Daily intakes of copper, zinc and arsenic in drinking water by population of Shanghai, China

Daily intakes of metals in drinking water are of extreme importance in risk assessment to human health. Some papers focused on this topic, but most of them did not consider the effect of age, gender and work location on daily intakes of metals in drinking water. The objective of present paper is to estimate the levels of Cu, Zn and As ingestion in drinking water in Shanghai, China and the effect of age, gender and work location on daily intakes of these metals. It was also the first time that such a detailed investigation on daily intakes of metals in drinking water was carried out in China in recent years. Drink/Sample (D/S) method was used to estimate the daily intakes of Cu, Zn and As in drinking water. The mean concentrations of Cu, Zn and As in drinking water were 10.8 microg/l, 0.29 mg/l and 0.91 microg/l, which were lower than U.S. EPA's Drinking Water Equivalent Level (DWEL) and WHO guideline values. The average daily intakes of Cu, Zn and As in drinking water was 21.12 microg/d, 0.65 mg/d, and 1.83 microg/d, which were on average 0.01%, 1.1% and 1.5% of the provisional maximum tolerable daily intake (PMTDI) set by the Joint FAO/WHO Expert Committee. There was a significant difference in daily intake of Zn for different work locations (P=0.04). But no other significant differences in daily intakes of metals in drinking water were found according to age, gender and work location.     

Drinking water and cancer mortality

The problem of understanding the possible adverse health effects of organic chemical contaminants in drinking water is not new, but national concern has intensified in recent years. Despite this concern and regulatory efforts, no definitive relationship has been established between organic contamination and human health effects. This paper examines some of the sources of possible organic contamination, current knowledge concerning human health effects and the most current epidemiological data. Historic CCE and CAE data were extracted from STORET and used in regression analyses. Age-adjusted 20-year average cancer mortality rates were regressed against the sum of CAE and CCE for those counties with STORET monitoring data of their drinking water source. Results indicate statistically highly significant relationships particularly for GI-urinary tract cancers.     

European case studies supporting the derivation of natural background levels and groundwater threshold values for the protection of dependent ecosystems and human health

The EU Water Framework and Groundwater directives stipulate that EU member states have to assess groundwater chemical status by the use of groundwater threshold values derived for the protection of dependent ecosystems and human health. This paper presents a synthesis of main results of 14 European case studies evaluating a methodology for derivation of natural background levels (NBLs) and groundwater threshold values (TVs) proposed by the EU research project "BRIDGE". The 14 investigated groundwater bodies were selected to represent as many aquifer types, climate settings and European ecoregions as possible within the project group that included partners from 17 EU countries. The selected case study sites include transboundary groundwater bodies, EU Pilot River Basins and other important groundwater systems. Some are known to interact with associated ecosystems, while others do not. The proposed method derives groundwater threshold values based on environmental objectives for dependent ecosystems or groundwater "itself" using relevant reference criteria such as natural background levels, environmental quality standards and drinking water standards. Derived groundwater threshold values for dissolved Cl and As applying drinking water standards as examples of reference values, are compared for all 14 case studies. Additionally, more detailed analyses are conducted for the Odense Pilot River Basin and the Vouga River Basin, where groundwater threshold values for N and P and Cl, As, Cd, Ni, Pb, and Zn, respectively, are derived based on environmental objectives and quality standards for groundwater dependent ecosystems. Results demonstrate that the proposed methodology is operational and may be used to protect human health and the environment. Further they show that groundwater threshold values derived from environmental objectives and environmental quality standards for dependent ecosystems in some cases may be significantly lower than drinking water standards, e.g. for nitrate.     

The Impact of Plastic Materials on Iron Levels in Village Groundwater Supplied in Malawi

I ron is not normally considered to be a constituent of health significance, and recommended limits for iron in drinking water supplies are based on aesthetic considerations. Experience in Malawi has demonstrated that, even when present in only trace amounts, iron can influence the consumer's acceptance of an improved borehole supply. The effect of the use of plastic construction materials on the iron content of village groundwater supplies was investigated using a statistical approach. The majority of groundwater points using only plastic materials was found to supply water containing less than the WHO guideline value of 0.3 mg/l iron. In contrast, the use of ferrous-materials increased the iron content of the water to unacceptable levels, sometimes causing the consumers to reject the borehole as a source of drinking water.
Bacteriological data show that the quality of the alternative, traditional supply is far inferior to the new improved supply. An otherwise perfectly safe supply may therefore be abandoned as a direct result of contamination introduced by 'down the hole' components. This frustrates efforts to improve the well-being of rural communities, and is a waste of precious development resources.     

Chemometrics in monitoring spatial and temporal variations in drinking water quality

This case study reports multivariate techniques applied for the evaluation of temporal/spatial variations and interpretation of monitoring data obtained by the determination of chloro/bromo disinfection by-products in drinking water at 12 locations in the Gdańsk area (Poland), over the period 1993-2000. The complex data matrix (1756 observations) was treated with various multivariate techniques. Cluster analysis (CA) was successful, yielding two different groups of similarity reflecting different types of drinking water supplied (surface and groundwater). The locations supplied in general with groundwater could be further classified into two subgroups, depending on whether the groundwater was mixed with surface water or not. Analysis of variance (ANOVA) was used to classify and thus confirm the groups found by means of cluster analysis and proved the existence of statistically significant differences between the concentration levels of CHCl3, CHBrCl2+C2HCl3, CHBr2Cl, and CH2Cl2 in the samples collected. Of all the variables evaluated, only three were characterized by statistically significant correlations (CHCl3, CHBrCl2+C2HCl3, CHBr2Cl). The analysis of correlation coefficients revealed that chloroform formed as the main chlorinated disinfection by-product and, furthermore, the natural presence of bromide in water (both ground and surface) results in the formation of brominated disinfection by-products (DBPs). Temporal variations of volatile organic chlorinated compounds (VOCls) were also evaluated by multidimensional ANOVA. Observation of temporal changes in the concentration of VOCls at the location supplied with both surface and groundwater reveals a steady improvement in drinking water quality. In general, the study shows the importance of drinking water monitoring in connection with simple but powerful statistical tools to better understand spatial and temporal variations in water quality.     

Groundwater recharge with reclaimed municipal wastewater: health and regulatory considerations

Groundwater recharge with reclaimed municipal wastewater presents a wide spectrum of technical and health challenges that must be carefully evaluated prior to undertaking a project. This review will provide a discussion of groundwater recharge and its management with special reference to health and regulatory aspects of groundwater recharge with reclaimed municipal wastewater. At present, some uncertainties with respect to health risk considerations have limited expanding use of reclaimed municipal wastewater for groundwater recharge, especially when a large portion of the groundwater contains reclaimed wastewater that may affect the domestic water supply. The proposed State of California criteria for groundwater recharge are discussed as an illustration of a cautious approach. In addition, a summary is provided of the methodology used in developing the World Health Organization's Guidelines for Drinking Water Quality to illustrate how numerical guideline values are generated for contaminants that may be applicable to groundwater recharge.     

Evaluation of potential health risk of arsenic-affected groundwater using indicator kriging and dose response model

This study analyzed the potential health risk associated with the ingestion of arsenic-affected groundwater in the arseniasis-endemic Lanyang plain of northeastern Taiwan. Indicator kriging was used to estimate arsenic concentrations in groundwater. Target cancer risk (TR) and dose response functions were adopted to evaluate the potential health risk based on the estimated arsenic concentration distributions. The estimated arsenic concentrations in groundwater reveal that arsenic concentrations (>50 microg/L) in well water are high in six townships - JiaoSi, YiLan, JhungWei, WuJie, DonShan and LouDon. Highest arsenic concentrations (70.32 microg/L) are in the YiLan and the JhungWei townships. The estimated TR values at the arsenic-affected townships are ten times more than an acceptable standard (10(-6)). The largest TR values are 145.5 and 91.2 times higher than an acceptable standard for males and females, respectively. The estimated annual mortalities by arsenic-induced internal cancers occur in the YiLan township (ten cases), LouDon (five cases), WuJie (three cases), JhungWei (two cases) and DonShan (one case). The highest number of mortalities per year in the study area is 24. Residents of the six townships with high arsenic-affected groundwater should use tap water as drinking water and use groundwater only for other purpose. The well water in other townships in the Lanyang plain has no adverse effects on human health.     

Electrodialysis and nanofiltration of surface water for subsequent use as infiltration water

In order to achieve stable groundwater levels, an equilibrium between the use of groundwater for drinking water production and natural or artificial groundwater recharge by infiltration is needed. Local governments usually require that the composition of the water used for artificial recharge is similar to the surface water that is naturally present in the specific recharge area. In this paper, electrodialysis (ED) and nanofiltration were evaluated as possible treatment technologies for surface water from a canal in Flanders, the North of Belgium, in view of infiltration at critical places on heathlands. Both methods were evaluated on the basis of a comparison between the water composition after treatment and the composition of local surface waters. The treatment generally consists of a tuning of pH and the removal of contaminants originating from industrial and agricultural activity, e.g., nitrates and pesticides. Further evaluation of the influence of the composition of the water on the characteristics of the artificial recharge, however, was not envisaged. In a case study of water from the canal Schoten-Dessel, satisfactory concentration reductions of Cl(-), SO(4)(2-), NO(3)(-), HCO(3)(-), Na(+), Mg(2+), K(+) and Ca(2+) were obtained by ultrafiltration pretreatment followed by ED. Nanofiltration with UTC-20, N30F, Desal 51 HL, UTC-60 and Desal 5 DL membranes resulted in an insufficient removal level, especially for the monovalent ions.     

The correlation of arsenic levels in drinking water with the biological samples of skin disorders

Arsenic (As) poisoning has become a worldwide public health concern. The skin is quite sensitive to As and skin lesions are the most common and earliest nonmalignant effects associated to chronic As exposure. In 2005-2007, a survey was carried out on surface and groundwater arsenic contamination and relationships between As exposure via the drinking water and related adverse health effects (melanosis and keratosis) on villagers resides on the banks of Manchar lake, southern part of Sindh, Pakistan. We screened the population from arsenic-affected villages, 61 to 73% population were identified patients suffering from chronic arsenic toxicity. The effects of As toxicity via drinking water were estimated by biological samples (scalp hair and blood) of adults (males and females), have or have not skin problem (n = 187). The referent samples of both genders were also collected from the areas having low level of As (< 10 μg/L) in drinking water (n = 121). Arsenic concentration in drinking water and biological samples were analyzed using electrothermal atomic absorption spectrometry. The range of arsenic concentrations in lake surface water was 35.2-158 μg/L, which is 3-15 folds higher than World Health Organization [WHO, 2004. Guidelines for drinking-water quality third ed., WHO Geneva Switzerland.]. It was observed that As concentration in the scalp hair and blood samples were above the range of permissible values 0.034-0.319 μg As/g for hair and < 0.5-4.2 μg/L for blood. The linear regressions showed good correlations between arsenic concentrations in water versus hair and blood samples of exposed skin diseased subjects (R² = 0.852 and 0.718) as compared to non-diseased subjects (R² = 0.573 and 0.351), respectively.     

Chemical drinking water quality in Ghana: Water costs and scope for advanced treatment

To reduce child mortality and improve health in Ghana boreholes and wells are being installed across the country by the private sector, NGO's and the Ghanaian government. Water quality is not generally monitored once a water source has been improved. Water supplies were sampled across Ghana from mostly boreholes, wells and rivers as well as some piped water from the different regions and analysed for the chemical quality. Chemical water quality was found to exceed the WHO guidelines in 38% of samples, while pH varied from 3.7 to 8.9. Excess levels of nitrate (NO₃⁻) were found in 21% of the samples, manganese (Mn) and fluoride (F⁻) in 11% and 6.7%, respectively. Heavy metals such as lead (Pb), arsenic (As) and uranium (U) were localised to mining areas. Elements without health based guideline values such as aluminium (Al, 95%) and chloride (Cl, 5.7%) were found above the provisional guideline value.Economic information was gathered to identify water costs and ability to pay. Capital costs of wells and boreholes are about £1200 and £3800 respectively. The majority of installation costs are generally paid by the government or NGO's, while the maintenance is expected to be covered by the community. At least 58% of the communities had a water payment system in place, either an annual fee/one-off fee or “pay-as-you-fetch”. The annual fee was between £0.3-21, while the boreholes had a water collection fee of £0.07-0.7/m³, many wells were free. Interestingly, the most expensive water (£2.9-3.5/m³) was brought by truck. Many groundwater sources were not used due to poor chemical water quality. Considering the cost of unsuccessful borehole development, the potential for integrating suitable water treatment into the capital and maintenance costs of water sources is discussed. Additionally, many sources were not in use due to lack of water capacity, equipment malfunction or lack of economic resources to repair and maintain equipment. Those issues need to be addressed in combination with water quality, coordinated water supply provision and possible treatment to ensure sustainability of improved water resources.     

The impact of the hyperacid Ijen Crater Lake: risks of excess fluoride to human health

The Asembagus irrigation area (East Java, Indonesia) receives a high input of fluoride (F) via surface water that partially originates from the hyperacid crater lake of the Ijen volcano. Endemic dental fluorosis among local residents has been ascribed to F in water wells. In this study, the total F intake by children and adults was estimated, based on concentrations in well waters and foods throughout the area. These values were compared with the Lowest Observed Adverse Effect Level (LOAEL) for dental fluorosis among children and skeletal fluorosis among adults. Fluorosis hazard maps were prepared, identifying the most hazardous locations in the area. It was concluded that there is not only a high risk of dental fluorosis, but also of skeletal fluorosis. Based on the total daily intake, the lowest F concentration in drinking water that poses a risk of developing fluorosis is approximately 0.5 mg/l for dental fluorosis and 1.1 mg/l for skeletal fluorosis. This is below 1.5 mg/l, which is both the guideline value for drinking water from the World Health Organization (WHO) and the Indonesian drinking water standard. This is the first documented case of human health problems that may be directly associated with natural pollutants originating from a volcano-hosted crater lake.     

Model for estimation of human exposure to copper in drinking water

A model denominated Consumption Habit Exposure Model, (CHEM), was developed for the calculation of human individual acute and chronic exposure to copper in drinking water. The model can estimate daily exposure of individuals as well as the maximum concentration of copper which individuals ingest during a 24-h period. The CHEM model requires carrying out a water consumption habit questionnaire and measuring the minimum and maximum concentration of copper in homes, as well as minimum and random copper concentration at work and study places. The case study employed was a representative sample of the population of Santiago, Chile. The validation of the model was established with reference to the application in a limited number of homes of the composite proportional method, (CPS), used to measure human chronic ingestion of contaminants from drinking water. It was found that 4.5% of the sampled population is exposed daily to one cup of water or more at the maximum copper concentration available at the tap. The probabilities that the different age groups are exposed to one cup or more of water at cMAX during 1 day are greater for the 20-64-year-old group, followed by the 64-year-old group, and then by the younger age groups in descending order. Ingestion of copper from drinking water by the population of Santiago is on average 9.0% of the World Health Organization recommendations for minimum total ingestion of copper for adults, assuming that 100% of the copper contained in drinking water is absorbed.     

净水中残余铝的危害与控制

净水中过量的残余铝对人体健康有较严重的危害,如抑制人胚神经的正常发育,导致痴呆、骨萎缩等症状。除此之外, 对输配水系统也有一定的影响。世界卫生组织( WHO) 及西方发达国家都把残余铝作为一项饮用水水质指标,制定了饮用水中总残余铝浓度标准。铝在天然水体中广泛存在, 但净水中的总残余铝主要是在铝盐混凝剂使用过程中不恰当操作条件所引入。因而, 通过调整和优化混凝过程的操作条件及其它一些方法,可以降低净水中总残余铝浓度     

Seasonal variation in drinking water concentrations of disinfection by-products in IZMIR and associated human health risks

Seasonal variation in concentrations of two different disinfection by-product groups, trihalomethanes (THMs) and haloacetonitriles (HANs), was investigated in tap water samples collected from five sampling points (one groundwater and four surface water sources) in Izmir, Turkey. Estimates of previously published carcinogenic and non-carcinogenic risks through oral exposure to THMs were re-evaluated using a probabilistic approach that took the seasonal concentration variation into account. Chloroform, bromoform, dibromochloromethane and dichloroacetonitrile were the most frequently detected compounds. Among these, chloroform was detected with the highest concentrations ranging from 0.03 to 98.4 microg/L. In tap water, at the groundwater supplied sampling point, brominated species, bromoform and dibromoacetonitrile, were detected at the highest levels most probably due to bromide ion intrusion from seawater. The highest total THM and total HAN concentrations were detected in spring while the lowest in summer and fall. The annual average total THM concentration measured at one of the surface water supplied sampling points exceeded the USEPA's limit of 80 microg/L. While all non-carcinogenic risks due to exposure to THMs in Izmir drinking water were negligible, carcinogenic risk levels associated with bromodichloromethane and dibromochloromethane were higher than one in million.     

Rapidity of RNA synthesis in human cells: A highly sensitive parameter for water cytotoxicity evaluation

To set up an in vitro cytotoxicity test much more sensitive that the currently available tests, toxic samples were directly assayed on eleven different human cell subcellular targets. This comparison clearly indicated that the rapidity of cellular RNA synthesis was the most sensitive target to many pollutants. When used in the water field this quantitative test does not require preliminary concentration of the water toxic compounds and, in the case of polluted river waters, requires the samples to be diluted. The application domain of the test was shown to be very large, ranging from surface and ground waters to drinking and mineral bottled waters.     

Occurrence, oral exposure and risk assessment of volatile organic compounds in drinking water for Izmir

Concentrations of volatile organic compounds (VOCs) were measured in the drinking water in Province of Izmir, Turkey, and associated health risks due to ingestion of these compounds were investigated using population weighted random samples. A total of 100 houses were visited in different districts of Izmir and drinking water samples were collected from consumers' drinking water source. Questionnaires were administered to one participant in each house to determine demographics and drinking water consumption rates. Oral exposure and risks were estimated for each participant and Izmir population by deterministic and probabilistic approaches, respectively. The four trihalomethane (THM) species (i.e., chloroform, bromodichloromethane, dibromochloromethane, and bromoform), benzene, toluene, p-xylene, and naphthalene were the most frequently detected VOCs with concentrations ranging from below detection limit to 35 microg/l. The risk estimates were found to be less than the values reported in the literature with few exceptions. Noncarcinogenic risks attributable to ingestion of VOCs for Izmir population were negligible, whereas the mean carcinogenic risk estimates for bromodichloromethane and dibromochloromethane were above the de minimis level of one in a million (10(-6)). For all VOCs, the concentrations measured in metropolitan area were greater than those in other districts. All THM species were detected in higher concentrations in tap water, whereas nontap water contained more benzene, toluene, p-xylene, and naphthalene. Therefore, the concentrations of the latter four compounds and associated risks increased with increasing income and education level since bottled water was used in larger proportions within these subgroups. The results of this study showed that oral exposure to drinking water contaminants and associated risks may be higher than the acceptable levels even if the concentrations fall below the standards.     

Dimensionierung wasserwirtschaftlicher Vorranggebiete in Kies-Grundwasserleitern unter Berücksichtigung von Schadstofftransport

Delineating of areas surrounding designated drinking water protection zones provides an administrative tool for preventing groundwater contamination. This delineation can be difficult for gravel aquifers due to their extended catchment areas and high groundwater flow velocities. A practical approach is proposed based on a combined consideration of aquifer characteristics such as surficial cover, recharge rate, surface area, groundwater flow velocity and those for common contaminants (transport, sorption and degradation behaviours). The possibility of applying this method to delimit the broader III and III B protection zones is also suggested.     

Indoor air quality and the associated health risk in primary school buildings in Central Europe – The InAirQ study

The indoor air quality (IAQ) was investigated in sixty-four primary school buildings in five Central European countries (Czech Republic, Hungary, Italy, Poland, and Slovenia). The concentration of volatile organic compounds, aldehydes, PM_2.5 mass, carbon dioxide, radon, as well as physical parameters were investigated during the heating period of 2017/2018. Significant differences were identified for the majority of the investigated IAQ parameters across the countries. The median indoor/outdoor ratios varied considerably. A comprehensive evaluation of IAQ in terms of potential health effects and comfort perception was performed. Hazard quotient values were below the threshold value of 1 with one exception. In contrast, 31% of the school buildings were characterized by hazard index values higher than 1. The maximum cumulative ratio approach highlighted that the concern for non-carcinogenic health effects was either low or the health risk was driven by more substances. The median excess lifetime cancer risk values exceeded the acceptable value of 1 × 10⁻⁶ in the case of radon and formaldehyde. PM_2.5 mass concentration values exceeded the 24 h and annual guideline values set by the World Health Organization in 56 and 85% of the cases, respectively. About 80% of the schools could not manage to comply with the recommended concentration value for carbon dioxide (1000 ppm).