Managing the Microbiological Risks of Drinking Water

Abstract

The microbiological contamination of drinking water supplies can have serious health consequences for consumers, and this has been dramatically illustrated in recent years by two disease outbreaks in Canada. In this paper, some factors that can influence the microbiological quality of drinking water and its management are examined. Frameworks have been proposed that help to clarify the main elements of health risk assessment and risk management, and, in accordance with these, risks can be logically characterized, evaluated and controlled. A protocol has been developed for microbiological risk assessment and a risk management framework now guides the development of Canada's national guidelines for drinking-water quality. Monitoring of indicator organisms and the application of adequate water treatment are the primary means recommended in the Canadian guidelines to safeguard health from the presence of water-borne pathogens. Understanding the biological characteristics of microbial pathogens is necessary for assessing their impact on community health and appraising the rationale behind drinking-water testing methods and their limitations. Improvements in health surveillance, monitoring, and risk characterization and application of concepts such as multiple barriers (source-to-tap) and total quality management should contribute to better management of the microbiological quality of drinking water.

Drinking water consumption patterns in Canadian communities (2001–2007)

“…population growth, synthetic chemical use and industrialization) continue to put increased pressures on water quality and quantity in Canada (Murdoch et al 2000;Carr & Neary 2008). Internationally, there have been efforts to understand the characteristics of individuals at risk and water consumption levels (Westrell et al 2006;Mons et al 2007;Kyunghee et al 2009) as these pressures have the potential to increase the susceptibility of drinking water to contamination from chemicals and microorganisms (Hunter et al 2003;Charron et al 2004;Krewski et al 2004; Thomas et al 2006). Throughout the world, contaminated water continues to be a cause of endemic and epidemic gastrointestinal illness (Craun et al 1998;WHO doi: 10.2166WHO doi: 10.…”

Risk of hypertension and reduced kidney function after acute gastroenteritis from bacteria-contaminated drinking water

“…Taken together, our findings will help guide future studies assessing the utility of screening and follow-up of patients who recover from acute bacterial gastroenteritis. More importantly, maintaining safe drinking water remains essential to human health, [36][37][38][39][40] as transient bacterial contaminations may have implications well beyond a period of acute self-limited illness. 41 …”

Current Technologies For On-Line Monitoring of Drinking Water Distribution Systems

“…An investigation revealed that the outbreak could have been prevented if free chlorine in the water supply was monitored daily. In the second case, that for North Battleford, more than 7,000 people became ill due to the contamination of drinking water by Cryptosporidium parvum (Krewski, et al 2004). Numerous other events have been reported (e.g.…”

“…E.coli) can be used to indicate the presence of other bacterial pathogens, but are less effective at predicting risk from protozoa and viruses (Payment, 1999). Further, in any type of monitoring system that involves, a delay between the time of sample collection and the time when the results are obtained, contaminated water may be distributed to the consumers before there is knowledge of any danger (Krewski, et al 2004). This is an especially important issue in pathogen detection, where many of the current detection/identification procedures require days for identification of an issue.…”

“…in Schuster et al (2005)) and it is clear that real-time monitoring or rapid detection systems in drinking water distribution systems would be invaluable for prevention of future water-related illnesses in Canada. Implementation of such systems is recommended as the first step in the development of Canadian drinking water protection (Krewski, et al 2004).…”