Evaluation of the hypothesis that Balkan endemic nephropathy is caused by drinking water exposure to contaminants leaching from Pliocene coal deposits

Balkan endemic nephropathy (BEN) is a kidney disease that has been reported in only certain rural villages in Serbia, Bulgaria, Romania, Croatia and Bosnia. The cause of BEN remains a mystery, but researchers seem to agree that exposure to one or more environmental agents is at least partially responsible. The Pliocene lignite hypothesis suggests the disease is due to long-term exposure to polycyclic aromatic hydrocarbons (PAHs) or other toxic organic compounds that have leached into drinking water supplies from low-rank coals. Although this hypothesis has been promoted by some researchers, efforts to substantiate it have been inconclusive due to limitations in sample size and methodology. The present study was designed to further examine this hypothesis by analyzing PAHs, which were implicated in the original hypothesis, in a larger number of water samples from endemic and nonendemic villages in Bulgaria and for other chemical differences between the villages. Results show that levels of all PAHs were low, with none exceeding the drinking water standard for benzo-[a]-pyrene, the most toxic PAH, and the only one for which a maximum contaminant level (MCL) has been set for drinking water. Comparison of additional unidentified chromatographic peaks from high-pressure liquid chromatography (HPLC) technique designed to detect dissolved organic compounds (DOCs) that leach from coal failed to show higher levels in BEN villages. This study finds no basis to connect PAHs or other unknown DOCs to the etiology of BEN, and suggests that the evidence in support of the Pliocene lignite hypothesis is limited to the spatial association originally proposed.     

Etiology of Balkan endemic nephropathy: A multifactorial disease?

Balkan endemic nephropathy (BEN) is of great clinical importance in the restricted areas of Bulgaria, Rumania, Croatia, Serbia, Bosnia and Herzegovina. So far, studies on the etiological factors for BEN have not discovered any single environmental causative agent of this puzzling disease. These data reject the possibility of a purely environmental causation of BEN. The pattern of BEN transmission in the risk families is not typical for single gene disorders. Extensive epidemiological and genetic studies disclose characteristics of multifactorial (polygenic) inheritance of BEN. The evidences of 'familial tendency', variation of the risk for BEN depending on the number of sick parents and the degree of relatedness; the development of BEN in individuals from at-risk families who were born in non-endemic areas; the data that disease is not found in the gypsy population and the expressions of 3q25 cytogenetic marker suggest that the genetic factors play an important role as causative factors in BEN development. The possible impact of environmental triggers on individuals genetically predisposed to BEN could be supposed by the following data: the cytogenetic results of the increased frequency of folate sensitive Fra sites, spontaneous or radiation-induced aberrations in several bands in BEN patients, the data from the detailed analysis of breaks in BEN patients and controls that generate structural chromosome aberrations; the occurrence of BEN in immigrants. Genetical epidemiological approaches to etiology and prevention of BEN are proposed. The predisposing genes for BEN could be genes localized in a region between 3q25-3q26; transforming growth factor- (TGF-), genetic heterogeneity of xenobiotic-metabolizing enzymes; defects in the host's immune system. The predisposing genes for BEN patients with urinary tract tumors could be germline mutations in tumor suppressor genes and acquired somatic mutations in oncogenes.     

Balkan endemic nephropathy in Vratza,Bulgaria, 1964-1987: an epidemiologic analysis of population-based disease registers

Balkan Endemic Nephropathy (BEN), first described in 1956 in Vratza region, Bulgaria, may result from prolonged, chronic exposure to environmental toxicants, but the underlying etiologic factors remain elusive. There has been no recent systematic characterization of the epidemiology of this disease. Recently, it has been suggested that the incidence of the disease is decreasing. We therefore abstracted data from registers of patients in 21 affected villages and the town of Vratza, Bulgaria maintained from 1964 through 1987. In 1964, the prevalence of BEN was 6.0 per 1000 inhabitants; among residents of the affected villages, the prevalence was 12.3 per 1000. From 1965 to 1975 the incidence rate was 0.7 per 1000 person-years, and from 1976 to 1987 the incidence rate was 0.3 per 1000 person-years (rate ratio 0.43; p < 0.001). Incidence was much lower in Vratza town; among residents of affected villages, the period-specific rates were 1.7 and 0.8 per 1000 per year, respectively (rate ratio 0.47; p < 0.01). These trends were consistent across all villages for which registers were maintained. Median survival following registration increased from 2.0 to 5.0 years over the same period (p < 0.001). BEN appears to be decreasing in incidence in this region.     

Limitations and plausibility of the Pliocene lignite hypothesis in explaining the etiology of Balkan endemic nephropathy

Background:

Balkan endemic nephropathy (BEN) is a chronic, tubulointerstitial renal disease often accompanied by urothelial cancer that has a lethality of nearly 100%.

Introduction:

One of the many factors that have been proposed to play an etiological role in BEN is exposure to organic compounds from Pliocene lignite coal deposits via the drinking water in endemic areas.

Objectives:

The objective of this study was to systematically evaluate the role of the tenets of the Pliocene lignite hypothesis in the etiology of BEN in order to provide an improved understanding of the hypothesis for colleagues and patients alike.

Methods:

A comprehensive compilation of the possible limitations of the hypothesis, with each limitation addressed in turn is presented.

Results:

The Pliocene lignite hypothesis can best account for, is consistent with, or has the potential to explain the evidence associated with the myriad of factors related to BEN.

Conclusions:

Residents of endemic areas are exposed to complex mixtures containing hundreds of organic compounds at varying doses and their potentially more toxic (including nephrotoxic) and/or carcinogenic metabolites; however, a multifactorial etiology of BEN appears most likely.     

Critical evaluation of environmental exposure agents suspected in the etiology of Balkan endemic nephropathy

Balkan endemic nephropathy (BEN), a kidney disease that occurs in rural villages in Bosnia, Bulgaria, Croatia, Romania, and Serbia, is thought to be linked to an environmental toxin. The authors review literature on proposed environmental exposure agents, report the results of field sampling and analysis studies to evaluate potentials for exposure to proposed agents, and propose criteria for future testing. They used these criteria to evaluate the evidence for suggested hypotheses, concluding that several proposed agents can be eliminated or considered unlikely based on apparent inconsistencies between clinical or epidemiologic evidence related to BEN and toxicologic or exposure evidence related to the agents. Mycotoxins and aristolochic acid are the primary targets of current toxicologic investigations, and while the evidence on exposures for both is potentially consistent, it is insufficient.     

Status of groundwater arsenic contamination and human suffering in a Gram Panchayet (cluster of villages) in Murshidabad, one of the nine arsenic affected districts in West Bengal, India

A detailed study was carried out in a cluster of villages known as Sagarpara Gram Panchayet (GP), covering an area of 20 km2 and population of 24,419 to determine the status of groundwater arsenic contamination and related health effects. The arsenic analysis of all hand tubewells (n = 565) in working condition showed, 86.2% and 58.8% of them had arsenic above 10, and 50 microgl(-1), respectively. The groundwater samples from all 21 villages in Sagarpara GP contained arsenic above 50 microgl(-1). In our preliminary clinical survey across the 21 villages, 3,302 villagers were examined and 679 among them (20.6%) were registered with arsenical skin lesions. A total of 850 biological samples (hair, nail and urine) were analysed from the affected villages and, on average, 85% of them contained arsenic above the normal level. Thus, many people of Sagarpara might be sub-clinically affected. Our data was compared with the international one to estimate population in Sagarpara GP at risk from arsenical skin lesions and cancer. Proper watershed management and economical utilization of available surface water resources along with the villagers' participation is urgently required to combat the present arsenic crisis.     

Survey of retail milk composition as affected by label claims regarding farm-management practices

A trend in food labeling is to make claims related to agricultural management, and this is occurring with dairy labels. A survey study was conducted to compare retail milk for quality (antibiotics and bacterial counts), nutritional value (fat, protein, and solids-not-fat), and hormonal composition (somatotropin, insulin-like growth factor-1 [IGF-1], estradiol, and progesterone) as affected by three label claims related to dairy-cow management: conventional, recombinant bovine somatotropin (rbST)-free (processor-certified not from cows supplemented with rbST), or organic (follows US Department of Agriculture organic practices). Retail milk samples (n=334) from 48 states were collected. Based on a statistical analysis that reflected the sampling schema and distributions appropriate to the various response variables, minor differences were observed for conventional, rbST-free, and organic milk labels. Conventionally labeled milk had the lowest (P<0.05) bacterial counts compared to either milk labeled rbST-free or organic; however, these differences were not biologically meaningful. In addition, conventionally labeled milk had significantly less (P<0.05) estradiol and progesterone than organic milk (4.97 vs 6.40 pg/mL and 12.0 vs 13.9 ng/mL, respectively). Milk labeled rbST-free had similar concentrations of progesterone vs conventional milk and similar concentrations of estradiol vs organic milk. Concentrations of IGF-1 in milk were similar between conventional milk and milk labeled rbST-free. Organic milk had less (P<0.05) IGF-1 than either conventional or rbST-free milk (2.73 ng/mL vs 3.12 and 3.04 ng/mL, respectively). The macronutrient profiles of the different milks were similar, except for a slight increase in protein in organic milk (about 0.1% greater for organic compared to other milks). Label claims were not related to any meaningful differences in the milk compositional variables measured. It is important for food and nutrition professionals to know that conventional, rbST-free, and organic milk are compositionally similar so they can serve as a key resource to consumers who are making milk purchase (and consumption) decisions in a marketplace where there are misleading milk label claims.     

基于捕获-再捕获方法的海南省2015 - 2017年死因监测漏报情况调查

目的 进一步了解海南省死因监测数据的真实情况,为科学制定公共卫生策略和措施提供依据。方法 采用捕获 - 再捕获方法开展调查,共分为三步:第一步,在海南省22个市、县（区）各选取满足以下条件的3个乡镇（街道）:人口数量和社会经济水平接近本县(区)各乡镇(街道)的平均水平,从3个乡镇（街道）中随机选择一个乡镇（街道）作为调查点,点内所有住户作为调查对象,在《人口死亡信息登记管理系统》中查询调查点死亡时间在2015 - 2017年的一批随机样本（“捕获”）,将其做标记。第二步,通过入户调查和查阅地民政和公安部门收集常住居民死亡信息,收集死亡时间在2015 - 2017年的随机样本（“再捕获”）,与“捕获”样本进行比对,发现漏报病例后,收集基本信息、死亡信息和生前诊断信息等。第三步,计算漏报率,剔除粗死亡率低于5‰的调查点。结果 共计12个乡镇的116个自然村纳入分析,共收集到死亡个案5 021例,死因监测系统查询到个案4 583例,两种方式中重复个案3 496例。全省2015 - 2017年的漏报率估计为27.44%、22.70%和24.46%,平均漏报率为24.97%（95%CI = 23.74%～26.24%）。漏报率高的前3位地区是海口市琼山区（49.21%）、龙华区（41.55%）、昌江县（39.29%）;漏报率低的3个地区为白沙县（0.56%）、五指山市（4.62%）、万宁市（9.63%）。调查点间漏报率的差异有统计学意义（χ2 = 721.25 ,P＜0.001）。年份、城市与农村、性别、年龄组间漏报率差异无统计学意义（都P＞0.05）。结论 海南省死因监测系统中漏报率较高,各市、区（县）都存在漏报现象,但漏报率高低存在地区差异。建议强化死因监测系统的培训和督查力度,将死因监测质量与绩效和奖惩机制挂钩,同时开展死因监测系统评估。     

Human Visceral Leishmaniasis in Kermanshah Province,Western Iran,During 2011-2012

Background

Visceral leishmaniasis (VL) or kala-azar is a parasitic disease caused by the species of Leishmania donovani complex. It is endemic in some parts of provinces of Iran. According to the reported cases of VL in Kermanshah Province in recent years, this study was conducted to determine the seroprevalence of VL in high risk villages of the province.

Methods

Totally, 1622 serum samples obtained from children under 15 years old and 178 from adults in 22 villages of studied areas. Serum samples were examined by direct agglutination test (DAT) for the detection of anti-Leishmania antibodies. Data were analyzed using SPSS software ver.11.5.

Results

Only 6 serum samples (0.33%) showed anti-Leishmania antibodies against L.infantum at titers ≥ 1/3200. Four of the seropositive cases had a history of kala-azar and Leishman bodies were seen in their bone marrows. The highest (0.5%) and lowest (0.29%) seroprevalence was seen in the age groups of 5-9 and 10-14 years old, respectively. None of the adults were seropositive. There were not any significant differences between the rate of seropositivity in males (0.36%) and females (0.31%). 66.7% of seropositive individuals showed clinical manifestations. The most important symptoms in Kala-azar patients were fever, hepato-spleenomegally and anemia.

Conclusion

Kala-azar is occurred sporadically in Kermanshah Province. But presence of significant number of positive sera confirms the necessity for attention of people and clinicians to kala-azar.     

Significance of urinary cadmium concentration as an indicator of cadmium exposure in a population exposed to cadmium in a general environment

Study was made on the significance of urinary cadmium concentration as an indicator of internal dose in a general environment polluted by cadmium. As an index of external dose, the mean rice cadmium concentration in each of 23 villages was employed. Morning urine samples were collected from 3,178 inhabitants of 23 cadmium-polluted villages of Kakehashi River basin in Ishikawa Prefecture and 294 inhabitants of two nonpolluted villages. Cadmium concentration in urine was determined. In addition, their residential history and intake of cadmium-polluted rice were obtained. All the subjects were 50 years of age or over. Participation rates were 91% for the polluted area and 94% for the nonpolluted area. Urinary cadmium concentrations were higher in the inhabitants of the cadmium-polluted area than in those of the nonpolluted area. Among the inhabitants in the cadmium-polluted area, urinary cadmium concentrations were higher in the subjects who had consumed cadmium polluted rice than in those who had not. The mean urinary cadmium concentrations in each village increased proportionally to increase in mean village rice cadmium concentration (intensity of exposure) when the inhabitants were classified according to period of residence at their present address. The mean urinary cadmium concentrations in each village were also significantly correlated with period of residence at the present address (duration of exposure) when the inhabitants were classified according to mean rice cadmium concentration of their village. It is concluded that urinary cadmium concentration mainly reflects the body burden of cadmium in a general environment polluted by cadmium.     

2018年四川省阿坝州大骨节病历史重病区内、外环境病情影响因素分析

目的:了解四川省阿坝州大骨节病历史重病区内、外环境硒及T-2毒素水平。方法:2018年7月至2019年2月,在阿坝州马尔康市、壤塘县、阿坝县、若尔盖县、红原县5个大骨节病历史重病区市（县）,分别选择1个历史重病区乡,每个乡选择1个历史重病区村和1个非病区村。每个村采集30名常住6 ~ 12周岁儿童发样,检测发硒含量;每...     

Opioid Peptides,Adrenocorticotrophic Hormone and Dietary Copper Intake in Humans

Copper plays an important role in cardiac and brain function possibly through endocrine and neuroendocrine systems. The syndrome of copper deficiency is worsened by dietary fructose and other trace metals such as zinc. We investigated the effect of a low copper diet on plasma opioid peptides in 11 healthy young volunteers who were fed foods low in copper but adequate in all other nutrients. The study was divided into three dietary periods. Copper was added to the diet so that the diet contained 0.66 mg/day for 24 days (marginal Cu), 0.38 mg/day for 42 days (low Cu) and 2.49 mg/day for 24 days (adequate Cu). The indices of copper status, ceruloplasmin and plasma copper concentrations, declined and were significantly lower (p < 0.05) at the end of the low Cu period than at the beginning of the study and the end of the marginal Cu period. They increased significantly at the end of the adequate Cu diet to the levels of the marginal Cu diet. Plasma β-endorphin (BEN), Leu-enkephalin (LE), Met-enkephalin (ME) and Adrenocorticotropic hormone (ACTH) were measured by radioimmunoassay at the beginning of the study and at the end of each dietary period. No significant differences were observed in BEN, LE or ME during any of the periods. There were only small increases in LE and ME at the end of marginal and low copper diet periods and no significant changes were observed on copper repletion. Plasma ACTH was significantly lower at the end of low copper compared to baseline value but was not lower after marginal copper. Copper repletion had no significant effect on ACTH. The data show that plasma opioid peptides did not respond significantly to differential copper intake.     

Distribution of vectors, transmission indices and microfilaria rates of subperiodic Wuchereria bancrofti in relation to village ecotypes in Samoa

Aedes polynesiensis and Ae. samoanus biting densities and Wuchereria bancrofti infection and infective rates were studied in 47 villages throughout the islands of Samoa Upolu, Manono and Savaii during 1978-79, and microfilaria (mf) rates were surveyed in 28 of the villages. The mf rate was correlated with both infection and infective rates of Ae. polynesiensis in Upolu, but not of Ae. samoanus. In Upolu, Ae. polynesiensis was apparently the major vector. It was relatively more abundant in more cultivated and populated areas, along the northern coast of Upolu, except Apia town area. In Savaii, Ae. samoanus predominated over Ae. polynesiensis except in "plantation" villages. Relatively high biting densities and rates of infection and infectivity indicated that Ae. samoanus was not less important than Ae. polynesiensis as a vector in Savaii. Ae. samoanus preferred natural vegetation, in contrast to Ae. polynesiensis which was found near human habitations in cultivated land. There was no difference between the biting densities of Ae. polynesiensis in "coastal" and "inland" villages, indicating that crab holes (numerous only in some coastal villages) may not influence the density of Ae. polynesiensis. Higher mf rates were associated with villages where Ae. polynesiensis, rather than Ae. samoanus, was dominant, indicating that Ae. polynesiensis was generally a more efficient vector. In the former villages, the difference in mf rates between males and females was smaller than in the latter, probably reflecting a difference in biting habits of the vectors. Ae. polynesiensis infections were recorded in plantations over 2 km from any village, suggesting that both habitats were foci of transmission.     

A comparative study of family functioning, health, and mental health awareness and utilization among female Bedouin-Arabs from recognized and unrecognized villages in the Negev

A good portion of geography is contested by the Israeli state and the country's Bedouin-Arab population. There are two categories of Bedouin villages: those areas that are "officially" recognized by the state and those that are not. In this article we determine utilization and awareness of health and mental health services among 376 Bedouin-Arab women in recognized and unrecognized villages in the Negev. Although there are differences between them, primary health care (PHC) services usually are available within recognized villages, accessible to those from unrecognized villages, and tend to precipitate user satisfaction. We conclude with various suggestions for improving health service delivery and making PHC and mental health delivery more accessible. Through this article we intend to help mental health practitioners on two levels: the policy level, regarding the design of mental health services for societies in transition, such as the Bedouin Arab, and the practical level by helping practitioners better appreciate the psychosocial status of women in Bedouin-Arab societies and the factors associated with Bedouin-Arab PHC utilization.     

Sustainability of a Community-Based CHOICE Program to Improve the Health and Nutrition Status of Mothers and Infants in Indonesia

Objectives Few studies have been undertaken to determine whether and how project results are sustained. University of Notre Dame (ND) and Project Concern International conducted a Post-Project Sustainability Study (PSS) of a USAID-funded program (CHOICE), implemented in Indonesia, Banten province, between 2003 and 2007, in order to determine lasting effects and improve PSS methodologies. Methods Sustainability was measured through a comparison of data collected on mother–infant pairs in 2014 with final evaluation data from 2007; and through a comparison of 2014 data collected from the CHOICE villages and comparison villages. Results The analysis showed positive differences in multiple indicators in CHOICE villages between 2007 and 2014, including births attended by skilled personnel (Mean Difference 48.56, 95% CI 38.68 to 58.43) and treatment of diarrhea (MD 16.42, 95% CI ??0.94 to 33.37). However, only one statistically significant difference between intervention and comparison groups in 2014 was observed, infants with diarrhea whose mothers sought advice or treatment (MD ??5.48, 95% CI ??9.55 to 1.39), showing more mothers in intervention group sought advice or treatment. Because contextual factors were not studied in detail and baseline data was not available for the comparison villages, it is difficult to determine the reasons for the results. Given that longitudinal data was not collected, it is also difficult to determine whether results fluctuated between 2007 and 2014. Conclusions for practice This PSS contributes to the limited body of knowledge in sustainability research. Lessons learned from this study will increase potential for sustainable impact of projects, as more rigorous measurement will lead to greater overall understanding of how sustainability actually “happens”.     

甘肃省合作市水源水含砷情况调查及对人群的影响

目的 调查甘肃省合作市水源水含砷情况及对人群的影响.方法 通过合作市7个乡、12个行政村、162个自然村进行的193份饮水水源样本的筛查和地砷病病情普查工作.按照《甘肃省地方病防治项目实施方案》和《甘肃省高砷区普查方案》的技术要求进行.凡筛查确定的高砷水源的自然村,以该自然村为中心采集全部饮用水源检测砷含量.结果 发现超标水样分布在合作市的4个乡的11个自然村,超标水样13份,占6.7%.在高砷区小学生、成年人中发现患皮肤疣状物者较多,其表面干燥、皲裂、出血.高砷水源区与低砷水源区人群尿砷水平比较,差异有统计学意义（P＜0.05）.结论 在少数民族聚居地区发现高砷水源的分布和地方性砷中毒疑似病人,为今后进行地方性砷中毒病区的确定和病人的确诊,以及病区改水驱砷等综合治理措施提供科学依据.     

Balkan endemic nephropathy: Still a mysterious disease

Balkan endemic nephropathy (BEN) is an acquired, environmental, polytopical disease of the entire urinary tract, with long latency. Tubulo-interstitial chronic nephritis, urotheliomas of all localities, and renal cell carcinoma occur with a significantly higher frequency in the affected population. These represent only clinical manifestations of one unique nosological entity. BEN occurs in focuses. Within them, it agglomerates in households, without any evidence of hereditary background. Patients with various clinical manifestations of the disease can be simultaneously found within one single household. BEN appears equally among members of different ethnic groups. Its aetiology is not clear enough. There is no evidence of a causal relationship with silicon compounds, heavy metals and viruses. Much attention has been recently focused on research of the aetiological role of mycotoxins, mainly ochratoxin A. Toxic and carcinogenic agents of natural origin are commonly accepted as the major cause of BEN.     

Soil radionuclide concentrations and radiological assessment in and around a refining and petrochemical company in Warri, Niger Delta, Nigeria

Radioactivity measurements have been carried out using gamma-ray spectroscopy to determine the radionuclide concentrations in soil samples in the premises of the Warri Refining and Petrochemical Company located in the Niger Delta region of Nigeria and also in communities around it. The radionuclide contents of the crude oil and petroleum additives were also similarly determined. Results indicate that on the premises used by the company, the ranges of activity concentrations of (40)K, (226)Ra and (228)Th in the soil samples were 261.3-932.3 Bq kg(-1),<4.2-23.0 Bq kg(-1) and<5.1-10.2 Bq kg(-1), respectively. For the 13 villages studied, activity concentrations ranged from <17.2-766.3 Bq kg(-1),<4.2-104.7 Bq kg(-1) and<5.1-13.7 Bq kg(-1), respectively, for (40)K, (226)Ra and (228)Th. The lowest radionuclide concentrations were found in the crude oil relative to the petroleum additives. The highest outdoor effective dose rate obtained in the study was 47.5 microSv y(-1) for the villages and 35.2 microSv y(-1) within the company premises. These values are less than the world average outdoor value of 70 microSv y(-1) given by UNSCEAR. Overall, it can be concluded that the long duration of refining activities does not seem to have affected radionuclide concentrations in the environment. Measurements also showed that the observed radiation dose rates did not vary significantly from the previously determined Warri City outdoor gamma radiation dose rates, for which the probability of occurrence of any health effects of radiation was judged low. The measurements, therefore, are interpreted to represent baseline radiometric data for future reference and research in the area.     

The etiology of Balkan endemic nephropathy: still more questions than answers.

Balkan endemic nephropathy (BEN) has attracted increasing attention as a possible environmental disease, and a significant amount of research from complementary scientific fields has been dedicated to its etiology. There are two actual competing theories attempting to explain the cause of this kidney disease: 1) the mycotoxin hypothesis, which considers that BEN is produced by ochratoxin A ingested intermittently in small amounts by the individuals in the endemic regions, and 2) the Pliocene lignite hypothesis, which proposes that the disease is caused by long-term exposure to polycyclic aromatic hydrocarbons and other toxic organic compounds leaching into the well drinking water from low rank coals underlying or proximal to the endemic settlements. We outline the current developments and future prospects in the study of BEN and differentiate possible factors and cofactors in disease etiology.     

Longitudinal study of the risks related to the consumption of water not conforming to bacteriological norms

A prospective follow-up study lasting 18 months in 1983-1984 was conducted in 50 villages in order to assess the risk related to the consumption of drinking water which did not meet the bacteriology standards. 119 physicians, 52 pharmacists and 118 primary-school teachers enumerated the cases of acute gastro-intestinal diseases observed among a population of 29,272 inhabitants. A weekly water sample was analysed in each village as to the presence of four indicator germs of fecal contamination: total plate count, total coliforms, fecal coliforms (thermotolerant) and fecal streptococci. 1,950 cases of acute gastro-intestinal diseases were registered by the physicians and pharmacists during a population experience of 1,873,303 persons-weeks, i.e. an incidence density of 1.06 X 10(-3) cases per person-week. The risk notified by the school teachers among children aged 7 to 11 was higher: 16.3 X 10(-3) cases per child-week. The villages were classified in 3 groups, according to the proportion of substandard samples: "good", "intermediate", and "bad" categories. The relative risk contrasting the "bad" and "good" villages was 3.5 for the cases notified by the physicians and the pharmacists among the general population (95% confidence interval = 2.5-4.8); it was 1.7 for the cases reported by the teachers among the children (95% confidence interval = 1.5-1.9). This concordant difference was very significant but not constant across the 18 months of the survey. The authors conclude that the bacteriology standards are a relevant indicator of a health hazard.