Chronic diseases and early exposure to airborne mixtures: Part III. Potential origin of pre-menopausal breast cancers.

This is the third in a series dealing with chronic diseases and early exposure to airborne mixtures from industrial releases. The purpose of this study is to increase the understanding of previously unconsidered factors in the physical environment potentially acting as risk factors for female breast cancer. Data are from the Environmental Quality Database containing lifetime residential records for about 20,000 cases, with 1 of 15 cancers and about 5000 controls. Subjects resided within 25 km of all kraft mills, sulfite mills, coke ovens, oil refineries, copper, nickel and lead/zinc smelters operating in Canada in 1967-1970, and were aged or = [DMS] and increases as [DMS] increases. The probability of an adverse effect from early, intermittent and simultaneous exposure to Dioxin and DMS, manifesting as a breast cancer after a latency period of as little as 26 years, is a function of age of first exposure, distance from the source and source type. The most susceptible age cohorts are the youngest.