Antagonistic Growth Effects of Mercury and Selenium in Caenorhabditis elegans Are Chemical-Species-Dependent and Do Not Depend on Internal Hg/Se Ratios.


The relationship between mercury (Hg) and selenium (Se) toxicity is complex, with coexposure reported to reduce, increase, and have no effect on toxicity. Different interactions may be related to chemical compound, but this has not been systematically examined. Our goal was to assess the interactive effects between the two elements on growth in the nematode Caenorhabditis elegans, focusing on inorganic and organic Hg (HgCl2 and MeHgCl) and Se (selenomethionine, sodium selenite, and sodium selenate) compounds. We utilized aqueous Hg/Se dosing molar ratios that were either above, below, or equal to 1 and measured the internal nematode total Hg and Se concentrations for the highest concentrations of each Se compound. Observed interactions were complicated, differed between Se and Hg compounds, and included greater-than-additive, additive, and less-than-additive growth impacts. Biologically significant interactions were only observed when the dosing Se solution concentration was 100-25,000 times greater than the dosing Hg concentration. Mitigation of growth impacts was not predictable on the basis of internal Hg/Se molar ratio; improved growth was observed at some internal Hg/Se molar ratios both above and below 1. These findings suggest that future assessments of the Hg and Se relationship should incorporate chemical compound into the evaluation.






Published Version (Please cite this version)


Publication Info

Wyatt, Lauren H, Sarah E Diringer, Laura A Rogers, Heileen Hsu-Kim, William K Pan and Joel N Meyer (2016). Antagonistic Growth Effects of Mercury and Selenium in Caenorhabditis elegans Are Chemical-Species-Dependent and Do Not Depend on Internal Hg/Se Ratios. Environ Sci Technol, 50(6). pp. 3256–3264. 10.1021/acs.est.5b06044 Retrieved from

This is constructed from limited available data and may be imprecise. To cite this article, please review & use the official citation provided by the journal.



Heileen Hsu-Kim

Professor in the Department of Civil and Environmental Engineering

Professor Heileen (Helen) Hsu-Kim is an environmental engineer who specializes in environmental aquatic chemistry and geochemistry. Her research tackles problems related to pollutant metals and the biogeochemical processes that alter their distribution in water, soil, and air. The applications of this work include environmental remediation technologies, the impacts of energy production on water resources, global environmental health, and the environmental implications and applications of nanotechnology.

Dr. Hsu-Kim's current research projects are focused on mercury biogeochemistry, the impacts of coal ash disposal on water quality, recovering valuable materials from geological wastes, and health impacts of trace metal/metalloid exposures. A central theme to her work is the utilization of chemical speciation for understanding and predicting the persistence, mobility and bioavailability of metals and minerals in the aquatic environment.

The methodologies her group employs for this research include laboratory techniques for quantifying trace element speciation, functional measures of reactivity and bioavailability of contaminant metals, and techniques to probe interactions at mineral, water and microbial interfaces.


William Kuang-Yao Pan

Elizabeth Brooks Reid and Whitelaw Reid Associate Professor

William Pan, DrPH, Elizabeth Brooks Reid and Whitelaw Reid Professor of Population Studies and Global Environmental Health, joined the faculty at Duke in 2011. He holds a joint appointment at DGHI and the Nicholas School of Environment, and is Adjunct Professor in the Department of International Health at Johns Hopkins Bloomberg School of Public Health. He is a biostatistician with expertise in spatial analysis, demography land use science, infectious disease epidemiology and environmental health.  He has over 20-years of experience leading large, multi-institutional and interdisciplinary research teams to study the impact of human-environment dynamics influencing human health in low- and middle-income countries (LMICs).  His work is primarily focused in Latin America, particularly the Amazon region.  His current research focuses on: (1) studying the health effects of mercury and other chemical exposures from artisanal and small-scale gold mining (ASGM); (2) developing tools for forecasting vector-borne disease risk, focusing particularly on the integration and modeling of climate, land use, population and malaria surveillance data; (3) studying the role of migration and social network connectivity influencing infectious disease transmission; (4) understanding the risk of lead exposure among hunters and their families, and to identify solutions to mitigate that risk; and (5) evaluating multi-faceted benefits of nature-based solutions related to agroforestry, climate resilience, livelihoods, and disease mitigation.


Joel Meyer

Sally Kleberg Distinguished Professorship

Dr. Meyer studies the effects of toxic agents and stressors on human and wildlife health. He is particularly interested in understanding the mechanisms by which environmental agents cause DNA damage, the molecular processes that organisms employ to protect prevent and repair DNA damage, and genetic differences that may lead to increased or decreased sensitivity to DNA damage. Mitochondrial DNA damage and repair, as well as mitochondrial function in general, are a particular focus. He studies these effects in the nematode Caenorhabditis elegans, in cell culture, and collaboratively in other laboratory model organisms as well as in human populations in the USA and globally.

Unless otherwise indicated, scholarly articles published by Duke faculty members are made available here with a CC-BY-NC (Creative Commons Attribution Non-Commercial) license, as enabled by the Duke Open Access Policy. If you wish to use the materials in ways not already permitted under CC-BY-NC, please consult the copyright owner. Other materials are made available here through the author’s grant of a non-exclusive license to make their work openly accessible.