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At least 19 recordsLinked to original sources
PubMed2005

[Investigation of Cryptosporidium spp. oocysts in tap water, well water, sewage water and sea water in Mersin, Turkey.].

Cryptosporidium spp. are protozoa which only live in a host cell and may cause an infection that may result in the death of people with immune deficiency. It is known that Cryptosporidium parvum and Cryptosporidium hominis infections may be spread by contaminated well and tap waters. The facts that there is no certain and reliable cure and that the organisms may be found asymptomatically in the healthy people increases the importance of cryptosporidiosis. Our study has been performed in the city of Mersin and surrounding areas. A total of 100 samples of water were taken from taps (44 samples), wells (2 samples), the sea (35 samples) and sewage (19 samples) to investigate the presence of Cryptosporidium oocysts. Cryptosporidium oocysts have been detected in 5 samples of tap water, one sample of well water, one sample of sea water and 4 samples of sewage water.

English Abstract↗
PubMed2001

The occurrence of Aeromonas spp. in natural mineral water and well water.

The presence of motile Aeromonas spp. in natural mineral water (NMW) and drinking well water in the area of Lecce (Italy) was investigated. Aeromonas spp. were not detected in any of the 60 NMW samples either by the direct and enrichment method. From a total of 20 wells, five were found to contain Aeromonas species with cell number ranging from 26 to 1609 250 ml(-1). In two wells the presence of Aeromonas spp. was not associated to the presence of faecal indicators, i.e. coliforms and faecal coliforms. Sixty-five Aeromonas spp. strains isolated in this survey were identified at species level and some were examined for haemolysis, Voges Proskauer reaction, lysine decarboxylase and sorbitol fermentation, tests which had been previously shown to correlate with production of enterotoxin/cytotoxin. Isolates identified as A. hydrophila and A. sobria showed potentially virulent properties.

Aeromonas↗
PubMed1983

DBCP pesticide in drinking water wells in Fresno and other communities in the central valley of California.

Spatial and temporal patterns of DBCP contamination of well water in eastern Fresno County were studied for the period 1979-1983. Associations were found between DBCP levels and land use, hydrological and geological variables and type of well. Large seasonal, monthly and daily fluctuations in DBCP concentrations appear to be due to well use patterns and time of sampling. These findings indicate that use of a formal sampling plan is essential for reliable monitoring of this and other pesticides in well water. Suggestions are made for improvements in the DBCP monitoring program in California.

Animals↗
PubMedDate not supplied

Public response to elevated nitrate in drinking water wells in Wisconsin.

The authors conducted a survey by mail of Wisconsin families who had their well water tested for nitrate to (a) assess their awareness and compliance with the state's health advisories for nitrate, (b) evaluate their reaction(s) to their test results, and (c) compare demographic differences between exposure levels. Owners of contaminated wells (i.e., > 12.9 mg/l nitrate-nitrogen) were more likely to have lived on a farm, had lower annual incomes, and had older and shallower wells than families whose wells were low in nitrate (i.e., < 2.0 mg/l nitrate-nitrogen). Most respondents were aware of the advisories for pregnant women and infants and, in accordance with these advisories, the majority of families with nitrate-contaminated drinking water took no remedial action. Given that many rural families consume nitrate-contaminated water daily, scientists should conduct additional research to determine whether chronic ingestion of nitrate-contaminated water poses a significant health threat to these families.

Adult↗
PubMed1993

Fluoride levels in well-water from a chronic arsenicism area of Northern Mexico.

This paper reports on the concentrations and geographical relationships between fluoride and total arsenic in 129 water wells of the Región Lagunera, Mexico, where arsenic has caused severe health effects. Fluoride concentrations ranged from less than 0.5 to 3.7 mg liter(-1); 25 samples (19.4%) had levels above 1.5mg liter(-1), the current WHO and Mexican drinking water standard, whereas 45 (34.9%) had levels below 0.5 mg liter(-1). The range of total arsenic concentrations was 0.008-0.624 mg liter(-1) and 64 (50%) had levels above 0.050 mg liter(-1), the current WHO standard. A linear regression analysis of arsenic and fluoride concentrations showed a highly positive correlation (r = 0.774), consistent with their geographical distribution. The highest concentrations of both elements were found in the northeastern part of the Región, mostly corresponding to rural areas, whereas the lowest concentrations were found in the southwestern part of the Región, as well as in the cities of Torreón in the state of Coahuila, and Gómez Palacio and Lerdo in the state of Durango. In consequence, people exposed to high arsenic concentrations are also exposed to fluoride at levels above the drinking water standard. The possibility of interactions between both elements is also discussed.

Journal Article↗
PubMed2003

[Possibility for the presence of Helicobacter pylori in drinking well water].

Forty three well waters which are currently used as drinking water were studied for the presence of Helicobacter pylori. Using magnetic-beads purification and PCR amplification of H. pylori-specific gene, 4 of the 43 samples were positive for H. pylori-ureA gene (9.3%) and 1 of the 43 samples was positive for H. pylori-16SrRNA gene (2.3%). The presence of H. pylori-specific amplified product did not correlate with the type, depth and location of the wells. This study demonstrated that H. pylori can be transmitted via drinking water, especially well water in Japan.

Helicobacter pylori↗
PubMed1997

A 4-year study of the diversity and persistence of coliforms and Aeromonas in the water of a Swedish drinking water well.

Coliforms and Aeromonas, isolated over a sampling period of 4 years from a Swedish drinking water well, were analysed for their phenotypical diversity and for their ability to persist in the well water. From each of the 40 water samples collected from the well, 32 bacterial isolates were subjected to typing by the PhenePlate (PhP) biochemical fingerprinting system. Strains able to persist in the well water were further characterized using the API 20E system, gas-liquid chromatographic cellular fatty acid analysis, and the DNA fingerprinting technique AFLP. Using the PhP system, a total of 170 different phenotypes were identified among 1143 studied isolates. Most phenotypes were only represented by a few isolates and (or) were restricted to one or two sampling occasions. However, one particular phenotype (RV-C01), identified as Aeromonas hydrophila using the API 20E system and fatty acid analysis, reoccurred in 28 samples distributed over the whole study period and often dominated the bacterial population in the well water. AFLP analysis revealed that the RV-C01 isolates displayed basically identical fingerprints. Our results thus suggest that a genetically stable Aeromonas clone resided in the well water over the whole 4-year study, whereas other bacterial strains studied were only transient inhabitants of the well.

Aeromonas↗
PubMed1999

A field study to compare performance of stainless steel research monitoring wells with existing on-farm drinking water wells in measuring pesticide and nitrate concentrations.

Existing drinking water wells are widely used for the collection of ground water samples to evaluate chemical contamination. A well comparison study was conducted to compare pesticide and nitrate-N data from specially designed stainless steel research monitoring wells with data from nearby existing on-farm drinking water wells. Results could help to determine whether adequate information concerning ground water contamination can be obtained from existing drinking water wells for use in making pollutant control decisions. The study was conducted during 1993-1994 in the Little Coharie Watershed, a 158 square mile area located in the coastal plain of eastern North Carolina. Statistical analysis indicated that research monitoring wells provided a greater probability of detecting pesticides in ground water than existing on-farm wells. Atrazine was the most frequently detected pesticide found in all wells, followed in order by fluometuron, carbofuran, metolachlor, alachlor, carbaryl, butylate, chlorothalonil, linuron and simazine. Ninety-seven percent of all wells had observed concentrations of nitrate-N, ranging from 0.1 to 30.1 mg/L. There was not a significant difference between research wells and existing wells for monitoring nitrate-N. Based on results of this study, existing drinking water wells can be used for monitoring nitrate; however, specialized stainless steel monitoring wells should be used for monitoring pesticides in ground water.

Databases, Factual↗
PubMed1988

[Microbiological analysis of well water samples in the rural areas near Ankara].

The water from wells and running water in different rural parts of Ankara were analyzed microbiologically with the thought in mind that the use of unhealthy well water could cause infections, as shown in other cities. We found that of the 50 running water samples all (100%) were drinkable from the microbiological point of view regard to coliform bacteria and total germ count, while only 20 of the 150 well water samples (13.3%) met these standards. It was pointed out by the users that chlorination was carried out in only 22 of the wells (14.6%) and only irregularly; no coliform bacteria were found in water samples from these wells. In 117 well water samples (78%) 120 coliform bacteria strains were isolated, of these 80 were E. coli, 27 Enterobacter and 13 Citrobacter. All samples were analyzed for Giardia intestinalis cysts but found to be negative.

Bacteria↗
PubMed1989

Magnitude of faecal contamination of rural community well waters in Nigeria and its relationship to well and water properties.

The possible relationship between high numbers of fecal coliforms (FCs), fecal streptococci (FS), standard plate count (SPCs) and well characteristics viz: well depth, water column, temperature, pH and non-filterable residue in 25 rural community wells in the Port Harcourt region, Nigeria, was studied. Zonal differences in residue level, well depth and fecal indicator bacteria were observed; these parameters were lowest in an area of high population density (slum) reclaimed from and adjacent to mangrove forests. Although some wells were covered and/or walled to protect them from surface runoff contamination, FCs and FS were recovered from all, except three, in numbers (log10 per 100 mL) ranging respectively from 0.40-3.79 and 0.70-3.44. The FC:FS ratio was less than 1.0 in 8 and greater than 1.0 in 14 samples. Well depth correlated with FCs (p = 0.01; r = 0.5684), FS (p = 0.001; r = 0.6423), pH (p = 0.0001; r = 0.5981); FCs and FS correlated significantly (p = 0.01; r = 0.4948). SPCs did not correlate significantly with FCs, FS and the well and water characteristics. Simultaneous analysis of samples by the Membrane-filtration (MF) and Most Probable Number (MPN) methods recovered mean FC counts in the decreasing sequence: Standard-MPN----Anaerobic----Aerobic MF----Direct-MPN. The underground water table is most probably contaminated via large numbers of soakaway pits and similar conveniences. Downward movement of contaminant from the shallow conveniences into deeper water tables may explain the well depth: indicator bacteria correlation.

Analysis of Variance↗
PubMed1993

The nitrate contamination of private well water in Iowa.

The State-Wide Rural Well-Water Survey was conducted between April 1988 and June 1989. About 18% of Iowa's private, rural drinking-water wells contain nitrate above the recommended health advisory level (levels of NO3-N greater than 10 mg/L); 37% of the wells have levels greater than 3 mg/L, typically considered indicative of anthropogenic pollution. Thirty-five percent of wells less than 15 m deep exceed the health advisory level, and the mean concentration of nitrate-nitrogen for these wells exceeds 10 mg/L. Depth of well is the best predictor of well-water contamination. Individually, NO3-N levels of more than 10 mg/L occurred alone in about 4% of the private wells statewide; pesticides were present alone in about 5%. Total coliform positives occurred alone at 27% of the sites. In a cumulative sense, these three contaminants were detected in nearly 55% of rural private water supplies.

Enterobacteriaceae↗
PubMed1998

Effects of xylem pH on transpiration from wild-type and flacca tomato leaves. A vital role for abscisic acid in preventing excessive water loss even from well-watered plants

The pH of xylem sap from tomato (Lycopersicon esculentum) plants increased from pH 5.0 to 8.0 as the soil dried. Detached wild-type but not flacca leaves exhibited reduced transpiration rates when the artificial xylem sap (AS) pH was increased. When a well-watered concentration of abscisic acid (0.03 &mgr;m) was provided in the AS, the wild-type transpirational response to pH was restored to flacca leaves. Transpiration from flacca but not from wild-type leaves actually increased in some cases when the pH of the AS was increased from 6.75 to 7.75, demonstrating an absolute requirement for abscisic acid in preventing stomatal opening and excessive water loss from plants growing in many different environments.

Journal Article↗
PubMedDate not supplied

Effects of water use on arsenic release to well water in a confined aquifer.

Field-based experiments were designed to investigate the release of naturally occurring, low to moderate (< 50 microg/L) arsenic concentrations to well water in a confined sandstone aquifer in northeastern Wisconsin. Geologic, geochemical, and hydrogeologic data collected from a 115 m2 site demonstrate that arsenic concentrations in ground water are heterogeneous at the scale of the field site, and that the distribution of arsenic in ground water correlates to solid-phase arsenic in aquifer materials. Arsenic concentrations in a test well varied from 1.8 to 22 microg/L during experiments conducted under no, low, and high pumping rates. The quality of ground water consumed from wells under typical domestic water use patterns differs from that of ground water in the aquifer because of reactions that occur within the well. Redox conditions in the well can change rapidly in response to ground water withdrawals. The well borehole is an environment conducive to microbiological growth, and biogeochemical reactions also affect borehole chemistry. While oxidation of sulfide minerals appears to release arsenic to ground water in zones within the aquifer, reduction of arsenic-bearing iron (hydr)oxides is a likely mechanism of arsenic release to water having a long residence time in the well borehole.

Arsenic↗
PubMed2004

An investigation on physical, chemical, and bacteriological quality of municipally supplied and well waters of the towns and city centre in the province of Niğde, Turkey.

Physical, chemical, and bacteriological properties of municipally supplied water and well water in selected towns and the city centre (Niğde, population 76,000) of the province of Niğde, located in central Anatolia, in Turkey, were investigated in this study. A composition of 70 samples were collected, 31 from Niğde city centre; 17 from Bor; 8 from Ulukişla; 6 from Altunhisar; 6 from Ciftlik and 2 from Camardi. Analyses showed that all the samples collected were found to have been chemically safe to consume for domestic purposes. Twenty-three water samples were found potentially unsafe because of the existence of coliform bacteria in them, which was probably caused by the inexistence of sufficient chlorination. Physical tests indicated that 11 water samples were found to have deposit; therefore, the use of such water causes risks where human health is a concern, based upon Turkish national standards (TSE, 1984).

Chlorine↗