Research Notes

Abstracts of 1998 Research Notes

This project was conducted in forested watersheds located along an air pollution gradient in the San Bernardino Mountains (SBM) of southern California. Sites at the western end of the SBM experience high pollutant exposures, while sites to the east experience moderate-to-low exposures. The objectives of the project were: (1) to measure nitrogen deposition from fog and throughfall (rain that deposits on tree foliage before dripping to the ground), (2) to measure nitrate levels in streams draining from the watersheds, and (3) to quantify nitric oxide fluxes from forest soils. Fog was found to be an important source of nitrogen at the western end of the SBM. Throughfall analyses confirmed the importance of dry deposition as a major source of atmospheric nitrogen in the SBM. At the western end, stream water nitrate levels in winter peaked at 350 µeq/L, compared to less than 200 µeq/L at the eastern end. Annual fluxes of nitric oxide from soils were 18 times higher at the western end of the SBM than at the eastern end. These data provide evidence of forest nitrogen saturation caused by the deposition of anthropogenic pollutants over a multi-decade period in the SBM. This study was conducted by U.S. Forest Service scientists.

Pollution-generating activities in one area can impact air quality in a neighboring area. For this reason, neighboring areas need to be able to share air quality and meteorological data on as close to a real-time basis as possible. The information can be used for forecasting air quality; scheduling burns of farmland, rangeland, and forest floors; and promptly identifying potential pollutant transport events. (Thus permitting pertinent transient information to be saved for more detailed analysis later.) In this project, investigators developed a pilot version of an air quality and meteorological information system that permits access to recent information (updated hourly) about conditions in specific areas. The information available on this system can be particularly useful to small air pollution control districts that have limited staffing and monitoring resources. This project was performed by California State University, Chico.

Emissions from cars used by a single occupant for commuting to work are the single largest contributor to poor air quality in many urban areas of the state. Removing some of the incentives to drive alone could help improve air quality. A 1992 California law created a program known as "parking cash-out" that eliminates subsidization of parking for solo drivers. In the present study, parking cash-out programs used by eight firms were evaluated to determine their effectiveness in encouraging the employees to switch from solo driving to using carpools, public transit, or other air-quality-friendly transportation modes. This study was performed by the University of California, Los Angeles.

In this study, information was obtained to guide and prioritize the development and improvement of test methods for determining emissions of volatile organic compounds from coating applications and related operations. Operations covered included those involving paints, inks, coatings, adhesives, and polyester resin materials, and the solvent cleaning associated with these operations. This project identified those physical characteristics to be tested and test methods that are specified by air pollution and air quality management districts in State and Federal regulations and in guidance documents. Any problems found with test methods were identified and ranked in order of importance or urgency. This study was performed by the University of California, Davis

California air quality has improved over the past decades, yet our various ambient air quality standards are frequently violated. Additional mobile source emission reductions are needed before ambient air quality standards can be consistently attained. Several of California's regional air quality plans have included transportation pricing strategies (fees, charges, taxes) as an option to be explored to reduce vehicle usage. This study was undertaken to determine the feasibility of using these strategies. The investigators surveyed the literature, analyzed data, and modeled alternatives to determine the effectiveness of pricing in reducing traffic congestion, air pollution, and fuel use. This study was performed by Deakin, Harvey, Skabardonis, Inc.