"DAVIS, Calif. -- What causes autism? The question has spurred about a billion dollars' worth of genetics research that has found no clear answer. But University of California, Davis, epidemiologist Irva Hertz-Picciotto has been pursuing another angle: Does the environment around a pregnant woman play a role in determining whether her child develops autism?"
"Over the last 10 years, her work with more than 1,000 autistic children has changed how science looks at autism, refocusing the debate on the crossroads of environment and genetics.
Hertz-Picciotto's group has published hundreds of papers, including one that suggests, among other things, that a mother's proximity to congested roads and, thus, dirty air increases her risk of giving birth to an autistic child. Her group more recently suggested that obese women may be 67 percent more likely to have autistic children."