Crabbe H, Fletcher T, Close R, Watts MJ, Ander EL, Smedley PL, Verlander NQ, Gregory M, Middleton DRS, Polya DA, Studden M, Leonardi GS. Hazard Ranking Method for Populations Exposed to Arsenic in Private Water Supplies: Relation to Bedrock Geology. Int J Environ Res Public Health. 2017 Dec 1;14(12). pii: E1490. doi: 10.3390/ijerph14121490.
Approximately one million people in the UK are served by private water supplies (PWS) where main municipal water supply system connection is not practical or where PWS is the preferred option. Chronic exposure to contaminants in PWS may have adverse effects on health. South West England is an area with elevated arsenic concentrations in groundwater and over 9000 domestic dwellings here are supplied by PWS. There remains uncertainty as to the extent of the population exposed to arsenic (As), and the factors predicting such exposure. We describe a hazard assessment model based on simplified geology with the potential to predict exposure to As in PWS. Households with a recorded PWS in Cornwall were recruited to take part in a water sampling programme from 2011 to 2013. Bedrock geologies were aggregated and classified into nine Simplified Bedrock Geological Categories (SBGC), plus a cross-cutting “mineralized” area. PWS were sampled by random selection within SBGCs and some 508 households volunteered for the study. Transformations of the data were explored to estimate the distribution of As concentrations for PWS by SBGC. Using the distribution per SBGC, we predict the proportion of dwellings that would be affected by high concentrations and rank the geologies according to hazard. Within most SBGCs, As concentrations were found to have log-normal distributions. Across these areas, the proportion of dwellings predicted to have drinking water over the prescribed concentration value (PCV) for As ranged from 0% to 20%. From these results, a pilot predictive model was developed calculating the proportion of PWS above the PCV for As and hazard ranking supports local decision making and prioritization. With further development and testing, this can help local authorities predict the number of dwellings that might fail the PCV for As, based on bedrock geology. The model presented here for Cornwall could be applied in areas with similar geologies. Application of the method requires independent validation and further groundwater-derived PWS sampling on other geological formations.
“The renewable lobby would like you to believe that solar power is an important part of our future energy strategy. But they don’t tell you just how little power is produced during winter months, at the time when demand is at its peak.” click here
“Clearly we don’t know everything about asthma, but there is little evidence to suggest that air pollution from traffic makes much difference.” click here
“I have concentrated on the UK, but let me finish with a couple of statistics for worldwide wind power, from the BP Energy Review.
- At 959 TWh, wind power accounted for 3.9% of world electricity generation last year.
- In terms of overall energy consumption, the share of wind was 1.6%.
Every year we hear how wind power is going up by leaps and bounds. It is wise though to bear in mind just what a low base it is starting from.” click here
“British Muslims have been urged to “stop pretending” violence and terrorism are completely alien to Islam. The call was made by Maajid Nawaz, a former leader of the UK branch of the hardline Islamist group Hizb ut-Tahrir (HuT).” click here for full story
“Central England Temperature stations, long considered a benchmark, have been affected by land use change and urbanization.” click here
Mahon M, Doyle S. Waterborne outbreak of cryptosporidiosis in the South East of Ireland: weighing up the evidence. Ir J Med Sci. 2017 Jan 13. doi: 10.1007/s11845-016-1552-1.
BACKGROUND: In late Spring 2012, 12 cases of cryptosporidiosis in a town in the South East of Ireland were notified to the regional Department of Public Health.
AIM: The purpose of this paper is to describe the outbreak and the investigative process which led to the conclusion that the source was a public drinking water supply.
METHODS: Outbreak and incident control teams were convened to investigate and control the outbreak.
RESULTS: Eleven cases were speciated as Cryptosporidium parvum. GP60 analysis demonstrated that 10 were C. parvum IIaA20G3R1, indicating that the cases were linked. The public water supply was the only common risk factor identified. Increased water sampling identified Cryptosporidium muris/andersoni in the treated water at one of two water treatment plants (Water Treatment Plant, WTP A) for the supply, and on the network. C. parvum was subsequently identified in raw water from WTP A.
CONCLUSIONS: The Health Service Executive (HSE) concluded that this outbreak was “probably associated with water” produced at WTP A based on (1) descriptive epidemiological evidence suggesting water-related illness and excluding other obvious explanations; and (2) water treatment failure at WTP A. WTP A was closed to facilitate an upgrade. No boil water notice was required as a supplementary supply was available. The upgrade was completed and the incident closed in 2013.