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USGS2005

Mapping and prediction of Coal Workers' Pneumoconiosis with bioavailable iron content in the bituminous coals

Based on the first National Study of Coal Workers' Pneumoconiosis (CWP) and the U.S. Geological Survey database of coal quality, we show that the prevalence of CWP in seven coal mine regions correlates with levels of bioavailable iron (BAI) in the coals from that particular region (correlation coefficient r = 0.94, p < 0.0015). CWP prevalence is also correlated with contents of pyritic sulfur (r = 0.91, p < 0.0048) or total iron (r = 0.85, p < 0.016) but not with coal rank (r = 0.59, p < 0.16) or silica (r = 0.28, p < 0.54). BAI was calculated using our model, taking into account chemical interactions of pyrite, sulfuric acid, calcite, and total iron. That is, iron present in coals can become bioavailable by pyrite oxidation, which produces ferrous sulfate and sulfuric acid. Calcite is the major component in coals that neutralizes the available acid and inhibits iron's bioavailabiity. Therefore, levels of BAI in the coals are determined by the available amounts of acid after neutralization of calcite and the amount of total iron in the coals. Using the linear fit of CWP prevalence and the calculated BAI in the seven coal mine regions, we have derived and mapped the pneumoconiotic potencies of 7,000 coal samples. Our studies indicate that levels of BAI in the coals may be used to predict coal's toxicity, even before large-scalen mining.

Environmental Health Perspectives↗

USGS2005

Workgroup report: Drinking-water nitrate and health - Recent findings and research needs

Human alteration of the nitrogen cycle has resulted in steadily accumulating nitrate in our water resources. The U.S. maximum contaminant level and World Health Organization guidelines for nitrate in drinking water were promulgated to protect infants from developing methemoglobinemia, an acute condition. Some scientists have recently suggested that the regulatory limit for nitrate is overly conservative; however, they have not thoroughly considered chronic health outcomes. In August 2004, a symposium on drinking-water nitrate and health was held at the International Society for Environmental Epidemiology meeting to evaluate nitrate exposures and associated health effects in relation to the current regulatory limit. The contribution of drinking-water nitrate toward endogenous formation of N-nitroso compounds was evaluated with a focus toward identifying subpopulations with increased rates of nitrosation. Adverse health effects may be the result of a complex interaction of the amount of nitrate ingested, the concomitant ingestion of nitrosation cofactors and precursors, and specific medical conditions that increase nitrosation. Workshop participants concluded that more experimental studies are needed and that a particularly fruitful approach may be to conduct epidemiologic studies among susceptible subgroups with increased endogenous nitrosation. The few epidemiologic studies that have evaluated intake of nitrosation precursors and/or nitrosation inhibitors have observed elevated risks for colon cancer and neural tube defects associated with drinking-water nitrate concentrations below the regulatory limit. The role of drinking-water nitrate exposure as a risk factor for specific cancers, reproductive outcomes, and other chronic health effects must be studied more thoroughly before changes to the regulatory level for nitrate in drinking water can be considered.

Environmental Health Perspectives↗

USGS2005

Evidence of detrimental effects of environmental contaminants on growth and reproductive physiology of white sturgeon in impounded areas of the Columbia River

This study sought to determine whether wild white sturgeon from the Columbia River (Oregon) were exhibiting signs of reproductive endocrine disruption. Fish were sampled in the free-flowing portion of the river (where the population is experiencing reproductive success) and from three reservoirs behind hydroelectric dams (where fish have reduced reproductive success). All of the 18 pesticides and almost all of the 28 polychlorinated biphenyls (PCBs) that were analyzed in livers and gonads were detected in at least some of the tissue samples. Metabolites of p,p???-dichlorodiphenyltrichloroethane (DDT) [p,p???-dichlorodiphenyldichloroethylene (DDE) and p,p???-1,1-dichloro-2,2-bis(4-chlorophenyl)ethane (DDD)] were consistently found at relatively high levels in fish. Some males and immature females showed elevated plasma vitellogenin; however, concentrations were not correlated with any of the pesticides or PCBs analyzed. Negative correlations were found between a number of physiologic parameters and tissue burdens of toxicants. Plasma triglycerides and condition factor were negatively correlated with total DDT (DDD + DDE + DDT), total pesticides (all pesticides detected - total DDT), and PCBs. In males, plasma androgens and gonad size were negatively correlated with total DDT, total pesticides, and PCBs. Fish residing in the reservoir behind the oldest dam had the highest contaminant loads and incidence of gonadal abnormalities, and the lowest triglycerides, condition factor, gonad size, and plasma androgens. These data suggest that endocrine-disrupting chemicals may be accumulating behind dams over time. Overall, results of this study indicate that exposure to environmental contaminants may be affecting both growth and reproductive physiology of sturgeon in some areas of the Columbia River.

Environmental Health Perspectives↗

USGS2006

Proximity to crops and residential to agricultural herbicides in Iowa

Rural residents can be exposed to agricultural pesticides through the proximity of their homes to crop fields. Previously, we developed a method to create historical crop maps using a geographic information system. The aim of the present study was to determine whether crop maps are useful for predicting levels of crop herbicides in carpet dust samples from residences. From homes of participants in a case-control study of non-Hodgkin lymphoma in Iowa (1998-2000), we collected vacuum cleaner dust and measured 14 herbicides with high use on corn and soybeans in Iowa. Of 112 homes, 58% of residences had crops within 500 m of their home, an intermediate distance for primary drift from aerial and ground applications. Detection rates for herbicides ranged from 0% for metribuzin and cyanazine to 95% for 2,4-dichlorophenoxyacetic acid. Six herbicides used almost exclusively in agriculture were detected in 28% of homes. Detections and concentrations were highest in homes with an active farmer. Increasing acreage of corn and soybean fields within 750 m of homes was associated with significantly elevated odds of detecting agricultural herbicides compared with homes with no crops within 750 m (adjusted odds ratio per 10 acres = 1.06; 95% confidence interval, 1.02-1.11). Herbicide concentrations also increased significantly with increasing acreage within 750 m. We evaluated the distance of crop fields from the home at < 100, 101-250, 251-500, and 501-750 m. Including the crop buffer distance parameters in the model did not significantly improve the fit compared with a model with total acres within 750 m. Our results indicate that crop maps may be a useful method for estimating levels of herbicides in homes from nearby crop fields.

Environmental Health Perspectives↗

USGS2007

Impacts of waste from concentrated animal feeding operations on water quality

Waste from agricultural livestock operations has been a long-standing concern with respect to contamination of water resources, particularly in terms of nutrient pollution. However, the recent growth of concentrated animal feeding operations (CAFOs) presents a greater risk to water quality because of both the increased volume of waste and to contaminants that may be present (e.g., antibiotics and other veterinary drugs) that may have both environmental and public health importance. Based on available data, generally accepted livestock waste management practices do not adequately or effectively protect water resources from contamination with excessive nutrients, microbial pathogens, and pharmaceuticals present in the waste. Impacts on surface water sources and wildlife have been documented in many agricultural areas in the United States. Potential impacts on human and environmental health from long-term inadvertent exposure to water contaminated with pharmaceuticals and other compounds are a growing public concern. This workgroup, which is part of the Conference on Environmental Health Impacts of Concentrated Animal Feeding Operations: Anticipating Hazards-Searching for Solutions, identified needs for rigorous ecosystem monitoring in the vicinity of CAFOs and for improved characterization of major toxicants affecting the environment and human health. Last, there is a need to promote and enforce best practices to minimize inputs of nutrients and toxicants from CAFOs into freshwater and marine ecosystems.

Environmental Health Perspectives↗

USGS2006

Endocrine disrupting chemicals research program of the U.S. Environmental Protection Agency: summary of a peer-review report

At the request of the U.S. Environmental Protection Agency (EPA) Office of Research and Development, a subcommittee of the Board of Scientific Counselors Executive Committee conducted an independent and open peer review of the Endocrine Disrupting Chemicals Research Program (EDC Research Program) of the U.S. EPA. The subcommittee was charged with reviewing the design, relevance, progress, scientific leadership, and resources of the program. The subcommittee found that the long-term goals and science questions in the EDC Program are appropriate and represent an understandable and solid framework for setting research priorities, representing a combination of problem-driven and core research. Long-term goal (LTG) 1, dealing with the underlying science surrounding endocrine disruptors, provides a solid scientific foundation for conducting risk assessments and making risk management decisions. LTG 2, dealing with defining the extent of the impact of endocrine-disrupting chemicals (EDCs), has shown greater progress on ecologic effects of EDCs compared with that on human health effects. LTG 3, which involves support of the Endocrine Disruptor Screening and Testing Program of the U.S. EPA, has two mammalian tests already through a validation program and soon available for use. Despite good progress, we recommend that the U.S. EPA a ) strengthen their expertise in wildlife toxicology, b ) expedite validation of the Endocrine Disruptors Screening and Testing Advisory Committee tests, c ) continue dependable funding for the EDC Research Program, d ) take a leadership role in the application of “omics” technologies to address many of the science questions critical for evaluating environmental and human health effects of EDCs, and e ) continue to sponsor multidisciplinary intramural research and interagency collaborations.

Environmental Health Perspectives↗

USGS1995

Gonadal steroidogenesis in-vitro from juvenile alligators obtained from contaminated or control lakes

The ubiquitous distribution of many contaminants and the nonlethal, multigenerational effects of such contaminants on reproductive, endocrine, and immune systems have led to concerns that wildlife worldwide are affected. Although the causal agents and effects are known for some species, the underlying physiological mechanisms associated with contaminant-induced reproductive modifications are still poorly understood and require extensive research. We describe a study examining the steroidogenic activity of gonads removed from juvenile alligators (Alligator mississippiensis) obtained from contaminated or control lakes in central Florida. Synthesis of estradiol-17 beta (E2) was significantly different when ovaries from the contaminated and control lakes were compared in vitro. Additionally, testes from males obtained from the contaminated lake. Lake Apopka, synthesized significantly higher concentrations of E2 when compared to testes obtained from control males. In contrast, testosterone (T) synthesis from all testes examined in this study displayed a normal pattern and produced concentrations greater than that observed from ovaries obtained from either lake. Interestingly, the pattern of gonadal steroidogenesis differs from previously reported plasma concentrations of these hormones obtained from the same individuals. We suggest that the differences between the in vivo and in vitro patterns are due to modifications in the hepatic degradation of plasma sex steroid hormones.

Environmental Health Perspectives↗

USGS1998

The US federal framework for research on endocrine disrupters and an analysis of research programs supported during fiscal year 1996

The potential health and ecological effects of endocrine disrupting chemicals has become a high visibility environmental issue. The 1990s have witnessed a growing concern, both on the part of the scientific community and the public, that environmental chemicals may be causing widespread effects in humans and in a variety of fish and wildlife species. This growing concern led the Committee on the Environment and Natural Resources (CENR) of the National Science and Technology Council to identify the endocrine disruptor issue as a major research initiative in early 1995 and subsequently establish an ad hoc Working Group on Endocrine Disruptors. The objectives of the working group are to 1) develop a planning framework for federal research related to human and ecological health effects of endocrine disrupting chemicals; 2) conduct an inventory of ongoing federal research programs; and 3) identify research gaps and develop a coordinated interagency plan to address priority research needs. This communication summarizes the activities of the federal government in defining a common framework for planning an endocrine disruptor research program and in assessing the status of the current effort. After developing the research framework and compiling an inventory of active research projects supported by the federal government in fiscal year 1996, the CENR working group evaluated the current federal effort by comparing the ongoing activities with the research needs identified in the framework. The analysis showed that the federal government supports considerable research on human health effects, ecological effects, and exposure assessment, with a predominance of activity occurring under human health effects. The analysis also indicates that studies on reproductive development and carcinogenesis are more prevalent than studies on neurotoxicity and immunotoxicity, that mammals (mostly laboratory animals) are the main species under study, and that chlorinated dibenzodioxins and polychlorinated biphenyls are the most commonly studied chemical classes. Comparison of the inventory with the research needs should allow identification of underrepresented research areas in need of attention.

Environmental Health Perspectives↗

USGS1998

Toxic equivalency factors (TEFs) for PCBs, PCDDs, PCDFs for humans and wildlife

An expert meeting was organized by the World Health Organization (WHO) and held in Stockholm on 15-18 June 1997. The objective of this meeting was to derive consensus toxic equivalency factors (TEFs) for polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) and dioxinlike polychlorinated biphenyls (PCBs) for both human, fish, and wildlife risk assessment. Based on existing literature data, TEFs were (re)evaluated and either revised (mammals) or established (fish and birds). A few mammalian WHO-TEFs were revised, including 1,2,3,7,8-pentachlorinated DD, octachlorinated DD, octachlorinated DF, and PCB 77. These mammalian TEFs are also considered applicable for humans and wild mammalian species. Furthermore, it was concluded that there was insufficient in vivo evidence to continue the use of TEFs for some di-ortho PCBs, as suggested earlier by Ahlborg et al. [Chemosphere 28:1049-1067 (1994)]. In addition, TEFs for fish and birds were determined. The WHO working group attempted to harmonize TEFs across different taxa to the extent possible. However, total synchronization of TEFs was not feasible, as there were orders of a magnitude difference in TEFs between taxa for some compounds. In this respect, the absent or very low response of fish to mono-ortho PCBs is most noticeable compared to mammals and birds. Uncertainties that could compromise the TEF concept were also reviewed, including nonadditive interactions, differences in shape of the dose-response curve, and species responsiveness. In spite of these uncertainties, it was concluded that the TEF concept is still the most plausible and feasible approach for risk assessment of halogenated aromatic hydrocarbons with dioxinlike properties.

Environmental Health Perspectives↗

USGS2017

Quantitative microbial risk assessment for spray irrigation of dairy manure based on an empirical fate and transport model

BACKGROUND: Spray irrigation for land-applying livestock manure is increasing in the United States as farms become larger and economies of scale make manure irrigation aﬀordable. Human health risks from exposure to zoonotic pathogens aerosolized during manure irrigation are not well understood. OBJECTIVES: We aimed to a) estimate human health risks due to aerosolized zoonotic pathogens downwind of spray-irrigated dairy manure; and b) determine which factors (e.g., distance, weather conditions) have the greatest inﬂuence on risk estimates. METHODS: We sampled downwind air concentrations of manure-borne fecal indicators and zoonotic pathogens during 21 full-scale dairy manure irri- gation events at three farms. We ﬁt these data to hierarchical empirical models and used model outputs in a quantitative microbial risk assessment (QMRA) to estimate risk [probability of acute gastrointestinal illness (AGI)] for individuals exposed to spray-irrigated dairy manure containing Campylobacter jejuni, enterohemorrhagic Escherichia coli (EHEC), or Salmonella spp. RESULTS: Median risk estimates from Monte Carlo simulations ranged from 10−5 to 10−2 and decreased with distance from the source. Risk estimates for Salmonella or EHEC-related AGI were most sensitive to the assumed level of pathogen prevalence in dairy manure, while risk estimates for C. jejuni were not sensitive to any single variable. Airborne microbe concentrations were negatively associated with distance and positively associated with wind speed, both of which were retained in models as a signiﬁcant predictor more often than relative humidity, solar irradiation, or temperature. CONCLUSIONS: Our model-based estimates suggest that reducing pathogen prevalence and concentration in source manure would reduce the risk of AGI from exposure to manure irrigation, and that increasing the distance from irrigated manure (i.e., setbacks) and limiting irrigation to times of low wind speed may also reduce risk.

Environmental Health Perspectives↗

USGS2021

Trends in agricultural triazole fungicide sse in the United States, 1992–2016 and possible implications for antifungal-resistant fungi in human disease

Background: The fungus Aspergillus fumigatus ( A. fumigatus ) is the leading cause of invasive mold infections, which cause severe disease and death in immunocompromised people. Use of triazole antifungal medications in recent decades has improved patient survival; however, triazole-resistant infections have become common in parts of Europe and are emerging in the United States. Triazoles are also a class of fungicides used in plant agriculture, and certain triazole-resistant A. fumigatus strains found causing disease in humans have been linked to environmental fungicide use. Objectives: We examined U.S. temporal and geographic trends in the use of triazole fungicides using U.S. Geological Survey agricultural pesticide use estimates. Discussion: Based on our analysis, overall tonnage of triazole fungicide use nationwide was relatively constant during 1992–2005 but increased > 4 -fold "> > 4 -fold >4-fold during 2006–2016 to 2.9   million   kg "> 2.9 million kg 2.9 million kg in 2016. During 1992–2005, triazole fungicide use occurred mostly in orchards and grapes, wheat, and other crops, but recent increases in use have occurred primarily in wheat, corn, soybeans, and other crops, particularly in Midwest and Southeast states. We conclude that, given the chemical similarities between triazole fungicides and triazole antifungal drugs used in human medicine, increased monitoring for environmental and clinical triazole resistance in A. fumigatus would improve overall understanding of these interactions, as well as help identify strategies to mitigate development and spread of resistance.

Environmental Health Perspectives↗

USGS2021

Sources and risk factors for nitrate and microbial contamination of private household wells in the fractured dolomite aquifer of northeastern Wisconsin

Background: Groundwater quality in the Silurian dolomite aquifer in northeastern Wisconsin, USA, has become contentious as dairy farms and exurban development expand. Objectives: We investigated private household wells in the region, determining the extent, sources, and risk factors of nitrate and microbial contamination. Methods: Total coliforms, Escherichia coli , and nitrate were evaluated by synoptic sampling during groundwater recharge and no-recharge periods. Additional seasonal sampling measured genetic markers of human and bovine fecal-associated microbes and enteric zoonotic pathogens. We constructed multivariable regression models of detection probability (log-binomial) and concentration (gamma) for each contaminant to identify risk factors related to land use, precipitation, hydrogeology, and well construction. Results: Total coliforms and nitrate were strongly associated with depth-to-bedrock at well sites and nearby agricultural land use, but not septic systems. Both human wastewater and cattle manure contributed to well contamination. Rotavirus group A, Cryptosporidium , and Salmonella were the most frequently detected pathogens. Wells positive for human fecal markers were associated with depth-to-groundwater and number of septic system drainfield within 229 m "> 229 m 229m . Manure-contaminated wells were associated with groundwater recharge and the area size of nearby agricultural land. Wells positive for any fecal-associated microbe, regardless of source, were associated with septic system density and manure storage proximity modified by bedrock depth. Well construction was generally not related to contamination, indicating land use, groundwater recharge, and bedrock depth were the most important risk factors. Discussion: These findings may inform policies to minimize contamination of the Silurian dolomite aquifer, a major water supply for the U.S. and Canadian Great Lakes region.

Wisconsin↗

USGS2021

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↗

USGS1991

Carcinogens and cancers in freshwater fishes

Epizootics of neoplasms in freshwater fish species are considered in relation to circumstantial and experimental evidence that suggest that some epizootics of neoplasia of hepatocellular, cholangiocellular, epidermal, and oral epithelial origin may be causally related to contaminant exposure. Although there is concern for the safety of consuming fish affected with neoplasms, this concern may be misdirected as direct transmission of cancer by ingesting cancerous tissue would seem unlikely. Of greater concern is the matter of toxic and cancer-causin chemicals present in edible fish that exhibit neoplasia as a symptom of past exposure via residence in a polluted waterway. There is ample evidence to suggest that contaminant chemicals ingested via contaminated Great Lakes fish may already be affecting both human and ecosystem health, but these effects are subtle and may require new approaches to the study of the affected systems.

Environmental Health Perspectives↗

USGS2003

In ovo exposure to o,p -DDE affects sexual development but not sexual differentiation in Japanese medaka (Oryzias latipes).

Despite being banned in many countries, dichlorodiphenyltrichloroethane (DDT) and its metabolites dichlorodiphenyldichloroethylene (DDE) and dichlorodiphenyldichloroethane (DDD) continue to be found in fish tissues at concentrations of concern. Like o,p -DDT, o,p -DDE is estrogenic and is believed to exert its effects through binding to the estrogen receptor. The limited toxicologic data for o,p -DDE suggest that it decreases fecundity and fertility of fishes. We conducted an egg injection study using the d-rR strain of medaka and environmentally relevant concentrations of o,p -DDE to examine its effects on sexual differentiation and development. The gonads of exposed fish showed no evidence of sex reversal or intersex. However, other gonad abnormalities occurred in exposed individuals. Females exhibited few vitellogenic oocytes and increased atresia. Male testes appeared morphologically normal but were very small. Gonadosomatic index values for both sexes were lower for exposed fish. Our observations of abnormal female and very small male gonads after in ovo o,p -DDE exposure may be indicative of effects on early endocrine processes important for normal ovarian and testicular development.

Environmental Health Perspectives↗

USGS2024

Perspectives on the future of host-microbe biology from the Council on Microbial Sciences of the American Society for Microbiology

Host-microbe biology (HMB) stands on the cusp of redefinition, challenging conventional paradigms to instead embrace a more holistic understanding of the microbial sciences. The American Society for Microbiology (ASM) Council on Microbial Sciences hosted a virtual retreat in 2023 to identify the future of the HMB field and innovations needed to advance the microbial sciences. The retreat presentations and discussions collectively emphasized the interconnectedness of microbes and their profound influence on humans, animals, and environmental health, as well as the need to broaden perspectives to fully embrace the complexity of these interactions. To advance HMB research, microbial scientists would benefit from enhancing interdisciplinary and transdisciplinary research to utilize expertise in diverse fields, integrate different disciplines, and promote equity and accessibility within HMB. Data integration will be pivotal in shaping the future of HMB research by bringing together varied scientific perspectives, new and innovative techniques, and ’omics approaches. ASM can empower under-resourced groups with the goal of ensuring that the benefits of cutting-edge research reach every corner of the scientific community. Thus, ASM will be poised to steer HMB toward a future that champions inclusivity, innovation, and accessible scientific progress.

mSphere↗

USGS2023

Land development and road salt usage drive long-term changes in major-ion chemistry of streamwater in six exurban and suburban watersheds, southeastern Pennsylvania, 1999-2019

In urbanized areas, the “freshwater salinization syndrome” (FSS), which pertains to long-term increases in concentrations of major ions and metals in fresh surface waters, has been attributed to road salt application. In addition to FSS, the water composition changes as an influx of sodium (Na + ) in recharge may displace calcium (Ca 2+ ), magnesium (Mg 2+ ), potassium (K + ), and trace metals by reverse cation exchange. These changing ion fluxes can result in adverse impacts on groundwater and surface waters used for municipal supplies. Few datasets exist to quantify the FSS on a watershed scale or link its manifestation to potential controlling factors such as changes in urban development, land use/land cover (LULC), or wastewater treatment plant (WWTP) discharges in upstream areas. Here, we use two decades (1999–2019) of monthly streamwater quality data combined with daily streamflow for six exurban and suburban watersheds in southeastern Pennsylvania to examine the relations among Ca 2+ , Mg 2+ , K + , Na + , chloride (Cl − ), sulfate (SO 4 2- ), and alkalinity (HCO 3 − ) concentrations and upstream controlling factors. Flow-normalized annual and baseflow (August ̶ November) concentrations for Ca 2+ , Mg 2+ , Na + , and Cl − increased in all six watersheds over the 20-year study, providing evidence of FSS’s impacts on groundwater that sustains streamflow. Additionally, a redundancy analysis using 2019 flow-normalized values identified the following positive associations between solute concentrations and controlling variables: 1) Cl − , Mg 2+ , and Ca 2+ with impervious surface cover (ISC), 2) Na + and SO 4 2- with ISC and total WWTP discharge volume, and 3) HCO 3 − with agriculture and total WWTP discharge volume. From a human health perspective, 2019 flow-normalized Na + concentrations exceeded the U.S. Environmental Protection Agency’s 20 mg L -1 threshold for individuals restricted to a low sodium diet. Furthermore, indices used to evaluate the corrosivity of source waters to drinking water infrastructure and inform municipal water treatment practices, such as the Chloride to Sulfate Mass Ratio and Larson Ratio, increased between two- and seven-fold over the 20-year time. Collectively, the results elucidate the causal factors of the FSS in suburban and exurban watersheds and its potential impacts on human health and drinking water infrastructure.

Pennsylvania↗

USGS2026

A fresh perspective - Advancing fish immunotoxicology in a complex world

Understanding how environmental changes affect the health of organisms and ecosystems is complex, but recent interdisciplinary advances and the recognition of immune function as a dynamic mediator offer exciting progress. Environmental immunotoxicology in teleost fishes is evolving beyond cataloguing stressors towards a mechanistic, integrative framework that leverages omics, in vivo tracking and cross-disciplinary modelling. However, knowledge gaps in immune mechanisms, toxicokinetics and multi-stressor interactions remain. The present work highlights these gaps, advocating for immune function as both a mechanistic lens and an integrative health indicator. Such a framework can improve predictive risk assessments, management strategies and our understanding of contaminant effects on resilience, disease susceptibility and population viability. While challenges remain, the field is poised for significant growth through collaborative innovation and advancing technology.

FEBS Letters↗