There's new research out about breast cancer that shows 17 everyday chemicals that have been shown to cause breast cancer in lab rats.
Julia Brody at the Silent Spring Institute says these chemicals are likely to do the same in women.
"Chemicals that are in gasoline, air pollution, diesel exhaust, and some consumer products like non-stick and stain resistant surfaces and some flame retardants and pesticides."
The research paper in the journal Environmental Health Perspectives offers women advice on how to minimise their risk.
Among the biggest environmental sources of breast cancer include: benzene and butadiene which can come from vehicle exhaust, lawn equipment, tobacco smoke and food charred on the barbeque.