New evidence confirms that exposure to organochlorine compounds raises a woman's risk of developing breast cancer.
A Danish study, conducted over 17 years, found a significantly increased dose related risk of breast cancer when organochlorine (OC) compounds, particularly dieldrin, were present.
In the study, The Danish group examined blood samples from 7,712 women originally taken in 1976. The blood samples were analysed and then frozen. During the follow up, 268 of the women developed invasive breast cancer. Each woman with breast cancer was matched to two healthy controls. The blood of breast cancer patients and controls was again analysed in 1996; the higher the levels of OCs, the greater the likelihood that the woman developed cancer.
Organochlorine compounds have a weak oestrogenic effect, and it is this which is suspected of increasing the risk of breast cancer (Lancet, 1998; 352: 1816-20).