If you can get sick from drinking most of the water that you encounter, how have humans lived so long?

Question

I am not anything close to an ecologist or a biologist so this question may be really dumb. But I know that water is essential. It is used in many important bodily processes and we would die without it very quickly.

So my question is, how did so many generations of humans survive without the water purification standards that we have today?

Is there a reasonable amount of dirt, toxins, bacteria, etc… that can be in water and it won’t make us sick?

I also know people have boiled water for a very long time but didn’t we only discover bacteria and viruses in the lasts several hundred years? Did people know that boiling water would purify it?

Also am I wrong for thinking that most water in nature is dangerous to drink?

Hopefully these questions make sense.

In: 1437

Answer 1

Early humans would have had a very low population density as hunter gatherers and pollution such as sewage and agricultural runoff would not have been an issue. Could people have gotten sick from accidentally drinking water contaminated with germs? Absolutely, but it would be much less likely than today. When humans started settling down in groups and founding villages and so on, polluted water became a much bigger issue. Beer came along with the invention of agriculture and served two purposes. The process of making beer and the alcohol content served to purify and preserve the water, and also as a way to preserve calories and nutrition from grain. As villages grew into cities, the problems that come with polluted water increased. Sewers were invented to control pollution and runoff, and helped. But diseases like cholera were common. Most pre-industrial revolution water pollution issues were related to large populations of people living close together and basically shitting in the drinking water. But water in rural areas was still pretty safe. Post-industrial revolution, and the reason why more water is dangerous to drink today, water became polluted with agricultural runoff, mining chemicals, and other hazards of industry, affecting even water in rural areas.

So, for most of human history, untreated water from a good source was not dangerous to drink.