Welcome to the USGS Mercury Research Laboratory. For over 25 years our team of multi-disciplinary investigators has operated a state-of-the-art analytical facility strictly dedicated to low-level speciation and analysis of mercury. We’re proud of our record and look forward to the next phase of our growth as we move to a centralized facility with improved capacity and leading-edge instrumentation.
Please reach out us with your questions or project ideas. We’re always interested in new ideas and collaboration opportunities on mercury science.
Message from the Team Leader
The overall goal of the USGS Mercury Research Lab is to provide an improved scientific understanding of factors leading to mercury contamination of aquatic ecosystems. We provide scientific leadership in study design and execution and provide expert assistance to collaborating scientists within the USGS and other state and Federal agencies.
A significant emphasis of the team is to ensure that the results from our studies are delivered to decision makers in a timely and effective manner. Our team of scientists covers a broad range of expertise (chemistry, biology, hydrology, limnology, and physical sciences) and our laboratory has a broad array of state-of-the-art instrumentation. Together, this allow us to implement mercury studies in just about any type of ecosystem in the world. The activities of the Mercury Research Laboratory fall into two broad categories: (1) research projects, and (2) technical and analytical support for collaborators.
As a national leader in mercury research, our projects are designed to answer land-resource management questions that help decision makers make informed choices. With projects stretching from Alaska to Florida, and California to Maine, we can provide a true national perspective on mercury in the environment.
Our analytical laboratory has a well-established, international reputation for excellence in the quantification and speciation of mercury in all forms of environmental samples (water, sediment, biota, and air). We have developed and published method validation papers for most of our techniques, and always strive to improve our capabilities. As new approaches emerge with the promise for improved speciation, sensitivity, or rate of analysis, we harness those ideas, verify their efficacy, and implement the new tools.
In all our endeavors, we strive for excellent customer service while providing the best possible data. Our collaborators can rely on our team to deliver expert assistance in method development for both field and laboratory procedures; sound interpretation of data; and timely progress reports. Please reach out to me or any of my teammates with your questions or project ideas. We’re always interested in new opportunities to apply our expertise.
Mercury is a persistent pollutant that has adverse effects on the neurological development of humans, fish and wildlife. Of particular concern is mercury exposure to the developing fetus or children from subsistence fishing populations. While these concerns are heightened in areas that exhibit substantial contamination from mercury use, it is important to note that remote areas that are free from point sources can also have elevated levels of mercury in fish. This is largely because of two mechanisms: (1) mercury emitted to the atmosphere can travel great distances before depositing; and, (2) microorganisms in the local environment can efficiently convert inorganic mercury into methylmercury – the form that bioaccumulates up the food web.
A long-term problem
Mercury is truly a global issue that has confronted resource managers and regulators for decades. In the 1980s, researchers could not reliably measure the concentration of mercury in environmental samples due to the very low levels (parts per trillion) generally observed. This made it difficult to consider remediation strategies – even into the start of the 21st century. Improvements in speciation and analytical techniques have steadily progressed since then, along with the reliability of the data produced. In recent years, scientific understanding of possible solutions has steadily emerged, and today it is possible to identify and track the sources of mercury through an ecosystem.
Sources of mercury
Mercury has many sources, including some that are dispersed globally. In freshwater systems, besides naturally occurring mercury, the dominant sources of mercury are atmospheric deposition, watershed inputs, and industrial point-source discharges. Research has shown that human-induced sources contribute more mercury to the environment than natural sources.
Globally, the largest man-related mercury source to the environment is artisanal and small-scale gold mining in South America and Sub-Saharan Africa (38%); however, in the developed portions of the world burning coal for energy production is the leading source (Global Mercury Assessment, 2018). It remains uncertain how far reaching mercury emissions from gold mining operations are transported.
Natural sources of mercury
Natural sources of atmospheric mercury include volcanoes, metalliferous geologic deposits, and volatilization from the ocean. Although all rocks, sediments, water, and soils naturally contain small amounts of mercury, scientists have found locations where with mercury enrichment due to geologic placement. In the United States, these are most often observed in California and Alaska.
Atmospheric mercury, the most commonly distributed source of mercury in the U.S., includes emissions from coal combustion, chlorine alkali processing, waste incineration, and metal processing. Once in the atmosphere, mercury is widely disseminated and can circulate for years, accounting for its global distribution.
Atmospherically-deposited mercury to terrestrial settings eventually accumulate in soils. Most of this soil-bound mercury is associated with organic carbon (e.g, soil humus) and is often transported with eroded soil particles, like those eroded during a storm. Runoff can carry watershed mercury downstream to receiving rivers, lakes, and wetlands.
Man-related (point-source) discharges
Man-related releases of mercury can contribute locally concentrated amounts of mercury into receiving water bodies. These point-source discharges include a wide variety of processing, including industrial or mining discharges, chlor alkali plant, metal processing, medical and other wastes, and mercury and gold mining. In the past, man-related sources mercury contributed a much larger amount of the total releases in the United States. However, since recognition of these sources became more clearly understood and environmental polices lead to significant reductions (and in some cases elimination) of some of these source categories, and it is only in developing countries where these sources remain prominent.