A physicist whose environmental work has helped clear the air in treasured places such as the Grand Canyon and an economist whose expertise on the movement of migrant laborers across national borders has earned him invitations to assist more than 40 countries are the recipients this year of the Distinguished Public Service Award at the University of California, Davis. Tom Cahill, a professor of physics and head of the campus Air Quality Group, and Philip Martin, a professor of agricultural economics, were honored today by their faculty peers at UC Davis during a meeting of the campus Academic Senate. The Academic Senate established the public service award four years ago to recognize faculty members who have made significant service contributions to the community, state and country, as well as internationally. Cahill's research and dedication have kept him involved with air-quality problems worldwide, supplying valuable information and creating new ways to track pollution. Key to this effort has been his leadership in the design and development of a national air-pollution monitoring network at UC Davis. Network analysts use a particle accelerator at the campus's Crocker Nuclear Laboratory to test air quality at more than 50 U.S. national parks, monuments and wilderness areas. The system has proved very successful in identifying pollution problems. With air samples from the Grand Canyon, for instance, Cahill and colleagues were able to document the impact on air in the park of emissions from a nearby coal-fired plant. Cahill's expert testimony proved critical to an agreement in 1991 by the plant to substantially reduce its emissions. The UC Davis Air Quality Group has established such a reputation that Cahill's assistance has been sought in developing other air-pollution laboratories around the world. In fact, in 1992 the United Nations adopted many aspects of the Davis program for its Global Atmospheric Watch. Another environmental issue that is greatly benefiting from Cahill's work is the assessment of air-quality problems at Owens and Mono lakes in California and the establishment of a connection between the lowering of the lake levels and the creation of dust storms with toxic particles. Working with UC Davis colleagues, he helped develop a 10-year proposal that has since been approved to restore certain lake areas to natural habitat. Colleagues physics department chair Barry Klein and atmospheric science chair Robert Flocchini wrote in a nomination letter, "Tom Cahill has boundless energy and enthusiasm, which has somehow carried him beyond the constraints of time." Martin's scholarship and analyses of issues surrounding immigrant labor have earned him an international reputation. Since his arrival at UC Davis in 1975, Martin has testified more than 60 times before state, federal and international organizations -- including the United Nations -- dealing with migrant worker issues. He also has traveled widely to assist other countries, including Mexico, Turkey, Japan and Germany. "Immigration arouses strong emotions, and Professor Martin has performed an enormous public service by being a leading figure in explaining what is and is not known about the causes and consequences of immigration," wrote colleagues Tom Hazlett, associate professor of agricultural economics, and Alan Olmstead, professor of economics and director of the Institute of Governmental Affairs. "His ability and willingness to be a neutral font of information on this complex and controversial issue has gained him the respect and trust of key policy-makers and opinion leaders in California, the United States and around the world," they wrote. Martin's key contributions have been in the areas of farm labor and international labor migration in Europe and Asia. During an especially controversial time for California farm labor in the 1970s -- focusing on implementation of the Agricultural Labor Relations Act -- Martin provided impartial analysis of sensitive farm labor issues. He provided the same service several years later when the California Rural Legal Assistance program sued the University of California for conducting mechanization research that displaced migrant farm workers. Colleagues identify Martin's most important public-service contribution as the analyses he performed on issues debated during the eight years prior to the passage of the Immigration Control and Reform Act of 1986.