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At least 19 recordsLinked to original sources
PubMedDate not supplied

Potential health effects of chlorine dioxide as a disinfectant in potable water supplies.

Chlorination of potable water supplies high in organics may yield carcinogenic compounds such as trihalomethanes. Chlorine dioxide has been proposed as an alternative disinfectant to chlorine. However, chlorine dioxide is a strong oxidant that forms significant amounts of chlorite when added to potable water supplies, and chlorite is similar to nitrite in its molecular structure and may be similar in its mechanism of methemoglobin production. Nitrites and chlorites are thought to act synergistically to produce MetHb. Neonates and persons with G-*-PD deficiency are likely to be unusually susceptible to MetHb formation from these compounds because their red cells lack the metabolic machinery to adequately protect against oxidant stress. Since male blacks represent the largest population in the U.S. to be G-6PD deficient, Black male neonates may represent the group at highest risk to the use of chlorine dioxide as a disinfectant in the nations water supplies.

Adult↗
PubMed1979

[Comparison of different types automatic water-supply system for mouse rearing (author's transl)].

Rearing and breeding scores were compared between groups of mice (JCL : ICR and ddN strains) raised with two different types of automatic water-supply systems; the Japanese type and the American type, using manual water-supply system as control. The mice raised with the manual water-supply system were superior in body weight gain as compared to those with two automatic water-supply systems. As to the survival rate, however, the m; anual water-supply system and the Japanese type gave better results than the American type. As to weanling rate in the breeding test, the manual water-supply system gave somewhat better result than either of the two automatic types. Accidental water leaks, which are serious problems of automatic systems, occurred frequently only when the American type was used. Only one defect of the Japanese type revealed was that it was unfavorable for mice with smaller size (e.g., young ddN mice), resulting in lower body weight gain as well as lower breeding scores.

Animals↗
PubMed1978

Residues of polychlorinated biphenyls, DDT, and DDT metabolites in Pennsylvania streams, community water supplies, and reservoirs, 1974--76.

Pennsylvania streams, community water supplies, and open water reservoirs were analyzed for PCB mixtures, DDT, and DDT metabolites. Streams were sampled in 1974 and again in 1975. Only 4 of 19 stream locations were contaminated. Maximum concentrations in community supplies of Aroclor 1242 (2 locations), Aroclor 1254 (3 locations), and sigmaDDT (2 locations) were 350, 260, and 620 ng/kg, respectively. Of the 110 community water supplies sampled in 1975 and 1976, only 7 contained residues. Maximum concentrations in community supplies of Aroclor 1242 (4 locations) and sigmaDDT (2 locations) were 460 ng/kg and 75 ng/kg, respectively. The seventh contained 0.7 ng/kg of dieldrin. None of the three open water reservoirs contained detectable residues of the compounds of interest. Essentially no correlation was found between PCB and DDT analogs in streams and those in fish from streams which had been samples at similar locations in a related study in 1976.

Chromatography, Gas↗
PubMed1978

Further observations from St Lucia on control of Schistosoma mansoni transmission by provision of domestic water supplies.

Individual households in five settlements were provided with piped water in a pilot scheme to investigate the effect on transmission of S. mansoni in St Lucia. Nearby comparison settlements, in the same valley, were provided with water through a public standpipe system. The incidence of S. mansoni infection among children decreased in the experimental area, leading to lower prevalence rates and lower intensity of infection in all age groups. Over the study period, indices of infection increased in the comparison settlements, but by the end of the period development was making those settlements less suitable for comparison purposes and some reduction in transmission was occurring.The changes in human infection rates were reflected in the results of studies with sentinel snails. In the experimental area, infection rates gradually fell owing to reduced water contact and consequently less contamination of the river and its banks, and possibly to the gradual reduction in contamination potential of the community with reduced prevalence and intensity of infection. It is suggested that a piped water supply be considered as a method of schistosomiasis control, but that the cost should not be debited only to the control of this disease since a clean water supply has other medical and social benefits.

Adolescent↗
PubMed1977

Composition of the domestic water supply and the incidence of fractures and encephalopathy in patients on home dialysis.

Of the 202 patients undergoing home dialysis in the Trent region, 11 developed dialysis encephalopathy, 21 suffered spontaneous fractures, and 36 who had undergone dialysis for over four years had neither of these complications. Because the incidence of complications seemed to be unevenly distributed the water supplies were analysed. Water supplied to the homes of the patients with fractures or encephalopathy contained significantly less calcium and fluorine and significantly more aluminium and manganese than that piped to patients without these complications. The high aluminium concentrations in the bone of patients with encephalopathy was confirmed, but aluminium concentrations in the brains from three patients with encephalopathy were not increased. Patients who undergo dialysis in areas where water contains high aluminium concentrations should be supplied with deionisers.

Aluminum↗
PubMed1978

Water supply and nutritional status in rural northern Nigeria.

A high incidence of protein energy malnutrition (PEM) was found in a community survey of preschool children in rural northern Nigeria among whom gastro-enteritis is common. Wasting (less than 80% Weight/Height) was more common (37.9%) among those with scanty, unprotected water supplies than in those with copious protected water (10.2%) whereas the incidence of stunting (less than 90% Height/Age)) was similar. Severe coliform contaminatin of all water sources was demonstrable. Even higher numbers of coliforms in foods sampled suggests that other factors related to water supply may be more important than water purity in the genesis of the PEM/gastro-enteritis complex.

Body Height↗
PubMed1979

Cancer mortality in selected New South Wales localities with fluoridated and non-fluoridated water supplies.

The standardized cancer mortality ratios for selected localities in New South Wales with fluoridated and non-fluoridated water supplies were examined. The cancer mortality ratios for both fluoridated and non-fluoridated localities were spread along a continuum. Two localities (one fluoridated, one non-fluoridated) had standardized mortality ratios significantly lower than the New South Wales State average. No relationship was found between cancer deaths and whether water supplies had been fluoridated or not.

Australia↗
PubMed1979

A review of environmental characteristics and health effects of barium in public water supplies.

A comprehensive review is made of sources, occurrence, removal, health effects and water quality standard of barium in public drinking water supplies. The primary source of naturally occurring barium in drinking water results from the leaching and eroding of this metal from sedimentary rocks into the aquifers of ground water. It is a localized problem in several areas of the United States. The removal of barium from drinking water appears to be most efficiently accomplished utilizing ion exchange softening. Health effects studies are based primarily on animal experimentation. Such effects include stimulation of smooth, striated, and cardiac muscle, elevation of blood pressure, initiation of catecholamine release, rapid and preferential deposition in bone, and excretion principally in the feces. Humans over 60 years of age appear to be at high risk to developing cardiac arrhythmias following the barium enema. The current United States drinking water standard of 1.0 mg/l is based on several faulty assumptions and should be critically reevaluated.

Animals↗
PubMed1979

[Investigation on the presence of salmonella in drinking water from water supplies and distribution systems in Togo (author's transl)].

Bacteriological drinking water examination of samples from water works and wells as well as from their distribution systems revealed that from 26 samples, where Salmonella organisms could be isolated, in 16 cases E. coli- and coliforms could not be found and that in 9 of these cases even the colony count was below 100 colonies per ml at 20 degrees C and 37 degrees C incubation temperature. The common reasons for such contaminations are technical deficiencies, mostly faulty well-heads or broken covers of reservoirs. Rainbow lizzards (Agama agama), very common in these regions, can thus easily gain access to wells and reservoirs and pollute the groundwater. Rainbow lizzards do not posses a constant and uniform microbial flora of the intestine. Among lizzards which excrete Salmonella organisms in great numbers, relatively often individuals could be found which harbour either no E. coli- and/or coliforms at all or only in very reduced numbers. In the light of these results an efficient primary protection of all water supplies by a secure covering of well-heads and reservoirs in particular seems to be of paramount importance in tropical countries. This is very much in contrast to the situation most commonly seen in these areas. The necessary measures would have to be accompanied and supplemented by alterations of the installations in the house where the creation of open reservoirs must be avoided.

Escherichia coli↗
PubMed1976

An epidemic of gastroenteritis traced to a contaminated public water supply.

Between January 1 and March 15, 1974, approximately 1200 cases of acute gastrointestinal illness occurred in Richmond Heights, Florida, a residential community of 6500 in south Dade County. Over one-third of all families in the area had at least one member affected. The findings of 10 culture-proven cases of shigellosis among those who became ill and clinical signs and symptoms in the others suggest that most of the other cases that were not cultured may have been shigellosis also. Epidemiologic investigation showed that consumption of tap water was associated with illness in the initial cases of affected families. Evaluation of the Richmond Heights public water supply disclosed numerous inadequacies in both design and operation. One of the wells providing water to the community was continuously contaminated with excessive levels of fecal coliforms from a nearby septic tank, and a breakdown in chlorination on January 14-15 caused approximately 1 million gallons of inadequately chlorinated water from the contaminated well to be distributed to the community 48 hours before the epidemic began. Correction of deficiencies in the water plant was undertaken by the utility company; the residents of Richmond Heights were instructed to boil their drinking water or to use commercially bottled water pending completion of corrective measures. A FUll scale study is planned for all similar public water supplies in Dade County.

Adolescent↗
PubMed1979

Scientific basis for the study of demineralization of highly mineralized water for use in public water supply systems.

New criteria (full physiological value and preservation of the properties of drinking water) are scientifically substantiated. Also discussed are indices (minimal admissible and optimal levels of basic water mineralization and calcium content, standards of microelements such as boron and bromine content, content of individual groups of microorganisms, water temperature) for evaluating the quality of demineralized water obtained from brackish and briny water (including water from the sea and ocean) by various methods which are designed for public water supply systems. Research results served as the scientific hygiene basis for the development of a new technology of obtaining drinking water. The necessity for developing a special quality standard for demineralized drinking water is shown.

International Cooperation↗
PubMedDate not supplied

Cancer mortality in relation to asbestos in municipal water supplies.

The mortality experience of twenty-two municipalities in Quebec grouped by evidence of exposure to asbestos fibers in water supplies (known high, possible high, and probable low exposures) was evaluated. Excess mortality due to cancer of the stomach (males), pancreas (females), and lung (males) was observed in the two municipalities with known high exposures. The excesses among males have been due to occupational exposure to asbestos. The absence of excess mortality due to pancreatic cancer among males suggested that the excess among females was not due to waterborne asbestos. The study therefore did not reveal evidence of excess cancer mortality that could be attributed to exposure to asbestos in drinking water.

Adult↗