"LONDON -- Exposure to certain chemicals and pollutants before a woman reaches her mid-30s could treble her risk of developing breast cancer after the menopause, Canadian scientists said on Thursday.

In a study in Occupational and Environmental Medicine, a British Medical Journal title, the researchers found that women exposed to synthetic fibers and petrol products during the course of their work appeared to be most at risk.

"Occupational exposure to acrylic and nylon fibers, and to polycyclic aromatic hydrocarbons may increase the risk of developing postmenopausal breast cancer," they wrote.

But some experts commenting on the study expressed caution, saying such links can crop up by chance."

Kate Kelland reports for Reuters April 1, 2010. [2]