Atmospheric mercury deposition in the environment

A long-term research focus has been to characterize and quantify atmospheric emissions and deposition of mercury and its fate, transport and effects in the environment. Atmospheric deposition is the largest input of mercury to ecosystems globally. This includes work in the Adirondacks and other regions globally. We have initiated work 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. in review; Figure 1). We are also examining spatial patterns of mercury in soil for the coterminous U.S. (Figure 2). 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).

Figure 2. Spatial patterns of mercury in surface soil for the coterminous U.S.

There is currently considerable activity in mercury management. The United Nations Environmental Programme (UNEP) developed an international mercury treaty in 2013, the Minamata Convention, to control on mercury releases. The Minamata Convention entered into force in September 2017.

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 and the accumulation of mercury in rice in China (Wang et al. 2019 and Wang et al. in review).  With Jackie Gerson (Duke, PhD student), we are investigating the effects of artisanal gold mining in Peru and mountaintop mining in West Virginia on mercury contamination. With Flor Fahnestock (Univ. New Hampshire, PhD student), we are studying the effects or permafrost thawing in northern Sweden on the mobilization pathways of mercury (Fahnestock et al. 2019). With Yang Yang (PhD graduate SUNY ESF) we examined how different climatic disturbances (soil warming, drought, ice storms) alter the fluxes of mercury entering and leaving the northern hardwood forest (Yang et al. 2019). With a group of researchers, I am involved in a synthesis of mercury and its effects in New York State (Evers et al. 2019; Adams et al. in review). We gave briefings on this work for personnel from the NYS Department of Environmental Conservation and the Office of the Attorney General; U.S. Senate and House staff; and the U.S. Environmental Protection Agency. As part of this effort, I am also serving as a guest editor for the journal Ecotoxicology for a series of 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. 2019) 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.

References:

Adams, E., J. E. Gulka, Y. Yang, M. E. Burton, D. A. Burns, V. Buxton, L. Cleckner, C. Desorbo, C. T. Driscoll, D. C. Evers, N. Fisher, O. Lane, H. Mao, K. R. Murray, G. Millard, R. Razavi, W. Richter, A. Sauer and N. Schoch. In review. Distribution and trends of mercury in aquatic and terrestrial biota of New York, USA: a synthesis of 50 years of research and monitoring. Science of the Total Environment.

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.

Fahnestock, M., J.Bryce, C. McCalley, M. Montesdeoca, S. Bai , Y. Li, C. T.  Driscoll, P. Crill, V. Rich and R. Varner. 2019. Mercury reallocation in thawing subarctic peatlands. Geochemical Perspectives Letters.2:33-38. doi: 10.7185/geochemlet.1922.

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, C. T. Driscoll. In review. Mercury emissions, atmospheric concentrations, and wet deposition across the conterminous United States: Changes over 20 years of monitoring. Environmental Science & Technology Letters.

Wang, Z., T. Sun, C. T. Driscoll, H. Zhang and X. Zhang. 2019. Dimethylmercury in floodwaters of mercury contaminated rice paddies. Environmental Science and Technology.53:9453-9461. doi: 10.1021/acs.est.8b07180.

Wang, Z., J.. Zhou; X. Zhang, C. T. Driscoll and C-J. Lin. In review. Soil emissions, soil air dynamics and model simulation of gaseous mercury in subtropical forest. Global Biochemical Cycles.

Yang, Y., L. Meng, R. Yanai, M. Montesdeoca, P. Templer, L. Rustad, H. Asbjornsen and C. T. Driscoll. 2019. Climate change may alter mercury fluxes in northern hardwood forests. Biogeochemistry. 146(1):1-16.doi:10.1007/s10533-019-00605-1