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Geoffrey S. Plumlee

Publications and source records attributed to Geoffrey S. Plumlee.

At least 37 records · Page 2Linked to original sources

Trace metals in Saharan dust: The use of in vitro bioaccessibility extractions to assess potential health risks in a dustier world

Exposure to fine particulate matter (PM) is acknowledged as a risk factor for human morbidity and mortality. Epidemiology and toxicology studies have focused on anthropogenic sources of PM and few consider contributions produced by natural processes (geogenic), or PM produced from natural sources as a result of human activities (geoanthropogenic PM). The focus of this study was to elucidate relationships between human/ecosystem health and dusts produced by a system transitioning from a dominantly natural to a geoanthropogenic PM source. As part of a larger study investigating the relationship between atmospheric transportation of African dust, human health, and coral reef declines, we examined dust samples sourced in Mali, Africa, collected using high-volume samplers from three sites (Mali, Tobago and U.S. Virgin Islands). Inhalation and ingestion exposure pathways were explored by filter extractions using simulated lung and gastric fluids. Bioaccessibility varied by metal and extraction fluid. Although too few samples were analyzed for robust statistics, concentrations for several metals decreased slightly while bioaccessibility increased at downwind sites.

Book chapter↗

U.S. Geological Survey environmental health science strategy — Providing environmental health science for a changing world

Executive Summary America has an abundance of natural resources. We have bountiful clean water, fertile soil, and unrivaled national parks, wildlife refuges, and public lands. These resources enrich our lives and preserve our health and wellbeing. These resources have been maintained because of our history of respect for their value and an enduring commitment to their vigilant protection. Awareness of the social, economic, and personal value of the health of our environment is increasing. The emergence of environmentally driven diseases caused by exposure to contaminants and pathogens is a growing concern worldwide. New health threats and patterns of established threats are affected by both natural and anthropogenic changes to the environment. Human activities are key drivers of emerging (new and re-emerging) health threats. Societal demands for land and natural resources, quality of life, and economic prosperity lead to environmental change. Natural earth processes, climate trends, and related climatic events will compound the environmental impact of human activities. These environmental drivers will influence exposure to disease agents, including viral, bacterial, prion, and fungal pathogens, parasites, synthetic chemicals and substances, natural earth materials, toxins, and other biogenic compounds. The U.S. Geological Survey (USGS) defines environmental health science broadly as the interdisciplinary study of relations among the quality of the physical environment, the health of the living environment, and human health. The interactions among these three spheres are driven by human activities, ecological processes, and natural earth processes; the interactions affect exposure to contaminants and pathogens and the severity of environmentally driven diseases in animals and people. This definition provides USGS with a framework for synthesizing natural science information from across the Bureau and providing it to environmental, natural resource, agricultural, and public health managers. USGS specializes in science at the environment-health interface, by characterizing the processes that affect the interaction among the physical environment, the living environment, and people, and the resulting factors that affect ecological and human exposure to disease agents. The USGS is a Federal science agency with a broad range of natural science expertise relevant to environmental health. USGS provides scientific information and tools as a scientific basis for management and policy decisionmaking. This report describes a 10-year strategy that encompasses the portfolio of USGS environmental health science. It summarizes national environmental health priorities that USGS is best suited to address, and will serve as a strategic framework for USGS environmental health science goals, actions, and outcomes for the next decade. Implementation of this strategy is intended to aid coordination of USGS environmental health activities and to provide a focal point for disseminating information to stakeholders. The “One Health” paradigm advocated by the World Health Organization (WHO; World Health Organization, 2011), and the American Veterinary Medical Association (AVMA; American Veterinary Medical Association, 2008), among others, is based on a general recognition that the health of humans, animals, and the environment are inextricably linked. Thus, successful efforts to protect that health will require increased interdisciplinary research and increased communication and collaboration among the broader scientific and health community. This strategy is built upon that paradigm.

Circular↗

Geologic occurrences of erionite in the United States: an emerging national public health concern for respiratory disease

Erionite, a mineral series within the zeolite group, is classified as a Group 1 known respiratory carcinogen. This designation resulted from extremely high incidences of mesothelioma discovered in three small villages from the Cappadocia region of Turkey, where the disease was linked to environmental exposures to fibrous forms of erionite. Natural deposits of erionite, including fibrous forms, have been identified in the past in the western United States. Until recently, these occurrences have generally been overlooked as a potential hazard. In the last several years, concerns have emerged regarding the potential for environmental and occupational exposures to erionite in the United States, such as erionite-bearing gravels in western North Dakota mined and used to surface unpaved roads. As a result, there has been much interest in identifying locations and geologic environments across the United States where erionite occurs naturally. A 1996 U.S. Geological Survey report describing erionite occurrences in the United States has been widely cited as a compilation of all US erionite deposits; however, this compilation only focused on one of several geologic environments in which erionite can form. Also, new occurrences of erionite have been identified in recent years. Using a detailed literature survey, this paper updates and expands the erionite occurrences database, provided in a supplemental file (US_erionite.xls). Epidemiology, public health, and natural hazard studies can incorporate this information on known erionite occurrences and their characteristics. By recognizing that only specific geologic settings and formations are hosts to erionite, this knowledge can be used in developing management plans designed to protect the public.

Arizona;California;Colorado;Idaho;Montana;New Mexi↗

The role of airborne mineral dusts in human disease

Exposure to fine particulate matter (PM) is generally acknowledged to increase risk for human morbidity and mortality. However, particulate matter (PM) research has generally examined anthropogenic (industry and combustion by-products) sources with few studies considering contributions from geogenic PM (produced from the Earth by natural processes, e.g., volcanic ash, windborne ash from wildfires, and mineral dusts) or geoanthropogenic PM (produced from natural sources by processes that are modified or enhanced by human activities, e.g., dusts from lakebeds dried by human removal of water, dusts produced from areas that have undergone desertification as a result of human practices). Globally, public health concerns are mounting, related to potential increases in dust emission from climate related changes such as desertification and the associated long range as well as local health effects. Recent epidemiological studies have identified associations between far-traveled dusts from primary sources and increased morbidity and mortality in Europe and Asia. This paper provides an outline of public health research and history as it relates to naturally occurring inorganic mineral dusts. We summarize results of current public health research and describe some of the many challenges related to understanding health effects from exposures to dust aerosols.

Aeolian Research↗

Linking geology and health sciences to assess childhood lead poisoning from artisanal gold mining in Nigeria

Background: In 2010, Médecins Sans Frontières discovered a lead poisoning outbreak linked to artisanal gold processing in northwestern Nigeria. The outbreak has killed approximately 400 young children and affected thousands more. Objectives: Our aim was to undertake an interdisciplinary geological- and health-science assessment to clarify lead sources and exposure pathways, identify additional toxicants of concern and populations at risk, and examine potential for similar lead poisoning globally. Methods: We applied diverse analytical methods to ore samples, soil and sweep samples from villages and family compounds, and plant foodstuff samples. Results: Natural weathering of lead-rich gold ores before mining formed abundant, highly gastric-bioaccessible lead carbonates. The same fingerprint of lead minerals found in all sample types confirms that ore processing caused extreme contamination, with up to 185,000 ppm lead in soils/sweep samples and up to 145 ppm lead in plant foodstuffs. Incidental ingestion of soils via hand-to-mouth transmission and of dusts cleared from the respiratory tract is the dominant exposure pathway. Consumption of water and foodstuffs contaminated by the processing is likely lesser, but these are still significant exposure pathways. Although young children suffered the most immediate and severe consequences, results indicate that older children, adult workers, pregnant women, and breastfed infants are also at risk for lead poisoning. Mercury, arsenic, manganese, antimony, and crystalline silica exposures pose additional health threats. Conclusions: Results inform ongoing efforts in Nigeria to assess lead contamination and poisoning, treat victims, mitigate exposures, and remediate contamination. Ore deposit geology, pre-mining weathering, and burgeoning artisanal mining may combine to cause similar lead poisoning disasters elsewhere globally.

Environmental Health Perspectives↗

The SAFRR tsunami scenario: Improving resilience for California

On March 11, 2011, the Tohoku earthquake and the resulting tsunami devastated Japan with a disaster of unfathomable proportions. Five thousand miles away, the waves from Tohoku caused $50 to 100 million in damages in California. Although this pales in comparison to the loss of lives and property in Japan, the U.S. Government must ask whether California, and the national economy, will someday face worse consequences from other distant-source tsunamis. Unfortunately, the answer is “yes.”

California↗

SAFRR (Science Application for Risk Reduction) Tsunami Scenario--Executive Summary and Introduction: Chapter A in The SAFRR (Science Application for Risk Reduction) Tsunami Scenario

The Science Application for Risk Reduction (SAFRR) tsunami scenario depicts a hypothetical but plausible tsunami created by an earthquake offshore from the Alaska Peninsula and its impacts on the California coast. The tsunami scenario is a collaboration between the U.S. Geological Survey (USGS), the California Geological Survey, the California Governor’s Office of Emergency Services (Cal OES), the National Oceanic and Atmospheric Administration (NOAA), other Federal, State, County, and local agencies, private companies, and academic and other institutions. This document presents evidence for past tsunamis, the scientific basis for the source, likely inundation areas, current velocities in key ports and harbors, physical damage and repair costs, economic consequences, environmental and ecological impacts, social vulnerability, emergency management and evacuation challenges, and policy implications for California associated with this hypothetical tsunami. We also discuss ongoing mitigation efforts by the State of California and new communication products. The intended users are those who need to make mitigation decisions before future tsunamis, and those who will need to make rapid decisions during tsunami events. The results of the tsunami scenario will help managers understand the context and consequences of their decisions and how they may improve preparedness and response. An evaluation component will assess the effectiveness of the scenario process for target stakeholders in a separate report to improve similar efforts in the future.

California↗

Potential Environmental and Environmental-Health Implications of the SAFRR Tsunami Scenario in California: Chapter F in The SAFRR (Science Application for Risk Reduction) Tsunami Scenario

The California Tsunami Scenario models the impacts of a hypothetical, yet plausible, tsunami caused by an earthquake offshore from the Alaska Peninsula. In this chapter, we interpret plausible tsunami-related contamination, environmental impacts, potential for human exposures to contaminants and hazardous materials, and implications for remediation and recovery. Inundation-related damages to major ports, boat yards, and many marinas could release complex debris, crude oil, various fuel types and other petroleum products, some liquid bulk cargo and dry bulk cargo, and diverse other pollutants into nearby coastal marine environments and onshore in the inundation zone. Tsunami-induced erosion of contaminated harbor bottom sediments could re-expose previously sequestered metal and organic pollutants (for example, organotin or DDT). Inundation-related damage to many older buildings could produce debris containing lead paint, asbestos, pesticides, and other legacy contaminants. Intermingled household debris and externally derived debris and sediments would be left in flooded buildings. Post tsunami, mold would likely develop in inundated houses, buildings, and debris piles. Tsunamigenic fires in spilled oil, debris, cargo, vehicles, vegetation, and residential, commercial, or industrial buildings and their contents would produce potentially toxic gases and smoke, airborne ash, and residual ash/debris containing caustic alkali solids, metal toxicants, asbestos, and various organic toxicants. Inundation of and damage to wastewater treatment plants in many coastal cities could release raw sewage containing fecal solids, pathogens, and waste chemicals, as well as chemicals used to treat wastewaters. Tsunami-related physical damages, debris, and contamination could have short- and longer-term impacts on the environment and the health of coastal marine and terrestrial ecosystems. Marine habitats in intertidal zones, marshes, sloughs, and lagoons could be damaged by erosion or sedimentation, and could receive an influx of debris, metal and organic contaminants, and sewage-related pathogens. Debris and re-exposed contaminated sediments would be a source of sea- or rain-water-leachable metal and organic contaminants that could pose chronic toxicity threats to ecosystems. If human populations are successfully evacuated prior to the tsunami arrival, there would be no or limited numbers of drownings, other casualties, or related injuries, wounds, and infections. Immediately after the tsunami, human populations away from the inundation zone could be transiently exposed to airborne gases, smoke, and ash from tsunamigenic fires. Cleanup and disposal, particularly of hazardous materials, would pose substantial logistical challenges and economic costs. Given the high value of the coastal residential and commercial properties in the inundation zone, it can be postulated that there would be substantial insurance claims for environmental restoration, mold mitigation, disposal of debris that contains hazardous materials, and costs of litigation related to environmental liability. Post-tsunami cleanup, if done with appropriate mitigation (for example, dust control), personal protection, and disposal measures, would help reduce the potential for cleanup-worker and resident exposures to toxicants and pathogens in harbor waters, debris, soils, ponded waters, and buildings. A number of other steps can be taken by governments, businesses, and residents to help reduce the environmental impacts of tsunamis and to recover more quickly from these environmental impacts. For example, development of State and local policies that foster rapid assessment of potential contamination, as well as rapid decision making for disposal options should hazardous debris or sediment be identified, would help enhance recovery by speeding cleanup.

California↗

Protocol for analysis of volcanic ash samples for assessment of hazards from leachable elements

Volcanic eruptions can produce a wide range of hazards. Although phenomena such as pyroclastic density currents and surges, sector collapses, lahars and ballistic blocks are the most destructive and dangerous, volcanic ash is by far the most widely distributed eruption product1 and the most likely to be encountered by the public. Following an eruption, the public, civil authorities and agricultural producers will often have major concerns about the effects of volcanic ash on human and animal health, drinking water supplies, crops, soils and surface runoff. Freshly‐erupted ash contains a range of potentially toxic soluble elements, which may be released either rapidly or more slowly upon contact with water or body fluids.

Report↗

Environmental and medical geochemistry in urban disaster response and preparedness

History abounds with accounts of cities that were destroyed or significantly damaged by natural or anthropogenic disasters, such as volcanic eruptions, earthquakes, wildland–urban wildfires, hurricanes, tsunamis, floods, urban firestorms, terrorist attacks, and armed conflicts. Burgeoning megacities place ever more people in the way of harm from future disasters. In addition to the physical damage, casualties, and injuries they cause, sudden urban disasters can also release into the environment large volumes of potentially hazardous materials. Environmental and medical geochemistry investigations help us to (1) understand the sources and environmental behavior of disaster materials, (2) assess potential threats the materials pose to the urban environment and health of urban populations, (3) develop strategies for their cleanup/disposal, and (4) anticipate and mitigate potential environmental and health effects from future urban disasters.

Elements↗

USGS Environmental health science strategy: providing environmental health science for a changing world: Public review release

America has an abundance of natural resources. We have bountiful clean water, fertile soil, and unrivaled national parks, wildlife refuges, and public lands. These resources enrich our lives and preserve our health and wellbeing. These resources have been maintained because of our history of respect for their value and an enduring commitment to their vigilant protection. Awareness of the social, economic, and personal value of the health of our environment is increasing. The emergence of environmentally driven diseases caused by environmental exposure to contaminants and pathogens is a growing concern worldwide. New health threats and patterns of established threats are affected by both natural and anthropogenic changes to the environment. Human activities are key drivers of emerging (new and re-emerging) health threats. Societal demands for land and natural resources, a better quality of life, improved economic prosperity, and the environmental impacts associated with these demands will continue to increase. Natural earth processes, climate trends, and related climatic events will add to the environmental impact of human activities. These environmental drivers will influence exposure to disease agents, including viral, bacterial, prion, and fungal pathogens, parasites, natural earth materials, toxins and other biogenic compounds, and synthetic chemicals and substances. The U.S. Geological Survey (USGS) defines environmental health science broadly as the interdisciplinary study of relations among the quality of the physical environment, the health of the living environment, and human health. The interactions among these three spheres are driven by human activities, ecological processes, and natural earth processes; the interactions affect exposure to contaminants and pathogens and the severity of environmentally driven diseases in animals and people. This definition provides USGS with a framework for synthesizing natural science information from across the Bureau and providing it to environmental, natural resource, agricultural, and public-health managers. The USGS is a Federal science agency with a broad range of natural science expertise relevant to environmental health. USGS provides scientific information and tools as a scientific basis for management and policy decision making. USGS specializes in science at the environment-health interface, by characterizing the processes that affect the interaction among the physical environment, the living environment, and people, and the resulting factors that affect ecological and human exposure to disease agents. This report describes a 10-year strategy that encompasses the portfolio of USGS environmental health science. It summarizes national environmental health priorities that USGS is best suited to address, and will serve as a strategic framework for USGS environmental health science goals, actions, and outcomes for the next decade. Implementation of this strategy is intended to aid coordination of USGS environmental health activities and to provide a focal point for disseminating information to stakeholders. The "One Health" paradigm advocated by the World Health Organization (WHO, 2011), and the American Veterinary Medicine Association (AVMA, 2008), among others, is based on a general recognition that the health of humans, animals, and the environment are inextricably linked. Thus, successful efforts to protect that health will require increased interdisciplinary research and increased communication and collaboration among the broader scientific and health community. This strategy is built upon that paradigm. The vision, mission, and five cornerstone goals of the USGS Environmental Health Science Strategy were developed with significant input from a wide range of stakeholders. Vision - The USGS is a premier source of the environmental health science needed to safeguard the health of the environment, fish, wildlife, and people. Mission - The mission of USGS in environmental health science is to contribute scientific information to environmental, natural resource, agricultural, and public-health managers, who use that science to support sound decision making. USGS provides the science to: - Goal 1: Identify, prioritize, and detect contaminants and pathogens of emerging environmental concern. - Goal 2: Reduce the impact of contaminants on the environment, fish, wildlife, and people. - Goal 3: Reduce the impact of pathogens on the environment, fish, wildlife, and people. - Goal 4: Discover the complex interactions and combined effects of exposure to contaminants and pathogens. - Goal 5: Prepare for and respond to environmental impacts and related health threats of natural and anthropogenic disasters. Goals 1 through 4 are intended to provide science to address environmental health threats in a logical order, from informing prevention and preparedness, to supporting systematic management response to environmental health issues. Goal 4 addresses the interaction among contaminants and pathogens, an issue of emerging concern in environmental health science. Goal 5 acknowledges the fact that natural and anthropogenic disasters can cause immediate and prolonged adverse environmental health threats. This strategy proposes that USGS take the following strategic science actions to achieve each of the five goals of this strategy: Goal 1: Identify, prioritize, and detect contaminants and pathogens of emerging environmental concern. - Strategic Science Action 1. - Prioritize contaminants and pathogens of emerging concern to guide research, detection, and management activities. - Strategic Science Action 2. - Conduct surveillance and monitoring to provide early warning of emerging health threats. - Strategic Science Action 3. - Develop approaches and tools that identify vulnerable environmental settings, ecosystems, and species. Goal 2: Reduce the impact of contaminants on the environment, fish, wildlife, and people. - Strategic Science Action 1. - Systematically characterize the sources, occurrence, transport and fate of environmental contaminants to guide efforts to manage and mitigate contamination. - Strategic Science Action 2. - Evaluate the threats of contamination on the health of the environment, fish, wildlife, and people, and inform the associated management and protection efforts. - Strategic Science Action 3. - Characterize potential human exposure to support establishment of health-based standards or guidelines and contamination-reduction efforts. Goal 3: Reduce the impact of pathogens on the environment, fish, wildlife, and people. - Strategic Science Action 1. - Determine the biotic and abiotic factors that control the ecology of infectious diseases affecting natural populations of aquatic and terrestrial species and potential transmission to other animals and humans. - Strategic Science Action 2. - Establish how natural and anthropogenic environmental changes affect the distribution and severity of infectious diseases in natural populations of aquatic and terrestrial species and potential transmission to other animals and humans. - Strategic Science Action 3. - Develop surveillance systems to identify changing patterns of disease activity in priority geographic areas. Goal 4: Discover the complex interactions and combined effects of exposure to contaminants and pathogens. - Strategic Science Action 1. - Identify how exposure to one class of disease agents (contaminants or pathogens) can make an organism more susceptible to effects from exposure to the other class of disease agents. - Strategic Science Action 2. - Implement interdisciplinary studies that characterize the effects of combined exposure to pathogens and contaminants. Goal 5: Prepare for and respond to the environmental impacts and related health threats of natural and anthropogenic disasters. - Strategic Science Action 1. - Establish a formal interdisciplinary science capability to rapidly assess the environmental health risks associated with disasters. - Strategic Science Action 2. - Enhance methods to anticipate, prepare for, and identify environmental, ecological, and related health impacts of future disasters. This strategy is one of seven USGS science strategies developed concurrently: - Climate and Land Use Change - Core Science Systems - Ecosystems - Energy and Mineral Resources - Environmental Health - Natural Hazards - Water. This strategy describes how USGS will address the highest priority environmental health issues facing the Nation. The ultimate intended outcome of this science strategy is prevention and reduction of adverse impacts to the quality of the environment, the health of our living resources, and human health. Communication with, and receiving input from, partners and stakeholders regarding their science needs is essential for successful implementation of this strategy. It is incumbent on USGS to reach out to all stakeholders to ensure that USGS efforts are focused on the highest priority environmental health issues and that products are provided in the most timely and usable form to all those who can use them. USGS must reach out to the scientific community, internally and externally, to ensure that our efforts are integrated with and take full advantage of the activities of others.

Open-File Report↗

Mine wastes and human health

Historical mining and mineral processing have been linked definitively to health problems resulting from occupational and environmental exposures to mine wastes. Modern mining and processing methods, when properly designed and implemented, prevent or greatly reduce potential environmental health impacts. However, particularly in developing countries, there are examples of health problems linked to recent mining. In other cases, recent mining has been blamed for health problems but no clear links have been found. The types and abundances of potential toxicants in mine wastes are predictably influenced by the geologic characteristics of the deposit being mined. Hence, Earth scientists can help understand, anticipate, and mitigate potential health issues associated with mining and mineral processing.

Elements↗

Simultaneous speciation of arsenic, selenium, and chromium: species, stability, sample preservation, and analysis of ash and soil leachates

An analytical method using high-performance liquid chromatography separation with inductively coupled plasma mass spectrometry (ICP-MS) detection previously developed for the determination of Cr(III) and Cr(VI) has been adapted to allow the determination of As(III), As(V), Se(IV), Se(VI), Cr(III), and Cr(VI) under the same chromatographic conditions. Using this method, all six inorganic species can be determined in less than 3 min. A dynamic reaction cell (DRC)-ICP-MS system was used to detect the species eluted from the chromatographic column in order to reduce interferences. A variety of reaction cell gases and conditions may be utilized with the DRC-ICP-MS, and final selection of conditions is determined by data quality objectives. Results indicated all starting standards, reagents, and sample vials should be thoroughly tested for contamination. Tests on species stability indicated that refrigeration at 10° C was preferential to freezing for most species, particularly when all species were present, and that sample solutions and extracts should be analyzed as soon as possible to eliminate species instability and interconversion effects. A variety of environmental and geological samples, including waters and deionized water [leachates] and simulated biological leachates from soils and wildfire ashes have been analyzed using this method. Analytical spikes performed on each sample were used to evaluate data quality. Speciation analyses were conducted on deionized water leachates and simulated lung fluid leachates of ash and soils impacted by wildfires. These results show that, for leachates containing high levels of total Cr, the majority of the chromium was present in the hexavalent Cr(VI) form. In general, total and hexavalent chromium levels for samples taken from burned residential areas were higher than those obtained from non-residential forested areas. Arsenic, when found, was generally in the more oxidized As(V) form. Selenium (IV) and (VI) were present, but typically at low levels.

Analytical and Bioanalytical Chemistry↗

Geology for a changing world 2010-2020-Implementing the U.S. Geological Survey science strategy

This report describes a science strategy for the geologic activities of the U.S. Geological Survey (USGS) for the years 2010-2020. It presents six goals with accompanying strategic actions and products that implement the science directions of USGS Circular 1309, 'Facing Tomorrow's Challenges-U.S. Geological Survey Science in the Decade 2007-2017.' These six goals focus on providing the geologic underpinning needed to wisely use our natural resources, understand and mitigate hazards and environmental change, and understand the relationship between humans and the environment. The goals emphasize the critical role of the USGS in providing long-term research, monitoring, and assessments for the Nation and the world. Further, they describe measures that must be undertaken to ensure geologic expertise and knowledge for the future. The natural science issues facing today's world are complex and cut across many scientific disciplines. The Earth is a system in which atmosphere, oceans, land, and life are all connected. Rocks and soils contain the answers to important questions about the origin of energy and mineral resources, the evolution of life, climate change, natural hazards, ecosystem structures and functions, and the movements of nutrients and toxicants. The science of geology has the power to help us understand the processes that link the physical and biological world so that we can model and forecast changes in the system. Ensuring the success of this strategy will require integration of geological knowledge with the other natural sciences and extensive collaboration across USGS science centers and with partners in Federal, State, and local agencies, academia, industry, nongovernmental organizations and, most importantly, the American public. The first four goals of this report describe the scientific issues facing society in the next 10 years and the actions and products needed to respond to these issues. The final two goals focus on the expertise and infrastructure needed to ensure the long-term sustainability of the geological sciences in the USGS. The ultimate goal of USGS science and of the strategy laid out in this document is to contribute to the development of a sustainable society that operates in harmony with the Earth systems that society depends upon. As we begin the second decade of the 21st century, our Nation faces growing challenges in resource availability, climate and environmental change, and natural hazards. Meeting these challenges will require strong collaboration across the natural and social sciences and extensive partnerships with both the public and private sectors. The six goals described in this document represent a mix of scientific focus areas and operational necessities that together provide a comprehensive roadmap for USGS geologic science to effectively contribute to the USGS mission, providing science for a changing world.

Circular↗

In vitro studies evaluating leaching of mercury from mine waste calcine using simulated human body fluids

In vitro bioaccessibility (IVBA) studies were carried out on samples of mercury (Hg) mine-waste calcine (roasted Hg ore) by leaching with simulated human body fluids. The objective was to estimate potential human exposure to Hg due to inhalation of airborne calcine particulates and hand-to-mouth ingestion of Hg-bearing calcines. Mine waste calcines collected from Hg mines at Almadén, Spain, and Terlingua, Texas, contain Hg sulfide, elemental Hg, and soluble Hg compounds, which constitute primary ore or compounds formed during Hg retorting. Elevated leachate Hg concentrations were found during calcine leaching using a simulated gastric fluid (as much as 6200 μg of Hg leached/g sample). Elevated Hg concentrations were also found in calcine leachates using a simulated lung fluid (as much as 9200 μg of Hg leached/g), serum-based fluid (as much as 1600 μg of Hg leached/g), and water of pH 5 (as much as 880 μg of Hg leached/g). The leaching capacity of Hg is controlled by calcine mineralogy; thus, calcines containing soluble Hg compounds contain higher leachate Hg concentrations. Results indicate that ingestion or inhalation of Hg mine-waste calcine may lead to increased Hg concentrations in the human body, especially through the ingestion pathway.

Environmental Science & Technology↗

Estimating natural background groundwater chemistry, Questa molybdenum mine, New Mexico

This 2 1/2 day field trip will present an overview of a U.S. Geological Survey (USGS) project whose objective was to estimate pre-mining groundwater chemistry at the Questa molybdenum mine, New Mexico. Because of intense debate among stakeholders regarding pre-mining groundwater chemistry standards, the New Mexico Environment Department and Chevron Mining Inc. (formerly Molycorp) agreed that the USGS should determine pre-mining groundwater quality at the site. In 2001, the USGS began a 5-year, multidisciplinary investigation to estimate pre-mining groundwater chemistry utilizing a detailed assessment of a proximal natural analog site and applied an interdisciplinary approach to infer pre-mining conditions. The trip will include a surface tour of the Questa mine and key locations in the erosion scar areas and along the Red River. The trip will provide participants with a detailed understanding of geochemical processes that influence pre-mining environmental baselines in mineralized areas and estimation techniques for determining pre-mining baseline conditions.

New Mexico↗

Estimated minimum discharge rates of the Deepwater Horizon spill— Interim report to the flow rate technical group from the Mass Balance Team

All of the calculations and results in this report are preliminary and intended for the purpose, and only for the purpose, of aiding the incident team in assessing the extent of the spilled oil for ongoing response efforts. Other applications of this report are not authorized and are not considered valid. Because of time constraints and limitations of data available to the experts, many of their estimates are approximate, are subject to revision, and certainly should not be used as the Federal Government's final values for assessing volume of the spill or its impact to the environment or to coastal communities. Each expert that contributed to this report reserves the right to alter his conclusions based upon further analysis or additional information. An estimated minimum total oil discharge was determined by calculations of oil volumes measured as of May 17, 2010. This included oil on the ocean surface measured with satellite and airborne images and with spectroscopic data (129,000 barrels to 246,000 barrels using less and more aggressive assumptions, respectively), oil skimmed off the surface (23,500 barrels from U.S. Coast Guard [USCG] estimates), oil burned off the surface (11,500 barrels from USCG estimates), dispersed subsea oil (67,000 to 114,000 barrels), and oil evaporated or dissolved (109,000 to 185,000 barrels). Sedimentation (oil captured from Mississippi River silt and deposited on the ocean bottom), biodegradation, and other processes may indicate significant oil volumes beyond our analyses, as will any subsurface volumes such as suspended tar balls or other emulsions that are not included in our estimates. The lower bounds of total measured volumes are estimated to be within the range of 340,000 to 580,000 barrels as of May 17, 2010, for an estimated average minimum discharge rate of 12,500 to 21,500 barrels per day for 27 days from April 20 to May 17, 2010.

Louisiana↗

Speciation of arsenic, selenium, and chromium in wildfire impacted soils and ashes

In 2007-09, California experienced several large wildfires that damaged large areas of forest and destroyed many homes and buildings. The U.S. Geological Survey collected samples from the Harris, Witch, Grass Valley, Ammo, Santiago, Canyon, Jesusita, and Station fires for testing to identify any possible characteristics of the ashes and soils from burned areas that may be of concern for their impact on water quality, human health, and endangered species. The samples were subjected to analysis for bulk chemical composition for 44 elements by inductively coupled plasma mass spectrometry (ICP-MS) after acid digestion and de-ionized water leach tests for pH, alkalinity, conductivity, and anions. Water leach tests generated solutions ranging from pH 10-12, suggesting that ashes can generate caustic alkalinity in contact with rainwater or body fluids (for example, sweat and fluids in the respiratory tract). Samples from burned residential areas in the 2007 fires had elevated levels for several metals, including: As, Pb, Sb, Cu, Zn, and Cr. In some cases, the levels found were above the U.S. Environmental Protection Agency (USEPA) preliminary remediation goals (PRG) for soils. Speciation analyses were conducted on de-ionized water and simulated lung fluid leachates for As(III), As(V), Se(IV), Se(VI), Cr(III), and Cr(VI). All species were determined in the same analytical run using an ion-pairing HPLC-ICP-MS method. For leachates containing high levels of total Cr, the majority of the chromium was present in the hexavalent, Cr(VI), form. Higher total and hexavalent chromium levels were observed for samples collected from burned residential areas. Arsenic was also generally present in the more oxidized, As(V), form. Selenium (IV) and (VI) were present, but typically at levels below 2 ppb for most samples. Stability studies of leachate solutions under different storage conditions were performed and the suitability of different sample preservation methods for speciation analysis will be discussed.

Open-File Report↗