A survey of Giardia and Cryptosporidium was conducted in surface water used as drinking water sources by public water systems in four densely urbanized regions of Sao Paulo State, Brazil. A Quantitative Microbial Risk Assessment, based on protozoa concentrations, was performed to estimate the probability of protozoa infection associated with drinking water ingestion. A total of 206 source water samples were analyzed over a 24 month period using the USEPA Method 1623. The risk of infection was estimated using an exponential dose response model, children and adults exposure and a gamma distribution for (oo)cyst concentrations with three scenarios for treating censored data. Giardia was detected in 102 of the samples, and 19 of them were also positive for Cryptosporidium, with maximum concentrations of 97.0 cysts/L and 6.0 oocysts/L, respectively. Risk distributions were similar for the three scenarios. In the four regions, the estimated risk of Giardia infection per year, for adults and children, ranged from 0.29% to 2.47% and from 0.08% to 0.70%, respectively. Cryptosporidium risk infection varied from 0.15% to 0.29% for adults and from 0.04% to 0.08% for children. In both cases, the calculated risk surpassed the risk of infection of 10(-4) (1:10,000) defined as tolerable by USEPA for a yearly exposure. The probability of Giardia infection was very close to the rates of acute diarrheic disease for adults (1% to 3%) but lower for children (2% to 7%). The daily consumption of drinking water was an important contributing factor for these differences. The Microbiological Risk Assessment carried out in this study provides an indication of infection risks by Giardia and Cryptosporidium in the population served by these source waters. Strategies for source water protection and performance targets for the water treatment should be established to achieve the required level of public health risk.
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http://dx.doi.org/10.1016/j.scitotenv.2012.09.077 | DOI Listing |
Ophthalmic Epidemiol
December 2024
Light for the World, Addis Ababa, Ethiopia.
Purpose: Baseline surveys were conducted in Tigray region, Ethiopia, in 2013. Since then, rounds of azithromycin mass drug administration (MDA) have been delivered in-line with international guidance. The purpose of these surveys was to assess trachomatous inflammation-follicular (TF) prevalence following those treatments to enable the region to plan the next steps towards elimination of trachoma.
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December 2024
Department of Microbiology, Faculty of Science, Bayelsa Medical University, Yenagoa, Bayelsa State, Nigeria.
This study assessed the safety of trace metal concentrations in locally produced nutritive food-drinks consumed in Yenagoa metropolis, Bayelsa State, Nigeria. Three different drink types (viz, tiger nut juice, a mixture of tiger nut and soya bean juice and soya bean juice) were purchased from various locations in Yenagoa metropolis, Bayelsa State, Nigeria, between January and February 2024. Thirty samples were analyzed for trace metals using atomic absorption spectrophotometry.
View Article and Find Full Text PDFVet Sci
December 2024
National Reference Laboratory of Veterinary Drug Residues (HZAU), Veterinary Medicine Research Center, Huazhong Agricultural University, Wuhan 430070, China.
The widespread utilization of antibiotic growth promoters (AGPs) boosts the growth rate of food animals and enhances human living standards. Nevertheless, it is accompanied by escalating antibiotic resistance. Consequently, there is an urgent demand to develop novel alternatives to growth promoters.
View Article and Find Full Text PDFMembranes (Basel)
November 2024
College of Civil Engineering, Zhejiang University of Technology, Hangzhou 310023, China.
This study investigated membrane fouling issues associated with the operation of a submerged ultrafiltration membrane in a drinking water treatment plant (DWTP) and optimized the associated chemical cleaning strategies. By analyzing the surface components of the membrane foulant and the compositions of the membrane cleaning solution, the primary causes of membrane fouling were identified. Membrane fouling control strategies suitable for the DWTP were evaluated through chemical cleaning tests conducted for bench-scale, full-scale, and engineering cases.
View Article and Find Full Text PDFCurr Issues Mol Biol
December 2024
Department of Histology and Embryology, Faculty of Medicine, Afyonkarahisar Health Sciences University, 03030 Afyonkarahisar, Turkey.
Modified citrus pectin (MCP) modulates galectin-3, a key player in neuroinflammation linked to Alzheimer's disease. By inhibiting galectin-3, MCP reduces the brain's inflammatory response and may alleviate cognitive decline. This study examines MCP's impact on neuroinflammation, cognitive function, and its role in galectin-3 inhibition in a dementia model.
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