Work-related lead exposure unrelated to thyroid function in men

Memory loss, weakness, irritability, and fatigue are just some of the obvious health effects of exposure to lead, but what about hidden risks? Of concern are the possible consequences of lead exposure on the thyroid gland and the hormones it produces, which are critical to cell function. Although studies have looked at this issue, a quantitative review, or meta-analysis, of the results of these studies was unavailable until now.

To address this research gap, an investigator at the National Institute for Occupational Safety and Health (NIOSH) reviewed 16 studies of lead-exposed workers. Each study measured the blood concentrations of the two major thyroid hormones, thyroxine and triiodothyronine, as well as a thyroid-stimulating hormone, which is produced by the pituitary gland and acts on the thyroid gland. The analysis, published in the American Journal of Industrial Medicine, showed that the average level of thyroid hormones in the blood was similar between workers exposed to lead on the job and those who were not exposed. In addition, the analysis did not find a link between duration of work-related exposure to lead and blood concentration of thyroid hormones. Since the studies in the analysis included few women, the effects of work-related lead exposure on thyroid hormone levels in this group remain unclear, and future research should include adequate numbers of women.

Fortunately, work-related exposure to lead is less common today than in past years, since many consumer products no longer contain the toxic metal. Certain industries, however, such as construction, mining, and manufacturing, still use lead-containing materials, posing a risk of exposure to workers. To prevent exposure, NIOSH recommends wearing proper personal protective equipment, such as goggles, gloves, boots, and protective clothing. Other recommendations on the NIOSH website include showering and changing clothes and shoes after working around lead and lead dust.