Research Studies & Publications


Below are abstracts for published research studies from a variety of sources. Click on the article title to be taken to the complete article or to receive directions on how to purchase it.

Detection of Poly- and Perfluoroalkyl Substances (PFASs) in U.S. Drinking Water Linked to Industrial Sites, Military Fire Training Areas, and Wastewater Treatment Plants

Hu, X.C. et. al., Environmental Science and Technology, August 9, 2016; Letters.

Drinking water contamination with poly- and perfluoroalkyl substances (PFASs) poses risks to the developmental, immune, metabolic, and endocrine health of consumers. We present a spatial analysis of 2013–2015 national drinking water PFAS concentrations from the U.S. Environmental Protection Agency’s (US EPA) third Unregulated Contaminant Monitoring Rule (UCMR3) program. The number of industrial sites that manufacture or use these compounds, the number of military fire training areas, and the number of wastewater treatment plants are all significant predictors of PFAS detection frequencies and concentrations in public water supplies. Among samples with detectable PFAS levels, each additional military site within a watershed’s eight-digit hydrologic unit is associated with a 20% increase in PFHxS, a 10% increase in both PFHpA and PFOA, and a 35% increase in PFOS. The number of civilian airports with personnel trained in the use of aqueous film-forming foams is significantly associated with the detection of PFASs above the minimal reporting level. We find drinking water supplies for 6 million U.S. residents exceed US EPA’s lifetime health advisory (70 ng/L) for PFOS and PFOA. Lower analytical reporting limits and additional sampling of smaller utilities serving <10000 individuals and private wells would greatly assist in further identifying PFAS contamination sources.

Do Low Levels of Blood Lead Reduce Children's Future Test Scores?

Aizer, A. et. al., NBER Bulletin on Aging and Health , August 2016.

We construct a unique individual-level longitudinal dataset linking preschool blood lead levels with third grade test scores for eight birth cohorts of Rhode Island children born between 1997 and 2005. Using these data, we show that reductions of lead from even historically low levels have significant positive effects on children's reading test scores in third grade. Our preferred estimates use the introduction of a lead remediation program as an instrument in order to control for the possibility of confounding and for considerable error in measured lead exposures. The estimates suggest that a one unit decrease in average blood lead levels reduces the probability of being substantially below proficient in reading by 3.1 percentage points (on a baseline of 12 percent). Moreover, as we show, poor and minority children are more likely to be exposed to lead, suggesting that lead poisoning may be one of the causes of continuing gaps in test scores between disadvantaged and other children.

Potential corrosivity of untreated groundwater in the United States

Potential corrosivity of untreated groundwater in the United States

Belitz, K., Jurgens, B.C., and Johnson, T.D., USGS Scientific Investigations Report 2016-5092, July 12, 2016; 10.3133/sir20165092

Corrosive groundwater, if untreated, can dissolve lead and other metals from pipes and other components in water distribution systems. Two indicators of potential corrosivity—the Langelier Saturation Index (LSI) and the Potential to Promote Galvanic Corrosion (PPGC)—were used to identify which areas in the United States might be more susceptible to elevated concentrations of metals in household drinking water and which areas might be less susceptible. On the basis of the LSI, about one-third of the samples collected from about 21,000 groundwater sites are classified as potentially corrosive. On the basis of the PPGC, about two-thirds of the samples collected from about 27,000 groundwater sites are classified as moderate PPGC, and about one-tenth as high PPGC. Potentially corrosive groundwater occurs in all 50 states and the District of Columbia. National maps have been prepared to identify the occurrence of potentially corrosive groundwater in the 50 states and the District of Columbia. Eleven states and the District of Columbia were classified as having a very high prevalence of potentially corrosive groundwater, 14 states as having a high prevalence of potentially corrosive groundwater, 19 states as having a moderate prevalence of potentially corrosive groundwater, and 6 states as having a low prevalence of potentially corrosive groundwater. These findings have the greatest implication for people dependent on untreated groundwater for drinking water, such as the 44 million people that are self-supplied and depend on domestic wells or springs for their water supply.

Health concerns of heterotrophic plate count (HPC) bacteria in dental equipment water lines

Allen, M.J., American Journal of Dentistry, June, 2016; Letters.

There is an unsubstantiated concern as to the health relevance of HPC (heterotrophic plate count) bacteria in dental equipment waterlines. The American Dental Association (ADA) web site includes guidelines for controlling HPC populations and implies that HPC populations >500 CFU/mL as a "health" benchmark. The world-wide published literature including the United Nations fully examined this situation and concluded that HPC bacteria are not a health risk, but merely a general water quality parameter for all waters including dental water lines. This review provides documentation that the standard measurement of HPC bacteria in waters alone do not pose a health risk and the ADA already provides appropriate practices to minimize HPC bacteria in dental equipment water.

The Flint Water Crisis Confirms That U.S. Drinking Water Needs Improved Risk Management

Baum R, et. al., Environmental Science and Technology, May 2016.

Since the Flint, MI water crisis, polls have shown that half of Americans are not very confident in the safety of their tap water and water contamination is believed to be a widespread problem. These Americans have more than just the recent events in Flint to support their beliefs. Before the Flint water crisis was the Toledo water crisis and before Toledo was the West Virginia water crisis and before that... The list goes on and shows the existence of larger public health concerns that the current regulatory system has repeatedly failed to address to protect US residents. So what will be done about it? Most likely, federal and state investigations will figure out exactly who to blame and will document with agonizing precision how such a failure occurred, but no preventive risk management will be implemented. This investigative process is necessary but insufficient. Those affected will be no better off. Monitoring of treated water quality against maximum contaminant levels (MCLs), no matter how stringent, is an inherently reactive approach. Effective risk management needs to be fundamentally preventive. Water system failures have been extensively analyzed, leading to a conclusion that most could have been prevented with better risk management. However, most utilities are reluctant to embrace any preventive measures beyond the precise limits of regulatory requirements that are already viewed as being onerous. Recent research shows the most reported reasons to be because of time and money constraints, but these may also reflect a lack of policy priority shared by the utility and regulator. U.S. public drinking water systems are focused on meeting nationally defined regulations that target certain MCLs and specific treatment techniques.

Contrasting regional and national mechanisms for predicting elevated arsenic in private wells across the United States using classification and regression trees

Frederick L, et. al., Water Research, March 15, 2016; 91:295-304

Arsenic contamination in groundwater is a public health and environmental concern in the United States (U.S.) particularly where monitoring is not required under the Safe Water Drinking Act. Previous studies suggest the influence of regional mechanisms for arsenic mobilization into groundwater; however, no study has examined how influencing parameters change at a continental scale spanning multiple regions. We herein examine covariates for groundwater in the western, central and eastern U.S. regions representing mechanisms associated with arsenic concentrations exceeding the U.S. Environmental Protection Agency maximum contamination level (MCL) of 10 parts per billion (ppb). Statistically significant covariates were identified via classification and regression tree (CART) analysis, and included hydrometeorological and groundwater chemical parameters. The CART analyses were performed at two scales: national and regional; for which three physiographic regions located in the western (Payette Section and the Snake River Plain), central (Osage Plains of the Central Lowlands), and eastern (Embayed Section of the Coastal Plains) U.S. were examined. Validity of each of the three regional CART models was indicated by values >85% for the area under the receiver-operating characteristic curve. Aridity (precipitation minus potential evapotranspiration) was identified as the primary covariate associated with elevated arsenic at the national scale. At the regional scale, aridity and pH were the major covariates in the arid to semi-arid (western) region; whereas dissolved iron (taken to represent chemically reducing conditions) and pH were major covariates in the temperate (eastern) region, although additional important covariates emerged, including elevated phosphate. Analysis in the central U.S. region indicated that elevated arsenic concentrations were driven by a mixture of those observed in the western and eastern regions.

Elevated Blood Lead Levels in Children Associated With the Flint Drinking Water Crisis: A Spatial Analysis of Risk and Public Health Response

Hanna-Attisha M, et. al., American Journal of Public Health, February, 2016; Vol. 106 no. 2

Objectives. We analyzed differences in pediatric elevated blood lead level incidence before and after Flint, Michigan, introduced a more corrosive water source into an aging water system without adequate corrosion control. Methods. We reviewed blood lead levels for children younger than 5 years before (2013) and after (2015) water source change in Greater Flint, Michigan. We assessed the percentage of elevated blood lead levels in both time periods, and identified geographical locations through spatial analysis. Results. Incidence of elevated blood lead levels increased from 2.4% to 4.9% ( P< .05) after water source change, and neighborhoods with the highest water lead levels experienced a 6.6% increase. No significant change was seen outside the city. Geospatial analysis identified disadvantaged neighborhoods as having the greatest elevated blood lead level increases and informed response prioritization during the now-declared public health emergency. Conclusions. The percentage of children with elevated blood lead levels increased after water source change, particularly in socioeconomically disadvantaged neighborhoods. Water is a growing source of childhood lead exposure because of aging infrastructure.

Human exposure to thallium through tap water: A study from Valdicastello Carducci and Pietrasanta (northern Tuscany, Italy)

Campanella B, et. al., Science of the Total Environment, January 19, 2016; 548 33-42.

A geological study evidenced the presence of thallium (Tl) at concentrations of concern in groundwaters near Valdicastello Carducci (Tuscany, Italy). The source of contamination has been identified in the Tl-bearing pyrite ores occurring in the abandoned mining sites of the area. The strongly acidic internal waters flowing in the mining tunnels can reach exceptional Tl concentrations, up to 9000μg/L. In September 2014 Tl contamination was also found in the tap water distributed in the same area (from 2 to 10μg/L). On October 3, 2014 the local authorities imposed a Do Not Drink order to the population. Here we report the results of the exposure study carried out from October 2014 to October 2015, and aimed at quantifying Tl levels in 150 urine and 318 hair samples from the population of Valdicastello Carducci and Pietrasanta. Thallium was quantified by inductively coupled plasma - mass spectrometry (ICP-MS). Urine and hair were chosen as model matrices indicative of different time periods of exposure (short-term and long-term, respectively). Thallium values found in biological samples were correlated with Tl concentrations found in tap water in the living area of each citizen, and with his/her habits. Thallium concentration range found in hair and urine was 1-498ng/g (values in unexposed subjects 0.1-6ng/g) and 0.046-5.44μg/L (reference value for the European population 0.006μg/L), respectively. Results show that Tl levels in biological samples were significantly associated with residency in zones containing elevated water Tl levels. The kinetics of decay of Tl concentration in urine samples was also investigated. At the best of our knowledge, this is the first study on human contamination by Tl through water involving such a high number of samples.

[Qualitative analysis of water quality deterioration and infection by Helicobacter pylori in a community with high risk of stomach cancer (Cauca, Colombia)]

Acosta CP, et. al., Salud Colectiva, 11 (4):575-590; DEC 2015.

This study looks at aspects of the environmental health of the rural population in Timbio (Cauca, Columbia) in relation to the deterioration of water quality. The information was obtained through participatory research methods exploring the management and use of water, the sources of pollution and the perception of water quality and its relation to Helicobacter pylori infection. The results are part of the qualitative analysis of a first research phase characterizing water and sanitation problems and their relation to emerging infectious diseases as well as possible solutions, which was carried out between November 2013 and August 2014. The results of this research are discussed from an ecosystemic approach to human health, recognizing the complexity of environmental conflicts related to water resources and their impacts on the health of populations. Through the methodology used, it is possible to detect and visualize the most urgent problems as well as frequent causes of contamination of water resources so as to propose solutions within a joint agenda of multiple social actors.

Microbial Health Risks of Regulated Drinking Waters in the United States — A Comparative Microbial Safety Assessment of Public Water Supplies and Bottled Water

Edberg SC, Topics in Public Health, June 2015, ISBN: 978-953-51-2132-9, InTech, DOI: 10.5772/58879.

The quality of drinking water in the United States (U.S.) is extensively monitored and regulated by federal, state and local agencies, yet there is increasing public concern and confusion about the safety and quality of drinking water –– both from public water systems and from bottled water products. In the U.S., tap water and bottled water are regulated by two different agencies: the Environmental Protection Agency (EPA) regulates public water system water (tap water) and the Food and Drug Administration (FDA) regulates bottled water. Federal law requires that the FDA’s regulations for bottled water must be at least as protective of public health as EPA standards for tap water.

Contamination of Groundwater Systems in the US and Canada by Enteric Pathogens, 1990–2013: A Review and Pooled-Analysis

Hynds PD, Thomas MK, Pintar KDM, PLOS ONE, May 2014, Vol. 9, issue 5, e93301.

A combined review and pooled-analysis approach was used to investigate groundwater contamination in Canada and the US from 1990 to 2013; fifty-five studies met eligibility criteria. Four study types were identified. It was found that study location affects study design, sample rate and studied pathogen category. Approximately 15% (316/2210) of samples from Canadian and US groundwater sources were positive for enteric pathogens, with no difference observed based on system type. Knowledge gaps exist, particularly in exposure assessment for attributing disease to groundwater supplies. Furthermore, there is a lack of consistency in risk factor reporting (local hydrogeology, well type, well use, etc). The widespread use of fecal indicator organisms in reported studies does not inform the assessment of human health risks associated with groundwater supplies.

Widespread Molecular Detection of Legionella pneumophila Serogroup 1 in Cold Water Taps across the United States

Donohue, MJ, Environmental Science and Technology, 2014, 48 (6), pp 3145–3152 (February 18, 2014).

In the United States, 6,868 cases of legionellosis were reported to the Center for Disease Control and Prevention in 2009–2010. Of these reports, it is estimated that 84% are caused by the microorganism Legionella pneumophila Serogroup (Sg) 1. Legionella spp. have been isolated and recovered from a variety of natural freshwater environments. Human exposure to L. pneumophila Sg1 may occur from aerosolization and subsequent inhalation of household and facility water. In this study, two primer/probe sets (one able to detect L. pneumophila and the other L. pneumophila Sg1) were determined to be highly sensitive and selective for their respective targets. Over 272 water samples, collected in 2009 and 2010 from 68 public and private water taps across the United States, were analyzed using the two qPCR assays to evaluate the incidence of L. pneumophila Sg1. Nearly half of the taps showed the presence of L. pneumophila Sg1 in one sampling event, and 16% of taps were positive in more than one sampling event. This study is the first United States survey to document the occurrence and colonization of L. pneumophila Sg1 in cold water delivered from point of use taps.

Methyl Tertiary Butyl Ether (MTBE) and Other Volatile Organic Compounds (VOCs) in Public Water Systems, Private Wells, and Ambient Groundwater Wells in New Jersey Compared to Regulatory and Human-Health Benchmarks

Williams, PRD, Environmental Forensics, Volume 15, Issue 1, 2014 (February 14, 2014).

Potential threats to drinking water and water quality continue to be a major concern in many regions of the United States. New Jersey, in particular, has been at the forefront of assessing and managing potential contamination of its drinking water supplies from hazardous substances. The purpose of the current analysis is to provide an up-to-date evaluation of the occurrence and detected concentrations of methyl tertiary butyl ether (MTBE) and several other volatile organic compounds (VOCs) in public water systems, private wells, and ambient groundwater wells in New Jersey based on the best available data, and to put these results into context with federal and state regulatory and human-health benchmarks. Analyses are based on the following three databases that contain water quality monitoring data for New Jersey: Safe Drinking Water Information System (SDWIS), Private Well Testing Act (PWTA), and National Water Information System (NWIS). For public water systems served by groundwater in New Jersey, MTBE was detected at a concentration ≥10 μg/L, ≥20 μg/L, and ≥70 μg/L at least once in 30 (2%), 21 (1.4%), and five (0.3%) of sampled systems from 1997 to 2011, respectively. For private wells in New Jersey, MTBE was detected at a concentration ≥10 μg/L, ≥20 μg/L, and ≥70 μg/L at least once in 385 (0.5%), 183 (0.2%), and 46 (0.05%) of sampled wells from 2001 to 2011, respectively. For ambient groundwater wells in New Jersey, MTBE was detected at a concentration ≥10 μg/L, ≥20 μg/L, and ≥70 μg/L at least once in 14 (2.1%), 9 (1.3%), and 4 (0.6%) of sampled wells from 1993 to 2012, respectively. Average detected concentrations of MTBE, as well as detected concentrations at upper-end percentiles, were less than corresponding benchmarks for all three datasets. The available data show that MTBE is rarely detected in various source waters in New Jersey at a concentration that exceeds the State's health-based drinking water standard or other published benchmarks, and there is no evidence of an increasing trend in the detection frequency of MTBE. Other VOCs, such as tetrachloroethylene (PCE), trichloroethylene (TCE), and benzene, are detected more often above corresponding regulatory or human-health benchmarks due to their higher detected concentrations in water and/or greater toxicity values. The current analysis provides useful data for evaluating the nature and extent of historical and current contamination of water supplies in New Jersey and potential opportunities for public exposures and health risks due to MTBE and other VOCs on a statewide basis. Additional forensic or forecasting analyses are required to identify the sources or timing of releases of individual contaminants at specific locations or to predict potential future water contamination in New Jersey.

Drinking Water Microbial Myths

Martin, JA, Edberg, SC, Clancy, JL and Hrudey, SE, Critical Reviews in Microbiology, November 25, 2013.

Accounts of drinking water-borne disease outbreaks have always captured the interest of the public, elected and health officials, and the media. During the twentieth century, the drinking water community and public health organizations have endeavored to craft regulations and guidelines on treatment and management practices that reduce risks from drinking water, specifically human pathogens. During this period there also evolved misunderstandings as to potential health risk associated with microorganisms that may be present in drinking waters. These misunderstanding or “myths” have led to confusion among the many stakeholders. The purpose of this article is to provide a scientific- and clinically-based discussion of these “myths” and recommendations for better ensuring the microbial safety of drinking water and valid public health decisions.

Microbial Health Risks of Regulated Drinking Water in the United States

Edberg, SC, DWRF, September 2013.

Drinking water regulations are designed to protect the public health. In the United States, the Environmental Protection Agency (EPA) is tasked with developing and maintaining drinking water regulations for the 276,607,387 people served by the country’s 54,293 community water systems. The Food and Drug Administration (FDA) regulates bottled water as a food product. By federal law, the FDA’s regulations for bottled water must be at least as protective of public health as the EPA’s regulations for public water system drinking water. Despite many similarities in EPA and FDA regulations, consumer perception regarding the safety of drinking waters varies widely. This paper examines and compares the microbial health risks of tap water and bottled water, specifically examining differences in quality monitoring, regulatory standards violations, advisories, and distribution system conditions. It also includes comparison data on the number of waterborne illness outbreaks caused by both tap and bottled water. Based on a review of existing research, it is clear that as a consequence of the differences in regulations, distribution systems, operating (manufacturing) practices, and microbial standards of quality, public drinking water supplies present a substantially higher human risk than do bottled waters for illness due to waterborne organisms.

Quantitative analysis of microbial contamination in private drinking water supply systems

Allevi RP, Krometis LA, Hagedorn C, Benham B, Lawrence AH, Ling EJ, Ziegler PE, Journal of Water and Health, June 2013.

Over one million households rely on private water supplies (e.g. well, spring, cistern) in the Commonwealth of Virginia, USA. The present study tested 538 private wells and springs in 20 Virginia counties for total coliforms (TCs) and Escherichia coli along with a suite of chemical contaminants. A logistic regression analysis was used to investigate potential correlations between TC contamination and chemical parameters (e.g. NO3(-), turbidity), as well as homeowner-provided survey data describing system characteristics and perceived water quality. Of the 538 samples collected, 41% (n = 221) were positive for TCs and 10% (n = 53) for E. coli. Chemical parameters were not statistically predictive of microbial contamination. Well depth, water treatment, and farm location proximate to the water supply were factors in a regression model that predicted presence/absence of TCs with 74% accuracy. Microbial and chemical source tracking techniques (Bacteroides gene Bac32F and HF183 detection via polymerase chain reaction and optical brightener detection via fluorometry) identified four samples as likely contaminated with human wastewater.

Strontium Concentrations in Corrosion Products from Residential Drinking Water Distribution Systems

Gerke TL, Little BJ, Luxton TP, Scheckel KG, and Maynard JB, Environmental Science and Technology, April 22, 2013.

The United States Environmental Protection Agency (US EPA) will require some U.S. drinking water distribution systems (DWDS) to monitor nonradioactive strontium (Sr2+) in drinking water in 2013. Iron corrosion products from four DWDS were examined to assess the potential for Sr2+ binding and release. Average Sr2+ concentrations in the outermost layer of the corrosion products ranged from 3 to 54 mg kg–1 and the Sr2+ drinking water concentrations were all ≤0.3 mg L–1. Micro-X-ray adsorption near edge structure spectroscopy and linear combination fitting determined that Sr2+ was principally associated with CaCO3. Sr2+ was also detected as a surface complex associated with α-FeOOH. Iron particulates deposited on a filter inside a home had an average Sr2+ concentration of 40.3 mg kg–1 and the associated drinking water at a tap was 210 μg L–1. The data suggest that elevated Sr2+ concentrations may be associated with iron corrosion products that, if disturbed, could increase Sr2+ concentrations above the 0.3 μg L–1 US EPA reporting threshold. Disassociation of very small particulates could result in drinking water Sr2+ concentrations that exceed the US EPA health reference limit (4.20 mg kg–1 body weight).

Lead (Pb) quantification in potable water samples: implications for regulatory compliance and assessment of human exposure.

Triantafyllidou S, Nguyen CK, Zhang Y, Edwards MA, Environmental Monitoring and Assessment, February 2013.

Assessing the health risk from lead (Pb) in potable water requires accurate quantification of the Pb concentration. Under worst-case scenarios of highly contaminated water samples, representative of public health concerns, up to 71-98 % of the total Pb was not quantified if water samples were not mixed thoroughly after standard preservation (i.e., addition of 0.15 % (v/v) HNO(3)). Thorough mixing after standard preservation improved recovery in all samples, but 35-81 % of the total Pb was still un-quantified in some samples. Transfer of samples from one bottle to another also created high errors (40-100 % of the total Pb was un-quantified in transferred samples). Although the United States Environmental Protection Agency's standard protocol avoids most of these errors, certain methods considered EPA-equivalent allow these errors for regulatory compliance sampling. Moreover, routine monitoring for assessment of human Pb exposure in the USA has no standardized protocols for water sample handling and pre-treatment. Overall, while there is no reason to believe that sample handling and pre-treatment dramatically skew regulatory compliance with the US Pb action level, slight variations from one approved protocol to another may cause Pb-in-water health risks to be significantly underestimated, especially for unusual situations of "worst case" individual exposure to highly contaminated water.

Clues to the Future of the Park Doctrine

Burroughs A, Rin D, FDLI Update, December 2012.

This article examines three recent cases brought under the controversial Park doctrine in search of clues to the doctrine's future. The responsible corporate officer (RCO) doctrine, also known as the Park doctrine, allows for criminal prosecution of individuals, typically high-ranking corporate executives of pharmaceutical companies, for violations of the Food, Drug and Cosmetic Act (FDCA), even absent any proof of the individual defendant's knowledge of or participation in the violation. It is relevant to drinking water because the Park law applies to bottled water, but not to tap water.

Direct healthcare costs of selected diseases primarily or partially transmitted by water

Collier SA, Stockman LJ, Hicks LA, Garrison LE, Zhou FJ, and Beach MJ, Epidemiology and Infection, November 2012;140(11):2003-13.

Despite US sanitation advancements, millions of waterborne disease cases occur annually, although the precise burden of disease is not well quantified. Estimating the direct healthcare cost of specific infections would be useful in prioritizing waterborne disease prevention activities. Hospitalization and outpatient visit costs per case and total US hospitalization costs for ten waterborne diseases were calculated using large healthcare claims and hospital discharge databases. The five primarily waterborne diseases in this analysis (giardiasis, cryptosporidiosis, Legionnaires' disease, otitis externa, and non-tuberculous mycobacterial infection) were responsible for over 40 000 hospitalizations at a cost of $970 million per year, including at least $430 million in hospitalization costs for Medicaid and Medicare patients. An additional 50 000 hospitalizations for campylobacteriosis, salmonellosis, shigellosis, haemolytic uraemic syndrome, and toxoplasmosis cost $860 million annually ($390 million in payments for Medicaid and Medicare patients), a portion of which can be assumed to be due to waterborne transmission.

The need for congressional action to finance arsenic reductions in drinking water

Levine, RL, Journal of Environmental Health, November 2012.

Many public water systems in the U.S. are unsafe because the communities cannot afford to comply with the current 10 parts per billion (ppb) federal arsenic standard for drinking water. Communities unable to afford improvements remain vulnerable to adverse health effects associated with higher levels of arsenic exposure. Scientific and bipartisan political consensus exists that the arsenic standard should not be less stringent than 10 ppb, and new data suggest additional adverse health effects related to arsenic exposure through drinking water. Congress has failed to reauthorize the Drinking Water State Revolving Fund program to provide reliable funding to promote compliance and reduce the risk of adverse health effects. Congress's recent ad hoc appropriations do not allow long-term planning and ongoing monitoring and maintenance. Investing in water infrastructure will lower health care costs and create American jobs. Delaying necessary upgrades will only increase the costs of improvements over time.

Risk of Viral Acute Gastrointestinal Illness from Nondisinfected Drinking Water Distribution Systems

Lambertini E, Borchardt M, Kieke BA, Spencer S, and Loge F, Environmental Science and Technology, July 27, 2012.

Acute gastrointestinal illness (AGI) resulting from pathogens directly entering the piping of drinking water distribution systems is insufficiently understood. Here, we estimate AGI incidence from virus intrusions into the distribution systems of 14 nondisinfecting, groundwater-source, community water systems. Water samples for virus quantification were collected monthly at wells and households during four 12-week periods in 2006–2007. Ultraviolet (UV) disinfection was installed on the communities’ wellheads during one study year; UV was absent the other year. UV was intended to eliminate virus contributions from the wells and without residual disinfectant present in these systems, any increase in virus concentration downstream at household taps represented virus contributions from the distribution system (Approach 1). During no-UV periods, distribution system viruses were estimated by the difference between well water and household tap virus concentrations (Approach 2). For both approaches, a Monte Carlo risk assessment framework was used to estimate AGI risk from distribution systems using study-specific exposure–response relationships. Depending on the exposure–response relationship selected, AGI risk from the distribution systems was 0.0180–0.0661 and 0.001–0.1047 episodes/person-year estimated by Approaches 1 and 2, respectively. These values represented 0.1–4.9% of AGI risk from all exposure routes, and 1.6–67.8% of risk related to drinking water exposure. Virus intrusions into nondisinfected drinking water distribution systems can contribute to sporadic AGI.

Screening-Level Risk Assessment of Coxiella burnetii (Q Fever) Transmission via Aeration of Drinking Water.

Sales-Ortells H, Medema G, Environmental Science and Technology, April 3, 2012.

A screening-level risk assessment of Q fever transmission through drinking water produced from groundwater in the vicinity of infected goat barnyards that employed aeration of the water was performed.

Waterborne Pathogens: Emerging Issues in Monitoring, Treatment and Control

Kelly A. Reynolds, MSPH, Ph.D., Water Conditioning & Purification, March 2012.

Microbial threats to water quality continue to emerge; however, technologies for monitoring, treating and controlling emerging waterborne pathogens are also evolving. Understanding the range of factors that lead to the contamination of water are important for developing appropriate tools to manage human health risks.

Migration of Bisphenol-A into the Natural Spring Water Packaged in Polycarbonate Carboys

Yasar Kemal Erdem, Furkan Acar, International Journal of Applied Science and Technology, 2012; Vol. 2 No. 1

Bisphenol-A is a widely used chemical in the structure of epoxy resins, polycarbonate packages, lacquer of metal food packages all over the world. Its weak estrogenic character and possible health effects are well known. For this reason the usage of the Bisphenol-A in food packages is limited and it’s daily intake by human is restrictly under control. The declaration of specific migration limit is 0.6 ppm, the tolerable daily intake is 0.05mg/kg body weight per day by EFSA and other authorities. The EFSA and others prevent the manufacturing and using of Bisphenol-A in baby bottles in 2010. In Turkey, the 70% of the population are living in 5 metropolitan cities and the drinking water consumption is mostly supplied by packaged drinking water industry. The household and bulk usage is covered by natural spring and natural mineral water packaged in 19 liters polycarbonate carboys. That’s why the possible migration of Bisphenol-A in drinking water packaged in polycarbonate carboys was decided to investigate. First of all, a screening test was carried out in the samples supplied by two main cities. And then 5 different trade mark packaged water samples was stored at 4, 25, and 35oC for 60 days and Bisphenol-A content was determined in given intervals. It is found that the BPA migration was detected at least 450 times lower than the specific migration limit of EFSA during 60 days storage at these conditions.

Risk of waterborne illness via drinking water in the United States.

Reynolds KA, Mena KD, Gerba CP, Reviews of Environmental Contamination & Toxicology, 2008;192:117-58

Outbreaks of disease attributable to drinking water are not common in the U.S., but they do still occur and can lead to serious acute, chronic, or sometimes fatal health consequences, particularly in sensitive and immunocompromised populations. From 1971 to 2002, there were 764 documented waterborne outbreaks associated with drinking water, resulting in 575,457 cases of illness and 79 deaths (Blackburn et al. 2004; Calderon 2004); however, the true impact of disease is estimated to be much higher. If properly applied, current protocols in municipal water treatment are effective at eliminating pathogens from water. However, inadequate, interrupted, or intermittent treatment has repeatedly been associated with waterborne disease outbreaks. Contamination is not evenly distributed but rather affected by the number of pathogens in the source water, the age of the distribution system, the quality of the delivered water, and climatic events that can tax treatment plant operations. Private water supplies are not regulated by the USEPA and are generally not treated or monitored, although very few of the municipal systems involved in documented outbreaks exceeded the USEPA's total coliform standard in the preceding 12 mon (Craun et al. 2002). We provide here estimates of waterborne infection and illness risks in the U.S. based on the total number of water systems, source water type, and total populations exposed. Furthermore, we evaluated all possible illnesses associated with the microbial infection and not just gastroenteritis. Our results indicate that 10.7 M infections/yr and 5.4 M illnesses/yr occur in populations served by community groundwater systems; 2.2 M infections/yr and 1.1 M illnesses/yr occur in noncommunity groundwater systems; and 26.0 M infections/yr and 13.0 M illnesses/yr occur in municipal surface water systems. The total estimated number of waterborne illnesses/yr in the U.S. is therefore estimated to be 19.5 M/yr. Others have recently estimated waterborne illness rates of 12M cases/yr (Colford et al. 2006) and 16 M cases/yr (Messner et al. 2006), yet our estimate considers all health outcomes associated with exposure to pathogens in drinking water rather than only gastrointestinal illness. Drinking water outbreaks exemplify known breaches in municipal water treatment and distribution processes and the failure of regulatory requirements to ensure water that is free of human pathogens. Water purification technologies applied at the point-of-use (POU) can be effective for limiting the effects of source water contamination, treatment plant inadequacies, minor intrusions in the distribution system, or deliberate posttreatment acts (i.e., bioterrorism). Epidemiological studies are conflicting on the benefits of POU water treatment. One prospective intervention study found that consumers of reverse-osmosis (POU) filtered water had 20%-35% less gastrointestinal illnesses than those consuming regular tap water, with an excess of 14% of illness due to contaminants introduced in the distribution system (Payment 1991, 1997). Two other studies using randomized, blinded, controlled trials determined that the risks were equal among groups supplied with POU-treated water compared to untreated tap water (Hellard et al. 2001; Colford et al. 2003). For immunocompromised populations, POU water treatment devices are recommended by the CDC and USEPA as one treatment option for reducing risks of Cryptosporidium and other types of infectious agents transmitted by drinking water. Other populations, including those experiencing "normal" life stages such as pregnancy, or those very young or very old, might also benefit from the utilization of additional water treatment options beyond the current multibarrier approach of municipal water treatment.

Maternal Exposure to Water Disinfection By-products During Gestation and Risk of Hypospadias

T. J. Luben,J. R. Nuckols, B. S. Mosley, C. Hobbs,J. S. Reif, Occupational and Environmental Medicine, June 2008

The use of chlorine for water disinfection results in the formation of numerous contaminants called disinfection by-products (DBPs), which may be associated with birth defects, including urinary tract defects. MethodsWe used Arkansas birth records (1998-2002) to conduct a population-based case-control study investigating the relationship between hypospadias and two classes of DBPs, trihalomethanes (THM) and haloacetic acids (HAA). We utilised monitoring data, spline regression and geographical information systems (GIS) to link daily concentrations of these DBPs from 263 water utilities to 320 cases and 614 controls. We calculated ORs for hypospadias and exposure to DBPs between 6 and 16 weeks' gestation, and conducted subset analyses for exposure from ingestion, and metrics incorporating consumption, showering and bathing. Results: We found no increase in risk when women in the highest tertiles of exposure were compared to those in the lowest for any DBP. When ingestion alone was used to assess exposure among a subset of 40 cases and 243 controls, the intermediate tertiles of exposure to total THM and the five most common HAA had ORs of 2.11 (95% CI 0.89 to 5.00) and 2.45 (95% CI 1.06 to 5.67), respectively, compared to women with no exposure. When exposure to total THM from consumption, showering and bathing exposures was evaluated, we found an OR of 1.96 (95% CI 0.65 to 6.42) for the highest tertile of exposure and weak evidence of a dose-response relationship. Conclusions: Our results provide little evidence for a positive relationship between DBP exposure during gestation and an increased risk of hypospadias but emphasize the necessity of including individual-level data when assessing exposure to DBPs.

Formation of N-Nitrosamines from Eleven Disinfection Treatments of Seven Different Surface Waters

Yuan-Yuan Zhao, Jessica M. Boyd, Matthew Woodbeck, Robert C. Andrews, Feng Qin, Steve E. Hrudey, Xing-Fang Li, Environmental Science & Technology, May 2008

Formation of nine N-nitrosamines has been investigated when seven different source waters representing various qualities were each treated with eleven bench-scale disinfection processes, without addition of nitrosamine precursors. These disinfection treatments included chlorine (OCl-) chloramine (NH2Cl), chlorine dioxide (ClO2), ozone (O3), ultraviolet (UV), advanced oxidation processes (AOP), and combinations. The total organic carbon (TOC) of the seven source waters ranged from 2 to 24 mg L-1. The disinfected water samples and the untreated source waters were analyzed for nine nitrosamines using a solid phase extraction and liquid chromatography-tandem mass spectrometry method. Prior to any treatment, N-nitrosodimethylamine (NDMA) was detected ranging from 0 to 53 ng L-1 in six of the seven source waters, and its concentrations increased in the disinfected water samples (0 - 118 ng L-1). N-nitrosodiethylamine (NDEA), N-nitrosomorpholine (NMor), and N-nitrosodiphenylamine (NDPhA) were also identified in some of the disinfected water samples. NDPhA (0.2- 0.6 ng L-1) was formed after disinfection with OCl-, NH2Cl, O3, and MPUV/OCl-. NMEA was produced with OCl- and MPUV/OCl-, and NMor formation was associated with O3. In addition, UV treatment alone degraded NDMA; however, UV/OCl- and AOP/OCl- treatments produced higher amounts of NDMA compared to UV and AOP alone, respectively. These results suggest that UV degradation or AOP oxidation treatment may provide a source of NDMA precursors. This study demonstrates that environmental concentrations and mixtures of unknown nitrosamine precursors in source waters can form NDMA and other nitrosamines.

N,N-Dimethylsulfamide as Precursor for N-Nitrosodimethylamine (NDMA) Formation upon Ozonation and its Fate During Drinking Water Treatment

Carsten K. Schmidt, Heinz-J- Brauch, Environmental Science & Technology, April 2008

Application and microbial degradation of the fungicide tolylfluanide gives rise to a new decomposition product named N,N-dimethylsulfamide (DMS). In Germany, DMS was found in groundwaters and surface waters with typical concentrations in the range of 100-1000 ng/L and 50-90 ng/L, respectively. Laboratory-scale and field investigations concerning its fate during drinking water treatment showed that DMS cannot be removed via riverbank filtration, activated carbon filtration, flocculation, and oxidation or disinfection procedures based on hydrogen peroxide, potassium permanganate, chlorine dioxide, or UV irradiation. Even nanofiltration does not provide a sufficient removal efficiency. During ozonation about 30-50% of DMS are converted to the carcinogenic N-nitrosodimethylamine (NDMA). The NDMA being formed is biodegradable and can at least partially be removed by subsequent biologically active drinking water treatment steps including sand or activated carbon filtration. Disinfection with hypochlorous acid converts DMS to so far unknown degradation products but not to NDMA or 1,1-dimethylhydrazine (UDMH).

Risk of Birth Defects in Australian Communities with High Brominated Disinfection By-product Levels

Kimberley Chisholm, Angus Cook, Carol Bower, Philip Weinstein, Environmental Health Perspective, April 2008

By international standards, water supplies in Perth, Western Australia contain high trihalomethane (THM) levels, particularly the brominated forms. Geographical variability in these levels provided an opportunity to examine cross-city spatial relationships between THM exposure and rates of birth defects. The objective is to examine birth defect rates by exposure to THMs with a highly brominated fraction in metropolitan locations in Perth, Western Australia. Water samples were collected from 47 separate locations. Samples were analyzed for total and individual THM concentrations in ?g/L, including separation into brominated forms.

Drinking Water Disinfection By-Products and Time to Pregnancy

Maclehose RF, Savitz DA, Herring AH, Hartmann KE, Singer PC, Weinberg HS, Epidemiology, March 2008

Laboratory evidence suggests tap water disinfection by-products (DBPs) could have an effect very early in pregnancy, typically before clinical detectability. Undetected early losses would be expected to increase the reported number of cycles to clinical pregnancy. METHODS:: We investigated the association between specific DBPs (trihalomethanes, haloacetic acids, brominated-trihalomethanes, brominated-haloacetic acids, total organic halides, and bromodichloromethane) and time to pregnancy among women who enrolled in a study of drinking water and reproductive outcomes. We quantified exposure to DBPs through concentrations in tap water, quantity ingested through drinking, quantity inhaled or absorbed while showering or bathing, and total integrated exposure. The effect of DBPs on time to pregnancy was estimated using a discrete time hazard model. RESULTS:: Overall, we found no evidence of an increased time to pregnancy among women who were exposed to higher levels of DBPs. A modestly decreased time to pregnancy (ie, increased fecundability) was seen among those exposed to the highest level of ingested DBPs, but not for tap water concentration, the amount absorbed while showering or bathing, or the integrated exposure. CONCLUSIONS: Our findings extend those of a recently published study suggesting a lack of association between DBPs and pregnancy loss.

Human Health Risk Assessment of Chlorinated Disinfection By-products in Drinking Water Using a Probabilistic Approach

Nasrul Hamidin, Qiming Jimmy Yu, Des W. Connell, Water Research, March 2008

The presence of chlorinated disinfection by-products (DBPs) in drinking water is a public health issue, due to their possible adverse health effects on humans. To gauge the risk of chlorinated DBPs on human health, a risk assessment of chloroform (trichloromethane (TCM)), bromodichloromethane (BDCM), dibromochloromethane (DBCM), bromoform (tribromomethane (TBM)), dichloroacetic acid (DCAA) and trichloroacetic acid (TCAA) in drinking water was carried out using probabilistic techniques. Literature data on exposure concentrations from more than 15 different countries and adverse health effects on test animals as well as human epidemiological studies were used. The risk assessment showed no overlap between the highest human exposure dose (EXP(D)) and the lowest human equivalent dose (HED) from animal test data, for TCM, BDCM, DBCM, TBM, DCAA and TCAA. All the HED values were approximately 10(4)-10(5) times higher than the 95th percentiles of EXP(D). However, from the human epidemiology data, there was a positive overlap between the highest EXP(D) and the lifetime average daily doses (LADD(H)) for TCM, BDCM, DCAA and TCAA. This suggests that there are possible adverse health risks such as a small increased incidence of cancers in males and developmental effects on infants. However, the epidemiological data comprised several risk factors and exposure classification levels which may affect the overall results.

Water Disinfection By-Products and the Risk of Specific Birth Defects: A Population-Based Cross-Sectional Study in Taiwan

Bing-Fang Hwang, Jouni Jaakkola, How-Ran Guo, Environmental Health, 2008

Recent findings suggest that exposure to disinfection by-products may increase the risk of birth defects. Previous studies have focused mainly on birth defects in general or groups of defects. The objective of the present study was to assess the effect of water disinfection by-products on the risk of most common specific birth defects. We conducted a population-based cross-sectional study of 396,049 Taiwanese births in 2001-2003 using information from the Birth Registry and Waterworks Registry. We compared the risk of eleven most common specific defects in four disinfection by-product exposure categories based on the levels of total trihalomethanes (TTHMs) representing high (TTHMs 20+ ug/L), medium (TTHMs 10-19 ug/L), low exposure (TTHMs 5-9 ug/L), and 0-4 ug/L as the reference category. In addition, we conducted a meta-analysis of the results from the present and previous studies focusing on the same birth defects.

Opportunistic Infections Series HIV/AIDS: Safe Food and Water

Center for Disease Control, June 2007

In this study, the Center for Disease Control (CDC) considers persons with weakened immune systems and makes a number of recommendations regarding drinking water, including the following. Because you cannot be sure your tap water is safe, you may wish to avoid tap water, including water or ice from a refrigerator ice-maker, which is made from tap water. Always check with the local health department and water utility to see if they have issued any special notices for people with HIV about tap water. You may also wish to boil or filter your water, or to drink bottled water. Processed carbonated (bubbly) drinks in cans or bottles should be safe, but drinks made at a fountain might not be because they are made with tap water. If you choose to boil or filter your water or to drink only bottled water, do this all the time, not just at home.

Massive Microbiological Groundwater Contamination Associated with a Waterborne Outbreak in Lake Erie, South Bass Island, Ohio

, Environmental Health Perspectives, June 2007

A groundwater-associated outbreak affected approximately 1,450 residents and visitors of South Bass Island, Ohio, between July and September 2004. To examine the microbiological quality of groundwater wells located on South Bass Island, we sampled 16 wells that provide potable water to public water systems 15–21 September 2004. We tested groundwater wells for fecal indicators, enteric viruses and bacteria, and protozoa (Cryptosporidium and Giardia). The hydrodynamics of Lake Erie were examined to explore the possible surface water–groundwater interactions. All wells were positive for both total coliform and Escherichia coli. Seven wells tested positive for enterococci and Arcobacter (an emerging bacterial pathogen), and F+-specific coliphage was present in four wells. Three wells were positive for all three bacterial indicators, coliphages, and Arcobacter; adenovirus DNA was recovered from two of these wells. We found a cluster of the most contaminated wells at the southeast side of the island. Conclusions: Massive groundwater contamination on the island was likely caused by transport of microbiological contaminants from wastewater treatment facilities and septic tanks to the lake and the subsurface, after extreme precipitation events in May–July 2004. This likely raised the water table, saturated the subsurface, and along with very strong Lake Erie currents on 24 July, forced a surge in water levels and rapid surface water–groundwater interchange throughout the island. Landsat images showed massive influx of organic material and turbidity surrounding the island before the peak of the outbreak. These combinations of factors and information can be used to examine vulnerabilities in other coastal systems. Both wastewater and drinking water issues are now being addressed by the Ohio Environmental Protection Agency and the Ohio Department of Health.

Water Quality Control in Premise Plumbing

Kelly A. Reynolds, Water Conditioning & Purification, February 2007

There is little published research regarding pathogen occurrence, growth and survival specifically in premise plumbing. Although limited data is available regarding HPC bacteria, these bacteria generally are not a human health risk and offer little information relative to the associative prevalence of harmful microbial populations. Pipe materials appear to be a factor in bacterial colonization and re-growth in the distribution system. Plastic faucets have been shown to harbor higher numbers of specific bacteria (i.e., coliforms) compared to metal; however, iron pipes appear to support a higher diversity of bacteria compared to PVC surfaces.3 We do not know the extent of the public health risks associated with microbes and their ecology in distribution systems or whether or not diversity and selectivity of specific bacterial groups is preferred. In fact, several studies have shown that HPC bacteria are antagonistic to pathogens when they are introduced to the established microflora of premise plumbing.

Information is not currently available regarding the changes that occur in microbial populations in the premise plumbing compared to the distribution system. While it is documented that 51.4 percent (4/7) of the waterborne outbreaks in community water systems in the US from 2001-2002 were related to problems in the distribution system, no information is available regarding exposures to harmful organisms in premise plumbing. This is surprising considering the increased potential for pathogen survival, growth and introduction. If waterborne disease outbreaks occur from problems in premise plumbing, they are unlikely to be detected or reported due to the small population affected (i.e., a single household). Overall, these data gaps mean that very little is known about the quality of water that consumers are actually drinking from the tap. In order to evaluate health risks and mitigation approaches, much more research is needed to determine the types, numbers, growth and disease potentials of the microbial communities at the point of consumption.

Drowning in Disinfection Byproducts? Assessing Swimming Pool Water

David M. DeMarini, Fritz H. Frimmel, Thomas Glauner, Tamara Grummt, Susan D. Richardson, Christian Zweiner, Environmental Science & Technology, January 2007

Disinfection is mandatory for swimming pools: public pools are usually disinfected by gaseous chlorine or sodium hypochlorite and cartridge filters; home pools typically use stabilized chlorine. These methods produce a variety of disinfection byproducts (DBPs), such as trihalomethanes (THMs), which are regulated carcinogenic DBPs in drinking water that have been detected in the blood and breath of swimmers and of nonswimmers at indoor pools. Also produced are halogenated acetic acids (HAAs) and haloketones, which irritate the eyes, skin, and mucous membranes; trichloramine, which is linked with swimming-pool-associated asthma; and halogenated derivatives of UV sun screens, some of which show endocrine effects. DBPs may be reduced by engineering and behavioral means, such as applying new oxidation and filtration methods, reducing bromide and iodide in the source water, increasing air circulation in indoor pools, and assuring the cleanliness of swimmers. The positive health effects gained by swimming can be increased by reducing the potential adverse health risks.

An approach for developing a national estimate of waterborne disease due to drinking water and a national estimate model application

Michael Messner, Susan Shaw, Stig Regli, Ken Rotert, Valerie Blank and Jeff Soller, Journal of Water and Health, 2006;04.suppl2:201-40

In this paper, the US Environmental Protection Agency (EPA) presents an approach and a national estimate of drinking water related endemic acute gastrointestinal illness (AGI) that uses information from epidemiologic studies. There have been a limited number of epidemiologic studies that have measured waterborne disease occurrence in the United States. For this analysis, we assume that certain unknown incidence of AGI in each public drinking water system is due to drinking water and that a statistical distribution of the different incidence rates for the population served by each system can be estimated to inform a mean national estimate of AGI illness due to drinking water. Data from public water systems suggest that the incidence rate of AGI due to drinking water may vary by several orders of magnitude. In addition, data from epidemiologic studies show AGI incidence due to drinking water ranging from essentially none (or less than the study detection level) to a rate of 0.26 cases per person-year. Considering these two perspectives collectively, and associated uncertainties, EPA has developed an analytical approach and model for generating a national estimate of annual AGI illness due to drinking water. EPA developed a national estimate of waterborne disease to address, in part, the 1996 Safe Drinking Water Act Amendments. The national estimate uses best available science, but also recognizes gaps in the data to support some of the model assumptions and uncertainties in the estimate. Based on the model presented, EPA estimates a mean incidence of AGI attributable to drinking water of 0.06 cases per year (with a 95% credible interval of 0.02–0.12). The mean estimate represents approximately 8.5% of cases of AGI illness due to all causes among the population served by community water systems. The estimated incidence translates to 16.4 million cases/year among the same population. The estimate illustrates the potential usefulness and challenges of the approach, and provides a focus for discussions of data needs and future study designs. Areas of major uncertainty that currently limit the usefulness of the approach are discussed in the context of the estimate analysis.

Tap Water Linked to Increase in Bladder Cancer

Kelly A. Reynolds, Water Conditioning & Purification, July 2006

As water treatment professionals, maybe you've been alerted to news stories suggesting a connection between tap water consumption and bladder cancer, but are these headlines true or just media hype? Although the most recently reported association of tap water consumption with bladder cancer is indeed based on numerous epidemiological studies with an international scope, all scientific research must be carefully evaluated; not just in terms of the data found, but also for the information possibly missed. The study that has everyone talking again about tap water consumption and its relationship to bladder cancer