Determinants of blood lead levels across the menopausal transition

In this study, the authors sought to evaluate the impact of menopause on le ad remobilization from bone-lead stores. The study was conducted between 19 93 and 1995 in Mexico City and included 903 women (mean age = 46.8 y [stand ard deviation = 8.2 y]). Participants provided information about reproducti ve variables and known risk factors for high PbB levels. PbB levels were de termined with graphite furnace atomic absorption spectrophotometry. The aut hors used linear-regression models to describe the relationship between PbB levels and variables of interest. PbB levels ranged from 1.0 mug/dl to 43. 8 mug/dl (mean = 11.0 mug/dl). Menopausal women at baseline had the highest PbB levels; the mean difference between pre- and postmenopausal women was 0.76 mug/dl (95% confidence interval = 0.024, 1.48). We observed an inverte d U-shaped relationship between PbB level and age. The highest PbB levels w ere observed in women aged 47-50 y. Other important predictors of PbB level s were use of lead-glazed ceramics, number of pregnancies, history of cigar ette smoking, and height. Our results support the hypothesis that bone lead may be mobilized during menopause and may constitute an important source o f exposure.