Geology ReportsSearch

SEARCH · Geology Reports

Results for “Environmental Health”

Search indexed USGS publications on groundwater, aquifers, geologic maps, mineral resources and earthquakes. Explore source records by subject and place.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 199 records · Page 11Linked to original sources

Subchronic hepatotoxicity of selenomethionine ingestion in mallard ducks

Twoyearold male mallards (Anas platyrhynchos) received a control diet (0.2 ppm Se) or diets containing 1, 2, 4, 8, 16, or 32 ppm Se as selenomethionine for 14 wk. Se accumulated readily in the liver in a dosedependent manner, reaching a mean concentration of 29 ppm (wet weight) in the 32 ppm group. Dietary Se of 2 ppm or greater increased plasma glutathione peroxidase activity. Mortality (10%) and histopathological effects, including bile duct hyperplasia and hemosiderin pigmentation of the liver and spleen, occurred in the 32 ppm group. These histopathological effects were accompanied by lower hemoglobin concentrations (16 and 32 ppm groups) and hematocrit (32 ppm group), and elevated plasma alkaline phosphatase activity (32 ppm group) indicative of cholestatic liver inJury. Other manifestations of hepatotoxicity included significant linear dose responses for hepatic oxidized glutathione (GSSG) concentrations and ratio of GSSG to reduced glutathione (GSH). Means for both of these responses differed from controls in groups receiving 832 ppm Se. Mean hepatic GSH and malondialdehyde (a measure of lipid peroxidation) concentrations were significantly elevated in the 16 and 32 ppm groups. Subchronic effects of selenomethionine, which occurs in vegetation, are of particular interest with respect to the health of wild aquatic birds in seleniferous locations.

Journal of Toxicology and Environmental Health

Characterization of flood sediments from Hurricanes Katrina and Rita and potential implications for human health and the environment

The flooding in the greater New Orleans, La., area that resulted from Hurricanes Katrina and Rita in August and September 2005 left behind accumulations of sediments up to many centimeters thick on streets, lawns, parking lots, and other flat surfaces (fig. 1). During the flood dewatering and subsequent cleanup, there were concerns that these sediments might contain pathogens and chemical contaminants that would pose a health risk to emergency responders, cleanup workers, and local residents who came into contact with the wet sediments or inhaled dusts generated from dried sediments. In response to these concerns, U.S. Geological Survey (USGS) scientists and colleagues characterized the potential environmental and health hazards of hurricane flood sediments from the greater New Orleans and Slidell, La., area.

Louisiana

National Acid Precipitation Assessment Program Report to Congress: An integrated assessment

Acid deposition, more commonly known as acid rain, occurs when emissions of sulfur dioxide (SO2) and nitrogen oxides (NOx) react in the atmosphere (with water, oxygen, and oxidants) to form various acidic compounds. These acidic compounds then fall to earth in either a wet form (rain, snow, and fog) or a dry form (gases, aerosols, and particles). Prevailing winds transport the acidic compounds hundreds of miles, often across state and national borders. At certain levels the acidic compounds, including small particles such as sulfates and nitrates can cause many negative human health and environmental effects. While ecosystems are subject to many stresses, including land-use changes, climate change, and variations in hydrologic and meteorologic cycles, the scientific literature has clearly demonstrated that these pollutants can: • Degrade air quality, • Impair visibility, • Damage public health, • Acidify lakes and streams, • Harm sensitive forests, • Harm sensitive coastal ecosystems, and • Accelerate the decay of building materials, paints, and cultural artifacts such as buildings, statues, and sculptures. Title IV was passed by Congress as part of the 1990 Clean Air Act Amendments to reduce emissions of SO 2 and NO x from fossil fuel-burning power plants in order to protect ecosystems suffering damage from acid deposition and to improve air quality. At the same time, the National Acid Precipitation Assessment Program (NAPAP) was asked to periodically assess and report to Congress on the implementation of the Acid Rain Program, recent scientific knowledge surrounding acid deposition and its effects, and the reduction in acid deposition necessary to prevent adverse ecological effects. This NAPAP Report focuses primarily on emission reductions from power plants, both in terms of assessing past reductions under the Acid Rain Program and in projecting the ecological effects of additional reductions of SO 2 and NO x . It should be noted that power generation currently contributes approximately 69% of the SO 2 emissions and 22% of the NO x emissions nationwide. This contribution is decreasing as emissions from power generation continue to decrease, making the other sources of these pollutants more prominent. Modeling suggests that even if SO 2 emissions from power generation were reduced to zero, some lakes and streams would remain acidic due to acid deposition. However, there are several other regulations that reduce emissions of SO 2 and NO x from these non-power generation sources, such as the Tier II mobile source standards, the Heavy Duty Diesel standards, and the Clean Air Non-Road Diesel Rule, that have also been promulgated since 1990. These regulations, primarily designed to bring counties into attainment with fine particle and ozone air quality standards, also incidentally reduce emissions that contribute to acid deposition. Implementation of Title IV has successfully and substantially reduced emissions of SO 2 and NO x from power generation at a significantly lower cost than expected: • In 2002, SO 2 emissions were 10.2 million tons, 35% lower than 1990 emissions and 40% lower than 1980 emissions.* • In 2002, NO x emissions were 4.5 million tons, 33% lower than 1990 emissions. In addition, SO 2 emissions from all sources have decreased by 32% since 1990 and emissions of NO x from all sources have decreased by 12% since 1990. Power generating sources continue to close in on the goal of reducing power plant SO 2 emissions from 1980 levels by 50% (to 8.95 million tons) as required by the 1990 Clean Air Act. Power generating sources have also exceed­ed the goal of a two million ton reduction in NO x emissions from projected 2000 levels as required by the 1990 Clean Air Act. These emission reductions have contributed to measurable improvements in air quality, reductions in acid deposition, and the beginnings of recovery of acid-sensitive waters in some areas: • SO2 concentrations in the atmosphere (a precursor to fine particles and acid deposition) have decreased since 1990. Average annual SO2 concentrations in the Northeast in 2000–2002 were 40% lower than they were in 1989–1991, concentrations in the mid-Atlantic were 30% lower, concentrations in the Southeast were 35% lower, and concentrations in the Midwest were 45% lower. • Sulfate concentrations in the atmosphere (a major component of fine particles, especially in the East) have decreased since 1990 as well. Average annual sulfate concentrations in the Northeast and Midwest in 2000–2002 were approximately 30% lower than they were in 1989–1991, and concentrations in the mid-Atlantic and Southeast were 25% lower. • Wet sulfate deposition, a major component of acid rain, has also decreased since 1990. Average annual sulfate deposition in the Northeast in 2000–2002 was 40% lower than it was in 1989–1991, deposition in the mid-Atlantic and Midwest was 35% lower, and deposition in the Southeast was 25% lower. • Wet nitrate deposition has not decreased regionally from historical levels because of the relatively moderate NO x reduction from power plants and the continuing large contribution (over 50% of total NOx emissions) from other sources of NO x such as vehicles and nonroad vehicles. • Although visibility has begun to improve in some parts of the U.S., there is still significant impairment of visibility in many national parks and other Class I areas throughout the U.S. • Acid neutralizing capacity is beginning to rise in some surface waters in the Northeast, including lakes in the Adirondack Mountains (see graphic below). This is an indication that recovery from acidification is occurring in those areas.

Report to Congress

Quantitative microbial risk assessment for contaminated private wells in the fractured dolomite aquifer of Kewaunee County, Wisconsin

Background: Private wells are an important source of drinking water in Kewaunee County, Wisconsin. Due to the region’s fractured dolomite aquifer, these wells are vulnerable to contamination by human and zoonotic gastrointestinal pathogens originating from land-applied cattle manure and private septic systems. Objective: We determined the magnitude of the health burden associated with contamination of private wells in Kewaunee County by feces-borne gastrointestinal pathogens. Methods: This study used data from a year-long countywide pathogen occurrence study as inputs into a quantitative microbial risk assessment (QMRA) to predict the total cases of acute gastrointestinal illness (AGI) caused by private well contamination in the county. Microbial source tracking was used to associate predicted cases of illness with bovine, human, or unknown fecal sources. Results: Results suggest that private well contamination could be responsible for as many as 301 AGI cases per year in Kewaunee County, and that 230 and 12 cases per year were associated with a bovine and human fecal source, respectively. Furthermore, Cryptosporidium parvum was predicted to cause 190 cases per year, the most out of all 8 pathogens included in the QMRA. Discussion: This study has important implications for land use and water resource management in Kewaunee County and informs the public health impacts of consuming drinking water produced in other similarly vulnerable hydrogeological settings.

Wisconsin

Atmospheric transport of mold spores in clouds of desert dust

Fungal spores can be transported globally in clouds of desert dust. Many species of fungi (commonly known as molds) and bacteria--including some that are human pathogens--have characteristics suited to long-range atmospheric transport. Dust from the African desert can affect air quality in Africa, Europe, the Middle East, and the Americas. Asian desert dust can affect air quality in Asia, the Arctic, North America, and Europe. Atmospheric exposure to mold-carrying desert dust may affect human health directly through allergic induction of respiratory stress. In addition, mold spores within these dust clouds may seed downwind ecosystems in both outdoor and indoor environments.

Archives of Environmental Health

Assessing the relationship between cyanobacteria blooms and respiratory-related hospital visits: Green Bay, Wisconsin 2017–2019

Potential acute and chronic human health effects associated with exposure to cyanobacteria and cyanotoxins, including respiratory symptoms, are an understudied public health concern. We examined the relationship between estimated cyanobacteria biomass and the frequency of respiratory-related hospital visits for residents living near Green Bay, Lake Michigan, Wisconsin during 2017–2019. Remote sensing data from the Cyanobacteria Assessment Network was used to approximate cyanobacteria exposure through creation of a metric for cyanobacteria chlorophyll-a (Chl BS ). We obtained counts of hospital visits for asthma, wheezing, and allergic rhinitis from the Wisconsin Hospital Association for ZIP codes within a 3-mile radius of Green Bay. We analyzed weekly counts of hospital visits versus cyanobacteria, which was modelled as a continuous measure (Chl BS ) or categorized according to World Health Organization's (WHO) alert levels using Poisson generalized linear models. Our data included 2743 individual hospital visits and 114 weeks of satellite derived cyanobacteria biomass indicator data. Peak values of Chl BS were observed between the months of June and October. Using the WHO alert levels, 60% of weeks were categorized as no risk, 19% as Vigilance Level, 15% as Alert Level 1, and 6% as Alert Level 2. In Poisson regression models adjusted for temperature, dewpoint, season, and year, there was no association between Chl BS and hospital visits (rate ratio [RR] [95% Confidence Interval (CI)] = 0.98 [0.77, 1.24]). There was also no consistent association between WHO alert level and hospital visits when adjusting for covariates (Vigilance Level: RR [95% CI] 0.88 [0.74, 1.05], Alert Level 1: 0.82 [0.67, 0.99], Alert Level 2: 0.98 [0.77, 1.24], compared to the reference no risk category). Our methodology and model provide a template for future studies that assess the association between cyanobacterial blooms and respiratory health.

Wisconsin

Economic valuation of health benefits from using geologic data to communicate radon risk potential

Background: Radon exposure is the second leading cause of lung cancer worldwide and represents a major health concern within and outside the United States. Mitigating exposure to radon is especially critical in places with high rates of tobacco smoking (e.g., Kentucky, USA), as radon-induced lung cancer is markedly greater among people exposed to tobacco smoke. Despite homes being a common source of radon exposure, convincing homeowners to test and mitigate for radon remains a challenge. A new communication strategy to increase radon testing among Kentucky homeowners utilizes fine-scale geologic map data to create detailed radon risk potential maps. We assessed the health benefits of this strategy via avoided lung cancer and associated premature mortality and quantified the economic value of these benefits to indicate the potential utility of using geologic map data in radon communication strategies. Methods: We estimated the change in radon testing among all 120 counties in Kentucky following a new communication strategy reliant on geologic maps. We approximated the resultant potential change in radon mitigation rates and subsequent expected lung cancer cases and mortality avoided among smokers and non-smokers exposed to ≥4 pCi/L of radon in the home. We then applied the value of a statistical life to derive the economic value of the expected avoided mortality. Results: The new communication strategy is estimated to help 75 Kentucky residents in one year avoid exposure to harmful radon levels via increased testing and mitigation rates. This equated to the potential avoidance of approximately one premature death due to lung cancer, with a net present value of \$3.4 to \$8.5 million (2016 USD). Conclusions: Our analysis illustrates the potential economic value of health benefits associated with geologic map data used as part of a communication strategy conveying radon risk to the public. Geologic map data are freely available in varying resolutions throughout the United States, suggesting Kentucky’s radon communication strategy using geologic maps can be employed in other states to educate the public about radon. As this is only a single application, in a single state, the economic and health benefits of geologic map data in educating the public about radon are likely to exceed our estimates.

Kentucky

Report from Ground Zero: How geoscientists aid in the aftermath of environmental disasters

People around the world remember when they first learned of the attacks on New York City’s World Trade Center towers on Sept. 11, 2001. For me, the memories are vivid — my feelings of shock, horror and sadness were similarly etched on the faces of all the attendees of a mining and the environment workshop in Buenos Aires, Argentina, where I was speaking. At that time, I had no idea that our small research group at the U.S. Geological Survey in Denver, Colo., would soon be called upon to help public officials understand the potential health and environmental implications of the disaster and the ensuing rescue, recovery and cleanup efforts.

Earth Magazine

Assessment of resource potential from mine tailings using geostatistical modeling for compositions: A methodology and application to Katherine Mine site, Arizona, USA

The mining industry, in most cases, targets a specific valuable commodity that is present in small quantities within large volumes of extracted material. After milling and processing, most of the extracted material and the effluents are stored as waste (tailings) in impoundments, such as dams or waste dumps, or are backfilled into underground mines. In time, tailing materials may become an issue of environmental and health concern due to the hazardous elements, ions, and oxides contained within the waste material. In addition, handling and storage of such waste in dams may pose the risk of dam failure with catastrophic consequences to nature and nearby communities. On the other hand, tailings may offer potential as secondary sources of critical elements (CEs), including rare earth elements (REEs), which may have been overlooked during primary production and processing. Therefore, treating mine tailings as a resource has economic and environmental benefits by reducing the waste from new and historical mine sites through remining. One of the critical steps for taking advantage of these benefits is to spatially quantify the resources and the pollutants, which require the application of adequate data analysis and modeling methods, often to compositional geochemical data. Utilizing adequate methods is especially important for correctly quantifying resource potential, as the quantities will often be at low concentrations. This work presents quantification of resource potential (Au, Ag, Cu, Zn, Pb) and elements of environmental concern (Hg and As) from the tailings of a historic mine site, Katherine Mine, AZ, USA. Data reported by the U.S. Bureau of Mines (USBM) after extensive field campaigns in the 1990s, including sampling from tailing impoundment and surrounding areas for geochemical characterization and geophysical surveys, were used. First, compositional data (CoDa) analysis was employed to explore associations of sampling locations, geochemical parts, and the clustering of samples. Next, sequential Gaussian simulation (SGSIM) was applied to samples that showed a genetic link to tailing material after isometric log-ratio transformation (ilr) and mix/max autocorrelation factor (MAF) transformation for spatial modeling and uncertainty evaluation. Geostatistical results revealed spatial variability of concentrations within the tailing area. Uncertainty evaluation based on realizations indicated that Cu (14.27–20.01 t), Zn (44.23–76.23 t), and Pb (22.56–38.28 t) are the most abundant elements within a 5 %–95 % interval, followed by Ag and Au (~5.3 and 0.18 t, at 50th percentile), respectively. Of the elements of health concern, As was found to be ~4.8 t (50th percentile) in the tailing area. The work also showed that ~0.51 t As, 0.005 t Hg, 0.020 t of Au, and 0.62 t of Ag were carried to Lake Mohave by an ephemeral stream called Katherine Wash, which transects the tailings.

Arizona

Preliminary Toxicological Analysis of the Effect of Coal Slurry Impoundment Water on Human Liver Cells

Coal is usually 'washed' with water and a variety of chemicals to reduce its content of sulfur and mineral matter. The 'washings' or 'coal slurry' derived from this process is a viscous black liquid containing fine particles of coal, mineral matter, and other dissolved and particulate substances. Coal slurry may be stored in impoundments or in abandoned underground mines. Human health and environmental effects potentially resulting from leakage of chemical substances from coal slurry into drinking water supplies or aquatic ecosystems have not been systematically examined. Impoundments are semipermeable, presenting the possibility that inorganic and organic substances, some of which may be toxic, may contaminate ground or surface water. The Agency for Toxic Substances and Disease Registry, part of the Centers for Disease Control and Prevention, has concluded that well water in Mingo County, West Virginia, constitutes a public health hazard.

Open-File Report

Global change-driven use of onshore habitat impacts polar bear faecal microbiota

The gut microbiota plays a critical role in host health, yet remains poorly studied in wild species. Polar bears (Ursus maritimus), key indicators of Arctic ecosystem health and environmental change, are currently affected by rapid shifts in habitat that may alter gut homeostasis. Declining sea ice has led to a divide in the southern Beaufort Sea polar bear subpopulation such that an increasing proportion of individuals now inhabit onshore coastal regions during the open-water period (‘onshore bears’) while others continue to exhibit their typical behaviour of remaining on the ice (‘offshore bears’). We propose that bears that have altered their habitat selection in response to climate change will exhibit a distinct gut microbiota diversity and composition, which may ultimately have important consequences for their health. Here, we perform the first assessment of abundance and diversity in the faecal microbiota of wild polar bears using 16S rRNA Illumina technology. We find that bacterial diversity is significantly higher in onshore bears compared to offshore bears. The majority of unique bacterial taxa for onshore bears belonged to the phyla Proteobacteria (a proposed indicator of poor health in adult humans), whereas for offshore bears, Firmicutes (associated with adiposity) dominated. We conclude that climate-driven changes in polar bear land use are associated with distinct microbial communities. In doing so, we present the first case of global change mediated alterations in the gut microbiota of a free-roaming wild animal.

Alaska

Contaminants of emerging concern in the Great Lakes: Science to inform management practices for protecting the health and integrity of wildlife populations from adverse effects: GLRI action plan I, focus area 1, goal 5

Executive Summary: Under Action Plan I (2010-2014) of the Great Lakes Restoration Initiative (GLRI), Federal and Academic partners began an investigation of the presence and distribution of contaminants of emerging concern (CECs) in the Great Lakes and potential impacts on fish and wildlife. The term CECs is applied to a broad range of chemicals that are currently in use but for which we currently lack good understanding of whether fish, wildlife, or humans are being exposed and/or whether negative health or environmental effects are expected if exposure occurs. Pharmaceuticals, personal care products, flame retardants, many current use pesticides, and poly- and perfluorinated chemicals are some well-known groups of CECs, but there is no definitive or comprehensive list that can be used to support the management of CECs to reduce impacts on the Great Lakes ecosystem. Four overarching goals were identified for this collaborative investigation: 1. Evaluate the sources, occurrence, and distribution of CECs across the Great Lakes Basin. 2. Examine associations between the distribution of CECs and land-use patterns. 3. Review both scientific literature and field-generated data to determine the potential for CECs to cause adverse effects on Great Lakes fish and wildlife populations. 4. Develop efficient strategies to survey and/or monitor for threats that CECs may pose in order to take effective management actions before those threats evolve into large scale impacts on Great Lakes ecosystems or the services they provide. Achievement of these goals ensures progress towards Focus Area 1: Toxic Substances and Areas of Concern from GLRI Action Plan I, Goal 5: “ The health and integrity of wildlife populations and habitat are protected from adverse chemical and biological effects associated with the presence of toxic substances in the Great Lakes Basin ”. This large-scale research effort was comprised of individual and collaborative projects from multiple federal agencies and academic institutions, involving over 85 investigators, and overseen by the U.S. Environmental Protection Agency (EPA) Region 5, Great Lakes National Program Office. Partners include the United States Geological Survey, the National Oceanic and Atmospheric Administration, U.S. Fish and Wildlife Service, Saint Cloud State University, the U.S. EPA Office of Research and Development, and the U.S. Army Corps of Engineers. Key findings: 1. Contaminants of emerging concern were found throughout the monitored Great Lakes tributaries, but types and concentrations vary in association with regional land use. CECs were detected in nearly all samples collected. The type and concentration of the specific contaminants detected varied considerably among field sites and in association with land use type, such as urban, agricultural, wetland, 2 or forest. Contaminants were detected in the water column, sediment, and tissues of all species surveyed in the current work (mussels, aquatic insects, fish, and insect-eating birds). 2. There were over 20 contaminants for which CEC concentrations approached or exceeded those reported to cause toxicity in laboratory experiments. This was based on detection in water, sediments and or biota at one or more field sites. These contaminants represent compounds that warrant further investigation and monitoring with respect to potential impacts in certain areas of the Great Lakes basin. Based on the present investigation, compounds of greatest concern include: polycyclic aromatic hydrocarbons, associated with oil-based products and combustion of organic matter; atrazine, an herbicide; dichlorvos, an insecticide; and ibuprofen and venlafaxine, both pharmaceuticals. 3. Results suggest that mixtures of CECs presently found in most Great Lakes tributary locations surveyed may elicit subtle biological effects, but likely are not, alone, causing obvious detriment to current communities of fish and wildlife. CECs detected in the Great Lakes were associated with subtle biological effects like changes in gene expression, altered circulating glucose, etc. in both wild-caught and laboratory-reared organisms. These effects were generally not indicative of reproductive failure or mortality. However, the effects may have more serious implications when combined with other sources of stress like habitat degradation, changing climate conditions, and competition with invasive species. Due to limited historical data, it is unknown whether severe CEC-related impacts have already affected aquatic communities in waterbodies that have received long-term inputs of these contaminants. Likewise, under Action Plan I, biological effects were not necessarily evaluated at the sites where CEC concentrations exceeding laboratory toxicity thresholds were detected. As a result, strategic, ongoing surveillance and monitoring of CECs is warranted. This collaborative investigation resulted in new tools, approaches, and data that can be used to inform and support the management of CECs to reduce their impacts on Great Lakes natural resources. The following products of this research effort are available through https://communities.geoplatform.gov/glri/ or by contacting the investigators (see technical chapters found in Appendices A-F): 1. Database of CEC occurrence and concentrations in US tributary streams. The database includes CEC detections in water, sediment, and fish and wildlife tissues, and represents the most comprehensive survey of CECs in the Great Lakes Region. 2. Synopses of results and key findings. Integrated summaries of results, conclusions, and management implications of the CEC research are available through reports, topical fact sheets, and presentations. 3. Technical publications: This collaborative research effort has resulted in over 50 peer-reviewed publications, agency reports, and data releases that can be of use to resource managers, the scientific community, and members of the public. 4. Innovative tools. Innovative monitoring devices, sampling equipment, conceptual frameworks, and software applications were developed over the course of this 3 research. These tools are transferable to stakeholders via internet accessibility or via specifications, instructions, and demonstration detailed in technical publications. Hypotheses to guide CECs research under Action Plan II. Findings from 2010-2014 were used to guide further research in 2015-2018 for basin-wide surveillance of CECs and for sites warranting further study of potential biological impacts of CECs. Additional surveillance included both evaluation of additional classes of contaminants and expanded lists for chemical classes shown to be of greatest concern. Mixtures of some of the most frequently detected contaminants were also tested in laboratory studies to understand whether long term exposures to multiple contaminants may result in effects not evident from uncontrolled, short-term field experiments.

Great Lakes

Taste and odor occurrence in Lake William C. Bowen and Municipal Reservoir #1, Spartanburg County, South Carolina

The U.S. Geological Survey and Spartanburg Water are working cooperatively on an ongoing study of Lake Bowen and Reservoir #1 to identify environmental factors that enhance or influence the production of geosmin in the source-water reservoirs. Spartanburg Water is using information from this study to develop management strategies to reduce (short-term solution) and prevent (long-term solution) geosmin occurrence. Spartanburg Water utility treats and distributes drinking water to the Spartanburg area of South Carolina. The drinking water sources for the area are Lake William C. Bowen (Lake Bowen) and Municipal Reservoir #1 (Reservoir #1), located north of Spartanburg. These reservoirs, which were formed by the impoundment of the South Pacolet River, were assessed in 2006 by the South Carolina Department of Health and Environmental Control (SCDHEC) as being fully supportive of all uses based on established criteria. Nonetheless, Spartanburg Water had noted periodic taste and odor problems due to the presence of geosmin, a naturally occurring compound in the source water. Geosmin is not harmful, but its presence in drinking water is aesthetically unpleasant.

South Carolina

Assessment of arsenic concentrations in domestic well water, by town, in Maine 2005-09

Prior studies have established that approximately 10 percent of domestic wells in Maine have arsenic levels greater than the U.S. Environmental Protection Agency maximum contaminant limit (10 micrograms per liter (ug/L)). Of even greater concern are multiple discoveries of wells with very high arsenic levels (> 500 ug/L) in several areas of the State. A study was initiated to assist the Maine Center for Disease Control and Prevention (ME-CDC) in developing a better understanding of the statewide spatial occurrence of wells with elevated arsenic levels at the individual town level, identify areas of the State that should be targeted for increased efforts to promote well-water testing, and generate data for potential use in predicting areas of the State likely to have very high levels of arsenic. The State's Health and Environmental and Testing Laboratory (HETL) annually analyzes samples from thousands of domestic wells for arsenic. Results of arsenic analyses of domestic well water submitted to the HETL from 2005 to 2009 were screened and organized, by town, in order to summarize the results for all towns with samples submitted to the HETL. In order to preserve the privacy of well owners, the screening and organization of samples was conducted in the offices of the ME-CDC, following applicable Maine and United States laws, rules, and privacy policies. After screening, the database contained samples from 531 towns in Maine and from 11,111 individual wells. Of those towns, 385 had samples from 5 or more individual wells, 174 towns had samples from 20 or more individual wells, and 49 towns had samples from 60 or more wells. These samples, because they were submitted by homeowners and were not part of a random sample, may not be representative of all wells in a given area. The minimum, maximum, and median arsenic values for the towns with five or more samples were calculated, and the maximum and median values were mapped for the State. The percentages of samples exceeding 10, 50, 100, and 500 ug/L were calculated for the 174 towns with 20 or more sampled wells, and statewide maps were prepared for each of these categories. More than 25 percent of the sampled wells in 44 towns exceeded 10 ug/L. Many fewer towns had wells with samples that exceeded the 50, 100, or 500 ug/L categories. For 19 towns, more than 10 percent of the sampled wells had arsenic concentrations that exceeded 50 ug/L, and in 45 towns, 1 percent or more exceeded 100 ug/L. Of these, Surry in Hancock County had 120 wells tested, and 23 percent of those wells had arsenic concentrations that exceeded 100 ug/L, which is a much higher rate than for other towns. In only four towns (Danforth in Washington County, Surry and Blue Hill in Hancock County, and Woolwich in Sagadahoc County), 1 percent or more of the sampled wells had arsenic concentrations greater than 500 ug/L during 2005-09. The distribution of high arsenic concentrations in wells follows some geographic patterns, which are generally geologically controlled. There are clusters or belts of towns with high arsenic concentrations (> 50 ug/L), such as in southern coastal areas, the Kennebec County area, and towns along the central coastal part of Maine. In contrast, there are areas of the State with low arsenic concentrations, such as the northernmost towns, as well as towns in the western and west-central areas. There appear to be three distinct large-scale areas of high concentrations of arsenic in groundwater-one in southern coastal areas, one in central Kennebec County, and one in the town of Ellsworth (Hancock County) and the surrounding areas. In addition, several smaller clusters of isolated high concentrations of arsenic in groundwater exist. Earlier testing has identified other clusters of very high arsenic concentrations in groundwater in the towns of Northport, Buxton/Hollis, and Waldoboro, but those samples were collected before 2005 and did not factor in this analysis.

Scientific Investigations Report

Effects of zinc smelter emissions on farms and gardens at Palmerton, PA

In 1979, before the primary Zn smelter at Palmerton was closed due to excessive Zn and Cd emissions and change in the price of Zn, we were contacted by a local veterinarian regarding death of foals (young horses) on farms near the smelter. To examine whether Zn or Cd contamination of forage or soils could be providing potentially toxic levels of Zn or other elements in the diets of foals, we measured metals in forages, soils, and feces of grazing livestock on two farms near Palmerton. The farms were about 2.5 and about 10 km northeast of the East stack. Soils, forages, and feces were greatly increased in Zn and Cd. Soil, forage, and fecal Zn were near 1000 mg/kg and Cd, 10-20 mg/kg at farm A (2.5 km) compared to normal background levels of 43 mg Zn and 0.2 mg Cd/kg, respectively. Liver and kidney of cattle raised on Farm A were increased in Zn and Cd, indicating that at least part of the Zn and Cd in smelter contaminated forages was bioavailable. During the farm sampling, we obtained soil from one garden in Palmerton within 200 m of the primary (West) smelter. The Borough surrounds the smelter facility in a valley. Because soil Cd was near 100 mg/kg, we sampled garden soils and vegetables from over 40 gardens in 6 randomly selected blocks and in rural areas at different distances from the smelter during September, 1980. All homes were contacted on each sampled block. Nearly all homes had some garden, while at least 2 appeared to grow over 50% of their annual vegetable and potato consumption. Palmerton garden soils averaged 76 mg Cd/kg and 5830 mg Zn/kg. Gardeners had been taught to add limestone and organic fertilizers to counteract yield reduction and chlorosis due to the excessive soil Zn. Gardens with over 5000 mg Zn/kg were nearly allover pH 7, and many were calcareous. Because the smelter had not yet ceased operations in 1980, crops could have been polluted by aerosol Zn and Cd emitted by the smelter. Crop Zn and Cd were extremely high, about 100 times normal Cd levels. In more distant gardens, soil metals were not so high, and gardeners had not added as much limestone. Bean rotated with the potatoes and leafy vegetables often suffered chlorosis and visible yield reduction. Potatoes contained up to 6 mg Cd/kg dry wt. compared to backgrournd 0.20 mg/kg DW. An estimate of potential Zn and Cd intakes due to the contaminated crops was made using the teen-aged male diet model, and average Cd intakes would be 250 ug/day if diets contained 100% locally grown leafy and root vegetables and potatoes. Gardeners were warned to restrict consumption of garden grown leafy and root vegetables and potatoes, and to apply 22 T/A of limestone to restrict Cd uptake. Use of improved adult diet models, and increased understanding of the effect of Zn on Cd bioavailability indicate that little Cd risk may result from consuming garden vegetables grown at Palmerton. Individuals appear to be protected because Zn accompanied crop Cd, they grew only small amounts of vegetables in most cases, and aerosol pollution of crops has ceased. Reduced Zn emissions, and Cu supplementation have prevented further health effects on foals or cattle. Detailed examination of these risks is needed to develop remedial measures for both farms and gardens in the Zn + Cd polluted soils near Zn smelters at many locations in the United States and other countries. Remedial actions are necessarary to prevent chronic Zn toxicity to crops and livestock, and minimize the risk of chronic Cd toxicity to humans who consume locally grown garden crops.

Pennsylvania

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

Geogenic organic contaminants in the low-rank coal-bearing Carrizo-Wilcox aquifer of East Texas, USA

The organic composition of groundwater along the Carrizo-Wilcox aquifer in East Texas (USA), sampled from rural wells in May and September 2015, was examined as part of a larger study of the potential health and environmental effects of organic compounds derived from low-rank coals. The quality of water from the low-rank coal-bearing Carrizo-Wilcox aquifer is a potential environmental concern and no detailed studies of the organic compounds in this aquifer have been published. Organic compounds identified in the water samples included: aliphatics and their fatty acid derivatives, phenols, biphenyls, N-, O-, and S-containing heterocyclic compounds, polycyclic aromatic hydrocarbons (PAHs), aromatic amines, and phthalates. Many of the identified organic compounds (aliphatics, phenols, heterocyclic compounds, PAHs) are geogenic and originated from groundwater leaching of young and unmetamorphosed low-rank coals. Estimated concentrations of individual compounds ranged from about 3.9 to 0.01 μg/L. In many rural areas in East Texas, coal strata provide aquifers for drinking water wells. Organic compounds observed in groundwater are likely to be present in drinking water supplied from wells that penetrate the coal. Some of the organic compounds identified in the water samples are potentially toxic to humans, but at the estimated levels in these samples, the compounds are unlikely to cause acute health problems. The human health effects of low-level chronic exposure to coal-derived organic compounds in drinking water in East Texas are currently unknown, and continuing studies will evaluate possible toxicity.

Texas

Assessing nonpoint-source uranium pollution in an irrigated stream-aquifer system

Uranium (U) in rocks and soils of arid and semi-arid environments can be mobilized by irrigation and fertilization, posing environmental and health risks. Elevated U, along with selenium (Se) and nitrate (NO 3 ) co-constituents, necessitates careful monitoring and management. We developed a distributed-parameter numerical model to assess U pollution in an irrigated stream-aquifer system, applying it to a 552 km 2 region in Colorado's Lower Arkansas River Valley (LARV) over 14 years. A MODFLOW model, describing groundwater and stream flow, was coupled with an RT3D-OTIS model to portray reactive U transport. Calibration using the PESTPP-iES iterative ensemble smoother (iES) software indicated good agreement with observed U concentrations. The model revealed substantial and variable U levels across the LARV, highlighting potential hotspots and possible contributing factors, such as geological composition of the bedrock and near-surface shale and aquifer sediments derived from them, irrigation practices, and riparian landscape. U levels exceed the chronic standard (85th percentile = 30 μg/L, set by the US Environmental Protection Agency), which is the permissible regulatory threshold, in groundwater across 44 % of the region and along the river by an average factor of 2.9. Simulated average U concentrations in the non-riparian aquifer and river are 124 μg/L and 60 μg/L, respectively, compared with 112 μg/L and 62 μg/L for measured values. The average 85th percentile U concentration is 222 μg/L in the aquifer and 82 μg/L in the river. Average simulated U mass loading to the river is 0.17 kg/day per km, compared to an estimated 0.23 kg/day per km. Findings provide a baseline for comparing future simulated outcomes of alternative best management practices (BMPs) for U pollution mitigation and offer a methodology applicable to other irrigated regions.

Colorado