Research Screening Committee Meeting
December 9, 2002

This page updated June 28, 2005.

State of California


Research Screening Committee Meeting

Cal/EPA Headquarters Building
1001 I Street
Conference Room 550
Sacramento, CA 95814
(916) 445-0753

December 9, 2002
8:00 a.m.



"Characterization of PM Emissions from Motor Vehicles and their Implications for Climate Change," California Institute of Technology, $200,260, Proposal No. 2524-227
  Motor vehicles emit a significant amount of fine organic carbon and black carbon (BC) particles. Recent studies have attributed significant global warming to BC particles originally released from diesel and gasoline engines. Several studies suggest that black carbon particles in the atmosphere exert a warming effect similar to that of greenhouse gases and their heat-trapping ability depends on how they clump together and join with other substances to make larger particles. While the warming effect of black carbon is well established, predicting the amount of warming from black carbon is highly uncertain. This uncertainty arises from two basic sources. First, black carbon emission inventories are highly uncertain, and therefore the actual amount of black carbon in the air is in question. Second, the manner in which black carbon is mixed with other aerosol material, such as sulfate and organics is critical to the radiative impact of the black carbon.
  In this research project, the investigators propose to estimate fuel-specific (i.e., gasoline and diesel) motor vehicle emissions for climate forcing PM pollutants, and to apply a global climate model to estimate the relative climate forcing of CO2, black carbon, sulfate, nitrate, and organic particle emissions from different motor vehicle fleets on both short and long timescales. The Caltech group, led by Professor John Seinfeld, is uniquely positioned to perform this research. Quantitative understanding of the absorbing aerosol's role in the climate change is required to accurately evaluate the radiative forcing impacts of PM emissions. Black carbon in the atmosphere exerts a warming effect similar to that of greenhouse gases. Thus, control of black carbon emissions has been suggested as a strategy to mitigate global warming, while at the same time providing human health benefits through decreased exposure to PM.


"Source Apportionment of Fine and Ultrafine Particles in California: Tailpipe and Roadside Measurement of Ultrafine Particles," University of California, Davis, $114,907, Contract No. 01-306
  Mobile source fuel combustion is one of the most likely sources of ultrafine particulate air pollution in California. A preliminary inventory of ultrafine particulate matter for Southern California estimates that mobile sources account for more than half of the ultrafine particulate matter emissions in that region. Tests that measured the size distribution of particles released from light-duty vehicles have detected ultrafine particles emitted from this source. Ultrafine particles are suspected to cause adverse health effects when inhaled. A sample of ultrafine particles released from light-duty vehicles must be collected so that tracer compounds can be identified that will help to quantify the contribution that light-duty vehicles make to the overall atmospheric burden of ultrafine particles. A roadside study is also needed to examine how ultrafine particles are transformed after release to the atmosphere in the polluted roadway environment.
  In this study, the investigators propose to enhance a current ARB research contract for source apportionment of ultrafine particulate matter by carrying out source tests for light-duty vehicles. Airborne particle samples collected
with filter-based samplers and Micro Orifice Uniform Deposit Impactors (MOUDIs) would be analyzed for unique chemical tracers that can be used in a source apportionment analysis. In the second phase of the enhanced project, the investigators propose to carry out a roadside test to study the evolution of ultrafine particulate matter in the polluted roadside environment. These transformations must be studied so that the signature for ultrafine particulate matter released from mobile sources can be recognized at receptor sites far away from roadways. By making these measurements more quantitative, improved source apportionment studies can be conducted to identify the contribution that light-duty vehicles make to overall airborne particle concentrations. Because fine particles have been implicated in serious health effects, a better understanding of source contributions to fine particle concentrations will enable decision-makers to formulate effective control strategies to protect public health.


"Characterization of the Composition of Personal, Indoor, and Outdoor Particulate Exposures," Harvard University, $434,929, Contract No. 98-330
  Previous studies of human exposure to particulate matter (PM) have shown that the relationship between ambient concentrations and human exposures is very complex. The objective of this study was to characterize the chemical composition of personal, indoor, and outdoor fine particulate (PM2.5) exposures for 15 individuals with Chronic Obstructive Pulmonary Disease (COPD) living in metropolitan Los Angeles. This project was an addition to a $1 million PM exposure study funded by U.S. EPA. Newly-developed Harvard mini-samplers were used to measure daily average concurrent personal, indoor, and outdoor mass concentrations of PM2.5, as well as PM2.5 elemental carbon (EC), nitrate (NO3-), and elemental concentrations, for each subject over seven consecutive days during Summer 1999 and / or Winter 2000.
  Results indicate that personal PM2.5 exposures were higher than corresponding indoor and outdoor concentrations in both seasons. In contrast, outdoor NO3- and EC concentrations were higher than indoor and personal levels in both seasons, reflecting the fact that motor vehicles are their major source. For PM2.5 and EC, the contributions of particles of outdoor and indoor origin to personal and indoor levels varied by season, with a greater contribution of outdoor particles in the summer and a greater indoor source contribution in the winter. Indoor concentrations for all three particulate measures were more strongly associated with personal exposures as compared to outdoor concentrations, which may be attributed to the fact that the participants spent most of their time indoors at home. The results provide additional information to increase our understanding of exposures to PM and its components in sensitive subpopulations such as individuals with COPD, and facilitate interpretation of epidemiological studies on PM health effects.


"Air Pollutant Exposure Associated with Distributed Electricity Generation," University of California, Berkeley, $13,441, Contract No. 01-341
  In California, electricity production is a significant contributor to statewide emissions of toxic and criteria air pollutants. Most of the State's electricity is produced at large, regulated power plants. However, "distributed generation," or the generation of electricity near its place of use, may be an important future source of electricity. A shift from central electric generation could lead to a proliferation of small distributed generation units in proximity to residential areas. Under these conditions, people living near these emission sources may be exposed to higher pollutant levels, leading to increased adverse health burdens. UCB assessed the air pollutant exposure implications of a shift in electricity generation from central station power plants to distributed generation in California. The project involved analysis of existing emissions inventory data and the use of established modeling tools to predict annual average pollutant concentrations adjacent to power plants and distributed generation units. Calculated population-weighted pollutant exposures were found to be more than an order of magnitude higher for distributed generation technologies than for conventional power plants.


"Quantification Methods for Identifying Emission Reductions Resulting from Seasonal and Episodic Public Education Programs," ESTC, $313,811, Contract No. 98-318
  Many air districts throughout the country conduct public education programs during the summer ozone season to encourage the public to reduce their driving on days forecast to violate ozone air quality standards. California air districts raised concerns that there was no method recommended by ARB or U.S. EPA to evaluate these programs, often called "Spare the Air". Funded by ARB, U.S. EPA, the Federal Highway Administration and the Sacramento air district, the goal of this research study was to develop a reliable yet "affordable" method air districts can use to quantify the emission impacts of their Spare the Air programs. The study developed survey methods and collected comprehensive travel data of a random sample of the general population and of individuals who reduced trips in response to the Spare the Air message. The data allowed researchers to compare the travel behavior of the Spare the Air participants and non-participants on both Spare the Air and regular (non-Spare the Air) days. The study found a statistically significant difference between the self-reported vehicle trip reductions and measured vehicle trip changes due to Spare the Air program among the Spare the Air participants. With a simple and less costly survey methodology developed by the study, air districts will be able to adjust future self-reported vehicle trip reductions and extrapolate them to the entire regional population of drivers within an acceptable margin of error. In addition, the method developed in the study may pave the way for allowing emission reduction credits for Spare the Air programs in State Implementation Plans.


"Vehicle-to-Grid Demonstration Project: Grid Regulation Ancillary Service with a Battery Electric Vehicle, A. C. Propulsion, $164,677, Contract No. 01-313
  This project investigated the technical feasibility of using parked electric vehicles (EVs) as grid regulation sources. "Grid regulation" is the automated matching of instantaneous electrical demand with power generated by sources that can provide quick responses to the California Independent System Operator's (ISO) call for supplemental power (or call to reduce generation). The value of power provided by EV batteries while parked could help offset the costs of EV ownership. The contractor integrated the software and hardware needed to make parked electric vehicles available as grid regulation sources. A prototype vehicle was connected to the power grid for 222 hours, during which time it provided energy to, and withdrew recharging energy from, the grid according to a schedule based on historical data on ISO's calls for power from normal sources. A. C. Propulsion measured wireless transmission times, energy flows into and out of the battery, battery temperature, state-of-charge, and the battery capacity during the 222 hours of operation. All the results support the technical feasibility of using battery EVs as grid regulation sources.
  A. C. Propulsion estimated the value of the grid regulation. The results of various hypothetical cases ranged from $1,000 to $5,000 per year, gross income. Gross income would be reduced by the charges of a power "aggregator" who would contract with the ISO and with the vehicle owners, and possibly, by accelerated "wear" on the battery (which was not studied). These costs are not known. However, the larger values of gross income may correspond to net incomes that could substantially meet battery replacement costs. No technical deterrents to using EVs for grid regulation were uncovered in this project. However, before the technology could be implemented, many practical and economic issues would need to be addressed.


Termination of Contact: "Demonstration of the High Volume Collection System for Direct Measurement of Mass Emission Rates of Hydrocarbon Leaks," University of California, Berkeley, $109,000, Contract No. 99-326
  The ARB staff and the Principal Investigator for Contract No. 99-326 have agreed to terminate work on the High Volume Collection System. The project, conducted by the subcontractor, Lawrence Berkeley National Laboratory (LBNL), was intended to modify an instrument that quantifies methane leaks to allow quantification of organic gas leaks (such as those at refineries or oil fields). The project required cooperation and assistance by the Gas Technology Institute (GTI), which owns the technology. After lengthy delays caused by GTI's inattention to the project, GTI informed LBNL that it is no longer interested in the project or the device and will no longer support them. Further work is infeasible; therefore the Research Division staff has terminated the contract. The total billable expenses were $72,000 from a budget of $109,000.

Research Screening Committee