Does Mercury in Fish Come from the Air?

Abstract

Concerns with public health risks associated with mercury-contaminated fish have prompted a variety of proposals to cut or eliminate mercury emissions. As a step toward assessing how such reductions could affect fish contamination, we develop a cross-sectional epidemiological model of mercury levels in fish. Using data on stream characteristics, land use, the presence of point sources and both measured and modeled atmospheric deposition of mercury, we explain two-thirds of the variation in mercury levels in fish. We find that greater mercury deposition is not generally associated with higher mercury levels in fish. These results suggest that reductions in deposition (and emissions) may affect mercury levels in fish only slightly or with a significant delay.