Atmospheric mercury deposition in the environment

A long-term research focus of my lab has been to characterize and quantify atmospheric mercury deposition and its fate, transport and effects in the environment. This includes work in the Adirondacks and other regions globally. We have initiated research with colleagues at Harvard (Elsie Sunderland) on land-atmosphere exchange of mercury in which we are conducting large scale data analysis of mercury and using these data to parameterize and test a terrestrial sub model of a global mercury model. There are several phases to this work. First, we are examining long-term changes in concentrations of air mercury species and atmospheric mercury deposition in the U.S. (Olson et al. 2020; Figure 2). We are also investigating spatial patterns of mercury in soil for the coterminous U.S. (Figure 1).  We will use data from intensive and regional study sites to parameterize and test the terrestrial model.

Figure 1. Long-term trends in volume-weighted concentrations of mercury in wet deposition. On map, circles indicate study sites. Blue circles represent decreasing trends, red circles increasing trends. Large circles are significant trends (p<0.05) and small circles are insignificant trends. The graph to the right shows the record length for sites with significant trends (blue- decreasing, red- increasing) (after Olson et al. 2020)
Figure 2. Mercury concentration in the upper 5 cm of soil of the coterminous United States. Mercury data were obtained from Smith et al. (2013) and interpolated based on latitude, longitude, temperature, elevation, and soil organic carbon.

We have other more focused projects on mercury in the environment. With Zhangwei Wang (Chinese Academy of Sciences) we are evaluating land-atmosphere exchange of mercury (Zhou et al 2020; Zhou et al. in review).  With Jackie Gerson (Duke, PhD student), we are investigating the effects of artisanal gold mining in Peru (Gerson et al. in review) and mountaintop mining in West Virginia on mercury contamination (Gerson et al. 2020). With a group of researchers, I participated in a synthesis of mercury and its effects in New York State (Evers et al. 2020). As part of this effort, I also served as a guest editor for the journal Ecotoxicology for a series of 23 papers on mercury in New York State.

The Trump Administration has decided to roll back the Mercury and Air Toxics Standard (MATS), which was implemented in 2015 to control mercury emissions from coal fired power plants.  I have been working with colleagues from Harvard University to provide technical input on this rollback. We submitted two comments to the EPA on the lack of scientific and technical basis for the rollback of MATS (Sunderland et al. 2018) and on the need to update the reference dose for methylmercury exposure (Grandjean et al, 2019). I also gave several interviews and briefings on MATS, including an oral comment to the EPA Science Advisory Board.


Evers, D. C., E. Adams, M. Burton, J. Gulka, A. Sauer and C. T. Driscoll. 2019. New York State mercury connections: the extent and effects of mercury pollution in the State. Biodiversity Research Institute. Portland, Maine. BRI Science Communications Series 2019-12. 41 pages.

Gerson, J. R., L. C. Nasland, H. Hsu-Kim, C. T. Driscoll, M. R. V. Ross, M. N. Waters and E. S. Bernhardt. 2020. Mercury and selenium loading in mountaintop mining impacted alkaline streams and riparian food webs. Biogeochemistry, 150(1):109-122. doi: 10.1007/s10533-020-00690-7.

Gerson, J. R., W. Pann,  N. Szpona, B. Bergquist, E.  Broadbent, C. T. Driscoll, L. Fernandez, H. Hsu-Kim, W. Pan, M. Silman, E. Ury, C. Vega, A. Almeyda Zambrano and E. S. Bernhardt. In review. Exceptionally high atmospheric mercury pollution captured by Amazon forests. Nature.

Grandjean, P., E. M. Sunderland, D. C. Bellinger, J. D. Blum, E. Budtz-Jørgensen, L. H. M. Chan, C. Y. Chen, C. T. Driscoll, D. C. Evers, K. F. Lambert, I. Hertz-Picciotto, M. Karagas, S. A. Lederman, G. Muckle, F. Perera, E. K. Silbergeld and the Emmett Environmental Law & Policy Clinic. May 6, 2019. Comments on Mercury IAP, Docket ID No. EPA-HQ-ORD-2018-0655.

Olson, C. I., H. Fakhraei and C. T. Driscoll. 2020. Mercury emissions, atmospheric concentrations, and wet deposition across the conterminous United States: Changes over 20 years of monitoring. Environmental Science & Technology Letters, 7(6):376-381 doi:10.1021/acs.estlett.0c00185.

Driscoll, C. T., E. Sunderland, K. F. Lambert, J. Blum, C. Chen, D. Evers, P. Grandjean, R. Mason, E. Oken and N. Selin. 2018. Comment to U.S. Environmental Protection Agency on National Emission Standards for Hazardous Air Pollutants: Coal-oil-fired electric utility steam generating units—Reconsideration of Supplemental Finding and Residual Risk and Technology Review, 84 FED. REG. 2670

Smith, D. B., W. F. Cannon, L. G. Woodruff, F. Solano, J. E. Kilburn and D. L. Fey. 2013, Geochemical and mineralogical data for soils of the conterminous United States: U.S. Geological Survey Data Series, 801.

Zhou, J., Z. Wang, X. Zhang, C. T. Driscoll and C-J. Lin. 2020. Soil-atmosphere exchange flux of total gaseous mercury (TGM) in subtropical and temperate forest catchments. Atmospheric Chemistry and Physics Discussions, 20:16117–16133. doi:10.5194/acp-2020-816.

Zhou, J., Z. Wang, X. Zhang and C. T.  Driscoll. In review. Measurement of the vertical distribution of gaseous elemental mercury concentrations in soil pore air at subtropical and temperate forests. Environmental Science & Technology.