Healthy drinking water in British Columbia: A physician's update

Access to safe water is a global priority. While Canada’s drinking water is recognized as both a valuable resource and an important determinant of population health, it is also a national concern following waterborne outbreaks in Walkerton[1,2] and North Battleford.[3,4]

Cryptosporidiosis (long known to farmers to cause diarrheal disease in young calves), toxoplasmosis (whose definitive host are felines), and giardiasis (well known cause of beaver fever) are waterborne parasitic infections for humans as well as animal hosts. They have been recognized in the past two decades as significant challenges to the drinking water industry and to public health. In British Columbia there have been 29 confirmed waterborne outbreaks since 1980: the largest number were due to parasitic agents such as Giardia and Cryptosporidium.[5] BC also has had the highest rate of enteric (gastrointestinal) infections of all provinces in Canada. Although these reportable communicable disease data do not indicate the source of infection, it has been suggested that a significant proportion may be due to waterborne disease transmission.

Current public health surveillance contributes to identification of waterborne outbreaks and levels of enteric infection, but it is a lagging indicator of disease impact. New tools are needed to detect contamination nearer the source and in real time. A multidisciplinary team is currently studying a more integrated and timely system of surveillance from source to tap using real-time sensing and a systems approach for source-to-tap alerts. If this enhanced surveillance is shown to be better than traditional methods of testing drinking water (as consumers drink the water), its use would mean more timely interventions and improvement of community health. This would be a significant step forward in the provision of safe drinking water, particularly for small water systems across BC and Canada.

Jurisdictional interactions associated with water are complex. Even within provinces, there are silos at municipal, regional and provincial levels. To effectively study water from “source-to-tap,” cross-jurisdictional, multidisciplinary partnerships are required.

In the provincial health officer’s report on Drinking Water Quality in British Columbia: The Public Health Perspective, two of the seven action categories directly involve the community. In this Blueprint for Action, public involvement and education are key actions to moving ahead, and ones in which BC physicians can assist. From the provincial health officer’s 2000 report we note that: “Consumers need to be aware of the risks, benefits, and costs of additional protection (for water supplies), so that they can make the best possible decisions about how their water supplies should be managed. Members of the public can play an important part in maintaining the safety of the water supply if they receive accurate and accessible information. In particular, people drawing their water from unregulated sources where there is only one connection (single-family dwellings on wells, individually piped sources, etc.) can benefit from the materials available from their local public health office.”

The Government of BC has developed an Action Plan for Safe Drinking water, and a new Drinking Water Protection Act Alert and Drinking Water Protection Regulation came into force on 16 May 2003. This act and regulation changed the requirements from just monitoring microbiological sampling at the tap to carrying out a source-to-tap assessment and implementing improvements in the drinking water system to reduce future hazards that may contribute to waterborne illness.[6]

Physicians have a unique opportunity working with their patients and within their communities. They can also get directly involved in local action through, for example, British Columbia Medical Association Environmental Health Committee, or by getting to know their local medical health officer’s activities and plans around safe drinking water. Physicians are the front line of public health surveillance, and this partnership is critical to BC’s Action Plan for Safe Drinking Water. Alert physicians in primary care or those in specialties like laboratory medicine have often been the first to identify outbreaks of waterborne illness after the analysis of stool specimens.

— Judith Isaac-Renton, 
MD, DPH, FRCPC

—Shaun Peck, MB, BCHIR, FRCPC

—Perry Kendall, MBBS, FRCPC
BC Centre for Disease Control

References

1. [No authors listed]. Waterborne outbreak of gastroenteritis associated with a contaminated municipal water supply, Walkerton, Ontario, May–June 2000. Can Commun Dis Rep 2000;26:170-173. PubMed Citation Full Text
2. Krewski D, Balbus J, Butler-Jones D, et al. Managing health risks from drinking water—A report to the Walkerton inquiry. J Toxicol Environ Health 2002;65:1635-1823. PubMed Citation
3. Hrudey SE, Hrudey EJ. Walkerton and North Battleford—Key lessons for public health professionals. Can J Public Health 2002;93:332-333. PubMed Citation
4. Stirling R, Aramini J, Ellis A, et al. North Battleford, Spring 2001 Waterborne Cryptosporidium Outbreak. Health Canada Report. www.health.gov.sk.ca/mc_dp_health_can_epi_report_NB.pdf (24 Sep 2001; retrieved 30 Sep 2003).
5. Office of the Provincial Health Officer, British Columbia Ministry of Health Planning, October 2001. Drinking Water Quality in British Columbia: The Public Health Perspective. A Report on the Health of British Columbians, Provincial Health Officer’s Annual Report 2000. www.healthplanning.gov.bc.ca/pho/pdf/phoannual2000.pdf (Oct 2001; retrieved 30 Sep 2003).
6. British Columbia Ministry of Health Planning. British Columbia Drinking Water Action Plan and Legislation. www.healthplanning.gov.bc.ca/protect/water.html (May 2003; retrieved 30 Sep 2003).