Fertility of workers chronically exposed to chemically contaminated sewer wastes

Occupational hazards for the male reproductive system

The etiology of male infertilities is largely undetermined, and our knowledge of exogenous factors affecting the male reproductive system is still limited. In particular, the role of specific environmental and occupational factors is incompletely elucidated. Various occupational (physical and chemical) agents have been shown to affect male reproductive functions in animals, but large differences in reproductive function and/or xenobiotic handling between species limit extrapolation to humans. When available, human data are often conflicting and, except in a few instances, usually refer to broad and heterogenous occupational categories or to groups of agents (e.g., solvents). It is often difficult to elucidate the role of a single agent because occupational exposure conditions are often complex and various confounding factors related to lifestyle (smoking, alcohol, and diet) or socioeconomic state may also affect sperm quality, fertility, or pregnancy outcomes. The objective of this work is to summarize the main epidemiological and, where relevant, experimental findings pertaining to agents (physical and chemical) encountered in the occupational environment that might affect the male reproductive system (sperm count, motility and morphology, libido, and fertility) and/or related pregnancy outcomes (spontaneous abortion, stillbirth, low birth weight, and birth defects and childhood malignancy in offspring). Some methodological issues related to research on the reproductive effects of toxicants are also discussed briefly.

Postural stability assessment in sewer workers

In this study, postural stability was measured with a microcomputer-based force platform as an indirect assessment of central nervous system effect in 28 sewer workers (age range 23.4 to 64.5 years, standard deviation of 8.7 years). All workers performed four 30-second postural sway tests. The organic-solvent exposure was measured by a photo-ionization detector. The photo-ionization detector was calibrated to measure volatile organic solvents in total benzene equivalence, and concentrations were measured in various parts of the plant. The mean exposure was .32 parts per million (ppm) benzene equivalent (range of .02 to .95 ppm, standard deviation .19 ppm). Based on a covariate adjusted linear multiple-regression model, a statistically significant (p < .05) positive correlation was demonstrated between postural sway and organic-solvent exposure. These workers also had increased postural sway compared with a nonexposed population. The statistically significant correlation between postural sway determinations and organic-solvent exposure was surprising given the very low exposures measured. It is possible that the organic-solvent exposure might not be the causative agent, but rather that the solvents themselves correlate with some other causative exposure, ie, total volatile organics as implicated in the cause of sick-building syndrome.