scholarly journals Seasonal lead release to drinking water and the effect of aluminum

2021 ◽  
Author(s):  
Benjamin F Trueman ◽  
Aaron Bleasdale-Pollowy ◽  
Javier A Locsin ◽  
Jessica L Bennett ◽  
Wendy H Krkošek ◽  
...  
Keyword(s):  
Public Health ◽  
Drinking Water ◽  
Generalized Additive Model ◽  
Seasonal Pattern ◽  
Additive Model ◽  
Quality Parameters ◽  
Aluminum Concentration ◽  
Point Of Use ◽  
Lead Release ◽  
Treated Drinking Water

Monitoring lead in drinking water is important for public health, but seasonality in lead concentrations can bias monitoring programs if it is not understood and accounted for. Here, we describe an apparent seasonal pattern in lead release to orthophosphate-treated drinking water, identified through point-of-use sampling at sites in Halifax, Canada, with various sources of lead. Using a generalized additive model, we extracted the seasonally-varying components of time series representing a suite of water quality parameters and we identified aluminum as a correlate of lead. To investigate aluminum’s role in lead release, we modeled the effect of variscite (AlPO4 · 2H2O) precipitation on lead solubility, and we evaluated the effects of aluminum, temperature, and orthophosphate concentration on lead release from new lead coupons. At environmentally relevant aluminum and orthophosphate concentrations, variscite precipitation increased predicted lead solubility by decreasing available orthophosphate. Increasing the aluminum concentration from 20–500 µg L-1 increased lead release from coupons by 41% and modified the effect of orthophosphate, rendering it less effective. We attributed this to a decrease in the concentration of soluble (<0.45 µm) phosphorus with increasing aluminum and an accompanying increase in particulate lead and phosphorus (>0.45 µm).

scholarly journals Prevalence and public health implications of mycotoxigenic fungi in treated drinking water systems

2019 ◽  
Vol 17 (4) ◽  
pp. 517-531 ◽  
Author(s):  
Ntombie Thandazile Mhlongo ◽  
Memory Tekere ◽  
Timothy Sibanda
Keyword(s):  
Public Health ◽  
Water Quality ◽  
Drinking Water ◽  
Distribution Systems ◽  
Water Distribution ◽  
Opportunistic Infections ◽  
Drinking Water Quality ◽  
Pathogenic Microorganisms ◽  
Mycotoxigenic Fungi ◽  
Treated Drinking Water

Abstract Insufficient potable water resources and poorly treated drinking water quality are the world's number one cause for preventable morbidity and mortality from water-related pathogenic microorganisms. Pathogenic microorganisms, including mycotoxigenic fungi, have been identified in treated drinking water. This paper presents a review of mycotoxigenic fungi as a health risk to the public as these fungi are responsible for allergies, cancers and opportunistic infections mainly to immunocompromised patients. The exacerbating factors contributing to fungal presence in water distribution systems, factors that lead to fungi being resistant to water treatment and treated drinking water quality legislations are also discussed. This paper provides a review on the prevalence of mycotoxigenic fungi and their implications to public health in treated drinking water, and the need for inclusion in treated drinking water quality regulations.

scholarly journals Legionella: A Promising Supplementary Indicator of Microbial Drinking Water Quality in Municipal Engineered Water Systems

2021 ◽  
Vol 9 ◽  
Author(s):  
Chiqian Zhang ◽  
Jingrang Lu
Keyword(s):  
Public Health ◽  
Water Quality ◽  
Drinking Water ◽  
Water Systems ◽  
Quality Parameters ◽  
Drinking Water Quality ◽  
Water Quality Parameters ◽  
Fecal Coliforms ◽  
Spatiotemporal Variations ◽  
Hydraulic Residence Time

Opportunistic pathogens (OPs) are natural inhabitants and the predominant disease causative biotic agents in municipal engineered water systems (EWSs). In EWSs, OPs occur at high frequencies and concentrations, cause drinking-water-related disease outbreaks, and are a major factor threatening public health. Therefore, the prevalence of OPs in EWSs represents microbial drinking water quality. Closely or routinely monitoring the dynamics of OPs in municipal EWSs is thus critical to ensuring drinking water quality and protecting public health. Monitoring the dynamics of conventional (fecal) indicators (e.g., total coliforms, fecal coliforms, and Escherichia coli) is the customary or even exclusive means of assessing microbial drinking water quality. However, those indicators infer only fecal contamination due to treatment (e.g., disinfection within water utilities) failure and EWS infrastructure issues (e.g., water main breaks and infiltration), whereas OPs are not contaminants in drinking water. In addition, those indicators appear in EWSs at low concentrations (often absent in well-maintained EWSs) and are uncorrelated with OPs. For instance, conventional indicators decay, while OPs regrow with increasing hydraulic residence time. As a result, conventional indicators are poor indicators of OPs (the major aspect of microbial drinking water quality) in EWSs. An additional or supplementary indicator that can well infer the prevalence of OPs in EWSs is highly needed. This systematic review argues that Legionella as a dominant OP-containing genus and natural inhabitant in EWSs is a promising candidate for such a supplementary indicator. Through comprehensively comparing the behavior (i.e., occurrence, growth and regrowth, spatiotemporal variations in concentrations, resistance to disinfectant residuals, and responses to physicochemical water quality parameters) of major OPs (e.g., Legionella especially L. pneumophila, Mycobacterium, and Pseudomonas especially P. aeruginosa), this review proves that Legionella is a promising supplementary indicator for the prevalence of OPs in EWSs while other OPs lack this indication feature. Legionella as a dominant natural inhabitant in EWSs occurs frequently, has a high concentration, and correlates with more microbial and physicochemical water quality parameters than other common OPs. Legionella and OPs in EWSs share multiple key features such as high disinfectant resistance, biofilm formation, proliferation within amoebae, and significant spatiotemporal variations in concentrations. Therefore, the presence and concentration of Legionella well indicate the presence and concentrations of OPs (especially L. pneumophila) and microbial drinking water quality in EWSs. In addition, Legionella concentration indicates the efficacies of disinfectant residuals in EWSs. Furthermore, with the development of modern Legionella quantification methods (especially quantitative polymerase chain reactions), monitoring Legionella in ESWs is becoming easier, more affordable, and less labor-intensive. Those features make Legionella a proper supplementary indicator for microbial drinking water quality (especially the prevalence of OPs) in EWSs. Water authorities may use Legionella and conventional indicators in combination to more comprehensively assess microbial drinking water quality in municipal EWSs. Future work should further explore the indication role of Legionella in EWSs and propose drinking water Legionella concentration limits that indicate serious public health effects and require enhanced treatment (e.g., booster disinfection).

scholarly journals Importance of applying Mixed Generalized Additive Model (MGAM) as a method for assessing the environmental health impacts: Ambient temperature and Acute Myocardial Infarction (AMI), among elderly in Shanghai, China

PLoS ONE ◽  
2021 ◽  
Vol 16 (8) ◽  
pp. e0255767
Author(s):  
Xiaoqian Huang ◽  
Weiping Ma ◽  
Chikin Law ◽  
Jianfeng Luo ◽  
Naiqing Zhao
Keyword(s):  
Myocardial Infarction ◽  
Acute Myocardial Infarction ◽  
Time Series ◽  
Ambient Temperature ◽  
Autocorrelation Function ◽  
Risk Ratio ◽  
Generalized Additive Model ◽  
Seasonal Pattern ◽  
Additive Model ◽  
Degree Of Freedom

Association between acute myocardial infarction (AMI) morbidity and ambient temperature has been examined with generalized linear model (GLM) or generalized additive model (GAM). However, the effect size by these two methods might be biased due to the autocorrelation of time series data and arbitrary selection of degree of freedom of natural cubic splines. The present study analyzed how the climatic factors affected AMI morbidity for older adults in Shanghai with Mixed generalized additive model (MGAM) that addressed these shortcomings mentioned. Autoregressive random effect was used to model the relationship between AMI and temperature, PM10, week days and time. The degree of freedom of time was chosen based on the seasonal pattern of temperature. The performance of MGAM was compared with GAM on autocorrelation function (ACF), partial autocorrelation function (PACF) and goodness of fit. One-year predictions of AMI counts in 2011 were conducted using MGAM with the moving average. Between 2007 and 2011, MGAM adjusted the autocorrelation of AMI time series and captured the seasonal pattern after choosing the degree of freedom of time at 5. Using MGAM, results were well fitted with data in terms of both internal (R2 = 0.86) and external validity (correlation coefficient = 0.85). The risk of AMI was relatively high in low temperature (Risk ratio = 0.988 (95% CI 0.984, 0.993) for under 12°C) and decreased as temperature increased and speeded up within the temperature zone from 12°C to 26°C (Risk ratio = 0.975 (95% CI 0.971, 0.979), but it become increasing again when it is 26°C although not significantly (Risk ratio = 0.999 (95% CI 0.986, 1.012). MGAM is more appropriate than GAM in the scenario of response variable with autocorrelation and predictors with seasonal variation. The risk of AMI was comparatively higher when temperature was lower than 12°C in Shanghai as a typical representative location of subtropical climate.

Decision support system to select sustainable point-of-use/point-of-entry treatment systems (D4SPOUTS)

2013 ◽  
Vol 49 (2) ◽  
pp. 104-113
Author(s):  
Mohamed A. Hamouda ◽  
William B. Anderson ◽  
Peter M. Huck
Keyword(s):  
Drinking Water ◽  
Decision Support ◽  
Decision Support System ◽  
Support System ◽  
Distribution System ◽  
Sustainability Assessment ◽  
Engineering Practice ◽  
Point Of Entry ◽  
Point Of Use ◽  
Treated Drinking Water

Point-of-use (POU) and point-of-entry (POE) devices are, in some situations, considered to be a viable solution for drinking water suppliers and consumers alike to deal with site specific drinking water issues. This paper introduces a newly developed decision support system (DSS) that employs decision making techniques to select among the various devices based on their characterization and sustainability assessment. Careful illustration of the various aspects and components of the DSS is provided and the decision process is explained. Aspects of validity, usability and sensitivity analysis are demonstrated through a hypothetical case study for removing lead introduced in the distribution system of municipally treated drinking water. The output of the DSS helps to determine the more sustainable treatment devices which should have positive implications for the application of POU and POE devices. Other potential uses of the DSS are described to illustrate its versatility and usefulness. The DSS is not intended to replace common engineering practice in selecting POU and POE treatment systems, but rather to give support to the users by providing the necessary information about all possible solutions.

Drinking Water and Public Health in an Era of Aging Distribution Infrastructure

2018 ◽  
Vol 23 (4) ◽  
pp. 301-309 ◽  
Author(s):  
Martin Allen ◽  
Robert Clark ◽  
Joseph A. Cotruvo ◽  
Neil Grigg
Keyword(s):  
Public Health ◽  
Drinking Water ◽  
Distribution Systems ◽  
Water Distribution ◽  
Microbial Contamination ◽  
Water Systems ◽  
Driving Factor ◽  
Public Drinking Water ◽  
Treated Drinking Water ◽  
Distribution Water

The provision of a safe and sustainable drinking water supply is one of the hallmarks of a successful society. Treated drinking water entering distribution systems in virtually all U.S. public drinking water systems meets regulations and is microbiologically safe. However, the opportunity for microbial contamination from decades to century old water distribution systems is increasing with time. Thus, increased health risk to consumers should be a driving factor in accelerating reinvestment in America’s aging water distribution water systems.

scholarly journals CLIMATE-DRIVEN STATISTICAL MODELS AS EFECTIVE PREDICTIONS OF LOCAL DENGUE INDICENCE IN COSTA RICA: A GENERALIZED ADDITIVE MODEL AND RANDOM FOREST APPROACH

2019 ◽  
Vol 27 (1) ◽  
pp. 1-21
Author(s):  
PAOLA VÁSQUEZ ◽  
ANTONIO LORÍA ◽  
FABIO SÁNCHEZ ◽  
LUIS ALBERTO BARBOZA
Keyword(s):  
Public Health ◽  
Relative Risk ◽  
Costa Rica ◽  
Random Forest ◽  
Prediction Model ◽  
Statistical Models ◽  
Generalized Additive Model ◽  
Additive Model ◽  
Climate Data ◽  
Tropical Country

Climate has been an important factor in shaping the distribution and incidence of dengue cases in tropical and subtropical countries. In Costa Rica, a tropical country with distinctive micro-climates, dengue has been endemic since its introduction in 1993, inflicting substantial economic, social, and public health repercussions. Using the number of dengue reported cases and climate data from 2007-2017, we fitted a prediction model applying a Generalized Additive Model (GAM) and Random Forest (RF) approach, which allowed us to retrospectively predict the relative risk of dengue in five climatological diverse municipalities around the country.

scholarly journals Microbial Quality of Drinking Water and Prevalence of Water-Related Diseases in Marigat Urban Centre, Kenya

2019 ◽  
Vol 13 ◽  
pp. 117863021983698 ◽  
Author(s):  
Mercy Mandere Osiemo ◽  
George Morara Ogendi ◽  
Charles M’Erimba
Keyword(s):  
Public Health ◽  
Drinking Water ◽  
Potable Water ◽  
Water Sources ◽  
Dry Season ◽  
Microbial Quality ◽  
Wet Season ◽  
E Coli ◽  
Point Of Use

Background: Accessibility to potable water is a fundamental right for dignity and well-being. Despite this observation, more than 1.1 billion people lack access to safe drinking water. This is particularly true in the Sub-Saharan Africa and South East Asia regions. Objective: The main aim of this study was to assess microbial quality of drinking water and prevalence of water-related diseases in Marigat town, Baringo County, Kenya. Methods: Samples of drinking water were collected from water sources (boreholes, rivers, and wells) and at the point of use (households) and analyzed for Escherichia coli and total coliform (TC) bacteria using the most probable number method. In situ measurements of pH and temperature were performed using a Wagtech International portable meter. Clinical health records from the local health centers were also reviewed to assess the prevalence rates of some of the water-related diseases. Results: There were significant differences among water sources during dry season for E coli (F2,21 = 3.629, P < .05) and TC (F2,21 = 4.041, P < .05). Similar observations were made during wet season for E coli (F2,21 = 4.090, P < .05) and TC (F2,21 = 1.893, P < .05). Furthermore, there were significant interactions between the water sources and season for E coli (F2,42 = 7.66, P < .01) and TC (F2,42 = 5.494, P < .05). Drinking water in large plastic storage containers (herein referred to as sky-plast) had the highest E coli and TC concentrations. Typhoid was the most prevalent water-related disease during the dry season (10%), whereas diarrhea (3%) was the most prevalent during the wet season. Conclusions and recommendations: All drinking water at abstraction and point of use for Marigat residents are microbiologically contaminated and therefore pose serious health risks to consumers of such water. Thus, there is need for public health awareness campaigns on household water management to curb incidences of water-related diseases. Public health practitioners at county and national levels need to ensure that households have adequate access to potable water and improved sanitation.

scholarly journals Resuscitation of Bacteria after Dechlorination of Treated Drinking Water

2021 ◽  
Vol 28 (1) ◽  
pp. 15-21
Author(s):  
O.O. Adebisi ◽  
Y.I. Kayode ◽  
T.M. Kayode-Isola ◽  
B.A. Saka
Keyword(s):  
Escherichia Coli ◽  
Drinking Water ◽  
Bacterial Load ◽  
Salmonella Typhi ◽  
Shigella Dysenteriae ◽  
Residual Chlorine ◽  
Safe Drinking Water ◽  
Recommended Dosage ◽  
Point Of Use ◽  
Treated Drinking Water

In this study, the effects of initial bacterial load (102 , 104 and 106 cells/ml) and dechlorination idiosyncrasy on the efficacy of varying concentrations (0.018–0.126% v/v applied for 30 minutes) of a point-of-use chlorine-based proprietary disinfectant (WaterCare®) were investigated in drinking water. Results indicated that higher initial cell populations significantly affected the efficacy of the disinfectant.Subsequent dechlorination of the disinfected water resulted in resuscitation of bacteria. This was demonstrated after 1440 minutes post-dechlorination for Salmonella typhi and after at least 120 minutes for Escherichia coli, Proteus vulgaris and Shigella dysenteriae, particularly at lower disinfectant concentrations (0.018–0.054% v/v). Thus, whilst the use of WaterCare® at the recommended dosage(0.072% v/v or 10 ml to 25 litres of clean water for 30 minutes) may produce microbiologically safe drinking water high initial microbial load and post-disinfection residual chlorine loss may limit its efficacy. Keywords: Bacterial resuscitation, Escherichia coli, Dechlorination, Drinking water, Salmonella typhi, WaterCare®

Sign in / Sign up

Export Citation Format

Share Document