A point-of-use drinking water quality dataset from fieldwork in Detroit, Michigan.

Drinking water quality sensor technology has rapidly advanced, facilitating the collection of rich datasets and real-time analytics. However, sensors have not yet been widely applied to monitor drinking water quality in premise plumbing. Richer quality of data in premise plumbing offers an improved understanding of the quality of drinking water present at the point-of-use. In this paper, online drinking water quality sensor nodes were temporarily installed in twenty-four homes in Detroit, Michigan. The water quality sensor nodes took measurements of five drinking water quality parameters every five minutes for four weeks. Additionally, free chlorine and lead were sampled periodically within each home. Together, these data make up a dataset that captures drinking water quality over time in a legacy city with an oversized drinking water system. This dataset offers more frequent measurements amongst more sample homes than are typically available in premise plumbing or at the tap. The data can be used to investigate temporal trends in drinking water quality, including diurnal patterns and anomaly detection. Additionally, this dataset could be utilized to evaluate water quality in comparison with other cities.

Boil water notices as health-risk communication: risk perceptions, efficacy, and compliance during winter storm Uri.

Winter Storm Uri was a disaster that impacted much of the United States during February of 2021. During and after the storm, Texas and Oklahoma experienced massive power grid failures. This led to cascading impacts, including water system disruptions and many boil water notices (BWNs). The breakdown of some communication channels and the inability to enact protective actions due to power outages, as well as travel limitations on public roads, complicated the dissemination and implementation of notifications. This research examined individuals' perceptions of risk, water quality, and BWNs during Uri. Additionally, this study sought to understand if previous experience with a BWN influenced compliance during Uri and how perceived efficacy impacted these variables. Surveying 893 Texans and Oklahomans revealed that most Uri-affected respondents believed the risks associated with BWNs were severe. Income and race were two factors that influenced BWN compliance. Age, gender, and level of education did not influence compliance. Previous experience with BWNs did not increase risk perceptions. Higher levels of perceived efficacy correlated to higher levels of compliance, perceptions of risk, and water quality, much of which support propositions of the Extended Parallel Process Model. Results suggest that pre-disaster planning and communication are imperative to helping reduce risk(s) and enhancing efficacy during a disaster, especially for novel disasters that have cascading risks, like Winter Storm Uri.

Effect of Community Water Service on Lead in Drinking Water in an Environmental Justice Community.

Multiple recent studies have found elevated lead (Pb) concentrations in tap water in U.S. homes relying on unregulated private wells. The main Pb source is dissolution from household plumbing, fixtures, and well components. Here, we leverage a natural experiment and citizen science approach to evaluate how extending community water service to an environmental justice community relying on private wells affects Pb in household water. We analyzed Pb in 260 first-draw kitchen tap water samples collected by individual homeowners over a 5-month period in residences that did and did not connect to the community system. Before the community water system was extended, 25% of homes had Pb > 15 µg/L (the U.S. regulatory action level for community water systems) in first-draw water samples. Pb was significantly correlated with nickel (ρ = 0.61), zinc (ρ = 0.50), and copper (ρ = 0.40), suggesting that corrosion of brass fittings and fixtures is the main Pb source. Among homes that connected to the community system, Pb decreased rapidly and was sustained at levels well below 15 µg/L over the study period. Overall, connecting to the municipal water supply was associated with a 92.5% decrease in first-draw tap water Pb.

Development of a Highly Selective Ni(II) Chelator in Aqueous Solution.

The design, synthesis, and characterization of a novel Ni(II) chelator SG-20 is reported. SG-20 is selective in binding to Ni(II) versus other metal ions including Cu(II), Fe(II), Co(II), and Zn(II). At pH = 7.1, SG-20 binds Ni(II) with a Kd = 7.0 ± 0.4 µM. Job analysis indicates that SG-20 binds to both Ni(II) and Cu(II) with a 1:1 stoichiometry. Affinity of SG-20 for Ni(II) is pH dependent and decreases upon lowering to pH 4.0. A green solid was isolated from the reaction of SG-20 with NiCl2·6H2O in MeOH and characterized by X-ray photoelectron spectroscopy (XPS), electronic absorption and infrared (IR) spectroscopies, and mass spectrometry. Collectively, XPS and IR analysis revealed Ni-N and Ni-O interactions and a shift in C-O asymmetric and symmetric stretches consistent with Ni binding. Attempts to crystalize a mononuclear complex were unsuccessful, likely due to the Ni-SG-20 complex being in equilibrium with higher order species in solution. However, reaction of SG-20 with NiCl2·6H2O in water followed by slow evaporation yielded green crystals that were characterized by electronic absorption spectroscopy (λmax = 260 nm) and X-ray crystallography. These analyses revealed that SG-20 supports formation of a complex cluster containing six SG-20 ligands, 15 Ni(II), and three Na(I) centers, with two distinct types of Ni atoms in its outer and inner core. The nine Ni atoms present in the inner core were bound by oxo and carbonate bridges, whereas the six Ni atoms present in its outer shell were bound to N, O, and S donor atoms derived from SG-20. Overall, X-ray crystallographic analysis revealed that two chelator arms of SG-20 bind to one Ni(II) ion with an axial aqua ligand, whereas the third arm is free to interact with Ni ions within the central cluster, supporting the goal of Ni capture.

An Automated Toolchain for Camera-Enabled Sensing of Drinking Water Chlorine Residual.

Chlorine residual concentration is an important parameter to prevent pathogen growth in drinking water. Disposable color changing test strips that measure chlorine in tap water are commercially available to the public; however, the color changes are difficult to read by eye, and the data are not captured for water service providers. Here we present an automated toolchain designed to process digital images of free chlorine residual test strips taken with mobile phone cameras. The toolchain crops the image using image processing algorithms that isolate the areas relevant for analysis and automatically white balances the image to allow for use with different phones and lighting conditions. The average red, green, and blue (RGB) color values of the image are used to predict a free chlorine concentration that is classified into three concentration tiers (<0.2 mg/L, 0.2-0.5 mg/L, or >0.5 mg/L), which can be reported to water users and recorded for utility use. The proposed approach was applied to three different phone types under three different lighting conditions using a standard background. This approach can discriminate between concentrations above and below 0.5 mg/L with an accuracy of 90% and 94% for training and testing data sets, respectively. Furthermore, it can discriminate between concentrations of <0.2 mg/L, 0.2-0.5 mg/L, or >0.5 mg/L with weighted-averaged F1 scores of 79% and 88% for training and testing data sets, respectively. This tool sets the stage for tap water consumers and water utilities to gather frequent measurements and high-resolution temporal and spatial data on drinking water quality.

Improved Decision-Making: A Sociotechnical Utility-Based Framework for Drinking Water Investment.

To achieve the goals of the Safe Drinking Water Act, state and local water authorities need to make decisions about where to direct limited funding for infrastructure improvements and currently do so in the absence of adequate evaluative metrics. We developed a framework grounded in utility theory that compares trade-offs explicitly and broadens the factors considered in prioritizing resource allocations. Relevant existing indices were reviewed to identify data applicable to drinking water decision-making. A utility-theory-based decision analysis framework was developed and applied to evaluate how different objectives affect funding decisions for lead service line replacement (LSLR) programs in Pennsylvania and Michigan, United States. The decision framework incorporates drinking water quality characteristics with community and environmental quality attributes. We compare additive and multiplicative model structures, different weights, and spatial scales. Our decision framework showed that the inclusion of additional data beyond what is usually considered in LSLR decisions could change the top 10 counties or public water systems prioritized. Further, the counties or water systems in the top 10 were influenced by the model structure and weights. Prioritization changed based on which data were included, and has implications for the use of evaluative metrics beyond traditional water system data.

Point-of-use carbon-block drinking water filters change gut microbiome of larval zebrafish.

Activated carbon block (ACB) point-of-use (PoU) drinking water filters can change the bacterial composition in drinking water. Consuming ACB PoU filtered water may also influence gut microbiomes. This study uses the zebrafish model to evaluate how the ACB PoU filter affects the gut microbiomes and phenotypic responses in larvae and adulthood. An ACB PoU filter manifold system was constructed to feed larval and adult zebrafish tap and filtered water at the early and late stages of the filter operation period. Adult zebrafish gut microbiomes were not affected by exposure to water types and filter stages. Unlike the adult, gut microbiomes of the larvae exposed to filtered water at the late stage of filter operation were dominated by more filter-relevant bacterial taxa, including Comamonadaceae and Brevundimonas, than the early stage-filtered-water- and tap water-exposed larvae. We also found some fish that were either exposed to filtered water at early and late stages or tap water supplied to the filter toward the end of the experiment showed hyperactive locomotion behaviour, and had significantly lower relative abundances of a Pseudomonas spp. (OTU3) than the normally behaved fish. Our findings indicate that ACB PoU filtered water can alter gut microbiomes and affect the behaviour patterns in larval zebrafish.

Boil Water Advisories as Risk Communication: Consistency between CDC Guidelines and Local News Media Articles.

The Safe Drinking Water Act Public Notification Rule requires that customers of public water systems (PWS) be informed of problems that may pose a risk to public health. Boil water advisories (BWA) are a form of communication intended to mitigate potential health risks. The Centers for Disease Control and Prevention (CDC) developed guidance for BWAs. We examined how local US news media incorporate the CDC's guidelines when reporting on BWAs. A content analysis of 1040 local news media articles shows these reports did not consistently incorporate CDC guidelines. Overall, 89% of the articles communicated enough information for readers to determine if they were included in the impacted area. Articles that included at least some of the CDC's instructions for boiling water were likely (p < .001) to include other risk information, such as the functions for which water should be boiled (e.g., drinking, brushing teeth) and that bottled water could be used as an alternative source. However, this information was included in only 47% of the articles evaluated. Results suggest public notifications often do not serve the public need for clear risk communication.

Detection of endocrine disrupting chemicals in Danio rerio and Daphnia pulex: Step-one, behavioral screen.

Anthropogenic surface and ground water contamination by chemicals is a global problem, and there is an urgent need to develop tools to identify and elucidate biological effects. Contaminants of emerging concern (CECs) are not typically monitored or regulated and those with known or suspected endocrine disrupting potential have been termed endocrine disrupting chemicals (EDCs). Many CECs are known to be neurotoxic (e.g., insecticides) and many are incompletely characterized. Behavioral responses can identify chemicals with neuroactive properties, which can be relevant to EDC mechanisms (e.g., neuroendocrine disturbances). Two freshwater species, Daphnia pulex and Danio rerio, were evaluated for swimming behavior alterations resulting from 24-hr exposure to 9 CECs: triclosan, triclocarban, chlorpyrifos, dieldrin, 4-nonylphenol, bisphenol-A, atrazine, metformin, and estrone. This is the first step in the development of a bioassay for detecting estrogenic and/or anti-androgenic activity with the goal to evaluate complex mixtures of uncharacterized contaminants in water samples. The second step, described in a subsequent report, examines transcriptome alterations following chemical exposure. Significant differences in the swimming behavior response and sensitivity were found across chemicals within a species and across species for a given chemical in this unique optical bioassay system. In the concentration ranges studied, significant behavioral alterations were detected for 6 of 9 CECs for D. pulex and 4 of 9 CECs for D. rerio. These results underscore the utility of this bioassay to identify behavioral effects of sublethal concentrations of CECs before exploration of transcriptomic alterations for EDC detection.

Trends in Legionnaires' Disease-Associated Hospitalizations, United States, 2006-2010.

BACKGROUND: Legionella pneumophila is a waterborne cause of both healthcare-associated and community-acquired pneumonia. Legionella pneumophila serogroup 1 is responsible for 80% of infections. There is currently limited published disease burden data on Legionnaires' disease-associated hospitalization in the United States. METHODS: In this study, we estimated the annual incidence of Legionnaires' disease-associated hospitalizations in United States and identified demographic, temporal, and regional characteristics of individuals hospitalized for Legionnaires' disease. A retrospective study was conducted using the National Hospital Discharge Survey (NHDS) data from 2006 to 2010. The NHDS is a nationally representative US survey, which includes estimates of inpatient stays in short-stay hospitals in the United States, excluding federal, military, and Veterans Administration hospitals. All discharges assigned with the Legionnaires' disease International Classification of Diseases 9th Clinical Modification discharge diagnostic code (482.84) were included in this study. RESULTS: We observed the annual incidence and number of Legionnaires' disease-associated hospitalizations (per 100 000 population) in the United States by year, age, sex, race, and region. Over a 5-year period, 14 574 individuals experienced Legionnaires' disease-associated hospitalizations in the United States The annual population-adjusted incidence (per 100 000 population) of Legionnaires' disease-associated hospitalizations was 5.37 (95% confidence interval [CI], 5.12-5.64) in 2006, 7.06 (95% CI, 6.80-7.40) in 2007, 8.77 (95% CI, 8.44-9.11) in 2008, 17.07 (95% CI, 16.62-17.54) in 2009, and 9.66 (95% CI, 9.32-10.01) in 2010. A summer peak of Legionnaires' disease-associated hospitalizations occurred from June through September in 2006, 2007, 2008, and 2010. CONCLUSIONS: Legionnaires' disease-associated hospitalizations significantly increased over the 5-year study period. The increasing disease burden of Legionnaires' disease suggests that large segments of the US population are at risk for exposure to this waterborne pathogen.

Water lead exposure risk in Flint, Michigan after switchback in water source: Implications for lead service line replacement policy.

In February of 2016, the City of Flint, Michigan commenced the FAST start initiative with the aim "to get the lead out of Flint" by replacing lead and galvanized steel service lines throughout the city. An estimated 29,100 parcels are scheduled for service line replacement (SLR) at an expected cost of $172 million. The lead exposure benefits of SLR are evaluated by analyzing Sentinel data on hundreds of repeatedly sampled homes in Flint from February 16, 2016 to July 21, 2017, comparing water lead (WL) in homes with and without lead service lines. Samples taken from homes with lead service lines were significantly more likely to exceed specified thresholds of WL than homes without lead service lines. Second, regardless of service line material type, sampled homes experienced significant reductions in WL with elapsed time from Flint's switchback to water provided by the Detroit Water and Sewage Department. Third, the risk of exceedance of WL > 15 µg/L was uncorrelated with service line material type. These results are robust to sample restrictions, period stratification, time operations, reference group definitions, and statistical modeling procedures. On the question of what is gained from SLR over optimal corrosion control techniques, we simulated age-specific lead uptake (µg/day) and blood lead levels (µg/dL) for children in Flint at 16 and 90 weeks of elapsed time from Flint's switchback to Detroit water. At 90 weeks from the switchback in water source, the quantity of water lead consumed by children in homes with lead service lines decreased 93%, as compared to 16 weeks. Lead exposure benefits of SLR have declined in time, with modest differences in lead uptake across homes with different service lines. In light of results, policy considerations for Flint and nationwide are discussed.

Informational Sources, Social Media Use, and Race in Flint, Michigan's Water Crisis.

Safe, clean water is necessary for health and wellbeing. Water issues affect minority and vulnerable populations at disproportionate rates, including the poor and racial and ethnic minorities. An investigation of the relationships of race, social media use, and informational sources during the municipal water crisis in Flint, Michigan reflects an instrumental view of communication and uses and gratifications theory in this study. Data from 208 Flint residents in 2016 indicated that African American respondents favored interpersonal networks and resources and were more likely than other racial groups to obtain current information about the water crisis via Instagram. Preferred channels and sources to receive additional crisis information varied on the basis of race.

Assessment of the Legionnaires' disease outbreak in Flint, Michigan.

The 2014-2015 Legionnaires' disease (LD) outbreak in Genesee County, MI, and the outbreak resolution in 2016 coincided with changes in the source of drinking water to Flint's municipal water system. Following the switch in water supply from Detroit to Flint River water, the odds of a Flint resident presenting with LD increased 6.3-fold (95% CI: 2.5, 14.0). This risk subsided following boil water advisories, likely due to residents avoiding water, and returned to historically normal levels with the switch back in water supply. During the crisis, as the concentration of free chlorine in water delivered to Flint residents decreased, their risk of acquiring LD increased. When the average weekly chlorine level in a census tract was <0.5 mg/L or <0.2 mg/L, the odds of an LD case presenting from a Flint neighborhood increased by a factor of 2.9 (95% CI: 1.4, 6.3) or 3.9 (95% CI: 1.8, 8.7), respectively. During the switch, the risk of a Flint neighborhood having a case of LD increased by 80% per 1 mg/L decrease in free chlorine, as calculated from the extensive variation in chlorine observed. In communities adjacent to Flint, the probability of LD occurring increased with the flow of commuters into Flint. Together, the results support the hypothesis that a system-wide proliferation of legionellae was responsible for the LD outbreak in Genesee County, MI.

Prevalence of Infection-Competent Serogroup 6 Legionella pneumophila within Premise Plumbing in Southeast Michigan.

Coinciding with major changes to its municipal water system, Flint, MI, endured Legionnaires' disease outbreaks in 2014 and 2015. By sampling premise plumbing in Flint in the fall of 2016, we found that 12% of homes harbored legionellae, a frequency similar to that in residences in neighboring areas. To evaluate the genetic diversity of Legionella pneumophila in Southeast Michigan, we determined the sequence type (ST) and serogroup (SG) of the 18 residential isolates from Flint and Detroit, MI, and the 33 clinical isolates submitted by hospitals in three area counties in 2013 to 2016. Common to one environmental and four clinical samples were strains of L. pneumophila SG1 and ST1, the most prevalent ST worldwide. Among the Flint premise plumbing isolates, 14 of 16 strains were of ST367 and ST461, two closely related SG6 strain types isolated previously from patients and corresponding environmental samples. Each of the representative SG1 clinical strains and SG6 environmental isolates from Southeast Michigan infected and survived within macrophage cultures at least as well as a virulent laboratory strain, as judged by microscopy and by enumerating CFU. Likewise, 72 h after infection, the yield of viable-cell counts increased >100-fold for each of the representative SG1 clinical isolates, Flint premise plumbing SG6 ST367 and -461 isolates, and two Detroit residential isolates. We verified by immunostaining that SG1-specific antibody does not cross-react with the SG6 L. pneumophila environmental strains. Because the widely used urinary antigen diagnostic test does not readily detect non-SG1 L. pneumophila, Legionnaires' disease caused by SG6 L. pneumophila is likely underreported worldwide.IMPORTANCEL. pneumophila is the leading cause of disease outbreaks associated with drinking water in the United States. Compared to what is known of the established risks of colonization within hospitals and hotels, relatively little is known about residential exposure to L. pneumophila One year after two outbreaks of Legionnaires' disease in Genesee County, MI, that coincided with damage to the Flint municipal water system, our multidisciplinary team launched an environmental surveillance and laboratory research campaign aimed at informing risk management strategies to provide safe public water supplies. The most prevalent L. pneumophila strains isolated from residential plumbing were closely related strains of SG6. In laboratory tests of virulence, the SG6 environmental isolates resembled SG1 clinical strains, yet they are not readily detected by the common diagnostic urinary antigen test, which is specific for SG1. Therefore, our study complements the existing epidemiological literature indicating that Legionnaires' disease due to non-SG1 strains is underreported around the globe.

Four phases of the Flint Water Crisis: Evidence from blood lead levels in children.

The Flint Water Crisis (FWC) is divisible into four phases of child water-lead exposure risk: Phase A) before the switch in water source to the Flint River (our baseline); Phase B) after the switch in water source, but before boil water advisories; Phase C) after boil water advisories, but before the switch back to the baseline water source of the Detroit Water and Sewerage Department (DWSD); and Phase D) after the switch back to DWSD. The objective of this work is to estimate water-lead attributable movements in child blood lead levels (BLLs) that correspond with the four phases in the FWC. With over 21,000 geo-referenced and time-stamped blood lead samples from children in Genesee County drawn from January 01, 2013 to July 19, 2016, we develop a series of quasi-experimental models to identify the causal effect of water-lead exposure on child BLLs in Flint. We find that the switch in water source (transitioning from phase A to B) caused mean BLLs to increase by about 0.5µg/dL, and increased the likelihood of a child presenting with a BLL ≥ 5µg/dL by a factor of 1.91-3.50, implying an additional 561 children exceeding 5µg/dL. We conservatively estimate cohort social costs (through lost earnings alone) of this increase in water-lead exposed children at $65 million, contrasted with expected annual savings of $2 million from switching water source. On the switch from Phase B to C, we find BLLs decreased about 50% from their initial rise following boil water advisories and subsequent water avoidance behaviors by households. Finally, the return to the baseline source water (Phase D) returned child BLLs to pre-FWC levels further implicating water-lead exposure as a causal source of child BLLs throughout the FWC.

Fast voltammetry of metals at carbon-fiber microelectrodes: towards an online speciation sensor.

Speciation controls the chemical behavior of trace metals. Thus, there is great demand for rapid speciation analysis in a variety of fields. In this study, we describe the application of fast scan cyclic voltammetry (FSCV) and fast scan adsorption controlled voltammetry (FSCAV) to trace metal speciation analysis. We show that Cu2+ can be detected using FSCAV in different matrices. We find that matrices with different Cu2+ binding ability do not affect the equilibrium of Cu2+ adsorption onto CFMs, and thus are an excellent predictor for free Cu2+ ([Cu2+]free) in solution. We modelled a correlation between the FSCV response, [Cu2+]free and log Kf for 15 different Cu2+ complexes. Using our model, we rapidly predicted, and verified [Cu2+]free and Kf of a real groundwater sample spiked with Cu2+. We thus highlight the potential of fast voltammetry as a rapid trace metal speciation sensor.

Fast voltammetry of metals at carbon-fiber microelectrodes: rapid determination of solution formation constants.

Metal speciation controls the behavior of aqueous metal ions. Fundamental thermodynamic parameters, such as the formation constant (Kf) of metal-ligand equilibria, provide useful speciation information. Although this information can be determined by spectroscopic techniques with high accuracy, it comes at the expense of time and cost. In this work, we studied Cu2+ complexation with different ligands using an ultra-fast method, fast scan cyclic voltammetry (FSCV) at carbon-fiber microelectrodes (CFMs). We observed a correlation between the FSCV response and the previously reported Cu2+-ligand equilibrium constants. This relationship allowed us to model a predictive relationship between Kf and 16 model ligands. We hence present an essential proof of principle study that highlights FSCV's capability to prove speciation information in real time.

Voltammetric Characterization of Cu(II) Complexation in Real-Time.

Aqueous metal behavior is strongly regulated by speciation, which in turn is highly dependent on complexation. Trace metal complexation is difficult to characterize in dynamically changing systems due to a lack of analytical methods that can rapidly report free-metal concentrations. In this paper, we perform proof-of-principle experiments that demonstrate the utility of fast-scan cyclic voltammetry (FSCV) for providing speciation information in real-time by characterizing dynamic Cu(II) binding. We study Cu(II) FSCV responses in 3-(N-morpholino)propanesulfonic acid (MOPS) buffer and characterize the hydrodynamic aspects of our experimental setup (continuously stirred tank reactor). We observe Cu(II) complexation in real-time using five ligands with differing formation constants of Cu(II) complexation. Finally, we utilize geochemical models to fit our real-time experimental Cu(II)-binding curves. Our proof-of-principle experiments show that FSCV is a powerful tool for studying real-time Cu(II) complexation, which is essential speciation information for better interpretation of Cu(II) behavior in dynamically changing systems, such as those encountered in biology or the environment.

Sulfamethoxazole, tetracycline and oxytetracycline and related antibiotic resistance genes in a large-scale landfill, China.

Landfills are likely to be important reservoirs of antibiotics and antibiotic resistant genes (ARGs) as they receive unused and unwanted antibiotics and ARGs in municipal solid waste (MSW). The distribution, transportation and dynamics of antibiotics and ARGs in landfills remain largely unknown. In the present study, 3 antibiotics - sulfamethoxazole (SMX), tetracycline (TC), and oxytetracycline (OTC) - and their related ARGs (sulI and tetO) were quantified in 51 refuse samples from different depths at 8 locations within a large-scale landfill in central China. The average concentration of OTC was the highest, up to 100.9±141.81µg/kg (dw, n=48), followed by TC (63.8±37.7µg/kg, n=40), and SMX (47.9±8.1µg/kg, n=30). Both sulI and tetO were detected in all samples. Of the ARGs, sul1 (-3.06±1.18, n=51, log10 ARGs/16SrDNA) was more abundant than tetO (-4.37±0.97) in all refuse samples (p<0.05). Both sulI and tetO negatively correlated to refuse age, suggesting they are attenuated during landfill stabilization. OTC and TC positively correlated to tetO (r=0.41, p<0.01) and sulI (r=0.29, p=0.04), respectively. Chemical conditions (e.g. moisture content and nitrate concentrations) within the refuse correlated to antibiotics and ARGs suggesting environmental factors impact the distribution of antibiotics and ARGs in landfill matrix. This study is the first comprehensive in situ landfill study to connect the concentrations of antibiotic residues to ARGs.