed that in-vehicle concentrations of fine particles and elemental carbon, indicators of diesel exhaust, were highest when in proximity to diesel-fueled vehicles. Because most California school buses are diesel powered, school children are potentially exposed to high concentrations of diesel particulates and other pollutants during their school bus commutes, and while waiting to board the buses as the buses are idling. A recently released study of in-bus conditions indicated elevated levels of toxic pollutants.

As a result, CARB is initiating a research project in the South Coast Air Basin, more specifically, within the Los Angeles Unified School District, to characterize school bus commute exposures experienced by children while riding on buses, waiting at bus stops, or waiting near idling buses during loading. The study would obtain data needed to characterize the range of exposures experienced by children by covering a range of commute scenarios, sampling locations, such as bus stops and loading areas, and fuel types. A full range of vehicle exhaust pollutants would be measured.

CARB is initiating an interagency agreement with CE-CERT to conduct this project, which includes a pilot study to: (1) field test the feasibility of the sampling and analytical methods; (2) test and refine protocols; and (3) refine the pollutant list to be conducted in the main study. Once the protocols and methods are finalized, the main study would be conducted. Conditions covered in the main study include: (1) different roadway conditions; (2) changing traffic densities; (3) changes in ventilation rates inside the buses; (4) parameters associated with loading, unloading, and waiting next to idling buses; and (5) different fuel uses, including diesel and natural gas (although the emphasis would be on diesel buses).

In February 2001, CARB’s Research Screening Committee (RSC) recommended that the study also include measurements in school buses retrofitted with particulate traps. Since retrofit programs are now underway, the Committee expressed the need to include such data as part of the study. CARB’s available budget is $450,000, and they have asked the AQMD for co-sponsorship of the additional testing needed for the retrofitted buses. Costs for the additional testing is $59,000. Staff believes these additional tests would be of substantial value to the study, as was recommended by the RSC.

CE-CERT is assisting the District in the analysis of tailpipe emissions data derived from a demonstration project using school buses from three local school districts retrofitted with particulate matter reduction technologies. The total contract value of that project is $50,000.

Proposal

For the additional testing, CE-CERT will conduct sampling for PM10, PM2.5, particle counts, CO, NO2, VOCs, formaldehyde, black carbon, and particle-bound PAH’s in school buses equipped with particulate traps. These measurements will be conducted according to the methods and protocols developed by CE-CERT after the conclusion of a pilot study. Up to 4 retrofitted buses will be tested, and a total of 4 tests will be conducted. The results will be used to add to the body of information collected as part of the testing funded by CARB. The project duration is 18 months.

Benefits to AQMD

The MATES-II Study found diesel particulates to be the major contributor to airborne toxic risk to residents of the Basin. The Board has recognized, through its Children’s Air Quality Agenda, the importance of pollutant exposures to children, and the need to reduce such exposures. This project will be the most in-depth study to directly measure children’s exposures to diesel particulates and other pollutants as a result of school bus commutes, and waiting at school bus stops and near idling buses. Because of the potential uses of retrofit particulate traps on school buses, information on children’s exposures while riding in such buses would be valuable in assessing the benefits of such traps as compared to diesel-fueled buses without traps; and also to compare such exposures to those experienced in natural gas buses.

Sole Source Justification

Section VIII.B.2 of the Procurement Policy and Procedure identifies four major provisions under which a sole source award 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, these circumstances are B.2.d.(1): Projects involving cost-sharing by multiple sponsors.

In this project, CARB will provide approximately $450,000 through an interagency agreement with CE-CERT. AQMD’s co-sponsorship of $59,000 for the testing in retrofit buses represents about 12% of the total project costs.

Resource Impacts

The total cost of the project is estimated to be $509,000, of which the AQMD cost shall not exceed $59,000. The CARB-funded portion is approximately $450,000.

Sufficient funds are available from the Clean Fuels Fund, 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.

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