Global distribution and environmental drivers of methylmercury production in sediments

Shu-Shen Dai; Ziming Yang; Yindong Tong; Long Chen; Si-Yuan Liu; Rong Pan; Yanbin Li; Cui-Jing Zhang; Yu-Rong Liu; Qiaoyun Huang

doi:10.1016/j.jhazmat.2020.124700

Global distribution and environmental drivers of methylmercury production in sediments

J Hazard Mater. 2021 Apr 5:407:124700. doi: 10.1016/j.jhazmat.2020.124700. Epub 2020 Dec 8.

Authors

Shu-Shen Dai¹, Ziming Yang², Yindong Tong³, Long Chen⁴, Si-Yuan Liu⁵, Rong Pan⁵, Yanbin Li⁶, Cui-Jing Zhang⁷, Yu-Rong Liu⁸, Qiaoyun Huang⁹

Affiliations

¹ State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China; College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China.
² Department of Chemistry, Oakland University, Rochester, MI 48309, United States.
³ School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China.
⁴ Key Laboratory of Geographic Information Science (Ministry of Education), School of Geographic Sciences, East China Normal University, Shanghai 200241, China.
⁵ College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China.
⁶ Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao 266100, China.
⁷ Shenzhen Key Laboratory of Marine Microbiome Engineering, Institute for Advanced Study, Shenzhen University, Shenzhen 518060, China.
⁸ State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China; College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China; Hubei Key Laboratory of Soil Environment and Pollution Remediation, Wuhan 430070, China. Electronic address: yrliu@mail.hzau.edu.cn.
⁹ State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China; College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China; Hubei Key Laboratory of Soil Environment and Pollution Remediation, Wuhan 430070, China.

PMID: 33333388
DOI: 10.1016/j.jhazmat.2020.124700

Abstract

Neurotoxic methylmercury (MeHg) in environments poses substantial risks to human health. Saturated sediments are basic sources of MeHg in food chains; however, distribution patterns and environmental drivers of MeHg at a global scale remain largely unexplored. Here, we characterized global patterns of MeHg distribution and environmental drivers of MeHg production based on 495 sediment samples across five typical ecosystems from the literature (1995-2018) and our own field survey. Our results showed the MeHg concentration ranged from 0.009 to 55.7 μg kg^-1 across the different ecosystems, and the highest MeHg concentration and Hg methylation potential were from the sediments of paddy and marine environments, respectively. Further, using combined analysis of random forest and structural equation modeling, we identified temperature and precipitation as important regulators of MeHg production after accounting for the well-known drivers including Hg availability and sediment geochemistry. More importantly, we found increased MeHg production in sediments with elevated mean annual Hg precipitation, and warmer temperature could also accelerate MeHg production by facilitating activities of microbial methylators. Together, this work advances our understanding of global MeHg distribution in sediments and environmental drivers, which are fundamental to the prediction and management of MeHg production and its potential health risk globally.

Keywords: Climatic drivers; Large-scale; Methylmercury; Precipitation; Sediments.

Publication types

Research Support, Non-U.S. Gov't