Professor Elsie M. Sunderland | |
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Education | Ph.D. Simon Fraser University, B.Sc. McGill University |
Scientific career | |
Fields | biogeochemistry of toxicants |
Institutions | Harvard University |
Thesis | Development of a marine mercury cycling model for Passamaquoddy Bay, New Brunswick (2003) |
Website | https://bgc.seas.harvard.edu |
Elsie M. Sunderland is a Canadian toxicologist and environmental scientist and the Gordon McKay Professor of Environmental Chemistry [1] at Harvard University. She studies processes through which human activities increase and modify pollutants in natural ecosystems and living systems. [2] [3] [4]
Sunderland's research attempts to trace how the introduction of synthetic chemical compounds into the natural environment affects the global environment and food supplies of animals and people. Sunderland refers to the accelerating use of anthropogenic chemicals as civilization’s "global chemical experiment” that is affecting all continents and life on Earth. Her research seeks to track and quantify where these compounds go in the environment, and how they make their way into the tissues of wildlife and humans. [5]
Sunderland and her research group at Harvard seek to model and quantify how human actions affect natural habitats and human food supplies, such as fish. The group develops mathematical models and conducts laboratory measurements of physical samples collected from ecosystems in order to develop mechanistic understanding that can inform policy and the public. These efforts seek to quantify and understand the “fate and transport” of natural and synthetic compounds. [4] [5]
Sunderland's research seeks to trace the impact of introducing novel exogenous compounds on natural ecosystems. These compounds are more and more prevalent in natural habitats, largely as a consequence of the fact that modern industry relies on a growing range of chemical compounds, including heavy metals such as lead (Pb), copper (Cu), zinc (Zn). [5] [6] Further, chemical companies such as Dow and DuPont have created almost 100,000 synthetic organic chemicals. [7] While these chemicals have enabled the Green Revolution and smart materials, they also combine elements from across the periodic table into new materials that were not present throughout most of Earth’s history during which natural organisms evolved. Modern science has limited understanding of how these new compounds behave once released into the environment. Many of these synthetic chemicals persist and do not break down in the natural environment. [7]
As described in Sunderland’s tenure talk at Harvard, the group has explored several classes of contaminants with different chemical properties, including Mercury, PFAS, and PCBs. [8]
Sunderland’s early work focused on methylmercury in Passamaquoddy Bay on the edge of the North Atlantic. [9] Over time, this interest expanded to the global processes that transport mercury through the world’s oceans, ecosystems, and human food supply. Mercury is a naturally occurring element that is toxic to nerve cells and can bioaccumulate when methylated. By organizing the central principles of the global mercury cycle, Sunderland’s group has led development of models that quantify the impacts of human activities on the fate and transport of mercury. [10] [11] [12]
These models have enabled deeper understanding of how climate change is affecting mercury levels in fish that people eat. [13] While US environmental regulations caused coal fired power plants to reduce their emissions of mercury, the group’s models have found that in some cases the effects of climate change on mercury levels have outpaced those reductions leading to more mercury in fish. [14] [15]
Related work has assessed how hydroelectric developments in NewFoundland increasing risk of methylmercury poisoning in indigenous peoples near the Arctic [16] [17]
Development of hydroelectric dams and as well as permafrost thaw from global warming could increase the impact of mercury on human populations in the arctic. [18]
Expanding beyond mercury, Sunderland’s group has sought to understand how people are exposed to poly- and perfluoroalkyl substances (PFAS) and to develop quantitative tools tracing PFAS exposures back to their sources. [19] [20] This thread of research includes work on Cape Cod, where a team of researchers including Sunderland have been studying drinking water. [21]
That work led to a widely read scientific paper titled “Detection of Poly- and Perfluoroalkyl Substances (PFASs) in U.S. Drinking Water Linked to Industrial Sites, Military Fire Training Areas, and Wastewater Treatment Plants” with several co-authors including Arlene Blum and Philippe Grandjean. [22] [23] [24]
More recently, PFAS have appeared in bottled drinking water, and Sunderland has been interviewed as an expert on the matter. [25]
The impact of PCBs on living organisms has been studied extensively, and the Sunderland group has extended this work by developing global models of how these long-lived persistent pollutants move through the world. [26]
In 2019, the Web of Science recognized Sunderland as a Highly Cited Researcher with multiple highly cited papers in top 1% of the field. [27]
In 2012, the Star Family gave awards to Sunderland recognizing her excellent and promising scientific research. [28]
Sunderland was recognized for her service as a peer reviewer by the journal Biogeochemistry and the Editorial Board of Estuaries and Coasts. [4]
While working at the US EPA, the agency recognized Sunderland with the U.S. EPA Level II Scientific & Technological Achievement (STAA) Award (2010), [29] U.S. EPA Level I (highest level) Scientific & Technological Achievement (STAA) Award (2008), [30] and U.S. EPA National Honor Award, Gold Medal for Exceptional Service (2005). [4]
SFU awarded the Dean’s Convocation Medal for best graduate thesis to Sunderland. [31]
Bioaccumulation is the gradual accumulation of substances, such as pesticides or other chemicals, in an organism. Bioaccumulation occurs when an organism absorbs a substance faster than it can be lost or eliminated by catabolism and excretion. Thus, the longer the biological half-life of a toxic substance, the greater the risk of chronic poisoning, even if environmental levels of the toxin are not very high. Bioaccumulation, for example in fish, can be predicted by models. Hypothesis for molecular size cutoff criteria for use as bioaccumulation potential indicators are not supported by data. Biotransformation can strongly modify bioaccumulation of chemicals in an organism.
Water pollution is the contamination of water bodies, usually as a result of human activities, so that it negatively affects its uses. Water bodies include lakes, rivers, oceans, aquifers, reservoirs and groundwater. Water pollution results when contaminants mix with these water bodies. Contaminants can come from one of four main sources: sewage discharges, industrial activities, agricultural activities, and urban runoff including stormwater. Water pollution is either surface water pollution or groundwater pollution. This form of pollution can lead to many problems, such as the degradation of aquatic ecosystems or spreading water-borne diseases when people use polluted water for drinking or irrigation. Another problem is that water pollution reduces the ecosystem services that the water resource would otherwise provide.
A biogeochemical cycle, or more generally a cycle of matter, is the movement and transformation of chemical elements and compounds between living organisms, the atmosphere, and the Earth's crust. Major biogeochemical cycles include the carbon cycle, the nitrogen cycle and the water cycle. In each cycle, the chemical element or molecule is transformed and cycled by living organisms and through various geological forms and reservoirs, including the atmosphere, the soil and the oceans. It can be thought of as the pathway by which a chemical substance cycles the biotic compartment and the abiotic compartments of Earth. The biotic compartment is the biosphere and the abiotic compartments are the atmosphere, lithosphere and hydrosphere.
Biogeochemistry is the scientific discipline that involves the study of the chemical, physical, geological, and biological processes and reactions that govern the composition of the natural environment. In particular, biogeochemistry is the study of biogeochemical cycles, the cycles of chemical elements such as carbon and nitrogen, and their interactions with and incorporation into living things transported through earth scale biological systems in space and time. The field focuses on chemical cycles which are either driven by or influence biological activity. Particular emphasis is placed on the study of carbon, nitrogen, oxygen, sulfur, iron, and phosphorus cycles. Biogeochemistry is a systems science closely related to systems ecology.
Perfluorooctanoic acid is a perfluorinated carboxylic acid produced and used worldwide as an industrial surfactant in chemical processes and as a material feedstock. PFOA is considered a surfactant, or fluorosurfactant, due to its chemical structure, which consists of a perfluorinated, n-heptyl "tail group" and a carboxylate "head group". The head group can be described as hydrophilic while the fluorocarbon tail is both hydrophobic and lipophobic.
Perfluorooctanesulfonic acid (PFOS) is a chemical compound having an eight-carbon fluorocarbon chain and a sulfonic acid functional group and thus a perfluorosulfonic acid. It is an anthropogenic (man-made) fluorosurfactant, now regarded as a global pollutant. PFOS was the key ingredient in Scotchgard, a fabric protector made by 3M, and related stain repellents. The acronym "PFOS" refers to the parent sulfonic acid and to various salts of perfluorooctanesulfonate. These are all colorless or white, water-soluble solids. Although of low acute toxicity, PFOS has attracted much attention for its pervasiveness and environmental impact. It was added to Annex B of the Stockholm Convention on Persistent Organic Pollutants in May 2009.
Methylmercury (sometimes methyl mercury) is an organometallic cation with the formula [CH3Hg]+. It is the simplest organomercury compound. Methylmercury is extremely toxic, and its derivatives are the major source of organic mercury for humans. It is a bioaccumulative environmental toxicant.
Persistent organic pollutants (POPs) are organic compounds that are resistant to degradation through chemical, biological, and photolytic processes. They are toxic chemicals that adversely affect human health and the environment around the world. Because they can be transported by wind and water, most POPs generated in one country can and do affect people and wildlife far from where they are used and released.
The iron cycle (Fe) is the biogeochemical cycle of iron through the atmosphere, hydrosphere, biosphere and lithosphere. While Fe is highly abundant in the Earth's crust, it is less common in oxygenated surface waters. Iron is a key micronutrient in primary productivity, and a limiting nutrient in the Southern ocean, eastern equatorial Pacific, and the subarctic Pacific referred to as High-Nutrient, Low-Chlorophyll (HNLC) regions of the ocean.
Environmental toxicology is a multidisciplinary field of science concerned with the study of the harmful effects of various chemical, biological and physical agents on living organisms. Ecotoxicology is a subdiscipline of environmental toxicology concerned with studying the harmful effects of toxicants at the population and ecosystem levels.
Perfluorononanoic acid, or PFNA, is a synthetic perfluorinated carboxylic acid and fluorosurfactant that is also an environmental contaminant found in people and wildlife along with PFOS and PFOA.
Per- and polyfluoroalkyl substances (PFAS or PFASs) are a group of synthetic organofluorine chemical compounds that have multiple fluorine atoms attached to an alkyl chain. An early definition, from 2011, required that they contain at least one perfluoroalkyl moiety, –CnF2n+1–. Beginning in 2021, the Organisation for Economic Co-operation and Development (OECD) expanded their terminology, stating that "PFASs are defined as fluorinated substances that contain at least one fully fluorinated methyl or methylene carbon atom (without any H/Cl/Br/I atom attached to it), i.e., with a few noted exceptions, any chemical with at least a perfluorinated methyl group (–CF3) or a perfluorinated methylene group (–CF2–) is a PFAS."
The mercury cycle is a biogeochemical cycle influenced by natural and anthropogenic processes that transform mercury through multiple chemical forms and environments.
Mercury regulation in the United States limit the maximum concentrations of mercury (Hg) that is permitted in air, water, soil, food and drugs. The regulations are promulgated by agencies such as the Environmental Protection Agency (EPA) and Food and Drug Administration (FDA), as well as a variety of state and local authorities. EPA published the Mercury and Air Toxics Standards (MATS) regulation in 2012; the first federal standards requiring power plants to limit emissions of mercury and other toxic gases.
Groundwater pollution occurs when pollutants are released to the ground and make their way into groundwater. This type of water pollution can also occur naturally due to the presence of a minor and unwanted constituent, contaminant, or impurity in the groundwater, in which case it is more likely referred to as contamination rather than pollution. Groundwater pollution can occur from on-site sanitation systems, landfill leachate, effluent from wastewater treatment plants, leaking sewers, petrol filling stations, hydraulic fracturing (fracking) or from over application of fertilizers in agriculture. Pollution can also occur from naturally occurring contaminants, such as arsenic or fluoride. Using polluted groundwater causes hazards to public health through poisoning or the spread of disease.
GenX is a Chemours trademark name for a synthetic, short-chain organofluorine chemical compound, the ammonium salt of hexafluoropropylene oxide dimer acid (HFPO-DA). It can also be used more informally to refer to the group of related fluorochemicals that are used to produce GenX. DuPont began the commercial development of GenX in 2009 as a replacement for perfluorooctanoic acid.
Noelle Eckley Selin is an atmospheric chemist and Associate Professor at Massachusetts Institute of Technology in the Institute for Data, Systems and Society and the Department of Earth, Atmospheric and Planetary Sciences.
Mercury methylation is the process of forming methylmercury (MeHg). The methylation of mercury can occur abiotically or biotically. Biotically, the primary methylators of mercury are sulfate-reducing and iron-reducing bacteria. Three mechanisms have been proposed for the biotic methylation of mercury by sulfate-reducing bacteria. Mercury methylation can be problematic as methylmercury is toxic and can be bio-magnified through the food web.
Perfluorohexanesulfonic acid (PFHxS) is a synthetic chemical compound. It is one of many compounds collectively known as per- and polyfluoroalkyl substances (PFASs). It is an anionic fluorosurfactant and a persistent organic pollutant with bioaccumulative properties. Although the use of products containing PFHxS and other PFASs have been banned or are being phased out in many jurisdictions, it remains ubiquitous in many environments and within the general population, and is one of the most commonly detected PFASs.
Alain Manceau, born September 19, 1955, is a French environmental mineralogist and biogeochemist. He is known for his research on the structure and reactivity of nanoparticulate iron and manganese oxides and clay minerals, on the crystal chemistry of strategic metals and rare-earth elements in marine sediments, and on the structural biogeochemistry of mercury in natural organic matter, animals, and humans.