Global and Local Impacts of Delayed Mercury Mitigation Efforts

Abstract

Mercury (Hg) is emitted to air by natural and anthropogenic sources, transports and deposits globally, and bioaccumulates to toxic levels in food webs. It is addressed under the global 2017 Minamata Convention, for which periodic effectiveness evaluation is required. Previous analyses have estimated the impact of different regulatory strategies for future mercury deposition. However, analyses using atmospheric models traditionally hold legacy emissions (recycling of previously deposited Hg) constant, and do not account for their possible future growth. Here, using an integrated modeling approach, we investigate how delays in implementing emissions reductions and the associated growing legacy reservoir affect deposition fluxes to ecosystems in different global regions. Assuming nearly constant yearly emissions relative to 2010, each 5-year delay in peak emissions defers by additional extra ca. 4 years the return to year 2010 global deposition. On a global average, each 5-year delay leads to a 14% decrease in policy impacts on local-scale Hg deposition. We also investigate the response of fish contamination in remote lakes to delayed action. We quantify the consequences of delay for limiting the Hg burden of future generations and show that traditional analyses of policy impacts provide best-case estimates.

Global health effects of future atmospheric mercury emissions

“…The inclusion of land and ocean in our model enables us to directly model the contribution of legacy sources (re-emissions from soil and ocean) without using a scale function 46 or box models 19 . The inclusion of the ocean model coupled with the plankton ecosystem in our integrated model is of great interest because seafood consumption is the major exposure pathway in most countries (Fig.…”

“…For instance, using atmospheric transport models, atmospheric deposition is considered as an indicator for the level of MeHg in seafood 5,11,13 . Zhang et al 13 included the impact of changing climate, land-use, and land-cover on atmospheric transport and deposition, and Amos et al 18 and Angot et al 19 considered the response of land/ ocean re-emissions to anthropogenic emission change with a box model.…”

Global Health Effects of Future Atmospheric Mercury Emissions

“…Selin, 2018) or box models (e.g. Angot et al, 2018). The inclusion of the ocean model coupled with the plankton ecosystem in our integrated model is of great interest because seafood consumption is the major exposure pathway in most countries (Figure S5).…”

“…For instance, using atmospheric transport models, atmospheric deposition is considered as an indicator for the level of MeHg in seafood (Chen et al, 2019;Giang & Selin, 2016;. included the impact of changing climate, land-use, and land-cover on atmospheric transport and deposition, and Amos et al (2013) and Angot et al (2018) considered the response of land/ocean re-emissions to anthropogenic emission change with a box model.…”

Estimating leaf mercury content in Phragmites australis based on leaf hyperspectral reflectance

“…Mercury (Hg) is a persistent pollutant that is highly toxic and volatile, and readily accumulates in organisms (Angot et al 2018). It is easily absorbed by plants and undergoes biomagnification that usually occurs in aquatic systems along the food chain, eventually posing a risk to humans (Zhang et al 2018).…”