Saturday, August 12, 2006
WATER WATER EVERYWHERE...
The first time this tepid glass of water was handed to me my health warning alarm bells began to clang. The water was a green colour – the hue of limeade. With sunlight shining through the small glass, I could see tiny bits floating in it - some appeared to be swimming. We were a seven hour rough drive to the nearest five hour flight to the nearest medical clinic. I looked at the gaunt, yet smiling faces of our hosts and wondered how to avoid downing this precious liquid.
Lucie saved me. She expressed with great feeling, “Oh, after such a long drive we were so looking forward to a glass of hot tea. Could you please take our water and boil it up for tea instead?” They did…and I dodged a probable water borne disease…that day at least.
I take it for granted that I won’t find green water and floaters in my tap water at home. I shouldn’t be so sure. There are more than 300 surface water systems in the British Columbia Interior Health region under boil water advisories, including mine. This means water protection workers have determined that water borne disease is a real risk in these systems.
Public Health instructions for drinking water under a boil advisory are straightforward. Boil the water for one minute (rolling boil) or disinfect the water by adding two drops of household bleach per litre and let it stand for twenty minutes. Otherwise use an alternate supply of water or commercially bottled water.
What is the rationale for a one minute rolling boil? Basically, boiling will inactivate or destroy pathogenic microbes that may be in contaminated water. The required temperature to accomplish this varies from 60 degrees Celsius for bacteria such as E. coli and Salmonella to 85 degrees Celsius to inactivate Norovirus (found in mollusks). Heating water until boiling is an easily recognized endpoint that doesn’t require the use of a thermometer.
Here’s some science. A rolling boil is when the little bubbles that form at the bottom of the pan break free and rise to break at the top – this is a true boil. And yes, water does boil at lower temperatures as altitude increases. At sea level it boils at 100 degrees Celsius. At 2,100 metres (7,000 feet) water boils at about 92 degrees Celsius. Since the highest communities in Canada fall below that altitude, the standard one minute boil will do its work across our land. If you happen to be scaling Mount Everest, you need to be more careful (about many things).
As for my drinking days in Sudan, it was under a glorious starry night sky, at the Camp David Café in the town of Nyala, when a pathogen found a comfortable home in me. I sipped water politely that evening and spent the next three days in a delirious haze – stumbling between bed, a bucket and the unpleasant outhouse behind our thatched roof home. My ordeal evolved to the above-noted five hour flight to Khartoum and a medical clinic. I was drugged enough to not soil the two-seater plane.
Remember, if in doubt, ask for the tea.
how about a book compilation of all your column pieces? the anecdotes are really worthy.
Ian, thanks for the confidence in my writing!
Lack of clean water is already a major problem all over the world. Many Rivers and lakes are in dire position!!
poor you..I'll remember the mantra though; hello luv, could you put the kettle on please??
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