in other words, suppose chemical treatment of water is discontinued and we are back to just boiling it religiously before drinking, like the medieval Chinese did. Plus maybe singing the dishes with boiling water after washing them with “dirty” untreated water.
Would there be water-borne disease outbreaks? Are any of these diseases immune to heat or would they spread through some mechanism that bypasses the boiling?
Water borne illness can be transmitted a variety of ways. Brushing teeth, washing hands, showers etc. in untreated water.
http://www.mass.gov/dep/water/drinking/boilfaq.htm
I know backpackers boil water 20 minutes to kill stubborn pathogens like giardia lamblia. A few drops of bleach per gallon is also effective.
good article on what can be in water
http://www.bae.ncsu.edu/programs/extension/publicat/wqwm/he393.html
I am told (and looked it up myself) that boiling for X minutes is unnecessary. Once the water gets to boiling point, the pathogens you can kill are already dead.
ok, here is a quote from this link:
well, sounds great, not onerous at all. Except, this tells me nothing about whether or not some water borne diseases will spread regardless of these measures, such as because they withstand boiling.
Similarly, if the Government tells me that it’s a good idea to hide under my desk when the aerial attack alarm sounds, it tells me fairly little about the risks inherent in being close to a nuclear blast.
Boiling won’t remove toxins.
A lot of bad stuff can be in water. I always bring a filter and water treatment tablets on my backpacking trips. I Always filter. I either boil or use the tablets. Even then I’ve gotten sick on a few trips. May have been unwashed berries, the water or who knows what. It happens.
Even that may not be enough in extreme cases…
could you elaborate? Is that let’s say toxins generated by cholera bacteria or another living organism? Or is that industrial contamination type of chemicals?
What toxins? Be specific.
I was thinking mainly of chemical contamination, but I suppose there might be toxins produced by bacteria that can survive too (I know nothing about such things).
Mercury poisoning is a disease, so that’s one answer to your original question.
my feelings about this particular wikipedia article rightfully belong in the pit :). A dumb laundry list of factual tidbits without context, analysis, comparison, well, without anything. Ignorance masquerading as scholarship. Gaah…
Oh, and the Waterborne diseases - Wikipedia article never bothers to even consider my OP question :(.
I’ll be less specific: boiling won’t remove all toxins.
Boiling won’t kill botulism, it survives to 118 C. Heavy metal contamination (arsenic, lead, mercury) is not removed by boiling water. Cyanobacteria is a deadly toxin and boiling doesn’t remove it.
interesting. The botulism article does not seem to discuss the water-borne spread of the disease. If it were to in fact start spreading like that in “premodern” conditions, presumably it would have to be controlled by heating water to 120C in a pressure cooker.
Cyanobacteria article is to me pretty unclear. Do they mean that water from some lakes ends up containing these toxins and they cannot be boiled or otherwise destroyed? Or does the water just contain the bacteria itself and it is dangerous to ingest?
According to Wikipedia, a toxin (Greek: τοξικόν, toxikon) is a poisonous substance produced by living cells or organisms, so something like arsenic or mercury would not be a toxin (but would be a poison).
Botulism can be removed by reverse osmosis.
Everything you ever wanted to know about cyanobacteria, but were afraid to ask: http://www.hc-sc.gc.ca/ewh-semt/pubs/water-eau/cyanobacter-eng.php
Boiling alone will not kill all the bad things in water, that’s why there are other methods of purification that are used to treat water.
Thanks. It seems “toxicant” is the term I should have used.
That would be one super pathogen what could survive 15 minutes of boiling. :eek:
Probably an element of confusion comes from the word “kill”. You can’t kill a toxin, it was never alive. Boiling or chemical treatment may cause some toxins to break down or become denatured enough that they are no longer harmful, but this is not killing it. Elemental contaminants like mercury, cadmium, lead, etc are clearly not in the least affected by boiling. Reverse osmosis or distillation will remove them.
Botulism is a curious one. The toxin is destroyed in heating. As is the live bacteria. But the spores will survive boiling, and is where where the 112 C number comes from. But unless you intend using the water to make a preserved meat there is no danger in drinking it. The spores themselves require anearobic conditions, low acidity, and nutrients for some time to produce the toxin. Your gut isn’t the place for this.
My biggest concern is the illegal industrial dumping. It still occasionally happens. A truck at midnight, stops at a creek. Takes only minutes to pump out the sludge and they are gone. I recall last year a truck got caught locally in my area doing that. It was a small creek that eventually fed into a important water source.
No telling what heavy metals and other toxins were in that stuff. The typical person at home won’t have the various methods needed to purify something like that. You can only do so much with a basic filter.
Cattle are another big issue in the wilderness. You can be camped at a sparkling beautiful creek or river. A few miles up stream may be a cattle ranch. Cattle stand in the water, pooping away and peeing in that water. You’ll have no idea unless the water is tested.
I agree. Heavy metals are the first thing that occurred to me, having just moved from what is called ‘chemical valley’ where such were always a concern in the local water supply.
And no amount of boiling is going to remove heavy metals. And what they can do to a person over long-term exposure isn’t pretty.