DANGER IN YOUR PIPES
Your shower mist could contain nasty bacteria
City-owned Epcor sends clean water to your house, but it might not stay that way as it flows through your household pipes, bringing tiny bugs out of the steamy shower head.
University of Alberta scientist Nicholas Ashbolt is doing groundbreaking research into this littleknown, little-studied hazard lurking in household plumbing and garden hoses that can lead to serious lung infection.
By breathing in the shower mist, the unsuspecting bather can take bacteria into the lungs and catch a mild infection or worse — potentially fatal pneumonia (Legionnaire’s disease), said Ashbolt, who holds the Alberta Innovates research chair at the School of Public Health.
“It’s a totally new range of pathogens and we don’t have any regulations in Canada on how to prevent them in plumbing systems,” said Ashbolt, whose groundbreaking work will assist Health Canada and the World Health Organization set new standards.
“All the drinking water testing in the world — and in Canada — has focused on fecal contamination to tell you if there is a problem, and that’s good.
“But that doesn’t tell you anything about the risk from these water-borne pathogens building up in the household pipes.”
Ashbolt’s brand new lab is designed to mimic variations of household plumbing. There are showers, urinals, toilets and garden hose outlets — all connected with three types of piping: copper, and two types of plastic pipes; PVC, and a new form, PEX.
The idea is to determine which type of pipe will best inhibit the pathogen growth, says Ashbolt.
The exact rate of infection from the legionella bacteria in pipes is hard to determine because many mild cases, called Pontiac fever, go unrecorded.
“People who are just not feeling so good for a few days don’t go to the doctor,” said Ashbolt.
But in the U.S., the legionella pathogen in plumbing is responsible for more hospital costs than infections from fecal pathogens in drinking water such as E. coli bac- teria, said Ashbolt.
It is estimated to cause about 10 per cent of community acquired respiratory infections, he says. Elderly people or those with weak immune systems are particularly vulnerable. That means there’s a big risk if the pathogen gets into the pipes in hospitals and seniors’ homes. Any big building where warm water — between 28C and 42C — sits in pipes can present a risk, said Ashbolt.
Three factors contribute to legionella growth — water temperature, stagnation (water that sits too long) and the pipe material.
“The stagnation is an important factor because it allows residual chlorine in drinking water to dissipate and that encourages the growth of pipe slime (biofilm) where the pathogens grow,” said Ashbolt.
Already some hospitals in the U.S. are keeping the hot water circulating constantly through pipes above 55C, and it might be necessary make sure cold water keeps moving if it is at 25C, says Ashbolt.
“It seems like adding more cost, but not doing it is also a cost to society in hospital bills.”
Meanwhile, said Ashbolt, when you’ve been away from home, be sure to run the taps and let the water run through the system until it feels cool. That’s the signal the fresh water from the city water main is pouring in and the stagnant, potentially hazardous water, is being cleared out.