California Air Resources Board

The State Air Resources Board today approved more than $2.5 million in research projects, highlighted by funds for Southern California's first system to measure dry acidic fallout, considered to be the region's biggest source of acidic air pollution, and to study the feasibility of a Smog Check-like program for big trucks and buses. 

Other projects are designed to study differences in the chemical makeup of acidity between Southern California and the Eastern U.S. and how clouds affect the creation of acids in the air. Also, others are intended to develop better methods of measuring acidity in air pollution. 

"These studies address two of the biggest air quality problems facing California," said Gordon Duffy, ARB chairman. "Acid rain is a new environmental problem here," he said, "and just like many of our smog-related problems, our acid rain is quite different from that found in the rest of the country. 

"These studies, and the rest of our $18 million, 5-year plan, should help us design pollution controls to bring this problem under control while we can still prevent the irreversible damage acid rain has caused elsewhere in the world," Duffy said. 

"Also, all of the projects we've approved today concentrate on acid rain studies in Southern California and will help the local anti-smog agency, the South Coast Air Quality Management District, set acid rain controls required by the Legislature." 

The dry acid monitoring system will be set up by the California Institute of Technology (Cal Tech) at Pasadena in nine sites throughout Southern California to record concentrations of dry acid particles in the air and to analyze their chemical makeup. Acids are formed in the air from some of the same 
polluting gases that cause the more typical smog problems, through the same type of chemical reactions triggered by sunlight. Because of Southern California's low annual rainfall and many sources of sulfur oxide and nitrogen oxide emissions, scientists believe that dry acid levels may be 5 to 15 times higher than those measured during rain. However, because this phenomenon occurs in so few other regions of the world, information about the chemical nature or extent of dry acid particles is scarce. 

In the $293,107 Cal Tech project, monitoring stations will be placed in Long Beach, Anaheim, Upland, San Nicolas Island, Burbank, Riverside, Lennox and Los Angeles. In addition to the ARB funds, the EPA will add $138,342 for the project. 

Cal Tech also will participate ir1 a $612,000 joint study with the University of Washington to investigate 
differences between Southern California acidity and that found in the Eastern U.S. Scientists have noted that acid concentrations in southern California are as high as those found elsewhere in the country. In other areas, however, the ratio of sulfur and nitrogen-based acids is about the same as the ratio of emissions, while in Southern California it is different. 

Researchers suspect that the same atmospheric conditions that cause rapid formation of typical smog problems causes more rapid creation of some acids over others, and more understanding of that phenomenon is needed to develop controls for the right proportion of specific pollutants. In addition to ARB funding, the National Science Foundation has provided $159,000 and the University of Washington has contributed $11,622. 

As part of the Cal Tech study the University of Washington will determine if chemical reactions among polluting gases in clouds affect acidity levels. In the study, the ratio of nitrogen and sulfur-based gases within clouds will be compared to levels entering the clouds to determine whether or not they influence the formation of acids. 

In other studies, the Radian Corporation of Sacramento, was awarded $99,798 to study the possibility of 
developing a Smog Check-like emissions inspection program for heavy-duty trucks and buses. These vehicles are a major source of smog-forming nitrogen oxide and health-threatening nitrogen dioxide levels and produce 95 percent of the diesel soot found in urban air. The study will determine the most 
feasible methods of inspecting the emission control systems on trucks and buses. It also will provide the Air Resources Board with information needed regarding the benefits and limitations of these inspections, needed to determine if an inspection program for trucks and buses could be operated.