Seveso Women's Health Study: A Study of TCDD and Reproductive and Chronic Health in a Female Cohort

On July 10, 1976, an explosion at a trichlorophenol manufacturing plant near Seveso, Italy, resulted in the highest TCDD levels known in human residential populations. Up to 30 kg of TCDD was deposited over the surrounding 18-km2 area, which was divided into exposure zones (A, B, R, non-ABR) based on TCDD measurements in soil. As part of an ongoing health assessment, residents' blood was drawn soon after the explosion for clinical chemistry tests; the remaining serum was stored for future use. In 1996, 20 years after the accident, we initiated the Seveso Women's Health Study (SWHS), a historical cohort study of the reproductive and chronic health effects of TCDD exposure. We investigated the relationship between individual-level serum TCDD and a variety of reproductive health outcomes, including endometriosis, breast cancer, menstrual cycle characteristics, birth outcomes, age at menarche, age at menopause, ovarian function, uterine fibroids, benign breast disease, initiation and duration of lactation, and fertility. In 2008, 32 years after the explosion, we initiated a second follow-up study of the SWHS cohort in order to study longer-term sequelae of TCDD exposure. At this follow-up, we examined the relationship between TCDD exposure and chronic health outcomes, including cancer, diabetes, metabolic syndrome, obesity, heart disease, bone mineral density, and thyroid function of the women and their children. SWHS is the only comprehensive study to date of the health of women exposed to TCDD. This study has the benefit of being a large cohort study with a wide range of TCDD exposure, documented by individual-level TCDD measured in sera collected soon after the explosion. Details of the above outcomes as well as ongoing analyses will be presented. We have found associations of serum dioxin levels and cancer as well as a number of reproductive endpoints.