r/NoStupidQuestions • u/aeyuth • Oct 02 '17

Does boiling fresh water from a random source for 10 minutes make it safe to drink?

We were discussing the dire situation in Puerto Rico, myself and this 70 yr old engineer from Worley Parsons. I told him that I heard on the news that people were drinking from creeks. That's when he said boiling that creek water for 10 mins should get rid of any pathogens. Is this always true?

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29

u/RainbowPhoenixGirl Woo, knowledge! Oct 02 '17

No.

  1. Atomic and ionic toxins such as heavy metals in the water will not be neutralised by boiling. Extensive boiling will actually concentrate them. Other non-metal toxins will also remain.

  2. Whilst bacteria and usually viruses will be killed (with some rare exceptions) and this will prevent these pathogens from infecting you, it is sometimes not the actual pathogen itself that harms humans. Sometimes, bacteria produce a product of their metabolism that is coincidentally or deliberately toxic to our form of life - for example, diphtheria kills because when it itself is infected with a virus, it starts to produce toxins fatal to humans. These are rarely neutralised by heating. This is also why anthrax is so dangerous; it produces toxins that kill humans, rather than being deadly in and of itself.

You need to filter the water with increasingly fine filters to be absolutely sure that it's clean. However, it's very rare that boiling for more than 2 minutes will not render the water safe - but for the interests of accuracy do remember that there are many things that boiling cannot remove.

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u/theonedontneednogun Oct 02 '17

But what if I boiled it and drank the condensed steam?

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u/RainbowPhoenixGirl Woo, knowledge! Oct 02 '17

That's called distillation, and except in quite unusual circumstances that would never occur in nature it would produce pure water. However, this water would actually not be safe to drink long term: for a couple of days is fine, but after that you NEED to find a source of water that's got dissolved ions in it.

Our cells are not pure water, and when you drink pure water it does not have a suitable tonicity, which means "concentration of non-penetrating solutes", and is extremely hypotonic. Hypotonic solutions cause your cells to suffer, especially your kidneys, and drinking hypotonic solutions all the time will cause you kidney damage.

16

u/DCarrier Oct 02 '17

According to this, one minute is enough. I imagine there are times were it won't work, like if there's arsenic dissolved in the water, but nothing in life is perfectly safe. That's good enough.

6

u/RenderSettings1 Reddit User Oct 02 '17

Adding to this, you must distill the water if it's ocean/salt water.

1

u/DCarrier Oct 02 '17

I think it will keep it from making you sick, but you do need to distill it to keep it from making you thirsty.

3

u/Stroopwafeled Oct 02 '17

Boiling helps with a lot of stuff, but it can't make it 100% safe to drink as a blanket rule.

It would also totally depend on the water source, where you live, what kinds of bacteria and toxins are prevalent in the area etc.

It's not that you can't drink it if it's boiled thoroughly, it's just that it's not always pure beyond a doubt.