Environment likely not to blame for Marin County breast cancer rates, scientists say SAN FRANCISCO ?EUR" Suspicions that something in the environment is causing Marin County's high rate of breast cancer have led to a big fund drive and public awareness campaign. But some scientists say the people, not the place, are the reason for the cancer levels. Some community activists have pronounced well-to-do Marin County "the breast cancer capital of the world" and are worried the air or the water is to blame. But some researchers who have studied the county doubt it. "It's not the geography; it's the demography," said Tina Clarke, an epidemiologist at the Northern California Cancer Center in Union City, which monitors cancer rates in Marin and eight other San Francisco Bay area counties. "It's the type of person living in Marin County." Many studies have suggested that breast cancer more often strikes highly educated, middle-class women, in part because they have children late in life or not at all, have greater access to hormone supplements, and are more likely to regularly drink alcohol. And Marin County, where incomes are twice the national average and the median single-family home costs $530,000, has an unusually high percentage of highly educated, middle-aged white women with these and other risk factors among its population of 250,000. Marin's cancer rate leaps out among other California counties, but researchers find similar rates in other relatively homogenous pockets of upper middle-class white women, said Clarke, whose research has been funded by the National Cancer Institute. The average number of new breast cancer cases reported in Marin County each year was 199 out of every 100,000 white females from 1995 to 1999, compared with 143 per 100,000 white females in the rest of urban California, a number that is on track with the rest of the nation, Clarke said. Breast cancer rates rose 37 percent in Marin County in the 1990s, while climbing only 3 percent in other urban California counties. The high rates have sparked a vigorous response from community groups seeking to raise awareness. One, the Marin Cancer Project, put out television shock ads showing women obliviously stepping over corpses in the supermarket aisles. The project mobilized 2,000 volunteers last month to go door-to-door throughout the county, gathering anecdotal information about cancer. The project has raised more than $140,000 so far. Meanwhile, Rep. Lynn Woolsey and Sen. Barbara Boxer, both of Marin County, last month helped secure $900,000 in federal grants to look at environmental risk factors for cancer. The money will be administered by the National Institute for Environmental Health Sciences. Members of the Marin Cancer Project want to investigate as possible sources such things as a San Rafael quarry, a plastic foam cup factory in Corte Madera, and the power lines that serve Marin County's many cul-de-sacs. "Science is science, but grass-roots groups have an opportunity to work faster and gather anecdotal data that's profound and powerful," said Judi Shils, the group's founder. Clarke agreed that more research is needed but said work focusing on socio-economic backgrounds and lifestyle choices would shed more light on Marin County's problems.