Figure 1.

Associations between 1976 (A) and 1996 (B) serum 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) concentrations and 1996 serum total thyroxine (T₄) concentrations by menarcheal status at the time of the explosion (n = 251), Seveso Women's Health Study, Italy, 1976–2009. Results were based on multiple linear regression models including exposure at both time points. Coefficients represent the mean change in total T₄ concentration for each 10-fold increase in TCDD. Models adjusted for age at thyroid hormone measurement and age at thyroid hormone measurement squared.