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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.

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.

The present study region comprises granite and granite gneisses aquifer system constituted by Precambrian rocks. Groundwater is the primary source for drinking and other domestic purposes. Many developing regions in the world suffer from lack of safe drinking water. A rural part of Wanaparthy District in Telangana State, India, is one of them. For this reason, the groundwater samples collected from the study region were analyzed for pH, TDS, Ca2+, Mg2+, Na+, K+, HCO3−, Cl−, SO42−, NO3− and F− and evaluated groundwater quality criteria, using ionic spatial distribution (ISD), entropy water quality index (EWQI) and principal component analysis (PCA). The ISD maps show that some locations are not suitable for drinking purpose due to exceeding concentrations of TDS, Mg2+, Na+, K+, HCO3−, Cl−, NO3−and F−, compared to those with national drinking water quality standards. According to the EWQI, about 3%, 47%, 43% and 7% of the total area come under the excellent, good, medium and extremely poor water quality types for drinking purpose, respectively. Chadha’s diagram classified the area as carbonate hardness (63%), non-carbonate alkali (17%), carbonates alkali (13%) and non-carbonate hardness (7%) zones. The binary diagrams (Na+ + K+ vs TC, Na+ vs Ca2+ and HCO3− vs TC) indicate that the quality of groundwater is controlled by influences of water–rock interactions, mineral weathering and dissolution, ion exchange and evaporation as well as the impact of anthropogenic sources. The PCA transferred the chemical variables into three principal components accounts for about 81% of the total variance. The high positive loadings of PC1 (Cl−, TDS, SO42−, Na+, NO3−, Mg2+ and HCO3−) stand for processes of silicate weathering and dissolution, ion exchange and evaporation, and the influence of domestic waste waters, irrigation return flows and chemical fertilizers on the groundwater system, the PC2 (F− and pH) signifies the alkaline nature of groundwater, which causes fluorosis, and the PC3 (K+) is a result of potassium fertilizers. The study helps to take remediate measures at a specific site and hence suggests the treatment of water before its drinking and also the recharge of the aquifer artificially to improve the groundwater quality.

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.

The World Health Organization (WHO) is mandated to provide health information to member countries as one of its major objective. In water quality, it developed health-based guidelines to assist nations and other organisations involved, with a baseline for developing their own enforceable water-quality standards. The European Union (EU), United States (US) and China have standards developed for their regions and nations. Such regional standards are useful for sharing and transferring technology among member countries or states to meet the respective set quality standards. However, Africa has not developed such regional standards. This study investigates 21 water-quality parameters of 18 selected African countries, to assess if they are significantly different across countries and compare them to those of WHO, EU, US and China. There were significant statistical differences among twenty of the twenty-one studied parameters. The mean quality standards of Africa were generally higher (weaker) than those of WHO, EU and China but compared well with those of US. Nations were urged to frequently update without delays, their standards as new information become available, as there are emerging novel pollutants that are of health concern. The African Union or smaller groupings like the Economic Community of West African States (ECOWAS) and Southern African Development Community (SADC) should develop regional water-quality standards and benefit from knowledge and technological sharing, leading to improved supply of high-quality water in their individual countries.

Hydraulic-fracturing fluids and wastewater from unconventional oil and natural gas development contain hundreds of substances with the potential to contaminate drinking water. Challenges to conducting well-designed human exposure and health studies include limited information about likely etiologic agents. We systematically evaluated 1021 chemicals identified in hydraulic-fracturing fluids ( n =925), wastewater ( n =132), or both ( n =36) for potential reproductive and developmental toxicity to triage those with potential for human health impact. We searched the REPROTOX database using Chemical Abstract Service registry numbers for chemicals with available data and evaluated the evidence for adverse reproductive and developmental effects. Next, we determined which chemicals linked to reproductive or developmental toxicity had water quality standards or guidelines. Toxicity information was lacking for 781 (76%) chemicals. Of the remaining 240 substances, evidence suggested reproductive toxicity for 103 (43%), developmental toxicity for 95 (40%), and both for 41 (17%). Of these 157 chemicals, 67 had or were proposed for a federal water quality standard or guideline. Our systematic screening approach identified a list of 67 hydraulic fracturing-related candidate analytes based on known or suspected toxicity. Incorporation of data on potency, physicochemical properties, and environmental concentrations could further prioritize these substances for future drinking water exposure assessments or reproductive and developmental health studies.

Evaluation of seasonal and spatial variations in vulnerable zones for poor groundwater quality is essential for the protection of human health and to maintain the crop yields. With this objective, groundwater samples were collected seasonally (i.e., pre- and post-monsoon) from the Yellareddygudem watershed of Telangana, India. These samples were analysed for major chemical parameters (pH, TDS, Ca2+, Mg2+, Na+, K+, HCO3-, Cl−, SO42-, NO3-, and F−). Geographical information system (GIS) tools were used to delineate the seasonal and spatial variations for vulnerable zones related to the drinking groundwater quality index (DGQI) and irrigation groundwater quality index (IGQI). Geochemical facies and relations, Piper diagrams, and principal component analysis indicated that the weathering, dissolution, leaching, ion exchange, and evaporation were the primary processes controlling the groundwater quality seasonally. Human influences were the secondary factors. The TDS, Na+, K+, Cl−, SO42-, and F− parameters were observed to be within the drinking water quality standard limits in most post-monsoon groundwater samples. However, the DGQI showed an increase in the number of samples with unsuitable quality for drinking in the post-monsoon period compared with the pre-monsoon period. The IGQI demonstrated that the number of samples with unsuitable quality for irrigation increased in the post-monsoon period compared to the pre-monsoon period. The differences in the vulnerable zones between the pre- and post-monsoon periods were due to variations in groundwater recharge, following the topography. Thus, the present study will help decision makers to plan groundwater treatment measures within vulnerable zones.

A computer-aided multivariate water quality index is developed based on partial least squares (PLS) regression. The index is termed as the partial least squares water quality index (PLS-WQI). Briefly, a training set was computationally generated based on the guideline of National Water Quality Standards for Malaysia (NWQS) to predict the water quality. The index is benchmarked with the well-established index developed by the Department of Environment, Malaysia (DOE-WQI). The PLS-WQI is a continuous variable with the value closer to I indicating good water quality and closer to V indicating poor water quality. Unlike other conventional indexing methods, the algorithm calculates the index in a multivariate manner. The algorithm allows rapid processing of a large dataset without tedious calculation; it can be an efficient tool for spatial and temporal routine monitoring of water quality. Although the algorithm is designed based on the guideline of NWQS, it can be easily adapted to accommodate other guidelines. The algorithm was evaluated and demonstrated on the simulated and real datasets. Results indicate that the algorithm is robust and reliable. Based on six parameters, the overall ratings derived are inversely correlated to DOE-WQI. When the number of parameter is increased, the overall ratings appear to provide better insights into the water quality.

The nitrogen cycle has been radically changed by human activities 1 . China consumes nearly one third of the world’s nitrogen fertilizers. The excessive application of fertilizers 2 , 3 and increased nitrogen discharge from livestock, domestic and industrial sources have resulted in pervasive water pollution. Quantifying a nitrogen ‘boundary’ 4 in heterogeneous environments is important for the effective management of local water quality. Here we use a combination of water-quality observations and simulated nitrogen discharge from agricultural and other sources to estimate spatial patterns of nitrogen discharge into water bodies across China from 1955 to 2014. We find that the critical surface-water quality standard (1.0 milligrams of nitrogen per litre) was being exceeded in most provinces by the mid-1980s, and that current rates of anthropogenic nitrogen discharge (14.5 ± 3.1 megatonnes of nitrogen per year) to fresh water are about 2.7 times the estimated ‘safe’ nitrogen discharge threshold (5.2 ± 0.7 megatonnes of nitrogen per year). Current efforts to reduce pollution through wastewater treatment and by improving cropland nitrogen management can partially remedy this situation. Domestic wastewater treatment has helped to reduce net discharge by 0.7 ± 0.1 megatonnes in 2014, but at high monetary and energy costs. Improved cropland nitrogen management could remove another 2.3 ± 0.3 megatonnes of nitrogen per year—about 25 per cent of the excess discharge to fresh water. Successfully restoring a clean water environment in China will further require transformational changes to boost the national nutrient recycling rate from its current average of 36 per cent to about 87 per cent, which is a level typical of traditional Chinese agriculture. Although ambitious, such a high level of nitrogen recycling is technologically achievable at an estimated capital cost of approximately 100 billion US dollars and operating costs of 18–29 billion US dollars per year, and could provide co-benefits such as recycled wastewater for crop irrigation and improved environmental quality and ecosystem services. Estimates of spatial patterns of nitrogen discharge into water bodies across China between 1955 and 2014 show that current discharge rates are almost three times the acceptable threshold, and ways to restore a clean water environment are suggested.

The quality of landscape water directly impacts the recreational and leisure experiences of the public. Factors such as water clarity, color, and taste can influence public perception, while contaminants like heavy metals, algae, and microorganisms may pose health risks. Stratified monitoring can reveal variations in the physical, chemical, and biological properties of water at different depths, thereby providing a more comprehensive understanding of water quality and aiding in the identification of pollution sources. This study examined aquatic landscapes at five parks in Xinxiang, China, monitoring thirteen indicators including Water Temperature (WT), Chroma (Ch), Turbidity (Tu), Suspended Solids (SS), Electrical Conductivity (EC), pH, Dissolved Oxygen (DO), Total Nitrogen (TN), Total Phosphorus (TP), Chemical Oxygen Demand (COD), Fe, Zn, and Cu. Utilizing the single-factor evaluation method, the water quality level of each indicator was assessed in accordance with the Water Quality Standard for Scenery and Recreation Area of the People’s Republic of China (GB12941-91). The findings revealed significant vertical variations in the levels of TN, TP, COD, Fe, Zn and Cu of aquatic landscapes at parks, while WT, Ch, Tu, SS, EC, and DO showed no marked differences (P>0.05). The monthly dynamics of the water quality indicators indicated generally consistent trends for WT, Ch, Tu, SS, EC, DO, TN, TP, Zn, and Cu, albeit with varying degrees of fluctuation; however, the trends for EC, pH, COD, and Fe exhibited greater variability. These results offer valuable insights for the environmental protection and management of aquatic landscapes in urban parks. Stratified monitoring can capture the dynamic changes in water quality, assisting managers in developing more effective water quality management strategies.