According to the new study conducted by the National Institute for Public Health in Mexico City, Mexican women exposed to secondhand smoke have higher risk of getting breast cancer than those women who are not exposed to it.

Researchers from the National Institute for Public Health in Mexico City examined 504 women with confirmed breast cancer and 504 healthy women of similar age regarding their smoking behaviors and exposure to secondhand smoke at home and work.

Compared with women who never had exposure to tobacco smoke either directly or indirectly, women with secondhand smoking exposure had a three times higher risk for breast cancer.

Women who smoked were also more likely to develop breast cancer,but only if they started smoking between the onset of puberty and the birth of their first child.

"Active and passive smoke exposure is a modifiable risk factor for breast cancer. Reducing not only active smoking, but also passive smoking, will prevent new breast cancer cases in this population," said Lizbeth Lopez-Carrillo, professor of epidemiology at the National Institute for Public Health, Mexico City, Mexico.