Odorous Substances and Cyanobacterial Toxins in Prairie Drinking Water Sources

1992 ◽  
Vol 25 (2) ◽  
pp. 147-154 ◽  
Author(s):  
S. L. Kenefick ◽  
S. E. Hrudey ◽  
E. E. Prepas ◽  
N. Motkosky ◽  
H. G. Peterson

Algal blooms in eutrophic lakes have been regarded by some as primarily an aesthetic nuisance for recreational and drinking water uses despite well documented incidents of livestock and wildlife poisoning attributed to cyanobacterial toxins. A survey was conducted of three eutrophic, water supply lakes and eight rural dugouts experiencing cyanobacterial blooms. Biomass was characterized for dominant cyanobacterial genera and analyses were conducted for the hepatotoxins, microcystin LR and RR and the neurotoxin, anatoxin-a. Some water samples collected simultaneously were screened for geosmin, 2-methylisoborneol and β-cyclocitral. Results showed that microcystin LR (LD50 of 50 µg/kg in mice) was present in concentrations up to 500 µg/g of algal biomass and microcystin LR levels were generally related to the proportion of Microcystis in the collected algal biomass. There was no relationship between the presence of microcystin LR and the presence of any of the odour compounds. Consequently, cyanobacterial odour-causing compounds in water did not provide reliable warning of the presence of the microcystin LR in these cyanobacterial blooms.

1993 ◽  
Vol 27 (3-4) ◽  
pp. 433-440 ◽  
Author(s):  
S. L. Kenefick ◽  
S. E. Hrudey ◽  
H. G. Peterson ◽  
E. E. Prepas

Cyanobacterial (blue-green algal) blooms in agricultural dugouts and eutrophic lakes or reservoirs are common across the Canadian prairies. These blooms have caused livestock and wildlife poisonings that have been attributed to neurotoxins and/or hepatotoxins produced by various species of cyanobacteria. The hepatotoxins are extremely potent acute poisons. For example, microcystin LR has an LD50 of 50 µg/kg, by intraperitoneal injection, in mice. Hepatotoxins may also pose chronic health risks. Consequently, their presence in drinking water sources is attracting increasing attention. Chemical treatment with copper sulfate is the most common technique used to control algal blooms in drinking water reservoirs. Application of lime (calcium hydroxide) is an alternative treatment for the control of blooms. The effects of copper sulfate versus lime treatment on the release of microcystin LR from a naturally occurring bloom, involving three species of cyanobacteria including toxin-producing Microcystis aeruginosa, were studied. Water samples collected after chemical treatment of algal bloom material were monitored for microcystin LR at specific time intervals. In three replicate trials, the cells treated with coppa- sulfate released the majority of the toxin present within cellular biomass during the first three days after treatment. Substantial toxin release was not observed when cells were untreated (control) or treated with lime. After release, the persistence of microcystin LR was monitored. The aqueous toxin concentrations declined according to first order kinetics with a decay constant of 0.25 d−1. The experimental conditions, involving high biomass content, may have favoured toxin degradation. The microcystin LR half life, under laboratory conditions, was 3 d from the time of maximum toxin release (2 to 4 d after chemical treatment), meaning that a 99% reduction would take approximately 3 weeks. These findings indicate that copper sulfate should not be used to treat potentially toxic cyanobacterial blooms in waters to be consumed by humans or animals within several weeks following treatment.


2016 ◽  
Vol 76 (s1) ◽  
Author(s):  
Mariano Bresciani ◽  
Claudia Giardino ◽  
Rosaria Lauceri ◽  
Erica Matta ◽  
Ilaria Cazzaniga ◽  
...  

Cyanobacterial blooms occur in many parts of the world as a result of entirely natural causes or human activity. Due to their negative effects on water resources, efforts are made to monitor cyanobacteria dynamics. This study discusses the contribution of remote sensing methods for mapping cyanobacterial blooms in lakes in northern Italy. Semi-empirical approaches were used to flag scum and cyanobacteria and spectral inversion of bio-optical models was adopted to retrieve chlorophyll-a (Chl-a) concentrations. Landsat-8 OLI data provided us both the spatial distribution of Chl-a concentrations in a small eutrophic lake and the patchy distribution of scum in Lake Como. ENVISAT MERIS time series collected from 2003 to 2011 enabled the identification of dates when cyanobacterial blooms affected water quality in three small meso-eutrophic lakes in the same region. On average, algal blooms occurred in the three lakes for about 5 days a year, typically in late summer and early autumn. A suite of hyperspectral sensors on air- and space-borne platforms was used to map Chl-a concentrations in the productive waters of the Mantua lakes, finding values in the range of 20 to 100 mgm-3. The present findings were obtained by applying state of the art of methods applied to remote sensing data. Further research will focus on improving the accuracy of cyanobacteria mapping and adapting the algorithms to the new-generation of satellite sensors.


2011 ◽  
Vol 11 (2) ◽  
pp. 69-79 ◽  
Author(s):  
Ewa Dembowska

Cyanobacterial blooms in shallow lakes of the Iławskie Lake DistrictThe dominance of blue-green algae observed in many lakes is related to a high trophic level. Shallow eutrophic lakes are particularly often abundant in blue-green algae. The research on phytoplankton, the results of which are presented in this paper, was carried out between 2002 and 2005 in six lakes. These lakes differed considerably in their size and management methods applied in the catchment (drainage) area. A few types of water blooms were distinguished, which is related to the catchment area management, the intensity of mixing and the trophic level. Algal blooms of the Planktothrix type appeared in lakes situated in an open area of agricultural catchment basins. Algal blooms of the Limnothrix type were characteristic of lakes with a forest-agricultural catchment area but surrounded by high shores, which reduced the wind influence on the mixing. Sporadic mixed algal blooms were typical of lakes situated in forest catchment areas.


Author(s):  
Todd R. Miller ◽  
Lucas J. Beversdorf ◽  
Chelsea A. Weirich ◽  
Sarah L. Bartlett

Cyanobacteria are ubiquitous phototrophic bacteria that inhabit diverse environments across the planet. They dominate many eutrophic lakes impacted by excess nitrogen (N) and phosphorus (P) forming dense accumulations of biomass known as cyanobacterial harmful algal blooms or cyanoHABs. Their dominance in eutrophic lakes is attributed to a variety of unique adaptations including N and P concentrating mechanisms, N fixation, colony formation that inhibits predation, vertical movement via gas vesicles, and the production of toxic or otherwise bioactive molecules. While some of these molecules have been explored for their medicinal benefits, others are potent toxins harmful to humans, animals, and other wildlife known as cyanotoxins. In humans these cyanotoxins affect various tissues, including the liver, central and peripheral nervous system, kidneys, and reproductive organs among others. They induce acute effects at low doses in the parts-per-billion range and some are tumor promoters linked to chronic diseases such as liver and colorectal cancer. The occurrence of cyanoHABs and cyanotoxins in lakes presents challenges for maintaining safe recreational aquatic environments and the production of potable drinking water. CyanoHABs are a growing problem in the North American (Laurentian) Great Lakes basin. This review summarizes information on the occurrence of cyanoHABs in the Great Lakes, toxicological effects of cyanotoxins, and appropriate numerical limits on cyanotoxins in finished drinking water.


2013 ◽  
Vol 14 (4) ◽  
pp. 393-398

The occurrence of trihalomethanes (THMs) was studied in the drinking water samples from urban water supply network of Karachi city that served more than 18 million people. Drinking water samples were collected from 58 locations in summer (May-August) and winter (November-February) seasons. The major constituent of THMs detected was chloroform in winter (92.34%) and summer (93.07%), while the other THMs determined at lower concentrations. Summer and winter concentrations of total THMs at places exceed the levels regulated by UEPA (80 μg l-1) and WHO (100 μg l-1). GIS linked temporal variability in two seasons showed significantly higher median concentration (2.5%-23.06%) of THMs compared to winter.


Author(s):  
V.V. Lapenko ◽  
L.N. Bikbulatova ◽  
E.M. Ternikova

Water is very important for humans, as it is a solvent for metabolic products. Moreover, it is necessary for metabolism, biochemical and transport processes. The elemental status in persons depends on the geochemical environment and consumption of bioelements with food and water. The aim of the paper is to conduct a comprehensive assessment of chemical composition of drinking tap water in Khanty-Mansiysk and Salekhard. Materials and Methods. The chemical composition of 100 samples of drinking tap water was analyzed by atomic absorption spectrometry, spectrophotometry and capillary electrophoresis. All in all, there were 50 samples from Khanty-Mansiysk and 50 samples from Salekhard. The results were compared with Sanitary Rules and Norms 2.1.4.1074-01. Results. Drinking tap water in Salekhard contains a significantly higher concentration of iron, which is much above the maximum allowable concentration, if compared to water samples in Khanty-Mansiysk (p=0.03). In the cities under consideration, the water undergoes high-quality reagent-free treatment. However, the deterioration of the water supply networks in Salekhard is 3 times as high as in Khanty-Mansiysk. Calcium and magnesium concentration in water samples from Khanty-Mansiysk is 5.6 and 3.9 times lower than the MAC; in water samples from Salekhard calcium concentration is 6.3 (p=0.008) and magnesium concentration 4.6 (p<0.001) times lower than the MAC. Conclusion. The consumption of ultra-fresh drinking water leads to low intake of bioelements, which are a part of enzymes contributing to the human antioxidant defense and can result in manifestation of cardiovascular diseases. This is especially true for Salekhard with very soft drinking water and high iron concentration, which excess can exhibit prooxidant properties. Keywords: tap water, bioelements, northern region, antioxidants. Вода является важнейшим соединением для человека: необходима в качестве растворителя продуктов метаболизма и протекания обменных, биохимических и транспортных процессов. Элементный статус организма человека зависит от геохимического окружения и поступления биоэлементов с пищей и водой. Цель. Провести комплексную оценку химического состава водопроводной воды городов Ханты-Мансийск и Салехард. Материалы и методы. Методами атомно-абсорбционной спектрометрии, спектрофотометрии и капиллярного электрофореза проанализирован химический состав 100 проб водопроводной воды: по 50 из Ханты-Мансийска и Салехарда. Результаты сравнивали с СанПиН 2.1.4.1074-01. Результаты. В водопроводной воде Салехарда установлена превышающая ПДК и достоверно более высокая концентрация железа сравнительно с водой Ханты-Мансийска (р=0,03). При условии качественной безреагентной водоподготовки в изучаемых городах это обусловлено изношенностью водопроводных сетей в Салехарде, более чем в 3 раза превышающей этот показатель в Ханты-Мансийске. Концентрация кальция и магния в воде Ханты-Мансийска в 5,6 и 3,9 раза ниже ПДК; в воде Салехарда – в 6,3 (р=0,008) и 4,6 (р<0,001) раза ниже ПДК соответственно. Заключение. Употребление ультрапресной питьевой воды на фоне очень малого поступления с водой биоэлементов, входящих в состав ферментов антиоксидантной защиты организма человека, может привести к манифестации кардиоваскулярных заболеваний. Это особенно актуально для г. Салехарда с очень мягкой питьевой водой с повышенным содержанием железа, избыток которого может проявлять прооксидантные свойства. Ключевые слова: водопроводная вода, биоэлементы, северный регион, антиоксиданты.


2006 ◽  
Vol 6 (2) ◽  
pp. 47-53 ◽  
Author(s):  
D. Simazaki ◽  
M. Asami ◽  
T. Nishimura ◽  
S. Kunikane ◽  
T. Aizawa ◽  
...  

Nationwide surveys of 1,4-dioxane and methyl-t-butyl ether (MTBE) levels in raw water used for the drinking water supply were conducted at 91 water treatment plants in Japan in 2001 and 2002, prior to the revision of the drinking water quality standards. 1,4-dioxane was widely and continuously detected in raw water samples and its occurrence was more frequent and its concentrations higher in groundwater than in surface water. However, its maximum concentration in raw water was much lower than its new standard value (50 μg/L), which was determined as a level of 10−5 excessive cancer risk to humans. Trace levels of MTBE were also detected in several surface water samples.


1988 ◽  
Vol 20 (11-12) ◽  
pp. 425-428 ◽  
Author(s):  
H. T. El-Zanfaly ◽  
A. M. Shabaan

A total of 111 water samples were drawn from 15 wells. These samples were subjected to bacteriological examinations to determine the suitability of the monitored wells as source for drinking water. Significant levels of bacterial pollution indicators were detected in the underground water samples during the period of study. Total bacterial counts ranged between 10-104CFU/ml. Faecal streptococci was the most common and detected in 9 6% of water samples. Lower percentages of samples (92, 55 and 45%) were contaminated with total coliforms, faecal coliforms and total clostridia, respectively. Faecal coliforms: faecal streptococci was less than 0.7 in 86% of the examined samples. Anaerobic bacteria were detected in the examined well water samples. Only 101 water samples were tested for anaerobic spore-formers and all showed positive results. Most examined wells do not meet the water quality standards for drinking water. Accordingly, the necessity of controllin bacterial pollution in ground-water through disinfection was clearly confirmed. Testing the underground water for more than one indicator represents an important approach for water quality assurance.


2021 ◽  
Vol 49 (1) ◽  
Author(s):  
Nathan Tintle ◽  
Kristin Van De Griend ◽  
Rachel Ulrich ◽  
Randall D. Wade ◽  
Tena M. Baar ◽  
...  

Abstract Background Lack of sustainable access to clean drinking water continues to be an issue of paramount global importance, leading to millions of preventable deaths annually. Best practices for providing sustainable access to clean drinking water, however, remain unclear. Widespread installation of low-cost, in-home, point of use water filtration systems is a promising strategy. Methods We conducted a prospective, randomized, controlled trial whereby 16 villages were selected and randomly assigned to one of four treatment arms based on the installation location of Sawyer® PointONE™ filters (filter in both home and school; filter in home only; filter in school only; control group). Water samples and self-reported information on diarrhea were collected at multiple times throughout the study. Results Self-reported household prevalence of diarrhea decreased from 25.6 to 9.76% from installation to follow-up (at least 7 days, and up to 200 days post-filter installation). These declines were also observed in diarrhea with economic or educational consequences (diarrhea which led to medical treatment and/or missing school or work) with baseline prevalence of 9.64% declining to 1.57%. Decreases in diarrhea prevalence were observed across age groups. There was no evidence of a loss of efficacy of filters up to 200 days post-filter installation. Installation of filters in schools was not associated with decreases in diarrhea prevalence in school-aged children or family members. Unfiltered water samples both at schools and homes contained potential waterborne bacterial pathogens, dissolved heavy metals and metals associated with particulates. All dissolved metals were detected at levels below World Health Organization action guidelines. Conclusions This controlled trial provides strong evidence of the effectiveness of point-of-use, hollow fiber membrane filters at reducing diarrhea from bacterial sources up to 200 days post-installation when installed in homes. No statistically significant reduction in diarrhea was found when filters were installed in schools. Further research is needed in order to explore filter efficacy and utilization after 200 days post-installation. Trial registration ClinicalTrials.gov, NCT03972618. Registered 3 June 2019—retrospectively registered.


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