Population-based inorganic mercury biomonitoring and the identification of skin care products as a source of exposure in New York City.

Background: Mercury is a toxic metal that has been used for centuries as a constituent of medicines and other items.

Objective: We assessed exposure to inorganic mercury in the adult population of New York City (NYC).

Methods: We measured mercury concentrations in spot urine specimens from a representative sample of 1,840 adult New Yorkers in the 2004 NYC Health and Nutrition Examination Survey. Cases with urine concentrations ≥ 20 µg/L were followed up with a telephone or in-person interview that asked about potential sources of exposure, including ritualistic/cultural practices, skin care products, mercury spills, herbal medicine products, and fish.

Results: Geometric mean urine mercury concentration in NYC was higher for Caribbean-born blacks [1.39 µg/L; 95% confidence interval (CI), 1.14-1.70] and Dominicans (1.04 µg/L; 95% CI, 0.82-1.33) than for non-Hispanic whites (0.67 µg/L; 95% CI, 0.60-0.75) or other racial/ethnic groups. It was also higher among those who reported at least 20 fish meals in the past 30 days (1.02 µg/L; 95% CI, 0.83-1.25) than among those who reported no fish meals (0.50 µg/L; 95% CI, 0.41-0.61). We observed the highest 95th percentile of exposure (21.18 µg/L; 95% CI, 7.25-51.29) among Dominican women. Mercury-containing skin-lightening creams were a source of exposure among those most highly exposed, and we subsequently identified 12 imported products containing illegal levels of mercury in NYC stores.

Conclusion: Population-based biomonitoring identified a previously unrecognized source of exposure to inorganic mercury among NYC residents. In response, the NYC Health Department embargoed products and notified store owners and the public that skin-lightening creams and other skin care products that contain mercury are dangerous and illegal. Although exposure to inorganic mercury is not a widespread problem in NYC, users of these products may be at risk of health effects from exposure.