scholarly journals Estimating the number of cases of acute gastrointestinal illness (AGI) associated with Canadian municipal drinking water systems

2015 ◽  
Vol 144 (7) ◽  
pp. 1371-1385 ◽  
Author(s):  
H. M. MURPHY ◽  
M. K. THOMAS ◽  
D. T. MEDEIROS ◽  
S. McFADYEN ◽  
K. D. M. PINTAR
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Tap Water ◽  
Gastrointestinal Illness ◽  
Water Type ◽  
Source Water ◽  
Acute Gastrointestinal Illness ◽  
Municipal Water ◽  
Intervention Trials ◽  
Water Plants

SUMMARYThe estimated burden of endemic acute gastrointestinal illness (AGI) annually in Canada is 20·5 million cases. Approximately 4 million of these cases are domestically acquired and foodborne, yet the proportion of waterborne cases is unknown. A number of randomized controlled trials have been completed to estimate the influence of tap water from municipal drinking water plants on the burden of AGI. In Canada, 83% of the population (28 521 761 people) consumes tap water from municipal drinking water plants serving >1000 people. The drinking water-related AGI burden associated with the consumption of water from these systems in Canada is unknown. The objective of this research was to estimate the number of AGI cases attributable to consumption of drinking water from large municipal water supplies in Canada, using data from four household drinking water intervention trials. Canadian municipal water treatment systems were ranked into four categories based on source water type and quality, population size served, and treatment capability and barriers. The water treatment plants studied in the four household drinking water intervention trials were also ranked according to the aforementioned criteria, and the Canadian treatment plants were then scored against these criteria to develop four AGI risk groups. The proportion of illnesses attributed to distribution system events vs. source water quality/treatment failures was also estimated, to inform the focus of future intervention efforts. It is estimated that 334 966 cases (90% probability interval 183 006-501 026) of AGI per year are associated with the consumption of tap water from municipal systems that serve >1000 people in Canada. This study provides a framework for estimating the burden of waterborne illness at a national level and identifying existing knowledge gaps for future research and surveillance efforts, in Canada and abroad.

scholarly journals Investigation on the fate of quinolone antibiotics in three drinking water treatment plants of China

2021 ◽  
Author(s):  
Zhiquan Liu ◽  
Yongpeng Xu ◽  
Yuan Wang ◽  
Fuyi Cui
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Tap Water ◽  
Drinking Water Treatment ◽  
Chemical Oxidation ◽  
Source Water ◽  
Water Treatment Plants ◽  
Detection Frequency ◽  
Quinolone Antibiotics ◽  
Carbon Filtration

Abstract Quinolone (QN) antibiotics are widely used all over the world and have been frequently detected in source water, but the occurrence in tap water and the treatment efficiencies of QNs by drinking-water treatment plants (DWTPs) were rarely reported. In the present study, the occurrence and distribution of six representative QNs in three urban DWTPs of China were investigated. The results showed that the concentrations of total QNs in the three source waters ranged from 26.4 ng/L to 313.8 ng/L and all of the six QNs were detectable with a detection frequency of 100% (4.6 to 121.7 ng/L). Enrofloxacin (ENR) and ofloxacin (OFL) were the dominant species of QNs and accounted for 40.1% to 79.5% of the total QNs. After the treatments, there were still considerable QNs in the finished water (total amounts of 74.9 ng/L to 148.4 ng/L). The adsorbed QNs could be readily treated with the removal of turbidity by DWTPs, but only a part of the dissolved QNs (13.6% to 68.5%) can be removed. This implies that the dissolved QNs were more hazardous in the source water. Pre-oxidation and disinfection could remove 15.8 ± 8.3% and 16.9 ± 10.8% of dissolved QNs, respectively, depending on the chemical structure of QNs and the types of oxidant. Chemical oxidation was more efficient than coagulation-sedimentation and filtration for the treatment of dissolved QNs. Ozone-granular activated carbon filtration may fail to remove dissolved QNs in the actual DWTPs, because of the insufficient dosage of oxidant and the competition effect of natural organic matter.

A qualitative exploration of the public perception of municipal drinking water

Water Policy ◽  
2007 ◽  
Vol 9 (4) ◽  
pp. 425-438 ◽  
Author(s):  
Andria Q. Jones ◽  
Catherine E. Dewey ◽  
Kathryn Doré ◽  
Shannon E. Majowicz ◽  
Scott A. McEwen ◽  
...  
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Water Use ◽  
Public Perception ◽  
Tap Water ◽  
Bottled Water ◽  
Men And Women ◽  
The Public ◽  
Municipal Water ◽  
Alternative Water

Surveys of water consumption patterns in Canada and the USA show a high frequency of alternative water use, including bottled water and water treatment devices. An in-depth understanding of the public perception of municipal water would enable public health and water utility professionals better to address the needs of residents in their jurisdictions. We explored these perceptions and the self-described behaviour and needs of participants served by municipal water systems in the City of Hamilton, Ontario (Canada). We conducted three focus groups; two with men and women aged between 36 and 65 years, and one with men and women aged between 20 and 35 years. In general, participants expressed negative views of the municipal water supplied to their homes. Concerns included unpleasant sensory qualities of the water, perceived poor source-water protection, a perceived insufficiency in water treatment and testing and potential contamination along the distribution system. Reasons for alternative water use included perceived improvements in quality and safety over regular tap water, although convenience also contributed to bottled water use. Participants wanted more information on water testing and suggested a variety of dissemination approaches. This study suggested important lines of inquiry and action regarding the perception of municipal drinking water in this population.

scholarly journals A pilot randomized, controlled trial of an in-home drinking water intervention among HIV+ persons

2005 ◽  
Vol 3 (2) ◽  
pp. 173-184 ◽  
Author(s):  
John M. Colford ◽  
Sona R. Saha ◽  
Catherine C. Wright ◽  
Alan Hubbard ◽  
Joseph N.S. Eisenberg ◽  
...  
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
San Francisco ◽  
Tap Water ◽  
Controlled Trial ◽  
Drinking Water Treatment ◽  
Gastrointestinal Illness ◽  
Point Estimate ◽  
Adjusted Relative Risk ◽  
Increased Risk

Although immunocompromised persons may be at increased risk for gastrointestinal illnesses, no trials investigating drinking water treatment and gastrointestinal illness in such patients have been published. Earlier results from San Francisco suggested an association (OR 6.76) between tap water and cryptosporidiosis among HIV+ persons. The authors conducted a randomized, triple-blinded intervention trial of home water treatment in San Francisco, California, from April 2000 to May 2001. Fifty HIV-positive patients were randomized to externally identical active (N = 24) or sham (N = 26) treatment devices. The active device contained a filter and UV light; the sham provided no treatment. Forty-five (90%) of the participants completed the study and were successfully blinded. Illness was measured using ‘highly credible gastrointestinal illness’ (HCGI), a previously published measure. There were 31 episodes of HCGI during 1,797 person-days in the sham group and 16 episodes during 1,478 person-days in the active group. The adjusted relative risk was 3.34 (95% CI: 0.99–11.21) times greater in those with the sham device. The magnitude of the point estimate of the risk, its consistency with recently published observational data, and its relevance for drinking water choices by immunocompromised individuals support the need for larger trials.

scholarly journals Prevalence of Antibiotic Resistance in Drinking Water Treatment and Distribution Systems

2009 ◽  
Vol 75 (17) ◽  
pp. 5714-5718 ◽  
Author(s):  
Chuanwu Xi ◽  
Yongli Zhang ◽  
Carl F. Marrs ◽  
Wen Ye ◽  
Carl Simon ◽  
...  
Keyword(s):  
Drinking Water ◽  
Antibiotic Resistance ◽  
Water Treatment ◽  
Distribution Systems ◽  
Water Distribution ◽  
Tap Water ◽  
Water Distribution Systems ◽  
Drinking Water Treatment ◽  
Molecular Techniques ◽  
Source Water

ABSTRACT The occurrence and spread of antibiotic-resistant bacteria (ARB) are pressing public health problems worldwide, and aquatic ecosystems are a recognized reservoir for ARB. We used culture-dependent methods and quantitative molecular techniques to detect and quantify ARB and antibiotic resistance genes (ARGs) in source waters, drinking water treatment plants, and tap water from several cities in Michigan and Ohio. We found ARGs and heterotrophic ARB in all finished water and tap water tested, although the amounts were small. The quantities of most ARGs were greater in tap water than in finished water and source water. In general, the levels of bacteria were higher in source water than in tap water, and the levels of ARB were higher in tap water than in finished water, indicating that there was regrowth of bacteria in drinking water distribution systems. Elevated resistance to some antibiotics was observed during water treatment and in tap water. Water treatment might increase the antibiotic resistance of surviving bacteria, and water distribution systems may serve as an important reservoir for the spread of antibiotic resistance to opportunistic pathogens.

Use of a stable carbon isotope to assess the efficiency of a drinking water treatment method with CO2

2012 ◽  
Vol 65 (6) ◽  
pp. 983-988 ◽  
Author(s):  
M. Poberžnik ◽  
A. Leis ◽  
A. Lobnik
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Dissolved Inorganic Carbon ◽  
Tap Water ◽  
Stable Carbon Isotope ◽  
Research Work ◽  
Drinking Water Treatment ◽  
Treatment Method ◽  
Water Supply Systems ◽  
Co2 Gas

CO2 gas with a special isotopic signature (δ13C = −35.2‰ vs. VPDB) was used as a marker to evaluate the efficiency of a drinking water treatment method and the effect of an ultrasonic (US) stirrer. This treatment was developed to prevent precipitation and corrosion effects in water–supply systems. The research work was performed using a laboratory-scale pilot plant that was filled with tap water. The stable isotope analyses of δ13C-DIC (Dissolved Inorganic Carbon) in the water samples indicated that the maximum content of added CO2 gas in DIC was in the range of 35 to 45%. The use of the US stirrer during the entire experiment decreased the method's overall efficiency by 10%, due to degassing at a late stage of the experiment but accelerated the dissolution process in the early experimental stage.

scholarly journals N-Nitrosodimethylamine Formation from Treatment of Seasonally and Spatially Varying Source Water

Water ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 2019
Author(s):  
Maxwell C. Meadows ◽  
Soni M. Pradhanang ◽  
Takahiro Fujioka ◽  
Hitoshi Kodamatani ◽  
Menu B. Leddy ◽  
...  
Keyword(s):  
Water Treatment ◽  
Treatment Plant ◽  
Treatment Strategies ◽  
Water Treatment Plant ◽  
Current Treatment ◽  
Additional Treatment ◽  
Water Type ◽  
Source Water ◽  
Treatment Techniques ◽  
Spatially Varying

N-nitrosodimethylamine (NDMA) is a disinfection by-product (DBP) that has been classified as a probable human carcinogen in multiple risk assessments. NDMA presence in drinking water is widespread and dependent on source water, disinfectant type, precursors, and water treatment strategies. The objectives of this study were to investigate NDMA formation potential in a modeled monochloramine water treatment plant (WTP) fed by seasonally and spatially varying source water; and to optimize DBP precursor removal by combining conventional and additional treatment techniques. After NDMA analysis, it was found that NDMA formation was significantly dependent on source water type and monochloramine contact time (CT); e.g., at 24 h CT, Cork Brook produced 12.2 ng/L NDMA and Bailey Brook produced 4.2 ng/L NDMA, compared with 72 h CT, Cork Brook produced 4.1 ng/L NDMA and Bailey Brook produced 3.4 ng/L NDMA. No correlations were found between traditional DBP precursors such as total organic carbon and total nitrogen, and the formation of NDMA. The laboratory bench-top treatment system was highly effective at removing traditional DBP precursors, highlighting the need for WTPs to alter their current treatment methods to best accommodate the complex system of DBP control.

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