Researchers from University of California, Berkeley, Brown University, Silent Spring Institute and Communities for a Better Environment took air samples in the summer of 2006 from inside and outside homes in Bolinas, where there is no nearby source of industrial pollution, and homes in two Richmond communities that border the refinery.
Scientists conducting the study, "Linking Breast Cancer Advocacy and Environmental Justice," analyzed air samples from 40 homes in Richmond's Atchison and Liberty villages and 10 in Bolinas. The samples were tested for the presence of 155 chemicals known to cause cancer in laboratory animals, respiratory diseases and endocrine system disorders, said Rachel Morello-Frosch, an associate professor at UC Berkeley's Department of Environmental Science and Policy Management and the School of Public Health.
Nearly half the homes tested in Richmond had inside levels of particulate matter known to come from oil refining that exceeded California's air quality standards, Morello-Frosch said.
Jessica Tovar, a community organizer with Communities for a Better Environment, an Oakland-based environmental justice organization, said particulate matter in Richmond also comes from diesel traffic at the nearby rail yard and on highways that run through the communities.
While the study found that the levels of particulate matter inside people's homes were directly correlated to outdoor levels, only a small percentage of outdoor levels of particulate matter exceeded the state's standard.
Levels of other chemicals known to come from oil refineries, including sulfates and vanadium, a heavy metal known to cause cancer and respiratory problems in laboratory rats, were also significantly higher in Richmond than they were in Bolinas both indoors and outdoors, according to the data.
One of the problems is that the standards only apply to outdoor air, according to Tovar. Indoor air quality is not regulated.
The findings also call into question the effectiveness of Contra Costa County's emergency response plan, which warns residents to go inside, close their doors and windows and shelter-in-place when there is an upset at the refinery that could potentially impact residents, Tovar said.
Levels of indoor pollutants that came from consumer products were similar in Richmond and Bolinas homes, but some of the results surprised Bolinas residents, who had thought their exposure levels would be lower than they were found to be, Tovar said.
The tests turned up chemicals found in household cleaners, including ammonia, and even trace levels of DDT, an insecticide that was banned in 1972 and classified a "probable human carcinogen."
The ban followed the 1962 publication of Rachel Carson's book "Silent Spring," which drew a link between the widespread use of pesticides and their impact on wildlife, according to the U.S. Environmental Protection Agency.
The Silent Spring Institute, one of the participants in the study, is named for Carson's book. The institute, based in Newton, Mass., is a partnership of scientists, physicians and public health advocates dedicated to finding the links between environmental pollutants and women's health, especially breast cancer.
Many of the chemicals tested for in the study are thought to cause breast cancer in humans, theories supported by toxicological studies on animals, but the link has yet to be scientifically proven, Morello-Frosch said.