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The book presents some of the findings of research into China?s water quality criteria for toxic pollutants, including heavy metals, PAHs and emerging pollutant. Water quality criteria (WQC) are the scientific basis for establishing water quality standards (WQSs). For a long time, the study of WQC in China has been neglected, so that almost all of China?s WQSs were developed based on foreign WQC. This book provides valuable information for environmental management and revision of WQSs. It has been written for researchers and graduate students in the field of environmental science and risk assessors for chemical and pollutants etc. Dr. Zhen-guang Yan is an Associate Professor at the Chinese Research Academy of Environmental Sciences. Dr. Zhengtao Liu is a Professor at the Chinese Research Academy of Environmental Sciences.

Unsafe drinking water and household air pollution (HAP) are major causes of morbidity and mortality among children under 5 in low and middle-income countries. Household water filters and higher-efficiency biomass-burning cookstoves have been widely promoted to improve water quality and reduce fuel use, but there is limited evidence of their health effects when delivered programmatically at scale. In a large-scale program in Western Province, Rwanda, water filters and portable biomass-burning natural draft rocket-style cookstoves were distributed between September and December 2014 and promoted to over 101,000 households in the poorest economic quartile in 72 (of 96) randomly selected sectors in Western Province. To assess the effects of the intervention, between August and December, 2014, we enrolled 1,582 households that included a child under 4 years from 174 randomly selected village-sized clusters, half from intervention sectors and half from nonintervention sectors. At baseline, 76% of households relied primarily on an improved source for drinking water (piped, borehole, protected spring/well, or rainwater) and over 99% cooked primarily on traditional biomass-burning stoves. We conducted follow-up at 3 time-points between February 2015 and March 2016 to assess reported diarrhea and acute respiratory infections (ARIs) among children <5 years in the preceding 7 days (primary outcomes) and patterns of intervention use, drinking water quality, and air quality. The intervention reduced the prevalence of reported child diarrhea by 29% (prevalence ratio [PR] 0.71, 95% confidence interval [CI] 0.59-0.87, p = 0.001) and reported child ARI by 25% (PR 0.75, 95% CI 0.60-0.93, p = 0.009). Overall, more than 62% of households were observed to have water in their filters at follow-up, while 65% reported using the intervention stove every day, and 55% reported using it primarily outdoors. Use of both the intervention filter and intervention stove decreased throughout follow-up, while reported traditional stove use increased. The intervention reduced the prevalence of households with detectable fecal contamination in drinking water samples by 38% (PR 0.62, 95% CI 0.57-0.68, p < 0.0001) but had no significant impact on 48-hour personal exposure to log-transformed fine particulate matter (PM2.5) concentrations among cooks (β = -0.089, p = 0.486) or children (β = -0.228, p = 0.127). The main limitations of this trial include the unblinded nature of the intervention, limited PM2.5 exposure measurement, and a reliance on reported intervention use and reported health outcomes. Our findings indicate that the intervention improved household drinking water quality and reduced caregiver-reported diarrhea among children <5 years. It also reduced caregiver-reported ARI despite no evidence of improved air quality. Further research is necessary to ascertain longer-term intervention use and benefits and to explore the potential synergistic effects between diarrhea and ARI. Clinical Trials.gov NCT02239250.

Due to alarming increase in population and rapid industrialization, drinking water quality is being deteriorated day by day in Pakistan. This review sums up the outcomes of various research studies conducted for drinking water quality status of different areas of Pakistan by taking into account the physicochemical properties of drinking water as well as the presence of various pathogenic microorganisms. About 20% of the whole population of Pakistan has access to safe drinking water. The remaining 80% of population is forced to use unsafe drinking water due to the scarcity of safe and healthy drinking water sources. The primary source of contamination is sewerage (fecal) which is extensively discharged into drinking water system supplies. Secondary source of pollution is the disposal of toxic chemicals from industrial effluents, pesticides, and fertilizers from agriculture sources into the water bodies. Anthropogenic activities cause waterborne diseases that constitute about 80% of all diseases and are responsible for 33% of deaths. This review highlights the drinking water quality, contamination sources, sanitation situation, and effects of unsafe drinking water on humans. There is immediate need to take protective measures and treatment technologies to overcome unhygienic condition of drinking water supplies in different areas of Pakistan.

Ensuring safe water supply for communities across the United States is a growing challenge in the face of aging infrastructure, impaired source water, and strained community finances. In the aftermath of the Flint lead crisis, there is an urgent need to assess the current state of US drinking water. However, no nationwide assessment has yet been conducted on trends in drinking water quality violations across several decades. Efforts to reduce violations are of national concern given that, in 2015, nearly 21 million people relied on community water systems that violated health-based quality standards. In this paper, we evaluate spatial and temporal patterns in health-related violations of the Safe Drinking Water Act using a panel dataset of 17,900 community water systems over the period 1982–2015. We also identify vulnerability factors of communities and water systems through probit regression. Increasing time trends and violation hot spots are detected in several states, particularly in the Southwest region. Repeat violations are prevalent in locations of violation hot spots, indicating that water systems in these regions struggle with recurring issues. In terms of vulnerability factors, we find that violation incidence in rural areas is substantially higher than in urbanized areas. Meanwhile, private ownership and purchased water source are associated with compliance. These findings indicate the types of underperforming systems that might benefit from assistance in achieving consistent compliance. We discuss why certain violations might be clustered in some regions and strategies for improving national drinking water quality.

In this study, the quality of groundwater was assessed in a semi-arid region of India by using an entropy weighted water quality index (EWQI) and a pollution index of groundwater (PIG). The EWQI and PIG methods were used to evaluate data on physicochemical parameters in relation to drinking water quality standards. Groundwater samples were collected from the Dubbak region, Telangana state, India, and were analyzed for pH, total hardness, electrical conductivity, total dissolved solids, bicarbonate (HCO3−), chloride (Cl−), sulfate (SO42−), nitrate (NO3−), fluoride (F−), calcium (Ca2+), magnesium (Mg2+), sodium (Na+), and potassium (K+). The groundwater of the study region is alkaline in nature. The abundance of cations and anions based on their mean values is in the following order: Na+ > Ca2+ > Mg2+ > K+ and Cl− > HCO3− > NO3− > SO42− > F−, respectively. The calculated EWQI values ranged from 49.0 to 174.6, with an average of 93.3. Overall, EWQI data showed that only 60% of groundwater samples were of suitable quality for drinking, although only marginally, whereas the remaining 40% of samples were unsuitable for drinking purposes and would therefore require treatment. The values of PIG varied from 0.5 to 1.8, with an average of 1.0, which showed that only 63% of groundwater samples from the study area were suitable for drinking purposes.

Rural water supplies have traditionally been overshadowed by urban ones. That must now change, as the Sustainable Development Goals calls for water for all. The objective of the paper is to assess the current access to and the perceived water quality in villages with various types of water supply. The survey was carried out during July–December 2017 in four villages in central Kazakhstan. Overall, 1369 randomly selected households were interviewed. The results revealed that even though villagers were provided with tap water, significant numbers used alternative sources. There were three reasons for this situation: residents’ doubts regarding the tap water quality; use of other sources out of habit; and availability of cheaper or free sources. Another problem concerned the volume of water consumption, which dropped sharply with decreased quality or inconvenience of sources used by households. Moreover, people gave a poor estimate to the quality and reliability of water from wells, open sources and tankered water. The paper suggests that as well decentralization of water management as monitoring of both water supply and water use are essential measures. There must be a tailor-made approach to each village for achieving the Sustainable Development Goal of providing rural Kazakhstan with safe water.

Background Low-income and minority communities often face disproportionately high pollutant exposures. The lead crisis in Flint, Michigan, has sparked concern about broader socioeconomic disparities in exposures to drinking water contaminants. Nitrate is commonly found in drinking water, especially in agricultural regions, and epidemiological evidence suggests elevated risk of cancer and birth defects at levels below U.S. EPA’s drinking water standard (10 mg/L NO 3 -N). However, there have been no nationwide assessments of socioeconomic disparities in exposures to nitrate or other contaminants in U.S. drinking water. The goals of this study are to identify determinants of nitrate concentrations in U.S. community water systems (CWSs) and to evaluate disparities related to wealth or race/ethnicity. Methods We compiled nitrate data from 39,466 U.S. CWSs for 2010–2014. We used EPA’s Safe Drinking Water Information System (SDWIS) to compile CWS characteristics and linked this information with both city- and county-level demographic data gathered from the U.S. Census Bureau. After applying multiple imputation methods to address censored nitrate concentration data, we conducted mixed-effects multivariable regression analyses at national and regional scales. Results 5.6 million Americans are served by a CWS that had an average nitrate concentration ≥ 5 mg/L NO 3 -N between 2010 and 2014. Extent of agricultural land use and reliance on groundwater sources were significantly associated with nitrate. The percent of Hispanic residents served by each system was significantly associated with nitrate even after accounting for county-level cropland and livestock production, and CWSs in the top quartile of percent Hispanic residents exceeded 5 mg/L nearly three times as often as CWSs serving the lowest quartile. By contrast, the percent of residents living in poverty and percent African American residents were both inversely associated with nitrate. Conclusions Epidemiological evidence for health effects associated with drinking water above 5 mg/L NO 3 -N raises concerns about increased risk for the 5.6 million Americans served by public water supplies with average nitrate concentrations above this level. The associations we observed between nitrate concentrations and proportions of Hispanic residents support the need for improved efforts to assist vulnerable communities in addressing contamination and protecting source waters. Future studies can extend our methods to evaluate disparities in exposures to other contaminants and links to health effects.

The focus of the present study was to assess the quality of different drinking water sources, impacts of poor water quality on human health, and to apportion pollution source(s) of the district Bajaur, Pakistan. Drinking water samples (n = 331) were randomly collected from springs, hand pumps, open wells, and tube wells and analyzed for physicochemical parameters including toxic elements, and bacteriological contamination (i.e., Escherichia coli). Furthermore, a questionnaire survey was conducted to record the cases of waterborne diseases in the study area. The results showed that total suspended solids and bacteriological contamination exceeded the permissible limits of the WHO in all four of the water sources. Among the potentially toxic elements, Cd, Pb, and Mn were above the permissible limits of the WHO in some samples. The hazard index for spring water was found to exceed the toxicity level (i.e., HI > 1) set by US EPA for both adults and children, while the sources from hand pumps, open wells, and tube wells were within the safe limit. The order for the overall safety level for water quality in the study area was tube wells > open wells > hand pumps > springs. The pollution source apportionment statistics revealed that both geogenic and anthropogenic activities are the sources of drinking water contamination. The results of the questionnaire survey indicated that reports of waterborne diseases were highest in respondents who took their drinking water from springs, whereas reports of diseases were moderate in respondents taking their water from open wells and hand pumps and lowest in respondents taking their water from tube wells. Based on the findings of the study, the tube well source of water is recommended for drinking water purposes.

Deterioration of groundwater quality due to the introduction of pollutants from natural and anthropic sources has become a major environmental issue. We tested three methodologies in assessing groundwater quality and intrinsic aquifer vulnerability in the Agro-Aversano area (Southern Italy). A geographic information system (GIS)-based groundwater quality index (GQI) was realized to assess groundwater quality for drinking and irrigation use and, in parallel, standard SINTACS was applied to evaluate the intrinsic vulnerability of the aquifer. Nitrate concentrations and sodium absorption ratio (SAR) in groundwater samples were used to verify the reliability of vulnerability data. GQI analysis pointed to a general poor quality of groundwater both for drinking and irrigation use, especially in sub-urban areas. The spatial pattern of water quality from GQI analysis was positively related to nitrate and fluoride concentrations for drinking use and to bicarbonate and sodium concentrations for irrigation use, whose levels exceeded the WHO and FAO recommended thresholds, respectively. Standard SINTACS was found to be inadequate for describing the aquifer state, its results showing no correlation with nitrate concentration or SAR. Because of this inconsistency, we tested a novel approach combining GQI with SINTACS analysis. Results showed positive correlation with nitrate ( r  = 0.63) and SAR ( r  = 0.64) contents, thus pointing to combined SINTACS-GQI as a more reliable approach than standard methodologies.

The purpose of a drinking water distribution system is to deliver drinking water to the consumer, preferably with the same quality as when it left the treatment plant. In this context, the maintenance of good microbiological quality is often referred to as biological stability, and the addition of sufficient chlorine residuals is regarded as one way to achieve this. The full-scale drinking water distribution system of Riga (Latvia) was investigated with respect to biological stability in chlorinated drinking water. Flow cytometric (FCM) intact cell concentrations, intracellular adenosine tri-phosphate (ATP), heterotrophic plate counts and residual chlorine measurements were performed to evaluate the drinking water quality and stability at 49 sampling points throughout the distribution network. Cell viability methods were compared and the importance of extracellular ATP measurements was examined as well. FCM intact cell concentrations varied from 5×10(3) cells mL(-1) to 4.66×10(5) cells mL(-1) in the network. While this parameter did not exceed 2.1×10(4) cells mL(-1) in the effluent from any water treatment plant, 50% of all the network samples contained more than 1.06×10(5) cells mL(-1). This indisputably demonstrates biological instability in this particular drinking water distribution system, which was ascribed to a loss of disinfectant residuals and concomitant bacterial growth. The study highlights the potential of using cultivation-independent methods for the assessment of chlorinated water samples. In addition, it underlines the complexity of full-scale drinking water distribution systems, and the resulting challenges to establish the causes of biological instability.