Drinking water from private wells and risks to children

Molecular Engineering of Hydrogen-Bonded Organic Framework for Enhanced Nitrate Electroreduction to Ammonia

Electrocatalytic nitrate reduction is an efficient way to produce ammonia sustainably. Herein, we rationally designed a copper metalloporphyrin-based hydrogen-bonded organic framework (HOF-Cu) through molecular engineering strategies for electrochemical nitrate reduction. As a result, the state-of-the-art HOF-Cu catalyst exhibits high NH3 Faradaic efficiency of 93.8%, and the NH3 production rate achieves a superior activity of 0.65 mmol h-1 cm-2. The in situ electrochemical spectroscopic combined with density functional theory calculations reveals that the dispersed Cu promotes the adsorption of NO3- and the mechanism is followed by deoxidation of NO3- to *NO and accompanied by deep hydrogenation. The generated *H participates in the deep hydrogenation of intermediate with fast kinetics as revealed by operando electrochemical impedance spectroscopy, and the competing hydrogen evolution reaction is suppressed. This research provides a promising approach to the conversion of nitrate to ammonia, maintaining the nitrogen balance in the atmosphere.

An economic evaluation of strategies to ensure safer drinking water in the homes of families with young children in select United States locations

Introduction

In the United States, safe, accessible drinking water is not equitable due to source water contamination, unreliable water treatment, or hazardous plumbing infrastructure. Drinking water free of lead, nitrates, and arsenic is vital for infant and young children's health.

Methods

Researchers conducted a study combining single-case study review methods and economic evaluation for 6 US policies or programs. Researchers used case-study findings, activity-based costing, publicly available US population data, and existing literature to create 5-year cost projections (2020-2024) for strategies to address lead, nitrates, or arsenic in drinking water from private wells or community water systems for families with low incomes and young children aged 0-5y. Researchers estimated the number of households reached and the costs by activity and payer of implementing each policy or program using case-specific geographic location and eligibility criteria.

Results

The total number of households reached varied from 295 to 135,000 depending on water source, population of focus, and geographic location. Focused strategies reached higher proportions of families with low incomes and young children. Community water system and state-wide strategies had the broadest reach. The total annual program cost per household that received information about their water quality ranged from $75 to $2,780. Of this cost, the portion paid by the household varied from $0.12 to $1,590, not including mitigation.

Conclusions

These findings can inform local decisions about policies and programs in communities seeking to increase awareness and access to safer drinking water, particularly in homes of families with low incomes and young children.

The Built Environment and Pediatric Health

Buildings, parks, and roads are all elements of the "built environment," which can be described as the human-made structures that comprise the neighborhoods and communities where people live, work, learn, and recreate (https://www.epa.gov/smm/basic-information-about-built-environment). The design of communities where children and adolescents live, learn, and play has a profound impact on their health. Moreover, the policies and practices that determine community design and the built environment are a root cause of disparities in the social determinants of health that contribute to health inequity. An understanding of the links between the built environment and pediatric health will help to inform pediatricians' and other pediatric health professionals' care for patients and advocacy on their behalf. This technical report describes the range of pediatric physical and mental health conditions influenced by the built environment, as well as historical and persistent effects of the built environment on health disparities. The accompanying policy statement outlines community design solutions that can improve pediatric health and health equity, including opportunities for pediatricians and the health care sector to incorporate this knowledge in patient care, as well as to play a role in advancing a health-promoting built environment for all children and families.

Water, Water Everywhere, but Every Drop Unique: Challenges in the Science to Understand the Role of Contaminants of Emerging Concern in the Management of Drinking Water Supplies

The protection and management of water resources continues to be challenged by multiple and ongoing factors such as shifts in demographic, social, economic, and public health requirements. Physical limitations placed on access to potable supplies include natural and human-caused factors such as aquifer depletion, aging infrastructure, saltwater intrusion, floods, and drought. These factors, although varying in magnitude, spatial extent, and timing, can exacerbate the potential for contaminants of concern (CECs) to be present in sources of drinking water, infrastructure, premise plumbing and associated tap water. This monograph examines how current and emerging scientific efforts and technologies increase our understanding of the range of CECs and drinking water issues facing current and future populations. It is not intended to be read in one sitting, but is instead a starting point for scientists wanting to learn more about the issues surrounding CECs. This text discusses the topical evolution CECs over time (Section 1), improvements in measuring chemical and microbial CECs, through both analysis of concentration and toxicity (Section 2) and modeling CEC exposure and fate (Section 3), forms of treatment effective at removing chemical and microbial CECs (Section 4), and potential for human health impacts from exposure to CECs (Section 5). The paper concludes with how changes to water quantity, both scarcity and surpluses, could affect water quality (Section 6). Taken together, these sections document the past 25 years of CEC research and the regulatory response to these contaminants, the current work to identify and monitor CECs and mitigate exposure, and the challenges facing the future.

Intermetallic Single-Atom Alloy In-Pd Bimetallene for Neutral Electrosynthesis of Ammonia from Nitrate

Harvesting recyclable ammonia (NH₃) from the electrocatalytic reduction of nitrate (NO₃RR) offers a sustainable strategy to close the ecological nitrogen cycle from nitration contamination in an energy-efficient and environmentally friendly manner. The emerging intermetallic single-atom alloys (ISAAs) are recognized to achieve the highest site density of single atoms by isolating contiguous metal atoms into single sites stabilized by another metal within the intermetallic structure, which holds promise to couple the catalytic benefits from intermetallic nanocrystals and single-atom catalysts for promoting NO₃RR. Herein, ISAA In-Pd bimetallene, in which the Pd single atoms are isolated by surrounding In atoms, is reported to boost neutral NO₃RR with a NH₃ Faradaic efficiency (FE) of 87.2%, a yield rate of 28.06 mg h^-1 mg_Pd^-1, and an exceptional electrocatalytic stability with increased activity/selectivity over 100 h and 20 cycles. The ISAA structure induces substantially diminished overlap of Pd d-orbitals and narrowed p-d hybridization of In-p and Pd-d states around the Fermi level, resulting in a stronger NO₃^- adsorption and a depressed energy barrier of the potential-determining step for NO₃RR. Further integrating the NO₃RR catalyst into a Zn-NO₃^- flow battery as the cathode delivers a power density of 12.64 mW cm^-2 and a FE of 93.4% for NH₃ production.

Juxtaposition of intensive agriculture, vulnerable aquifers, and mixed chemical/microbial exposures in private-well tapwater in northeast Iowa

In the United States and globally, contaminant exposure in unregulated private-well point-of-use tapwater (TW) is a recognized public-health data gap and an obstacle to both risk-management and homeowner decision making. To help address the lack of data on broad contaminant exposures in private-well TW from hydrologically-vulnerable (alluvial, karst) aquifers in agriculturally-intensive landscapes, samples were collected in 2018-2019 from 47 northeast Iowa farms and analyzed for 35 inorganics, 437 unique organics, 5 in vitro bioassays, and 11 microbial assays. Twenty-six inorganics and 51 organics, dominated by pesticides and related transformation products (35 herbicide-, 5 insecticide-, and 2 fungicide-related), were observed in TW. Heterotrophic bacteria detections were near ubiquitous (94 % of the samples), with detection of total coliform bacteria in 28 % of the samples and growth on at least one putative-pathogen selective media across all TW samples. Health-based hazard index screening levels were exceeded frequently in private-well TW and attributed primarily to inorganics (nitrate, uranium). Results support incorporation of residential treatment systems to protect against contaminant exposure and the need for increased monitoring of rural private-well homes. Continued assessment of unmonitored and unregulated private-supply TW is needed to model contaminant exposures and human-health risks.

Bottled water contaminant exposures and potential human effects

BACKGROUND

Bottled water (BW) consumption in the United States and globally has increased amidst heightened concern about environmental contaminant exposures and health risks in drinking water supplies, despite a paucity of directly comparable, environmentally-relevant contaminant exposure data for BW. This study provides insight into exposures and cumulative risks to human health from inorganic/organic/microbial contaminants in BW.

METHODS

BW from 30 total domestic US (23) and imported (7) sources, including purified tapwater (7) and spring water (23), were analyzed for 3 field parameters, 53 inorganics, 465 organics, 14 microbial metrics, and in vitro estrogen receptor (ER) bioactivity. Health-benchmark-weighted cumulative hazard indices and ratios of organic-contaminant in vitro exposure-activity cutoffs were assessed for detected regulated and unregulated inorganic and organic contaminants.

RESULTS

48 inorganics and 45 organics were detected in sampled BW. No enforceable chemical quality standards were exceeded, but several inorganic and organic contaminants with maximum contaminant level goal(s) (MCLG) of zero (no known safe level of exposure to vulnerable sub-populations) were detected. Among these, arsenic, lead, and uranium were detected in 67 %, 17 %, and 57 % of BW, respectively, almost exclusively in spring-sourced samples not treated by advanced filtration. Organic MCLG exceedances included frequent detections of disinfection byproducts (DBP) in tapwater-sourced BW and sporadic detections of DBP and volatile organic chemicals in BW sourced from tapwater and springs. Precautionary health-based screening levels were exceeded frequently and attributed primarily to DBP in tapwater-sourced BW and co-occurring inorganic and organic contaminants in spring-sourced BW.

CONCLUSION

The results indicate that simultaneous exposures to multiple drinking-water contaminants of potential human-health concern are common in BW. Improved understandings of human exposures based on more environmentally realistic and directly comparable point-of-use exposure characterizations, like this BW study, are essential to public health because drinking water is a biological necessity and, consequently, a high-vulnerability vector for human contaminant exposures.

Gis-Based Assessment of Risk for Drinking Water Contamination to Children’s Health in Rural Settlements

Nitrates and heavy metals are two of the most significant groundwater pollutants that have an impact on people’s health all around the world. In order to assess their risk to children’s health, this study aims to determine the total iron, manganese, and nitrate content in drinking water sources of non-centralized water supply of the educational institutions in the rural settlements of Zhytomyr region. A total of 114 water samples from wells and bores used by the educational institutions to supply domestic and drinking water to rural residential areas were collected. The Measurement Laboratory of Polissia National University conducted analytical studies. The danger to children’s health was evaluated using the hazard quotient and following the methodology recommended by the US Environmental Protection Agency. The software ArcGIS Pro was used to identify risk zones.

The average total iron content in the drinking water of the Berdichev, Zhytomyr, and Novohrad-Volinsky districts was 1.5–2.8 times higher. In all regions, the average manganese concentration did not go above the allowable level. On average, the nitrate content was also below the threshold, but in 22.6–42.9% of the samples, it exceeded the allowable level. Children aged 6–12 years were at the highest risk, and children living in Berdichev district had the highest hazard quotient at 1.972. The fact that nitrates accounted for 67–84% of the total risk indicates the danger associated with the intake of nitrates, even in amounts below the allowable concentration.

Environmental Health: A Position Paper From the American College of Physicians

Environmental health refers to the health effects associated with environmental factors, such as air pollution, water contamination, and climate change. Environmental hazards are associated with poor outcomes in common diseases, including diabetes and heart disease. In this position paper, the American College of Physicians (ACP) seeks to inform physicians about environmental health and offers policymakers recommendations to reduce the adverse health consequences of climate change, improve air and water quality, reduce exposure to toxic substances, and address environmental injustice. ACP affirms that all communities, including people of color, people with low income, and marginalized populations, deserve to live in a healthy environment.

Tapwater Exposures, Effects Potential, and Residential Risk Management in Northern Plains Nations

In the United States (US), private-supply tapwater (TW) is rarely monitored. This data gap undermines individual/community risk-management decision-making, leading to an increased probability of unrecognized contaminant exposures in rural and remote locations that rely on private wells. We assessed point-of-use (POU) TW in three northern plains Tribal Nations, where ongoing TW arsenic (As) interventions include expansion of small community water systems and POU adsorptive-media treatment for Strong Heart Water Study participants. Samples from 34 private-well and 22 public-supply sites were analyzed for 476 organics, 34 inorganics, and 3 in vitro bioactivities. 63 organics and 30 inorganics were detected. Arsenic, uranium (U), and lead (Pb) were detected in 54%, 43%, and 20% of samples, respectively. Concentrations equivalent to public-supply maximum contaminant level(s) (MCL) were exceeded only in untreated private-well samples (As 47%, U 3%). Precautionary health-based screening levels were exceeded frequently, due to inorganics in private supplies and chlorine-based disinfection byproducts in public supplies. The results indicate that simultaneous exposures to co-occurring TW contaminants are common, warranting consideration of expanded source, point-of-entry, or POU treatment(s). This study illustrates the importance of increased monitoring of private-well TW, employing a broad, environmentally informative analytical scope, to reduce the risks of unrecognized contaminant exposures.

Coordination Symmetry Breaking of Single-Atom Catalysts for Robust and Efficient Nitrate Electroreduction to Ammonia

Nitrate electrocatalytic reduction (NO₃ RR) for ammonia production is a promising strategy to close the N-cycle from nitration contamination, as well as an alternative to the Haber-Bosch process with less energy consumption and carbon dioxide release. However, current long-term stability of NO₃ RR catalysts is usually tens of hours, far from the requirements for industrialization. Here, symmetry-broken Cusingle-atom catalysts are designed, and the catalytic activity is retained after operation for more than 2000 h, while an average ammonia production rate of 27.84 mg h^-1 cm^-2 at an industrial level current density of 366 mA cm^-2 is achieved, obtaining a good balance between catalytic activity and long-term stability. Coordination symmetry breaking is achieved by embedding one Cu atom in graphene nanosheets with two N and two O atoms in the cis-configuration, effectively lowering the coordination symmetry, rendering the active site more polar, and accumulating more NO₃ ^- near the electrocatalyst surface. Additionally, the cis-coordination splits the Cu 3d orbitals, which generates an orbital-symmetry-matched π-complex of the key intermediate *ONH and reduces the energy barrier, compared with the σ-complex generated with other catalysts. These results reveal the critical role of coordination symmetry in single-atom catalysts, prompting the design of more coordination-symmetry-broken electrocatalysts toward possible industrialization.

Facile Tailoring of the Electronic Structure and the d-Band Center of Copper-Doped Cobaltate for Efficient Nitrate Electrochemical Hydrogenation

Electrocatalytic nitrate reduction is an effective strategy to eliminate nitrate's environmental impact and produce high-value-added ammonia products. However, most of the current reports focus on preparation strategies of catalysts, with poor exploration of the mechanism. In this work, we fabricated a binding-free Cu-doped Co₃O₄ electrode (Cu-Co₃O₄) to reveal the structure-activity relationship. Cu-Co₃O₄ exhibited a maximum Faradaic efficiency of ammonia of up to 86.5% at -0.6 V vs reversible hydrogen electrode in a neutral electrolyte, with the corresponding yield rate of 36.71 mmol h^-1 g^-1. In situ electrochemical Raman spectroscopy confirmed that the structure of Cu-Co₃O₄ exhibits excellent stability and durability. Theoretical analysis revealed that the interaction between Cu and Co induces the d-band center position of the mono-metal oxide to shift toward the center to optimize the nitrate reduction intermediate hydrodeoxygenation free-energy change, especially of *NO_x (x = 1, 2, and 3). These results offer guidelines for the electrochemical reduction of nitrate with transition metal oxide electrocatalysts.

Batch-Scale Synthesis of Nanoparticle-Agminated Three-Dimensional Porous Cu@Cu2O Microspheres for Highly Selective Electrocatalysis of Nitrate to Ammonia

The electrochemical nitrate reduction reaction (NITRR), which converts nitrate to ammonia, is promising for artificial ammonia synthesis at mild conditions. However, the lack of favorable electrocatalysts has hampered its large-scale applications. Herein, we report the batch-scale synthesis of three-dimensional (3D) porous Cu@Cu₂O microspheres (Cu@Cu₂O MSs) composed of fine Cu@Cu₂O nanoparticles (NPs) using a convenient electric explosion method with outstanding activity and stability for the electrochemical reduction of nitrate to ammonia. Density functional theory (DFT) calculations revealed that the Cu₂O (111) facets could facilitate the formation of *NO₃H and *NO₂H intermediates and suppress the hydrogen evolution reaction (HER), resulting in high selectivity for the NITRR. Moreover, the 3D porous structure of Cu@Cu₂O MSs facilitates electrolyte penetration and increases the localized concentration of reactive species for the NITRR. As expected, the obtained Cu@Cu₂O MSs exhibited an ultrahigh NH₃ production rate of 327.6 mmol·h^-1·g^-1_cat. (which is superior to that of the Haber-Bosch process with a typical NH₃ yield <200 mmol h^-1g^-1_cat.), a maximum Faradaic efficiency of 80.57%, and remarkable stability for the NITRR under ambient conditions. Quantitative ¹⁵N isotope labeling experiments indicated that the synthesized ammonia originated from the electrochemical reduction of nitrate. Achieving the batch-scale and low-cost production of high-performance Cu@Cu₂O MSs electrocatalysts using the electric explosion method is promising for the large-scale realization of selective electrochemical reduction of nitrate toward artificial ammonia synthesis.

Atomic-dispersed copper simultaneously achieve high-efficiency removal and high-value-added conversion to ammonia of nitrate in sewage

Environmentally friendly electrochemical reduction pathways from NO₃^- to NH₃ or N₂ have provided feasible strategy into the green production of ammonia or the treatment of nitrate wastewater. Here, we anchored single-atom Cu with boron carbon nitride on carbon nanotube (BCN@Cu/CNT), and achieved the efficient operation of electrochemical nitrate reduction reaction (NIRR). BCN@Cu/CNT can efficiently catalyze the selective conversion of high-concentration nitrate into high-value-added ammonia, where the ammonia yield rate and Faradaic efficiency are as high as 172,226.5 μg h^-1 mg_cat.^-1 and 95.32% (at -0.6 V), respectively. BCN@Cu/CNT also shows the ability to efficiently remove low-concentration nitrates in sewage. Specifically, here only takes 5 h to nearly 100% (99.32%) eliminate NO₃^- (50 mg L^-1) in sewage without any residual NO₂^-. The excellent catalytic activity and physicochemical stability of BCN@Cu/CNT for NIRR suggest the promising industrial application prospects, including the green production of ammonia and the purification of nitrate wastewater.

Public and private tapwater: Comparative analysis of contaminant exposure and potential risk, Cape Cod, Massachusetts, USA

BACKGROUND

Humans are primary drivers of environmental contamination worldwide, including in drinking-water resources. In the United States (US), federal and state agencies regulate and monitor public-supply drinking water while private-supply monitoring is rare; the current lack of directly comparable information on contaminant-mixture exposures and risks between private- and public-supplies undermines tapwater (TW) consumer decision-making.

METHODS

We compared private- and public-supply residential point-of-use TW at Cape Cod, Massachusetts, where both supplies share the same groundwater source. TW from 10 private- and 10 public-supply homes was analyzed for 487 organic, 38 inorganic, 8 microbial indicators, and 3 in vitro bioactivities. Concentrations were compared to existing protective health-based benchmarks, and aggregated Hazard Indices (HI) of regulated and unregulated TW contaminants were calculated along with ratios of in vitro exposure-activity cutoffs.

RESULTS

Seventy organic and 28 inorganic constituents were detected in TW. Median detections were comparable, but median cumulative concentrations were substantially higher in public supply due to 6 chlorine-disinfected samples characterized by disinfection byproducts and corresponding lower heterotrophic plate counts. Public-supply applicable maximum contaminant (nitrate) and treatment action (lead and copper) levels were exceeded in private-supply TW samples only. Exceedances of health-based HI screening levels of concern were common to both TW supplies.

DISCUSSION

These Cape Cod results indicate comparable cumulative human-health concerns from contaminant exposures in private- and public-supply TW in a shared source-water setting. Importantly, although this study's analytical coverage exceeds that currently feasible for water purveyors or homeowners, it nevertheless is a substantial underestimation of the full breadth of contaminant mixtures documented in the environment and potentially present in drinking water.

CONCLUSION

Regardless of the supply, increased public engagement in source-water protection and drinking-water treatment, including consumer point-of-use treatment, is warranted to reduce risks associated with long-term TW contaminant exposures, especially in vulnerable populations.

Private well water testing promotion in pediatric preventive care: A randomized intervention study

Over 43 million U.S. residents rely on private unregulated wells for their drinking water, raising public health concerns, particularly in regions like northern New England where widespread groundwater arsenic contamination is now recognized. Children are particularly vulnerable to adverse health effects from arsenic exposure. Despite AAP Guidelines, approaches to engage pediatric clinicians in promoting private well testing have not been previously described. We sought to determine the most effective practice approaches to achieve successful well water testing in routine pediatric care. 12 primary care clinics were block randomized to one of four study arms. Two intervention variables were assessed: (1) test results access (parent only vs. parent and clinic) and (2) follow up approaches (yes/no). Parents of children under 12 months using a private well were eligible. Prepaid water tests were provided. Primary outcome was parental water test completion. Eleven clinics successfully implemented processes identifying well users. 240 testing kits were dispensed. Completion rates averaged 29% (range 10 to 61%). The study arm with both clinic results access and staff follow up system was 2.3 times more likely to achieve test completion than other arms (95% CI 1.12-4.86, p = .03). Kit distribution by clinicians versus nursing staff, irrespective of study arm, had 2.4 times greater completion (95% CI 1.13-5.11, p = .02). Systematic drinking water source screening can be improved in pediatric care. Higher testing completion was found in practices randomized to reminders and structured follow up versus single visit discussion, but clinician involvement was the most predictive factor.

Perspectives from the Society for Pediatric Research: contaminants of water and children's health: Can we do better?

Children are uniquely susceptible to the health consequences of water contamination. In this review, we summarize the existing, robust literature supporting the importance of examining specific water contaminants (i.e., lead, pesticides, nitrates, arsenic, perchlorate) and the routes of contamination in the United States and globally. We also discuss the health effects of exposure to contaminated water and significant disparities related to access to clean water. Lastly, we offer strategies for prevention and intervention-including those focused on the individual patient level-and review the current US policy framework pertaining to regulation of these toxicants. IMPACT: A key message in this article is that exposure to water contaminants have serious and long-lasting consequences on children's health. This review summarizes current existing literature and adds policy recommendations supporting clean water for children. Information from this review has two potential impacts: Guide health professionals in screening and/or treating children's health problems resulting from water contaminant exposure. Guide policy makers in using evidence-based approaches to improve water quality and clean water access.

Evaluating the risks associated with Shiga-toxin-producing Escherichia coli (STEC) in private well waters in Canada

Shiga-toxin-producing Escherichia coli (STEC) represent a major concern for waterborne disease outbreaks associated with consumption of contaminated groundwater. Over 4 million people rely on private groundwater systems as their primary drinking water source in Canada; many of these systems do not meet current standards for water quality. This manuscript provides a scoping overview of studies examining STEC prevalence and occurrence in groundwater, and it includes a synopsis of the environmental variables affecting survival, transport, persistence, and overall occurrence of these important pathogenic microbes in private groundwater wells used for drinking purposes.

Risk Communication and Factors Influencing Private Well Testing Behavior: A Systematic Scoping Review

Unregulated private wells may be at risk for certain types of contamination associated with adverse health effects. Well water testing is a primary method to identify such risks, although testing rates are generally low. Risk communication is used as an intervention to promote private well testing behavior; however, little is known about whether these efforts are effective as well as the mechanisms that influence effectiveness. A systematic scoping review was conducted to evaluate the current evidence base for risk communication effectiveness and factors that influence well testing behavior. The review was conducted with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews (PRISMA-ScR) framework. Data were synthesized using a health behavior model (Health Belief Model) to identify areas amenable to intervention and factors to consider when designing risk communication interventions. We identified a significant shortage of studies examining the effectiveness of risk communication interventions targeted to well testing behavior, with only two quasi-experimental studies identified. The review also identified seventeen studies that examined or described factors relating to well testing behavior. The two empirical studies suggest risk communication methods can be successful in motivating private well owners to test their water, while the remaining studies present considerations for developing effective, community-specific content.

Seasonal Variation of Water Quality in Unregulated Domestic Wells

In the United States (U.S.), up to 14% of the population depend on private wells as their primary drinking water source. The U.S. government does not regulate contaminants in private wells. The goals of this study were to investigate the quality of drinking water from unregulated private wells within one mile (1.6 kilometers) of an effluent-dominated river in the arid Southwest, determine differences in contaminant levels between wet and dry seasons, and identify contributions from human sources by specifically measuring man-made organic contaminants (perfluorooctanoic acid (PFOA), perfluorooctane sulfate (PFOS), and sucralose). Samples were collected during two dry seasons and two wet seasons over the course of two years and analyzed for microbial (Escherichia coli), inorganic (arsenic, cadmium, chromium, copper, lead, mercury, nitrate), and synthetic organic (PFOA, PFOS, and sucralose) contaminants. Arsenic, nitrate, and Escherichia coli concentrations exceeded their respective regulatory levels of 0.01 mg/L, 10 mg/L, and 1 colony forming unit (CFU)/100 mL, respectively. The measured concentrations of PFOA and PFOS exceeded the respective Public Health Advisory level. Arsenic, PFOA, PFOS, and sucralose were significantly higher during the dry seasons, whereas E. coli was higher during the wet seasons. While some contaminants were correlated (e.g., As and Hg ρ = 0.87; PFOA and PFOS ρ = 0.45), the lack of correlation between different contaminant types indicates that they may arise from different sources. Multi-faceted interventions are needed to reduce exposure to drinking water above health-based guidelines.

Methemoglobinemia: Infants at risk

Methemoglobin is formed when the iron center in hemoglobin is oxidized from ferrous iron to ferric iron. The functional consequence of this change is that hemoglobin is transformed to methemoglobin and cannot oxygenate tissues adequately, causing hypoxia and cyanosis. Infants have unique physiology that increases their risk of developing methemoglobinemia. Infants drink more water per body weight compared to children and adults, have lower NADH cyb5r reductase activity that converts methemoglobin to hemoglobin, and have a higher percentage of fetal hemoglobin, which is easier to convert to methemoglobin. A well-studied exposure to a chemical that can cause methemoglobinemia in infants is nitrate in well water. For the first part specifically about methemoglobin in infants, articles that were recent (2015-now) were given preference over articles that were older. Search terms included: methemoglobin, methemoglobinemia, infant, acquired, congenital, and methylene blue. For the latter half of the paper on nitrate and methemoglobinemia, preference was given to articles that described regionally important cases. In addition, search terms were: Minnesota, methemoglobinemia, nitrate, well water, drinking water, and infant. Acquired methemoglobinemia is rare, yet can still be seen in medical settings, and when an infant is exposed to nitrate in well water above 10 mg/L. To prevent exposure, parents should have their water tested for nitrate before the baby comes home. Physicians should make it practice to ask what the source of drinking water is for newly pregnant women and urge them to test for nitrate and bacteria if using a well. Using bottled water to make formula is also an option, but the best option is still breastfeeding.

Microwave synthesised Pd-TiO2 for photocatalytic ammonia production

Palladium doped anatase TiO2 nanoparticles were synthesised by a rapid (3 min) one-pot microwave synthesis technique at low temperature and pressure. After being fully characterised by SEM, XRD, Raman, XPS and EDX, photocatalytic nitrate reduction and ammonia production were studied over various dopant levels between 0-3.97 wt% Pd and compared to similar previous literature. Improved yields of ammonia were observed with most dopant levels when compared to non-doped microwave synthesised TiO2 with 2.65 wt% found to be the optimum dopant level producing 21.2 μmol NH3. Electrochemical impedance spectroscopy of TiO2 and Pd-TiO2 photoelectrodes revealed improvements in charge transfer characteristics at high Pd dopant levels.

Reconnaissance of Mixed Organic and Inorganic Chemicals in Private and Public Supply Tapwaters at Selected Residential and Workplace Sites in the United States

Safe drinking water at the point-of-use (tapwater, TW) is a United States public health priority. Multiple lines of evidence were used to evaluate potential human health concerns of 482 organics and 19 inorganics in TW from 13 (7 public supply, 6 private well self-supply) home and 12 (public supply) workplace locations in 11 states. Only uranium (61.9 μg L-1, private well) exceeded a National Primary Drinking Water Regulation maximum contaminant level (MCL: 30 μg L-1). Lead was detected in 23 samples (MCL goal: zero). Seventy-five organics were detected at least once, with median detections of 5 and 17 compounds in self-supply and public supply samples, respectively (corresponding maxima: 12 and 29). Disinfection byproducts predominated in public supply samples, comprising 21% of all detected and 6 of the 10 most frequently detected. Chemicals designed to be bioactive (26 pesticides, 10 pharmaceuticals) comprised 48% of detected organics. Site-specific cumulative exposure-activity ratios (∑EAR) were calculated for the 36 detected organics with ToxCast data. Because these detections are fractional indicators of a largely uncharacterized contaminant space, ∑EAR in excess of 0.001 and 0.01 in 74 and 26% of public supply samples, respectively, provide an argument for prioritized assessment of cumulative effects to vulnerable populations from trace-level TW exposures.

Challenges and Opportunities for Tribal Waters: Addressing Disparities in Safe Public Drinking Water on the Crow Reservation in Montana, USA

Disparities in access to safe public drinking water are increasingly being recognized as contributing to health disparities and environmental injustice for vulnerable communities in the United States. As the Co-Directors of the Apsaálooke Water and Wastewater Authority (AWWWA) for the Crow Tribe, with our academic partners, we present here the multiple and complex challenges we have addressed in improving and maintaining tribal water and wastewater infrastructure, including the identification of diverse funding sources for infrastructure construction, the need for many kinds of specialized expertise and long-term stability of project personnel, ratepayer difficulty in paying for services, an ongoing legacy of inadequate infrastructure planning, and lack of water quality research capacity. As a tribal entity, the AWWWA faces additional challenges, including the complex jurisdictional issues affecting all phases of our work, lack of authority to create water districts, and additional legal and regulatory gaps-especially with regards to environmental protection. Despite these obstacles, the AWWWA and Crow Tribe have successfully upgraded much of the local water and wastewater infrastructure. We find that ensuring safe public drinking water for tribal and other disadvantaged U.S. communities will require comprehensive, community-engaged approaches across a broad range of stakeholders to successfully address these complex legal, regulatory, policy, community capacity, and financial challenges.

Community Engaged Cumulative Risk Assessment of Exposure to Inorganic Well Water Contaminants, Crow Reservation, Montana

An estimated 11 million people in the US have home wells with unsafe levels of hazardous metals and nitrate. The national scope of the health risk from consuming this water has not been assessed as home wells are largely unregulated and data on well water treatment and consumption are lacking. Here, we assessed health risks from consumption of contaminated well water on the Crow Reservation by conducting a community-engaged, cumulative risk assessment. Well water testing, surveys and interviews were used to collect data on contaminant concentrations, water treatment methods, well water consumption, and well and septic system protection and maintenance practices. Additive Hazard Index calculations show that the water in more than 39% of wells is unsafe due to uranium, manganese, nitrate, zinc and/or arsenic. Most families' financial resources are limited, and 95% of participants do not employ water treatment technologies. Despite widespread high total dissolved solids, poor taste and odor, 80% of families consume their well water. Lack of environmental health literacy about well water safety, pre-existing health conditions and limited environmental enforcement also contribute to vulnerability. Ensuring access to safe drinking water and providing accompanying education are urgent public health priorities for Crow and other rural US families with low environmental health literacy and limited financial resources.

Lessons Learned from Arsenic Mitigation among Private Well Households

PURPOSE OF REVIEW

Many thousands of research papers have been published on the occurrence, health effects, and mitigation of arsenic in drinking water sourced from groundwater around the world. Here, an attempt is made to summarize this large body of knowledge into a small number of lessons.

RECENT FINDINGS

This is an opinion paper reflecting on why we are far from the goal of eliminating this silent and widespread poison to protect the health of many millions. The lessons are drawn from research in countries representing a range of economic development and cultural contexts. The replacement of household wells with centralized water supplies has reduced population level exposure to moderate (50-100 μg/L) and high (>100 μg/L) levels of arsenic in drinking water in some countries as they become wealthier. However, there remains a very large rural population in all countries where the exposure to low levels (10-50 μg/L) of arsenic continues due to its dispersed occurrence in the environment and frequent reliance on private well. A set of natural (geological and biological), socioeconomic, and behavioral barriers to progress are summarized as lessons. They range from challenges in identifying the exposed households due to spatially heterogeneous arsenic distribution in groundwater, difficulties in quantifying the exposure let alone reducing the exposure, failures in maintaining compliance to arsenic drinking water standards, to misplaced risk perceptions and environmental justice issues. Environmental health professionals have an ethical obligation to help As mitigation among private well water households, along with physicians, hydrogeologists, water treatment specialists, community organizations, and government.

The Case for Universal Screening of Private Well Water Quality in the U.S. and Testing Requirements to Achieve It: Evidence from Arsenic

BACKGROUND

The 1974 Safe Drinking Water Act (SDWA) regulates >170,000 public water systems to protect health, but not >13 million private wells. State and local government requirements for private well water testing are rare and inconsistent; the responsibility to ensure water safety remains with individual households. Over the last two decades, geogenic arsenic has emerged as a significant public health concern due to high prevalence in many rural American communities.

OBJECTIVES

We build the case for universal screening of private well water quality around arsenic, the most toxic and widespread of common private water contaminants. We argue that achieving universal screening will require policy intervention, and that testing should be made easy, accessible, and in many cases free to all private well households in the United States, considering the invisible, tasteless, odorless, and thus silent nature of arsenic.

DISCUSSION

Our research has identified behavioral, situational and financial barriers to households managing their own well water safety, resulting in far from universal screening despite traditional public health outreach efforts. We observe significant socioeconomic disparities in arsenic testing and treatment when private water is unregulated. Testing requirements can be a partial answer to these challenges.

CONCLUSIONS

Universal screening, achieved through local testing requirements complemented by greater community engagement targeting biologically and socioeconomically vulnerable groups, would reduce population arsenic exposure greater than any promotional efforts to date. Universal screening of private well water will identify the dangers hidden in America's drinking water supply and redirect attention to ensure safe water among affected households. https://doi.org/10.1289/EHP629.

Strategies to Improve Private-Well Water Quality: A North Carolina Perspective

BACKGROUND

Evidence suggests that the 44.5 million U.S. residents drawing their drinking water from private wells face higher risks of waterborne contaminant exposure than those served by regulated community water supplies. Among U.S. states, North Carolina (N.C.) has the second-largest population relying on private wells, making it a useful microcosm to study challenges to maintaining private-well water quality.

OBJECTIVES

This paper summarizes recommendations from a two-day summit to identify options to improve drinking-water quality for N.C. residents served by private wells.

METHODS

The Research Triangle Environmental Health Collaborative invited 111 participants with knowledge of private-well water challenges to attend the Summit. Participants worked in small groups that focused on specific aspects and reconvened in plenary sessions to formulate consensus recommendations.

DISCUSSION

Summit participants highlighted four main barriers to ensuring safe water for residents currently relying on private wells: (1) a database of private well locations is unavailable; (2) racial disparities have perpetuated reliance on private wells in some urbanized areas; (3) many private-well users lack information or resources to monitor and maintain their wells; and (4) private-well support programs are fragmented and lack sufficient resources. The Summit produced 10 consensus recommendations for ways to overcome these barriers.

CONCLUSIONS

The Summit recommendations, if undertaken, could improve the health of North Carolinians facing elevated risks of exposure to waterborne contaminants because of their reliance on inadequately monitored and maintained private wells. Because many of the challenges in N.C. are common nationwide, these recommendations could serve as models for other states. https://doi.org/10.1289/EHP890.

Meeting the public health challenge of protecting private wells: Proceedings and recommendations from an expert panel workshop

Private wells serving fewer than 25 people are federally unregulated, and their users may be exposed to naturally occurring agents of concern such as arsenic and radionuclides, as well as anthropogenic contaminants. The Centers for Disease Control and Prevention's Clean Water for Health Program works to protect private wells and prevent adverse health outcomes for the roughly 15% of Americans who rely on them. To understand current and emerging challenges to the private drinking water supply, an interdisciplinary expert panel workshop on "Future and Emerging Issues for Private Wells" was organized to inform strategic planning for the Clean Water for Health Program. The panel assessed current conditions of ground water as a source for private wells, identified emerging threats, critical gaps in knowledge, and public health needs, and recommended strategies to guide future activities to ensure the safety of private drinking water wells. These strategies addressed topics of broad interest to the environmental public health community including: development of new methods to support citizen science; addressing contaminant mixtures; expanding capacity for well testing; evaluating treatment technologies; building an evidence base on best practices on well owner outreach and stewardship; and research and data needs.

Home Water Treatment Habits and Effectiveness in a Rural Arizona Community

Drinking water quality in the United States (US) is among the safest in the world. However, many residents, often in rural areas, rely on unregulated private wells or small municipal utilities for water needs. These utilities may violate the Safe Drinking Water Act contaminant guidelines, often because they lack the required financial resources. Residents may use alternative water sources or install a home water treatment system. Despite increased home water treatment adoption, few studies have examined their use and effectiveness in the US. Our study addresses this knowledge gap by examining home water treatment in a rural Arizona community. Water samples were analyzed for metal(loid)s, and home treatment and demographic data were recorded in 31 homes. Approximately 42% of homes treated their water. Independent of source water quality, residents with higher income (OR = 1.25; 95%CI (1.00 - 1.64)) and education levels (OR = 1.49; 95%CI (1.12 - 2.12)) were more likely to treat their water. Some contaminant concentrations were effectively reduced with treatment, while some were not. We conclude that increased educational outreach on contaminant testing and treatment, especially to rural areas with endemic water contamination, would result in a greater public health impact while reducing rural health disparities.

At the crossroads: Hazard assessment and reduction of health risks from arsenic in private well waters of the northeastern United States and Atlantic Canada

This special issue contains 12 papers that report on new understanding of arsenic (As) hydrogeochemistry, performance of household well water treatment systems, and testing and treatment behaviors of well users in several states of the northeastern region of the United States and Nova Scotia, Canada. The responsibility to ensure water safety of private wells falls on well owners. In the U.S., 43 million Americans, mostly from rural areas, use private wells. In order to reduce As exposure in rural populations that rely on private wells for drinking water, risk assessment, which includes estimation of population at risk of exposure to As above the EPA Maximum Contaminant Level, is helpful but insufficient because it does not identify individual households at risk. Persistent optimistic bias among well owners against testing and barriers such as cost of treatment mean that a large percentage of the population will not act to reduce their exposure to harmful substances such as As. If households are in areas with known As occurrence, a potentially large percentage of well owners will remain unaware of their exposure. To ensure that everyone, including vulnerable populations such as low income families with children and pregnant women, is not exposed to arsenic in their drinking water, alternative action will be required and warrants further research.

Spatial relationships among dairy farms, drinking water quality, and maternal-child health outcomes in the San Joaquin Valley

OBJECTIVE

Access to clean and affordable water is a significant public health issue globally, in the United States, and in California where land is heavily used for agriculture and dairy operations. The purpose of this study was to explore the geographic relationships among dairy farms, nitrate levels in drinking water, low birth weight, and socioeconomic data at the ZIP code level in the San Joaquin Valley.

DESIGN AND SAMPLE

This ecological study used a Geographic Information System (GIS) to explore and analyze secondary data.

MEASURES

A total of 211 ZIP codes were analyzed using spatial autocorrelation and regression analysis methods in ArcGIS version 10.1.

RESULTS

ZIP codes with dairies had a higher percentage of Hispanic births (p = .001). Spatial statistics revealed that ZIP codes with more dairy farms and a higher dairy cow density had higher levels of nitrate contamination. No correlation was detected between LBW and unsafe nitrate levels at the ZIP code level.

CONCLUSION

Further research examining communities that use private and small community wells in the San Joaquin Valley should be conducted. Birth data from smaller geographic areas should be used to continue exploring the relationship between birth outcomes and nitrate contamination in drinking water.

Simultaneous removal of cadmium and nitrate in aqueous media by nanoscale zerovalent iron (nZVI) and Au doped nZVI particles

Nanoscale zerovalent iron (nZVI) has demonstrated high efficacy for treating nitrate or cadmium (Cd) contamination, but its efficiency for simultaneous removal of nitrate and Cd has not been investigated. This study evaluated the reactivity of nZVI to the co-contaminants and by-product formation, employed different catalysts to reduce nitrite yield from nitrate, and examined the transformation of nZVI after reaction. Nitrate reduction resulted in high solution pH, negatively charged surface of nZVI, formation of Fe3O4 (a stable transformation of nZVI), and no release of ionic iron. Increased pH and negative charge contributed to significant increase in Cd(II) removal capacity (from 40 mg/g to 188 mg/g) with nitrate present. In addition, nitrate reduction by nZVI could be catalyzed by Cd(II): while 30% of nitrate was reduced by nZVI within 2 h in the absence of Cd(II), complete nitrate reduction was observed in the presence of 40 mg-Cd/L due to the formation of Cd islands (Cd(0) and CdO) on the nZVI particles. While nitrate was reduced mostly to ammonium when Cd(II) was not present or at Cd(II) concentrations ≥ 40 mg/L, up to 20% of the initial nitrate was reduced to nitrite at Cd(II) concentrations < 40 mg/L. Among nZVI particles doped with 1 wt. % Cu, Ag, or Au, nZVI deposited with 1 wt. % Au reduced nitrite yield to less than 3% of the initial nitrate, while maintaining a high Cd(II) removal capacity.

Iodine deficiency, pollutant chemicals, and the thyroid: new information on an old problem

Many women of reproductive age in the United States are marginally iodine deficient, perhaps because the salt in processed foods is not iodized. Iodine deficiency, per se, can interfere with normal brain development in their offspring; in addition, it increases vulnerability to the effects of certain environmental pollutants, such as nitrate, thiocyanate, and perchlorate. Although pregnant and lactating women should take a supplement containing adequate iodide, only about 15% do so. Such supplements, however, may not contain enough iodide and may not be labeled accurately. The American Thyroid Association recommends that pregnant and lactating women take a supplement with adequate iodide. The American Academy of Pediatrics recommends that pregnant and lactating women also avoid exposure to excess nitrate, which would usually occur from contaminated well water, and thiocyanate, which is in cigarette smoke. Perchlorate is currently a candidate for regulation as a water pollutant. The Environmental Protection Agency should proceed with appropriate regulation, and the Food and Drug Administration should address the mislabeling of the iodine content of prenatal/lactation supplements.

Unregulated private wells in the Republic of Ireland: consumer awareness, source susceptibility and protective actions

While the safety of public drinking water supplies in the Republic of Ireland is governed and monitored at both local and national levels, there are currently no legislative tools in place relating to private supplies. It is therefore paramount that private well owners (and users) be aware of source specifications and potential contamination risks, to ensure adequate water quality. The objective of this study was to investigate the level of awareness among private well owners in the Republic of Ireland, relating to source characterisation and groundwater contamination issues. This was undertaken through interviews with 245 private well owners. Statistical analysis indicates that respondents' source type significantly influences owner awareness, particularly regarding well construction and design parameters. Water treatment, source maintenance and regular water quality testing are considered the three primary "protective actions" (or "stewardship activities") to consumption of contaminated groundwater and were reported as being absent in 64%, 72% and 40% of cases, respectively. Results indicate that the level of awareness exhibited by well users did not significantly affect the likelihood of their source being contaminated (source susceptibility); increased awareness on behalf of well users was associated with increased levels of protective action, particularly among borehole owners. Hence, lower levels of awareness may result in increased contraction of waterborne illnesses where contaminants have entered the well. Accordingly, focused educational strategies to increase awareness among private groundwater users are advocated in the short-term; the development and introdiction of formal legislation is recommended in the long-term, including an integrated programme of well inspections and risk assessments.

Parents' perceptions of water safety and quality

Every day parents make choices about the source of water their families consume. There are many contributing factors which could affect decisions about water consumption including taste, smell, color, safety, cost, and convenience. However, few studies have investigated what parents with young children think about water quality and safety in the US and how this affects the choices they are making. This study aimed to describe the perceptions of parents with regard to water quality and safety and to compare bottled water and tap water use, as well as to examine motivation for water choices. We conducted an online questionnaire to survey parents living in Pennsylvania about water quality and safety, and preference for bottled versus tap water. Parents were recruited through child care centers, and 143 surveys were returned. The survey results showed high overall scores for perception of tap water quality and safety, and a preference for tap water over bottled water. We found that parents were concerned for the environmental impact that buying bottled water may have but were also concerned about potential contamination of tap water by natural gas drilling processes and nuclear power plants. These findings regarding parental concerns are critical to inform pediatric health care providers, water sellers, and suppliers in order that they may provide parents with the necessary information to make educated choices for their families.

Future challenges to protecting public health from drinking-water contaminants

Over the past several decades, human health protection for chemical contaminants in drinking water has been accomplished by development of chemical-specific standards. This approach alone is not feasible to address current issues of the occurrence of multiple contaminants in drinking water, some of which have little health effects information, and water scarcity. In this article, we describe the current chemical-specific paradigm for regulating chemicals in drinking water and discuss some potential additional approaches currently being explored to focus more on sustaining quality water for specific purposes. Also discussed are strategies being explored by the federal government to screen more efficiently the toxicity of large numbers of chemicals to prioritize further intensive testing. Water reuse and water treatment are described as sustainable measures for managing water resources for potable uses as well as other uses such as irrigation.

Clinical services in environmental pediatrics

Pediatric healthcare providers are confronted with environmental health problems frequently: the child with asthma exacerbated by the odor of paint in school or mouse antigen at home, the family who wants to know the risks and benefits of using different types of sunblock, or the community that asks the provider for advice on the potential health impacts of building the new elementary school next to the on-ramp to the interstate highway. Pediatric providers have not been well trained to deal with these questions in medical or nursing schools, residency training, or continuing-education settings. This article provides guidance on history taking, the physical examination, laboratory evaluations of patients and the environment, and making an assessment about and managing environmental health problems. Pediatric Environmental Health Specialty Units are discussed as a source of consultation and referral. The identification and utilization of evidence-based resources are stressed and clinicians are cautioned about non-evidence-based assessments such as clinical ecology and hair analysis and non-evidence-based management strategies such as chelation for autism.

Rural children's exposure to well water contaminants: implications in light of the American Academy of Pediatrics' recent policy statement

PURPOSE

Implementing the recent American Academy of Pediatrics' (AAP) policy for annual well water testing will impact pediatric healthcare providers, who will be called upon for advice regarding testing, interpretation, and mitigation. We report findings from a study of low-income rural families' participation in household well water testing.

DATA SOURCES

We collected data from 188 rural low-income households inclusive of 320 children under the age of seven. Participating families lived in one of two western U.S. counties and received water from a well with <15 connections. Household water samples and questionnaire data were collected for analysis.

CONCLUSIONS

Twenty-seven percent of households tested positive for at least one contaminant, including total coliforms (18%), arsenic (6%), synthetic organic chemicals (6%), nitrates (2%), fluoride (2%), and E. coli (<1%). Eighty-nine percent of households testing positive for total coliforms were positive at re-test. Respondents expressed greatest concern for biological contamination and took multiple precautionary actions, although only 31% had ever tested their water for contaminants. Higher levels of education, income, and age, as well as homeowner status, were significantly associated with previous testing.

IMPLICATIONS FOR PRACTICE

Recommendations for communicating abnormal results, mitigating risks, and overcoming logistical challenges are presented.

Understanding stewardship behaviour: factors facilitating and constraining private water well stewardship

Regulatory frameworks to ensure municipal drinking water safety exist in most North American jurisdictions. However, similar protection is rarely provided to people reliant on water provided from private wells. In Canada, approximately 4 million people depend on privately owned, domestic wells for their drinking water. Numerous studies have shown that people who rely on private wells for their water supplies are at risk from nitrate and bacterial contamination. Given the fact that regulations relating to private wells tend to be weak or poorly enforced, actions taken by well owners to protect their own drinking water safety are extremely important. Drawing on one of the largest and most comprehensive surveys of private well owners ever conducted in Canada or elsewhere, this paper explores factors that influence well owner stewardship behaviour. Key behaviours examined included annual testing of well water and inspection of wells, measures to protect water quality, and proper decommissioning of unused wells. A geographically-stratified survey, sent to 4950 well owners in Ontario, Canada, resulted in an effective response rate of 34% (n = 1567). Logistic regression analyses revealed that motivations for well stewardship behaviours included reassurance, the perception of problems, and knowledge of the environment. Knowing how to perform stewardship behaviours was an important antecedent to action. Barriers to stewardship included complacency, inconvenience, ignorance, cost, and privacy concerns. To promote stewardship, local initiatives, better educational materials, and enforcement through real estate laws are all required. Ultimately, drinking water safety for people reliant on private wells is shown to be a responsibility shared by governments and private well owners.