An examination of the potential added value of water safety plans to the United States national drinking water legislation

National and sub-national governments develop and enforce regulations to ensure the delivery of safe drinking water in the United States (US) and countries worldwide. However, periodic contamination events, waterborne endemic illness and outbreaks of waterborne disease still occur, illustrating that delivery of safe drinking water is not guaranteed. In this study, we examined the potential added value of a preventive risk management approach, specifically, water safety plans (WSPs), in the US in order to improve drinking water quality. We undertook a comparative analysis between US drinking water regulations and WSP steps to analyze the similarities and differences between them, and identify how WSPs might complement drinking water regulations in the US. Findings show that US drinking water regulations and WSP steps were aligned in the areas of describing the water supply system and defining monitoring and controls. However, gaps exist between US drinking water regulations and WSPs in the areas of team procedures and training, internal risk assessment and prioritization, and management procedures and plans. The study contributes to understanding both required and voluntary drinking water management practices in the US and how implementing water safety plans could benefit water systems to improve drinking water quality and human health.     

合肥市水源与饮用水中挥发性卤代烃健康风险评价

目的调查合肥市水源与饮用水中挥发性卤代烃污染水平,评估对人体潜在健康风险。方法顶空气相色谱法测定合肥市A、B两水厂水源水、出厂水及管网末梢水中7种卤代烃;采用美国环保暑(USEPA)水环境健康风险评价模型,从摄入、皮肤接触和吸入3种途径进行定量评估。结果水源水检出CHCl3、CCl4和C2Cl43种卤代烃,出厂水和管网末梢水除CHBr3,其余6种均有检出,平均浓度范围分别为0.17～3.64μg/L、0.11～37.05μg/L和0.03～52.25μg/L,均未超过国家标准。致癌风险主要来自CHCl3、C2HCl3和CHBrCl2,风险值男性6.61E-07～8.21E-05,女性6.70E-10～7.69E-05。不同暴露途径致癌风险,经口摄入>吸入>皮肤接触。引起非致癌风险的化合物主要为CHCl3和C2HCl3,风险指数男性5.05E-02～7.83E-01,女性5.11E-02～7.94E-01。A、B两水厂所检挥发性卤代烃种类和浓度不同,致癌风险和非致癌风险有所差异。结论目前合肥市水源及饮用水中挥发性卤代烃致癌风险和非致癌风险均在可接受水平,不会对成人产生明显的健康危害。     

A review of health-based comparative risk assessments in the United States

Comparing the risks posed by specific environmental hazards has become attractive to policy makers and legislative bodies as an aid to budgeting and other policy decisions. This paper reviews the human health-based findings from the first federal comparative risk assessment project and subsequent reviews conducted by 15 states and local government agencies in the United States. Methods are described on conducting comparative risk assessments that include substantive involvement of the public and special interest organizations. A consolidation of the comparative risk assessments of 15 states revealed good agreement with federal health-based environmental hazard priorities and partial agreement with local-government health departments. In descending order of priority, indoor air pollutants (excluding radon), criteria air pollutants, hazardous air pollutants, indoor radon, lead contamination, inactive hazardous waste sites, and drinking water at the tap are the highest ranked environmental hazards to human health.     

某市市政管网末梢水中氟化物健康风险分析

目的 了解武汉市市政管网末梢水中氟化物的浓度水平,并通过健康风险评价初步评估其对成人及儿童身体健康的潜在危害度。方法 对2017年武汉市市政管网末梢水中氟化物的浓度进行调查,并利用美国环保局推荐的风险评估模型进行健康风险评价。结果 武汉市市政管网末梢水中氟化物的含量为0.13~0.35 mg/L,均在国家生活饮用水卫生标准范围内,所致成人和儿童健康风险分别为1.32×10^-9/a和1.59×10^-9/a,均低于国际放射防护委员会推荐的最大可接受风险度5×10^-5/a。结论 武汉市市政管网末梢水中氟化物浓度较低,应在各城区及时开展儿童龋齿患病率的监测,注意预防儿童龋病的流行。     

Drinking water consumption patterns in Sweden

Estimates on drinking water consumption are necessary in risk assessments on microbial hazards in drinking water. Large differences in consumption habits between countries have been reported. In order to establish estimates for the Swedish population, water consumption data from a waterborne outbreak investigation (157 people), a small water consumption study (75 people) and a large study on health and environmental factors (10,957 people) were analysed. A lognormal distribution for the daily direct/cold water intake in litres with mu = - 0.299 and sigma = 0.570 was fitted to the quantitative data, representing the general population. The average daily consumption of tap water as plain drinking water and as heated tap water, e.g. in coffee and tea, was 0.86 +/- 0.48 l and 0.94 +/- 0.69 l, respectively. Women consumed more cold tap water than did men, while men appeared to have a higher consumption of heated tap water. Cold tap water intake was highest in the oldest age group, (> or =70 years). The consumption of bottled water was very low (mean 0.06 l/d) when compared to other countries.     

A strategic approach for Water Safety Plans implementation in Portugal

Effective risk assessment and risk management approaches in public drinking water systems can benefit from a systematic process for hazards identification and effective management control based on the Water Safety Plan (WSP) concept. Good results from WSP development and implementation in a small number of Portuguese water utilities have shown that a more ambitious nationwide strategic approach to disseminate this methodology is needed. However, the establishment of strategic frameworks for systematic and organic scaling-up of WSP implementation at a national level requires major constraints to be overcome: lack of legislation and policies and the need for appropriate monitoring tools. This study presents a framework to inform future policy making by understanding the key constraints and needs related to institutional, organizational and research issues for WSP development and implementation in Portugal. This methodological contribution for WSP implementation can be replicated at a global scale. National health authorities and the Regulator may promote changes in legislation and policies. Independent global monitoring and benchmarking are adequate tools for measuring the progress over time and for comparing the performance of water utilities. Water utilities self-assessment must include performance improvement, operational monitoring and verification. Research and education and resources dissemination ensure knowledge acquisition and transfer.     

Incorporation of the Multiple Barrier Approach in drinking water risk assessment tools

A number of existing risk assessment tools make reference to, or incorporate, a Multiple Barrier Approach to drinking water safety. Three waterborne disease outbreaks that occurred in developed nations were used as case studies to test a selected set of risk assessment tools. The outbreaks were used to determine how well the risk assessment tools identify hazards and vulnerabilities associated with different barriers to drinking water contamination.     

Fluoride and bacterial content of bottled water vs tap water

CONTEXT: Bottled water has become a status symbol and is frequently used in place of tap water. While both waters are considered safe to drink, is either more beneficial in preventing tooth decay and is there a difference in purity? OBJECTIVE: To determine the fluoride level and bacterial content of commercially bottled waters municipal tap water and to compare the results. DESIGN: Comparative study. SETTING: Cleveland, Ohio. SAMPLE: Fifty-seven samples of 5 categories of bottled waters were purchased from local stores. Samples of tap water were collected in sterile containers from the 4 local water processing plants. Fluoride levels were determined by an ion-selective electrode method. Water was cultured quantitatively and levels of bacteria were calculated as colony-forming units (CFUs) per milliliter. MAIN OUTCOME MEASURE: Fluoride levels and bacterial counts. RESULTS: Fluoride levels within the range recommended for drinking water by the Ohio Environmental Protection Agency, Cincinnati, 0.80 to 1.30 mg/L, were found in only 3 samples of bottled water tested. The fluoride levels of tap water samples were within 0.04 mg/L of the optimal fluoride level of 1.00 mg/L. The bacterial counts in the bottled water samples ranged from less than 0.01 CFU/mL to 4900 CFUs/mL, including 6 samples with levels substantially above 1000 CFUs/mL. In contrast, bacterial counts in samples of tap water ranged from 0.2 to 2.7 CFUs/mL. CONCLUSIONS: Five percent of the bottled water purchased in Cleveland fell within the required fluoride range recommended by the state, compared with 100% of the tap water samples, all of which were also within 0.04 mg/L of the optimal fluoride level of 1.00 mg/L. Use of bottled water based on the assumption of purity can be misguided. Recently, the Environmental Protection Agency, Washington, DC, published a final ruling that requires community water systems to regularly report to the public on the quality of local tap water; there are no similar proposals to determine the quality of bottled water through labeling.     

安徽省农村地区自来水用户饮用水卫生需求的调查

目的了解安徽省农村自来水用户对饮用水的卫生需求和意见,为研究并提出能持续推进安徽省农村改水的对策提供依据.方法采用现场问卷调查与快速评价法,了解农村已使用自来水居民的相关态度与需求.结果被调查200个人中,只饮用自来水占65.00%,同时饮用其他饮用水的占35.00%;对自来水供应满意度为56.00%;认为当前供应的自来水需要改进占69.00%,改进要求主要在水质和价格方面.大多数人对自来水供应情况表示满意,部分人对供水时间、水质和水压不满意,并要求改进.结论通过本次调研反映了已使用自来水用户相关态度以及要求,为进一步推进农村自来水普及提供参考依据.     

The relation of communication to risk judgment and preventive behavior related to lead in tap water

More and more communities are becoming concerned about health risks posed by lead and other health hazards in their drinking water. Our study, applying the model of innovation diffusion to the adoption of preventive health behaviors, found that reliance on health professionals for information about lead in tap water was associated with residents perceiving risk from this hazard, their sense of efficacy in dealing with it, and their adoption of preventive behaviors. Mass media and pamphlets mailed directly to residents were relatively ineffective. Results suggest that interpersonal channels may be the best way to reach individuals who live in areas of highest risk from tap water lead.     

The case for re-evaluating the upper limit value for selenium in drinking water in Europe

Selenium is an essential trace element for life, which can be toxic for humans when intakes reach a certain amount. Therefore, since the margin between healthy intake and toxic intake is narrow, the selenium concentration of tap water is a parameter that must be monitored because of its potential for increased intake. The present work gives an overview of the different approaches used to calculate safe limits for selenium. As recommended by WHO, the guidelines for drinking water form the basis of national legislated standards for drinking water. Before setting a maximum acceptable level in drinking water, it is necessary to take into account the total intake of selenium in both food and beverage. The limit value of 10 mg l^-1 for drinking water laid down in the European regulations for all countries should be adapted depending on geographic area, as previously recommended by WHO.     

我国农村安全饮用水地区差异及对策研究

目前我国农村安全饮用水卫生状况形势依然严峻。各地区农村改水不平衡,东西部差距加大。本文使用2007年、2008年统计数据,对农村自来水普及率、安全饮用水率、人均GDP、孕产妇死亡率等指标进行比较及研究,揭示饮用水地区差异及与经济社会发展之间的密切联系;从机制、资金、观念、人员等不同角度对改水不平衡的原因进行了探讨,并提出了一些政策建议。     

重庆市北碚区农村饮水安全工程水质调查分析

目的 掌握重庆市北碚区农村饮水安全工程卫生状况,为政府决策提供科学依据.方法 对2008～2009年建成投用的42个农村饮水安全工程进行卫生学调查,并对枯水期、丰水期水质进行分析评价.结果 监测点均为小型集中式供水工程,59.5％的工程以地下水为水源,未经完全处理(沉淀、过滤、消毒)的工程21个,占50％.2008～2009年期间检测的168件水样合格率为38.09％,其中2008年合格率31.67％,2009年合格率54.17％,高于2008年(x2=7.36,P＜ 0.01);两年里枯水期与丰水期、出厂水与末梢水水质合格率相近,差异无统计学意义,但经过消毒处理的水合格率达60.71％,明显高于未消毒水(x2=36.45,P＜0.01).水中最常见的不合格指标是总大肠菌群、耐热大肠菌群以及肉眼可见物、浑浊度.结论 重庆市北碚农村饮水安全工程的水质合格率较低,微生物染污严重,水处理工艺不完善,普遍缺乏水质净化与消毒设施,应加强工程建设与卫生管理.     

Bottled water: United States consumers and their perceptions of water quality

Consumption of bottled water is increasing worldwide. Prior research shows many consumers believe bottled water is convenient and has better taste than tap water, despite reports of a number of water quality incidents with bottled water. The authors explore the demographic and social factors associated with bottled water users in the U.S. and the relationship between bottled water use and perceptions of the quality of local water supply. They find that U.S. consumers are more likely to report bottled water as their primary drinking water source when they perceive that drinking water is not safe. Furthermore, those who give lower ratings to the quality of their ground water are more likely to regularly purchase bottle water for drinking and use bottle water as their primary drinking water source.     

Assessment of water use for estimating exposure to tap water contaminants.

Epidemiological studies examining the association between exposure to tap water contaminants (such as chlorination by-products) and disease outcomes (such as cancer and adverse reproductive outcomes) have been limited by inaccurate exposure assessment. Failure to take into account the variation in beverage and tap water consumption and exposure to volatile contaminants through inhalation and dermal absorption can introduce misclassification in assessing the association between exposure to tap water contaminants and health. To refine exposure assessment of tap water contaminants, we describe in detail the tap water consumption, showering, and bathing habits of pregnant women and their male partners as assessed by a questionnaire and a 3-day water diary. We found good agreement between questionnaire and 3-day water diary values for drinking water intake (Pearson''s r = 0.78) and for time spent showering(r = 0.68) and bathing (r = 0.78). Half of the participants consumed tap water on a regular basis with an overall mean +/- 1 standard deviation (SD) of 0. 78 +/- 0.51 l/day. Our results further suggest that full-time employees, compared to women working part-time or less, have more heterogeneous consumption patterns over time. Seventy-nine percent of women and 94% of men took showers for an average of 11.6 +/-4.0 min and 10.4 +/- 4.8 min, respectively. Baths were taken more frequently by women than men (21% vs. 3%) for an average of 22.9 +/-10.1 min and 21.3 +/- 12.4 min, respectively. Thus, these patterns of tap water use should be considered in the design and interpretation of environmental epidemiology studies.     

Drinking water consumption patterns of residents in a Canadian community

A cross-sectional survey using computer-assisted telephone interviewing was performed to assess the drinking water consumption patterns in a Canadian community, and to examine the associations between these patterns and various demographic characteristics. The median amount of water consumed daily was four 250 ml servings (1.01), although responses were highly variable (0 to 8.01). Bottled water consumption was common, and represented the primary source of drinking water for approximately 27% of respondents. Approximately 49% of households used water treatment devices to treat their tap water. The observed associations between some demographic characteristics and drinking water consumption patterns indicated potential differences in risk of exposure to waterborne hazards in the population. Our results lend support to the federal review of the bottled water regulations currently in progress in Canada. Additionally, they may lend support to a provincial/territorial government review of bottled water regulations, and both federal and provincial/territorial level reviews of the water treatment device industry. Further investigation of the use of alternative water sources and the perceptions of drinking water in Canada is also needed to better understand, and subsequently address, concerns among Canadians.     

Occurrence of aquatic organisms in water pipes and the resulting problems with drinking water disinfection]

The present text is the first part of a paper aimed at specification of the requirements ensuring effective disinfection of drinking water. The discussed health hazards result not only from the presence of pathogenic microorganisms in water, but also from the occurrence of micro- and macroscopic plant and animal organisms. It was shown that while the traditional method for water treatment and disinfection reduces the number of these organisms, it fails to eliminate them completely, particularly in the case of tap water intake from shore intakes of surface waters.     

云南省K市水厂出厂水中卤乙酸的健康风险评估

目的 监测饮用水中卤乙酸污染状况,并对其健康风险进行评价,了解K市人群通过饮水途径可能引起的健康风险。 方法 依据《生活饮用水标准检测方法》(GB/T 5750-2006)对K市市政水厂出厂水卤乙酸进行监测,利用美国国家环保局推荐的健康风险模型进行风险评价。结果 K市饮用水二氯乙酸、三氯乙酸致癌风险范围分别为3.33×10^-6～1.38×10^-4、1.12×10^-6～1.91×10^-4,二氯乙酸致癌风险占比最高;非致癌健康危害指数分别为1.67×10^-2～6.90×10^-1、8.34×10^-4～1.42×10^-1,三氯乙酸对非致癌健康危害风险贡献最大。结论 K市应重视长期暴露于饮用水中消毒副产物卤乙酸引起的潜在健康风险,降低水中卤乙酸类消毒副产物对人群的健康危害。     

马鞍山市农村生活饮用水卫生监督监测工作问题与对策

目的　研究农村生活饮用水卫生监督监测工作现况 ,探讨进一步改善和提高农村生活饮用水卫生监督监测工作的策略。方法　对全市各区县农村饮用水卫生监督监测工作进行全面检查考核 ,并进行系统分析。结果　马鞍山市农村生活饮用水监督员数量和素质建设、监督执法的实际效果、水质监测的监控效能、行政处罚的实施、对水污染隐患的认识、部门之间的沟通协作等方面均存在问题。结论　应进一步加强和规范对农村水厂的卫生监督监测工作 ,以预防和控制饮用水突发事件的发生。     

Assessment of source water pathogen contamination

During the last decade, the source to tap risk-based approach to pathogens in drinking water has been largely promoted. This paper addresses the issue of source water pathogen contamination, which is the first step of quantitative microbial risk assessment. It is focused on a selection of pathogens considered to be a major risk to human health. Source water quality is highly variable and understanding the reasons for this variability is important as it will influence the requirements for treatment, treatment efficiency and the resulting health risk associated with the finished water. A framework for source water microbial quality assessment based on catchment surveys and monitoring programmes was set and tested on ten water sources. The monitoring programmes included faecal indicators and pathogens, during both baseline and hazardous event conditions. Concentrations varied greatly within and between systems. Faecal indicators were shown to be poor surrogates for pathogen presence and concentrations. There was no recurring evidence that the pathogens correlated together and links between microbial parameters appeared to be very site specific. Such variability between systems shows the importance of running local monitoring programs for use in risk assessment. Finally, pathogen detection methods are not yet optimal due to their sensitivity and to the lack of knowledge on viability and infectivity of pathogens. A great effort needs to be made in the future to ensure better quality data as this may have large implications in the statistical risk assessment calculations.