Not on tap: 'Raw water' could transmit potentially deadly pathogens: experts warn
TORONTO â€” Drinking â€œraw waterâ€ collected from springs and other so-called pure sources appears to be a growing natural health craze in the U.S. â€” and one in the era of social media that could quickly find its way to Canada.
But public health experts advise Canadians against embracing the raw water fad, saying untreated water can carry a host of micro-organisms that may cause severe illness and even death.
â€œThereâ€™s a long human history of consuming raw water over millennia and centuries and that has resulted in numerous documented outbreaks of serious infectious diseases and fatalities,â€ Dr. Ray Copes, chief of environmental and occupational health at Public Health Ontario, said Friday.
â€œAnd Iâ€™m puzzled as to why, given the benefit we have of adequate disinfection and safe water today, that people would want to go back to consuming water that hasnâ€™t been treated and may be a source of serious infection.â€
The New York Times recently reported on a number of U.S. companies supplying raw water, which adherents argue is â€œhealthierâ€ than tap or bottled water because it doesnâ€™t contain fluoride and retains beneficial minerals and â€œgoodâ€ bacteria, which would otherwise be removed through filtration or disinfection methods.
Among the start-ups promoting living off the water grid is San Francisco-based Live Water, which delivers untreated water to customers sourced from Opal Spring in Madras, Ore., according to the companyâ€™s website. Raw water from various U.S. suppliers isnâ€™t cheap, selling for up to US$70 for a 9.5-litre jug.
However, Copes said water taken directly from nature can contain bacteria like E. coli, salmonella and campylobacter, along with such parasites as cryptosporidium and giardia.
Such disease-causing microbes are shed by domestic animals like cattle and sheep, as well as by wild animals, contaminating surface water that can lead to disease outbreaks in people.
â€œWe have to be aware that there are many species out there that are defecating, that are emptying the contents of their enteric tracts onto the land and into the water,â€ he said.
â€œThat is why for any surface water, we have to assume that micro-organisms may be present that could create serious infectious disease.â€
A case in point is the May 2000 outbreak in Walkerton, Ont., of E. coli 0157:H7, a virulent strain that sickened about 2,500 residents and killed seven as the result of a contaminated water supply. The E. coli is believed to have originated in seeping groundwater adulterated by cattle at nearby farms.
In 1996, cryptosporidium sickened about 2,000 people in Cranbrook, B.C. An outbreak in Kelowna, B.C., weeks later caused an estimated 10,000 to 15,000 people to become ill with the gastrointestinal illness caused by the parasite.
A cryptosporidium outbreak in Milwaukee in 1993 made about 400,000 ill and left 100 people dead.
Contaminated wells and groundwater are also responsible for hundreds of boil-water advisories in effect in remote communities across Canada, some of which have been in place for decades.
Jan Sargeant, director of the Centre for Public Health and Zoonoses at the University of Guelph in southwestern Ontario, said micro-organisms are always a concern when drinking â€œrawâ€ water.
â€œMost of these pathogens are from fecal contamination â€¦ from a human or livestock source,â€ Sargeant said in an emailed interview. â€œEven the most pristine water could be contaminated from wildlife feces.â€
For instance, giardia â€” also known as â€œbeaver feverâ€ â€” has been known to infect campers and canoeists who drink from lakes and rivers, she noted.
And while some people prefer the taste of untreated water, Sargeant doesnâ€™t believe itâ€™s healthier.
â€œMunicipalities treat their drinking water for a reason â€” and that is to make it safer.â€