Microcystin class of toxins: health effects and safety of drinking water supplies

1994 ◽  
Vol 2 (2) ◽  
pp. 167-186 ◽  
Author(s):  
T. W. Lambert ◽  
C. F. B. Holmes ◽  
S. E. Hrudey
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Health Risk ◽  
Health Effects ◽  
Tumor Promoter ◽  
Water Supplies ◽  
Blue Green Algae ◽  
Adverse Health Effects ◽  
Human Illness ◽  
Safety Of Drinking Water

The microcystins are produced by several species of common planktonic cyanobacteria found in surface waters, but their biological function remains unknown. The microcystins have been shown to be extremely potent hepatotoxins in a variety of experimental animals and they are lethal at low doses. Microcystin-LR, one of over 40 microcystin analogues, has also been shown to be a potent tumor promoter. The toxic effects of the microcystins have been attributed to the inhibition of protein phosphatases. This inhibition causes collapse of the cytoskeleton and interferes with a general signal transduction mechanism in cells. The presence of toxic cyanobacteria in surface water has been documented in all parts of the world. The microcystins have been related to a few incidents of human illness and several incidents of animal poisoning in Canada, United States, Australia, Europe, and Africa. Therefore, exposure to the microcystins is a potentially significant health risk and toxin removal from drinking water is becoming a concern worldwide. Conventional water treatment processes (coagulation/sedimentation, chlorination) have generally proven ineffective at removing microcystin toxins from drinking water. Activated carbon, ozone, and free chlorine have been effective in removing microcystins below detectable concentrations in laboratory experiments. Considering these factors, the occurrence of microcystins in drinking water supplies deserves serious attention to insure that adverse health effects are prevented.Key words: microcystins, hepatotoxins, cyanobacteria, blue-green algae, water treatment, health risk.

scholarly journals Prolonged exposure to arsenic in UK private water supplies: toenail, hair and drinking water concentrations

2016 ◽  
Vol 18 (5) ◽  
pp. 562-574 ◽  
Author(s):  
D. R. S. Middleton ◽  
M. J. Watts ◽  
E. M. Hamilton ◽  
T. Fletcher ◽  
G. S. Leonardi ◽  
...  
Keyword(s):  
Drinking Water ◽  
Health Effects ◽  
Chronic Exposure ◽  
Prolonged Exposure ◽  
Water Supplies ◽  
Adverse Health Effects ◽  
Adverse Health

Chronic exposure to arsenic (As) in drinking water is an established cause of cancer and other adverse health effects.

Water Treatment Considerations–Aquatic Humus

1983 ◽  
Vol 15 (S2) ◽  
pp. 95-101 ◽  
Author(s):  
E T Gjessing
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Humic Substances ◽  
Health Effects ◽  
Surface Waters ◽  
Cold Climate ◽  
Treatment Processes ◽  
Aquatic Humus ◽  
Treatment Considerations

For several reasons the surface waters in cold climate areas are coloured due to humic substances. There are two major objections against humus in drinking water, the first is concerned with aesthetical and practical problems and the second is due to indirect negative health effects. There are essentially three different methods in use today for the removal or reduction of humus colour in water: (1) Addition of chemicals with the intention of reducing the “solubility”, (2) Addition of chemicals in order to bleach or mineralize the humus, and (3) Filtration with the intention of removal of coloured particles and some of the “soluble” colour. The treatment processes are discussed.

Sources of Uncertainty in Assessing the Health Risk of Cyanobacterial Blooms in Drinking Water Supplies

1994 ◽  
pp. 122-126 ◽  
Author(s):  
Steve E. Hrudey ◽  
Sandra L. Kenefick ◽  
Timothy W. Lambert ◽  
Brian G. Kotak ◽  
Ellie E. Prepas ◽  
...  
Keyword(s):  
Drinking Water ◽  
Health Risk ◽  
Cyanobacterial Blooms ◽  
Water Supplies ◽  
Sources Of Uncertainty

Accumulation and re-release of metallic pollutants during drinking water distribution and health risk assessment

2019 ◽  
Vol 5 (8) ◽  
pp. 1371-1379
Author(s):  
Quanli Liu ◽  
Jiali Gao ◽  
Guiwei Li ◽  
Hui Tao ◽  
Baoyou Shi
Keyword(s):  
Heavy Metals ◽  
Risk Assessment ◽  
Drinking Water ◽  
Health Risk ◽  
Distribution Systems ◽  
Water Distribution ◽  
Drinking Water Distribution Systems ◽  
Drinking Water Distribution ◽  
Safety Of Drinking Water ◽  
Metallic Pollutants

Heavy metals easily accumulate and re-release in drinking water distribution systems (DWDS), which greatly affects the safety of drinking water.

scholarly journals Determination of cytotoxicity and invasiveness of heterotrophic plate count bacteria isolated from drinking water

2002 ◽  
Vol 2 (3) ◽  
pp. 115-122 ◽  
Author(s):  
D. Pavlov ◽  
C.M.E. de Wet ◽  
W.O.K. Grabow ◽  
M.M. Ehlers
Keyword(s):  
Drinking Water ◽  
Health Risk ◽  
Heterotrophic Bacteria ◽  
Penicillin G ◽  
Plate Count ◽  
Heterotrophic Plate Count ◽  
Water Supplies ◽  
Plate Counts ◽  
Study Support ◽  
Heterotrophic Plate Counts

Evidence has been presented that some heterotrophic bacteria often detected in drinking water supplies possess features associated with pathogenicity. This suggests that even the low numbers of heterotrophic bacteria considered acceptable by drinking water specifications may constitute a health risk, particularly to immunocompromised consumers. In this study, 339 bacteria were isolated at random from routine heterotrophic plate count (HPC) tests on selected drinking water supplies in South Africa. In a first screen for potentially pathogenic properties, 188 of the isolates (55.5%) displayed a- or b-haemolysis on blood agar. Further analysis of the haemolytic isolates for enzymes associated with virulence revealed the presence of chondroitinase (5.3%), coagulase (16.0%), DNase (60.6%), elastase (33.0%), fibrinolysin (53.7%), gelatinase (62.2%), hyaluronidase (21.3%), lecithinase (47.9%), lipase (54.8%) and proteinase (64.4%) of the isolates. No fluorescein or pyocyanin was detected in any of the isolates. Among the haemolytic isolates 68.6% were resistant to oxacillin (1 μg), 59.6% to penicillin G (2 units), 47.3% to penicillin G (10 units), 53.7% to ampicillin (10 μg) and 42.6% to ampicillin (25 μg). Cytotoxicity, invasiveness and adherence properties of the haemolytic isolates was determined on HEp-2 and Caco2 cell lines. Among the haemolytic isolates 96% were cytolytic on the HEp-2 cell line. All the haemolytic isolates adhered to HEp-2 and Caco2 cells but gram-negative isolates tended to adhere in larger numbers than gram-positive isolates. HEp-2 cells were invaded by 42% of the haemolytic isolates. Heterotrophic bacteria, which most frequently revealed the above features associated with pathogenicity included species of the following genera: Aeromonas, Acinetobacter, Aureobacterium, Bacillus, Klebsiella, Moraxella, Pseudomonas, Staphylococcus, Tsukamurella and Vibrio. The results obtained in this study support earlier indications that bacteria detected by routine heterotrophic plate counts on drinking water supplies may include bacteria associated with potentially pathogenic properties. The extent to which these bacteria in drinking water supplies may constitute a health risk remains to be investigated.

scholarly journals The Health Risk Associated with Chronic Diseases in Villages with High Arsenic Levels in Drinking Water Supplies

2016 ◽  
Vol 9 (4) ◽  
pp. 261-273 ◽  
Author(s):  
Orhan Gunduz ◽  
Coskun Bakar ◽  
Celalettin Simsek ◽  
Alper Baba ◽  
Alper Elci ◽  
...  
Keyword(s):  
Drinking Water ◽  
Health Risk ◽  
Chronic Diseases ◽  
Water Supplies ◽  
High Arsenic

scholarly journals The Effect of Different Boiling and Filtering Devices on the Concentration of Disinfection By-Products in Tap Water

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Glòria Carrasco-Turigas ◽  
Cristina M. Villanueva ◽  
Fernando Goñi ◽  
Panu Rantakokko ◽  
Mark J. Nieuwenhuijsen
Keyword(s):  
Drinking Water ◽  
Health Effects ◽  
Reverse Osmosis ◽  
Tap Water ◽  
Epidemiological Studies ◽  
The Other ◽  
Large Decrease ◽  
Adverse Health Effects ◽  
Before And After ◽  
By Products

Disinfection by-products (DBPs) are ubiquitous contaminants in tap drinking water with the potential to produce adverse health effects. Filtering and boiling tap water can lead to changes in the DBP concentrations and modify the exposure through ingestion. Changes in the concentration of 4 individual trihalomethanes (THM4) (chloroform (TCM), bromodichloromethane (BDCM), dibromochloromethane (DBCM), and bromoform (TBM)), MX, and bromate were tested when boiling and filtering high bromine-containing tap water from Barcelona. For filtering, we used a pitcher-type filter and a household reverse osmosis filter; for boiling, an electric kettle, a saucepan, and a microwave were used. Samples were taken before and after each treatment to determine the change in the DBP concentration. pH, conductivity, and free/total chlorine were also measured. A large decrease of THM4 (from 48% to 97%) and MX concentrations was observed for all experiments. Bromine-containing trihalomethanes were mostly eliminated when filtering while chloroform when boiling. There was a large decrease in the concentration of bromate with reverse osmosis, but there was a little effect in the other experiments. These findings suggest that the exposure to THM4 and MX through ingestion is reduced when using these household appliances, while the decrease of bromate is device dependent. This needs to be considered in the exposure assessment of the epidemiological studies.

scholarly journals Health risk of cyanotoxins in Lake Victoria and household drinking water for riparian communities along Nyanza Gulf

2020 ◽  
Author(s):  
Lilian Otoigo
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Health Risk ◽  
Lake Victoria ◽  
Primary Liver Cancer ◽  
Statistical Significance ◽  
Epidemiological Studies ◽  
Assay Method ◽  
Toxic Cyanobacteria ◽  
Riparian Communities

Cyanotoxins are produced by cyanobacteria which are single-celled algae that thrive in warm and nutrient rich water bodies including lakes. There are different kinds of cyanotoxins and microcystin is the most common. Microcystin mostly affects the liver. Epidemiological studies in China and Serbia have shown an association between cyanotoxins and occurrence of Primary Liver Cancer. Cyanobacteria have been reported in Lake Victoria, which is an important source of drinking water for the riparian communities, thus posing a danger to human health. However, the health risk from exposure to toxic cyanobacteria in the Nyanza Gulf water remains unknown. The purpose of this study was to assess the health risk of toxic cyanobacteria to the riparian communities in the Nyanza Gulf. In a longitudinal study adopting survey and experimental design, 127 samples were collected monthly from both households and six beaches over six months. Cyanobacterial levels were determined using an enzyme assay method (PP2A). Different methods of household water treatment were compared. Two-way ANOVA was done to determine statistical significance of microcystins levels. 84% of water samples contained microcystins. Concentration of microcystins was 3.44g/L which is over the WHO limit of 1g/L. There was no variation between beaches and water treatment (ANOVA: F=0.97, p=0.47). Filtration proved to be the most efficient method of water treatment. The health risk factor of cyanotoxins in drinking water is 3.86. There is a health risk posed by cyanotoxins to the residents of the Nyanza Gulf who use the lake water for drinking since is over the WHO limit. This information provides an insight into the quality of Lake Victoria water for drinking. The study recommends development of cyanobacteria removal methods as well as sensitizing the riparian communities on the health risk of cyanotoxins in drinking water.

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