Impact of Occupational Exposure on Lead Levels in Women

Abstract

In 1994, 207 women participated in a study designed to examine the effects of occupational exposure and various lifestyle factors on bone and blood lead levels. In vivo measurements of Pb concentrations in tibia were performed by X-ray fluorescence. All 108 former smelter employees and 99 referents provided blood samples and answered a questionnaire on lifestyle characteristics and the relevant medical history. Lead concentrations in tibia and blood were significantly higher in the exposed group. The difference in mean bone Pb concentrations of the two groups is markedly greater than the difference in the mean blood Pb concentrations, supporting the view that bone Pb measurements are a more reliable determinant of Pb body burden. Chronic exposure did not result in any statistically significant differences in adverse pregnancy outcomes. A significantly lower age at the onset of menopause in occupationally exposed women may suggest that Pb causes adverse changes in the pattern of estrus and menses. The exposed women had lower bone Pb concentrations than those found in most studies on predominantly male workers. Blood Pb concentrations remain increased in women long after the cessation of occupational exposure, reflecting the importance of the endogenous exposure. The endogenous exposure relation found for postmenopausal exposed women is consistent with data on male smelter workers, whereas the relation found for premenopausal women is significantly lower. This suggests that sex plays an important role in the metabolism of lead, and current models of exposure extrapolated from male data may be inappropriate for use on women.

Lead Exposure in Female Workers Who are Pregnant or of Childbearing Age

“…The bone lead level is higher in men than in women 25,44) . For example, the lead concentration in tibial bone was reported to be 9.7 µ g/g higher in men than in women 45) .…”

“…Like many toxic substances, the health risk assessment of lead has largely been based on data from exposed men 23) , and women have mainly been investigated in mixed-gender studies. However, studies of men exposed to lead have many limitations when trying to understand the effects in women because of differences in organs, hormones, and other aspects such as lead metabolism and biokinetics [24][25][26] , dose-response relationships, thyroid function, and accumulation of lead in the liver [27][28][29] .…”

“…For example, the lead concentration in tibial bone was reported to be 9.7 µ g/g higher in men than in women 45) . In addition, lead stored in bone is released more slowly into the bloodstream in women than in men 25) , so blood lead levels remain high much longer after the cessation of occupational/environmental exposure, reflecting the endogenous source of lead in women 37) . The accumulated lead in women's bones is released more quickly during periods of increased bone turnover, particularly in pregnancy and menopause.…”

Biological Monitoring Among Workers Exposed to Inorganic Lead and Its Compounds

“…Kemal et al [28] in the analysis to assess the impact of sex on urinary delta-ALA levels among workers in lead acid battery repair units of transport service enterprises in Ethiopia, failed to show any significant sex-related differences, although levels in males tended to increase than females. Interestingly, Popovic et al recently reported very different long-term lead kinetics between men and women, with pre-menopausal women appearing to retain lead more avidly or release lead more slowly compared to postmenopausal women and men [30].…”

Herbal Supplement Use and Blood Lead Levels of United States Adults

“…We defined high lead content to be >1.5 mcg/serving, based on the 1999 California criteria for acceptable lead levels of <1.5 mcg/serving of natural calcium supplement. 27 We stratified the analysis by sex, given different potential health concerns related to low-level lead exposure and because men and women typically use different types of herbs, 28 have different lead exposures, 29 and may metabolize lead differently.…”