Daily Archives: March 31, 2015

Microbial Contamination in Community Water Systems

Ashbolt NJ. Microbial Contamination of Drinking Water and Human Health from Community Water Systems. Current Environmental Health Reports. 2015;2(1):95-106.

A relatively short list of reference viral, bacterial and protozoan pathogens appears adequate to assess microbial risks and inform a system-based management of drinking waters. Nonetheless, there are data gaps, e.g. human enteric viruses resulting in endemic infection levels if poorly performing disinfection and/or distribution systems are used, and the risks from fungi. Where disinfection is the only treatment and/or filtration is poor, cryptosporidiosis is the most likely enteric disease to be identified during waterborne outbreaks, but generally non-human-infectious genotypes are present in the absence of human or calf fecal contamination. Enteric bacteria may dominate risks during major fecal contamination events that are ineffectively managed. Reliance on culture-based methods exaggerates treatment efficacy and reduces our ability to identify pathogens/indicators; however, next-generation sequencing and polymerase chain reaction approaches are on the cusp of changing that. Overall, water-based Legionella and non-tuberculous mycobacteria probably dominate health burden at exposure points following the various societal uses of drinking water.

Click here for paper (Open Access).

“Climate Change” Does Not Cause Extreme Winters

“Cold snaps like the ones that hit the eastern United States in the past winters are not a consequence of climate change. Scientists at ETH Zurich and the California Institute of Technology have shown that global warming actually tends to reduce temperature variability.” click here

Joint Risk of Arsenic Exposure, Cigarette Smoking, and Genotype

Yuan-Hung Wang, Shauh-Der Yeh, Meei-Maan Wu, Chi-Tung Liu, Cheng-Hung Shen, Kun-Hung Shen, Yeong-Shiau Pu, Ling-I Hsu, Hung-Yi Chiou, Chien-Jen Chen. Comparing the joint effect of arsenic exposure, cigarette smoking and risk genotypes of vascular endothelial growth factor on upper urinary tract urothelial carcinoma and bladder cancer. Journal Of Hazardous Materials 2013 Nov 15; Vol. 262, pp. 1132-8.

Arsenic exposure and cigarette smoking are environmental risk factors for urothelial carcinoma (UC). Vascular endothelial growth factor (VEGF) is the key regulator of angiogenesis in various malignancies. This study investigates the joint effect of arsenic exposure, cigarette smoking, and VEGF polymorphisms on UC risk. This was a hospital-based case–control study consisting of 730 histopathologically confirmed UC cases, including 470 bladder cancers, 260 upper urinary tract UCs (UUTUCs), and 850 age-matched controls, recruited from September 1998 to December 2009. UC risk was estimated by odds ratios and 95% confidence intervals using unconditional logistic regression. Ever smokers with high arsenic exposure had significantly increased risks of 5.7 and 6.4 for bladder cancer and UUTUC, respectively. Moreover, ever smokers with high arsenic exposure carrying 1 or 2 risk genotypes of the VEGF gene had a significantly increased risk of 6.6 for bladder cancer and a strikingly higher risk of 9.9 for UUTUC. Additionally, UUTUC cases with high arsenic exposure carrying 1 or 2 risk genotypes of the VEGF gene had a non-significant increased risk of advanced tumor stage. Our findings suggest that arsenic exposure, cigarette smoking, and risk genotypes of VEGF contribute to a higher risk of UUTUC than of bladder cancer.

Click here for paper (Open Access).