Occurrence and fate of pharmaceutical products and by-products,from resource to drinking water

Among all emerging substances in water, pharmaceutical products (PPs) and residues are a lot of concern. These last two years, the number of studies has increased drastically, however much less for water resources and drinking water than for wastewater. This literature review based on recent works, deals with water resources (surface or groundwater), focusing on characteristics, occurrence and fate of numerous PPs studied, and drinking water including water quality. Through this review, it appears that the pharmaceutical risk must be considered even in drinking water where concentrations are very low. Moreover, there is a lack of research for by-products (metabolites and transformation products) characterization, occurrence and fate in all water types and especially in drinking water.     

我国水资源污染与饮用水安全性研究

对我国水资源状况和饮用水安全性进行了分析研究,结果表明：我国水资源贫乏,水资源环境污染日益严重。许多水厂不得不面临着使用更多的水质不符合要求的受污染水源原水作为生活饮用水水源。水污染主要是有机物和氨氮污染,常规净水工艺系统难以将这些污染物有效除去,降低了饮用水水质,对人体健康构成潜在威胁。随着人们生活水平的提高和健康安全意识的不断增强,对饮用水水质标准提出了更高要求。为从受污染的水源原水中除去对人体健康有害的污染物,提高饮用水的安全可靠性,强化传统工艺、替换传统的消毒剂、吸附、膜过滤和生物预处理等净水技术得到了国内外广泛重视和关注,尤其是经济、高效的生物除污染技术。     

Assessing the human health impacts of exposure to disinfection by-products — A critical review of concepts and methods

Understanding the public health implications of chemical contamination of drinking water is important for societies and their decision-makers. The possible population health impacts associated with exposure to disinfection by-products (DBPs) are of particular interest due to their potential carcinogenicity and their widespread occurrence as a result of treatments employed to control waterborne infectious disease.We searched the literature for studies that have attempted quantitatively to assess population health impacts and health risks associated with exposure to DBPs in drinking water. We summarised and evaluated these assessments in terms of their objectives, methods, treatment of uncertainties, and interpretation and communication of results.In total we identified 40 studies matching our search criteria. The vast majority of studies presented estimates of generic cancer and non-cancer risks based on toxicological data and methods that were designed with regulatory, health-protective purposes in mind, and therefore presented imprecise and biased estimates of health impacts. Many studies insufficiently addressed the numerous challenges to DBP risk assessment, failing to evaluate the evidence for a causal relationship, not appropriately addressing the complex nature of DBP occurrence as a mixture of chemicals, not adequately characterising exposure in space and time, not defining specific health outcomes, not accounting for characteristics of target populations, and not balancing potential risks of DBPs against the health benefits related with drinking water disinfection. Uncertainties were often poorly explained or insufficiently accounted for, and important limitations of data and methods frequently not discussed. Grave conceptual and methodological limitations in study design, as well as erroneous use of available dose–response data, seriously impede the extent to which many of these assessments contribute to understanding the public health implications of exposure to DBPs. In some cases, assessment results may cause unwarranted alarm among the public and potentially lead to poor decisions being made in sourcing, treatment, and provision of drinking water. We recommend that the assessment of public health impacts of DBPs should be viewed as a means of answering real world policy questions relating to drinking water quality, including microbial contaminants; that they should be conducted using the most appropriate and up-to-date data and methods, and that associated uncertainties and limitations should be accounted for using quantitative methods where appropriate.     

Perchlorate in sewage sludge, rice, bottled water and milk collected from different areas in China

As a new emerging environmental contaminant, perchlorate has prompted people to pay more attention. The presence of perchlorate in the human body can result in improper regulation of metabolism for adults. Furthermore, it also causes developmental and behavioral problems for infants and children because it can interfere with iodide uptake into the thyroid tissue. In this paper, perchlorate in sewage sludge, rice, bottled drinking water and milk was detected for investigating the perchlorate pollution status in China. The places, where the samples were collected, cover most regions of China. Therefore, the final data on perchlorate levels will give an indication of the perchlorate pollution status in China. The final determination of perchlorate was performed by ion chromatography-electrospray tandem mass spectrometry with negative mode. The concentration of perchlorate in sewage sludge, rice, bottled drinking water and milk was in the range of 0.56-379.9 microg/kg, 0.16-4.88 mug/kg, 0.037-2.013 microg/L and 0.30-9.1 microg/L, respectively. The results show that perchlorate has been widespread in China.     

Wastewater re-use for peri-urban agriculture: a viable option for adaptive water management?

Urbanization is known to spur land modification in the form of conversion of common land to human settlements. This factor, combined with climate variability, can alter the duration, frequency and intensity of storm drain overflows in urban areas and lead to public health risks. In peri-urban regions where these risks are especially high it has been argued that, when domestic wastewater is managed, better prospects for freshwater water savings through swaps between urban water supply and irrigated agriculture may be possible. As a consequence of re-use of domestic wastewater, expenditure on inorganic inputs by farmers may decline and source sustainability of water supply could be enhanced. Given the fact that, at present, approximately 20 million ha of land worldwide is being cultivated by re-using domestic wastewater, this paper draws on evidence from India to explore: (1) the economic costs–benefits of wastewater reuse in the context of hypothesized links to climate variability; (2) the role of local farming practices, market conditions and crop variety in influencing wastewater reuse in agriculture; and (3) the role of inter-governmental financing in influencing the selection of technical adaptation options for collection, treatment and disposal of wastewater.     

Consumption-based approach for assessing the contribution of hospitals towards the load of pharmaceutical residues in municipal wastewater

Hospitals are considered as major sources of pharmaceutical residues discharged to municipal wastewater, but recent experimental studies showed that the contribution of hospitals to the loads of selected, quantifiable pharmaceuticals in sewage treatment plant (STP) influents was limited. However such conclusions are made based on the experimental analysis of pharmaceuticals in hospital wastewater which is hindered by a number of factors such as access to suitable sampling sites, difficulties in obtaining representative samples and availability of analytical methods. Therefore, this study explores a refined and extended consumption-based approach to predict the contribution of six selected Australian hospitals to the loads of 589 pharmaceuticals in municipal wastewater. In addition, the possibility that hospital-specific substances are present at levels that may pose a risk for human health was evaluated. For 63 to 84% of the pharmaceuticals investigated, the selected hospitals are not a major point source with individual contributions likely to be less than 15% which is in line with previous experimental studies. In contrast, between 10 and 20% of the pharmaceuticals consumed in the selected hospitals are exclusively used in these hospitals. For these hospital-specific substances, 57 distinct pharmaceuticals may cause concerns for human health as concentrations predicted in hospital effluents are less than 100-fold lower than effect thresholds. However, when concentrations were predicted in the influent of the corresponding STP, only 12 compounds (including the antineoplastic vincristine, the antibiotics tazobactam and piperacillin) remain in concentration close to effect thresholds, but further decrease is expected after removal in STP, dilution in the receiving stream and drinking water treatment. The results of this study suggest that risks of human exposure to the pharmaceuticals exclusively administered in the investigated hospitals are limited and decentralised wastewater treatment at these sites would not have a substantial impact on pharmaceutical loads entering STPs, and finally the environment. Overall, our approach demonstrates a unique opportunity to screen for pharmaceuticals used in hospitals and identifying priority pollutants in hospital wastewater explicitly accounting for site-specific conditions. Being based on consumption and loads discharged by hospitals into municipal wastewater, it is not limited by 1) the big effort to obtain representative samples from sewers, 2) the availability of sensitive chemical analysis or 3) a pre-selection of consumption data (e.g. consumption volume).     

Drinking water quality: An in vitro approach for the assessment of cytotoxic and genotoxic load in water sampled along distribution system

An in vitro approach was performed to assess the quality of drinking water collected at two treatment/distribution networks located near the source (Plant #1) and the mouth of River Po (Plant #2). The water was sampled at different points of each distribution network, before (raw water) and after the chlorine dioxide disinfection, and in two points of the pipeline system to evaluate the influence of the distribution system on the amount and quality of the disinfection by-product. Cytotoxicity and genotoxicity of water extracts were evaluated in human peripheral lymphocytes and Hep-G2 cells by the use of the micronucleus (MN) test and Comet assay. Raw water samples of both plants induced cytotoxic effects, but not the increases of MN frequency in Hep-G2 cells and in human lymphocytes. Increases of DNA damage in human leukocytes was detected by Comet assay for raw water of Plant #2 at concentration ≥ 0.25 Leq/mL. The disinfection process generally has reduced the toxicity of water samples, even if potential direct DNA-damaging compounds have been detectable in drinking water samples. The proposal approach, if currently used together with chemical analysis, can contribute to improve the monitoring drinking water.     

Chemical contaminants in swimming pools: Occurrence,implications and control

A range of trace chemical contaminants have been reported to occur in swimming pools. Current disinfection practices and monitoring of swimming pool water quality are aimed at preventing the spread of microbial infections and diseases. However, disinfection by-products (DBPs) are formed when the disinfectants used react with organic and inorganic matter in the pool. Additional chemicals may be present in swimming pools originating from anthropogenic sources (bodily excretions, lotions, cosmetics, etc.) or from the source water used where trace chemicals may already be present. DBPs have been the most widely investigated trace chemical contaminants, including trihalomethanes (THMs), haloacetic acids (HAAs), halobenzoquinones (HBQs), haloacetonitriles (HANs), halonitromethanes (HNMs), N-nitrosamines, nitrite, nitrates and chloramines. The presence and concentrations of these chemical contaminants are dependent upon several factors including the types of pools, types of disinfectants used, disinfectant dosages, bather loads, temperature and pH of swimming pool waters. Chemical constituents of personal care products (PCPs) such as parabens and ultraviolet (UV) filters from sunscreens have also been reported. By-products from reactions of these chemicals with disinfectants and UV irradiation have been reported and some may be more toxic than their parent compounds. There is evidence to suggest that exposure to some of these chemicals may lead to health risks. This paper provides a detailed review of various chemical contaminants reported in swimming pools. The concentrations of chemicals present in swimming pools may also provide an alternative indicator to swimming pool water quality, providing insights to contamination sources. Alternative treatment methods such as activated carbon filtration and advanced oxidation processes may be beneficial in improving swimming pool water quality.     

Groundwater contamination by microbiological and chemical substances released from hospital wastewater: Health risk assessment for drinking water consumers

Contamination of natural aquatic ecosystems by hospital wastewater is a major environmental and human health issue. Disinfectants, pharmaceuticals, radionuclides and solvents are widely used in hospitals for medical purposes and research. After application, some of these substances combine with hospital effluents and, in industrialised countries, reach the municipal sewer network. In certain developing countries, hospitals usually discharge their wastewater into septic tanks equipped with diffusion wells. The discharge of chemical compounds from hospital activities into the natural environment can lead to the pollution of water resources and risks for human health. The aim of this article is to present: (i) the steps of a procedure intended to evaluate risks to human health linked to hospital effluents discharged into a septic tank equipped with a diffusion well; and (ii) the results of its application on the effluents of a hospital in Port-au-Prince. The procedure is based on a scenario that describes the discharge of hospital effluents, via septic tanks, into a karstic formation where water resources are used for human consumption. COD, Chloroform, dichlomethane, dibromochloromethane, dichlorobromomethane and bromoform contents were measured. Furthermore, the presence of heavy metals (chrome, nickel and lead) and faecal coliforms were studied. Maximum concentrations were 700 NPP/100 ml for faecal coliforms and 112 mg/L for COD. A risk of infection of 10^? 5 infection per year was calculated. Major chemical risks, particularly for children, relating to Pb(II), Cr(III), Cr(VI) and Ni(II) contained in the ground water were also characterised. Certain aspects of the scenario studied require improvement, especially those relating to the characterisation of drugs in groundwater and the detection of other microbiological indicators such as protozoa, enterococcus and viruses.     

Contamination of drinking water resources in the Mekong delta floodplains: arsenic and other trace metals pose serious health risks to population

This study presents a transnational groundwater survey of the 62,000 km(2) Mekong delta floodplain (Southern Vietnam and bordering Cambodia) and assesses human health risks associated with elevated concentrations of dissolved toxic elements. The lower Mekong delta generally features saline groundwater. However, where groundwater salinity is <1 g L(-)(1) Total Dissolved Solids (TDS), the rural population started exploiting shallow groundwater as drinking water in replacement of microbially contaminated surface water. In groundwater used as drinking water, arsenic concentrations ranged from 0.1-1340 microg L(-)(1), with 37% of the studied wells exceeding the WHO guidelines of 10 microg L(-)(1) arsenic. In addition, 50% exceeded the manganese WHO guideline of 0.4 mg L(-)(1), with concentrations being particularly high in Vietnam (range 1.0-34 mg L(-)(1)). Other elements of (minor) concern are Ba, Cd, Ni, Se, Pb and U. Our measurements imply that groundwater contamination is of geogenic origin and caused by natural anoxic conditions in the aquifers. Chronic arsenic poisoning is the most serious health risk for the ~2 million people drinking this groundwater without treatment, followed by malfunction in children's development through excessive manganese uptake. Government agencies, water specialists and scientists must get aware of the serious situation. Mitigation measures are urgently needed to protect the unaware people from such health problems.     

Risk assessment on disinfection by-products of drinking water of different water sources and disinfection processes

The occurrences of trihalomethanes (THMs) and haloacetics (HAAs) in the water supply in Beijing and Canada were investigated. The concentrations of THMs and HAAs in Beijing and Canada were below the maximum contaminant levels specified by the USEPA and WHO standards. The multi-pathway risk assessment (assessed through oral ingestion, dermal absorption and inhalation exposure to drinking water) was used to assess the cancer risk and the hazard index of THMs and HAAs from fifteen waterworks in Beijing, China and three treatment plants using different disinfection processes in Canada. Residents in Beijing and residents who were served by three treatment plants using different disinfection processes in Canada had a higher risk of cancer through oral ingestion than through the other two pathways. The cancer risk resulted from disinfection by-products (DBPs) was 8.50E-05(for males), 9.25E-05(for females) in Beijing, China, while it was 1.18E-04, 1.44E-04 in Canada. The risk was higher when water treatment plants used surface water source than when they used ground water source and mixture water source in Beijing. The risk showed different changes in three treatment plants using different disinfection processes in Canada. The lifetime cancer risk for THMs followed the order: Plant 2>Plant 1>Plant 3. And, the lifetime cancer risk for HAAs was: Plant 1>Plant 2>Plant 3.     

A commentary on recent water safety initiatives in the context of water utility risk management

Over the last decade, suppliers of drinking water have recognised the limitations of relying solely on end-product monitoring to ensure safe water quality and have sought to reinforce their approach by adopting preventative strategies where risks are proactively identified, assessed and managed. This is leading to the development of water safety plans; structured 'route maps' for managing risks to water supply, from catchment to consumer taps. This paper reviews the Hazard Analysis and Critical Control Point (HACCP) procedure on which many water safety plans are based and considers its appropriateness in the context of drinking water risk management. We examine water safety plans in a broad context, looking at a variety of monitoring, optimisation and risk management initiatives that can be taken to improve drinking water safety. These are cross-compared using a simple framework that facilitates an integrated approach to water safety. Finally, we look at how risk management practices are being integrated across water companies and how this is likely to affect the future development of water safety plans.     

An aggregate analysis of personal care products in the environment: Identifying the distribution of environmentally-relevant concentrations

Over the past 3–4 decades, per capita consumption of personal care products (PCPs) has steadily risen, resulting in increased discharge of the active and inactive ingredients present in these products into wastewater collection systems. PCPs comprise a long list of compounds employed in toothpaste, sunscreen, lotions, soaps, body washes, and insect repellants, among others. While comprehensive toxicological studies are not yet available, an increasing body of literature has shown that PCPs of all classes can impact aquatic wildlife, bacteria, and/or mammalian cells at low concentrations. Ongoing research efforts have identified PCPs in a variety of environmental compartments, including raw wastewater, wastewater effluent, surface water, wastewater solids, sediment, groundwater, and drinking water. Here, an aggregate analysis of over 5000 reported detections was conducted to better understand the distribution of environmentally-relevant PCP concentrations in, and between, these compartments. The distributions were used to identify whether aggregated environmentally-relevant concentration ranges intersected with available toxicity data. For raw wastewater, wastewater effluent, and surface water, a clear overlap was present between the 25th–75th percentiles and identified toxicity levels. This analysis suggests that improved wastewater treatment of antimicrobials, UV filters, and polycyclic musks is required to prevent negative impacts on aquatic species.     

Impacts of climate change on surface water quality in relation to drinking water production

Besides climate change impacts on water availability and hydrological risks, the consequences on water quality is just beginning to be studied. This review aims at proposing a synthesis of the most recent existing interdisciplinary literature on the topic. After a short presentation about the role of the main factors (warming and consequences of extreme events) explaining climate change effects on water quality, the focus will be on two main points. First, the impacts on water quality of resources (rivers and lakes) modifying parameters values (physico-chemical parameters, micropollutants and biological parameters) are considered. Then, the expected impacts on drinking water production and quality of supplied water are discussed. The main conclusion which can be drawn is that a degradation trend of drinking water quality in the context of climate change leads to an increase of at risk situations related to potential health impact.     

Determination of non-steroidal anti-inflammatory drug (NSAIDs) residues in water samples

Pharmacologically active substances used to treat human and animal illnesses can enter the aquatic environment via effluents from wastewater treatment plants or in the case of veterinary drugs directly through liquid manure discharge. Some of these substances enter the environment either as the parent compound or as active/inactive metabolites. Due to their pharmacological activity, their determination and understanding their behavior and fate in the environment are important. The scope of this paper was to develop an analytical procedure to determine common pharmaceutical residues in wastewaters. Pharmacologically active substances were chosen according to their wide spread application in Slovenia and Central Europe and are members of analgesics, e.g., non-steroidal anti-inflammatory drugs: ibuprofen, naproxen, ketoprofen and diclofenac. Selected compounds were isolated from synthetic water using a novel SPE sorbent Strata X. Due to the non-volatile nature of these compounds they were first silylised prior to gas chromatographic-mass spectrometric detection. The developed procedure was tested with synthetic wastewaters and their extraction efficiency (>84%) and method limits of detection (2-6 ng L(-1)) were determined. Our procedure has been adopted and optimised for "real" water samples and applied to eleven drinking and ten river water samples from Slovenia. The results showed no traces of NSAIDs in all potable water samples and low-range contamination (ng L(-1)) of Slovene rivers. These results show that NSAIDs contamination of Slovene waters is comparable with published results of water contamination in Central Europe.     

Fuzzy rule-based modelling for human health risk from naturally occurring radioactive materials in produced water

Produced water, discharged from offshore oil and gas operations, contains chemicals from formation water, condensed water, and any chemical added down hole or during the oil/water separation process. Although, most of the contaminants fall below the detection limits within a short distance from the discharge port, a few of the remaining contaminants including naturally occurring radioactive materials (NORM) are of concern due to their bioavailability in the media and bioaccumulation characteristics in finfish and shellfish species used for human consumption. In the past, several initiatives have been taken to model human health risk from NORM in produced water. The parameters of the available risk assessment models are imprecise and sparse in nature. In this study, a fuzzy possibilistic evaluation using fuzzy rule based modeling has been presented. Being conservative in nature, the possibilistic approach considers possible input parameter values; thus provides better environmental prediction than the Monte Carlo (MC) calculation. The uncertainties of the input parameters were captured with fuzzy triangular membership functions (TFNs). Fuzzy if-then rules were applied for input concentrations of two isotopes of radium, namely (226)Ra, and (228)Ra, available in produced water and bulk dilution to evaluate the radium concentration in fish tissue used for human consumption. The bulk dilution was predicted using four input parameters: produced water discharge rate, ambient seawater velocity, depth of discharge port and density gradient. The evaluated cancer risk shows compliance with the regulatory guidelines; thus minimum risk to human health is expected from NORM components in produced water.     

Chemical evaluation of potable water in Eastern Qinghai Province, China: human health aspects

Electric conductivity, pH, COD(Mn), nutrient concentration, chloride and sulfate concentrations, total dissolved sodium, potassium, calcium, magnesium, manganese, iron, cadmium, copper, arsenic, nickel, zinc, chromium and lead were evaluated to clarify concerns about the quality and safety of water used for drinking purposes in Qinghai Province, China. For this purpose, 12 water samples were collected from different villages, Qinghai (Koko Nor) Lake and medicinal springs close to the Town of Pingang during a study visit to China in 2003. The results showed that National Chinese and WHO drinking water standards were exceeded for nutrient concentration (3.2 mg l(-1) of TOT-N and 0.2 mg l(-1) of TOT-P) from Qinghai Lake. The presence of elevated electric conductivity (550 mS m(-1)) in mineral water resort samples should be a matter of a public concern. Also, samples from medicinal springs showed high concentrations of Fe (up to 1.9 mg l(-1)), As (up to 0.1 mg l(-1)) and Ni (0.05 mg l(-1)), which may be detrimental for human health if the water is consumed on a daily basis. The concentrations of Cu, Cd, Cr and Pb did not exceed the National Chinese and WHO drinking water standards, and therefore, water from the sampling area does not pose any significant threat to the consumers' health regarding these metals.     

Resourceful Utilization of Tannery Wastewater

Leather industry is an important light industry in China.Leather making requires a series of chemical treatment.Degreasing,unhairing and chrome tanning wastewaters are the main portions of tannery wastewater.Reclaiming and reusing these wastewaters can eliminate 80% of COD,75% of BOD,95% of chromium and 93% of sulfuret,furthermore reduce environment impact,decrease treatment costs,save chemicals and water.Some application methods of wastewater reclamation and reuse for different operations were reported.The suitable reclamation and reuse technologies can enable leather making processes more rational,and realize the recovery and recycle of several chemicals in the tannery.Resourceful utilization of tannery wastewater should mate with renovating production technology,updating equipment,and must be guaranteed sufficiently by environmental protection measures.     

Viruses in wastewaters

Viruses of animals, plants, and bacteria abound in sewage and receiving waters. Their ecological impact has, for the most part, gone unheeded except as it relates to viruses from human sources. Viruses present at levels infective to man have been recovered from waters used for recreational or drinking purposes. Their presence in a water environment virtually always denotes prior contamination by domestic wastes. Neither conventional sewage treatment processes nor the discharge to land or water of sludges produced by these processes achieve full viral control. Many environmental virologists advocate the setting of permissible virus limits for those recreational and potable waters dominated by wastewater effluents. The initiation of regulatory pressure to restrict virus discharges into these water environments has been instituted in Montgomery County, Maryland, and in the states of California and Arizona.     

Effect of typhoon with extreme precipitation on mountain reservoir drinking water treatment: a case study in Ningbo,China

Due to frequent drinking water pollution accidents in the past decade, it is common that mountain reservoirs were used as the source of drinking water in China. However, some coastal areas frequently suffer from typhoon with extreme precipitation, which results in the water quality deterioration of the reservoirs. The influence of typhoons with extreme precipitation on Jiaokou reservoir and the emergency treatment process of Maojiaping water treatment plant in the past three typical typhoons with extreme precipitation from the year of 2012–2015 were studied. It was found that the degradation of water quality, such as the increase of turbidity and bacteria index, may not merely appear during the events, but last for several days. Changing the dosage of water purification agent, such as coagulant and disinfectant at right time and place may be an efficient emergency water treatment process. Based on the analysis of water quality variation rule during and after the events, it was also found that emergency treatment can be fully prepared before the arrival of a typhoon with extreme precipitation. And in order to better respond to the typhoon with extreme precipitation, several suggestions are also proposed in this paper as follows: establishing vegetated buffers at right place, such as macrophanerophytes, shrub or herbage, increasing investments in infrastructure management, merging or cancelling the small-scale water treatment plants, preparing adequate water purification agent before the typhoon comes, etc.