Calcitropic hormones, bone turnover, and lead exposure among female smelter workers.

To study the association between levels of lead in blood and bone among female former smelter workers in Bunker Hill, Idaho, the authors performed a longitudinal study using homeostatic regulators of calcium and biomarkers of bone turnover. The authors measured participants' blood lead levels (by means of a graphite furnace atomic absorption spectrophotometer) and tibia-bone lead levels (by means of the 109Cd K x-ray fluorescence system) in 1994 and again in 2000; serum ionized calcium, parathyroid hormone, osteocalcin, urinary deoxypyridinoline, pyridinoline, and 1, 25-dihydroxyvitamin D were measured. After controlling for weight and age, significant predictors of changes in blood lead levels from 1994 to 2000 in postmenopausal women were duration of employment, higher ionized calcium levels, alcohol consumption, and higher parathyroid hormone levels. Predictors of change in tibia-bone lead levels in the same group of women were employment in a technical job such as mining and higher urinary pyridinoline levels (p < .05). Changes in blood and bone lead levels over time were associated with increased bone resorption, especially among postmenopausal women.