Protecting Drinking Water Sources and Public Health

Abstract

Microbial agents of waterborne disease include bacteria, viruses and parasites. Microbes in drinking water have caused at least 29 outbreaks in British Columbia over the last 20 years, 17 of which (59%) were caused by protozoan parasites that are resistant to chlorine. Bacteria, viruses and parasites that can cause waterborne disease all share common characteristics. Most have an animal host and can infect humans through drinking water supplies. Human infection by these microorganisms most commonly appears as gastrointestinal illness; however, some can cause systemic disease, such as hepatitis (viruses) and kidney failure (E. coli 0157:H7). Evidence from recent water contamination crises from across Canada suggests that traditional water treatment such as chlorination and filtration may no longer suffice to provide clean water. Source water protection, the first line of defence in the multi-barrier approach to safe drinking water, has rapidly gained favour within the water industry and government regulators. It is now prudent for health professionals to recognize the connection between source water protection and public health.