Occupational Exposure to Endocrine Disruptors and Reproductive Health
Over the years, toxicological evidence on a variety of naturally occurring or anthropogenic substances has raised concern about their potential to interfere with the endocrine systems. This chapter illustrates a few cases of these potential endocrine active substances, focusing on occupational exposure and reproductive health effects. Four examples were selected for the exercise: bisphenol A (BPA), lead (Pb), hexachlorobenzene (HCB) and pesticides. For each, epidemiological information has been collected, evaluated and integrated with relevant experimental toxicological data; in addition, compound-related reproductive effects in humans and animals have been compared. In general, the number of epidemiological studies in workers in relation to endocrine-mediated effects on reproduction is limited and, in certain cases, of uncertain reliability. For BPA, there is still limited evidence of effects on reproduction in humans, with many uncertainties. Animal data indicated reproductive effects, but generally at experimental doses significantly higher than estimated exposure levels in workers. For lead there is evidence of endocrine-related reproductive effects at blood lead concentrations close to, or even lower than, those allowed in workers. For HCB, accidental non-occupational high exposures caused clear reproductive effects that were not seen in workers. For pesticides, no consistent evidence exists of adverse human reproductive effects following occupational exposure: available studies have significant limitations, such as exposure assessment. Certainly, careful epidemiological studies in workers will provide more precise information than studies on the general population.