> Modern people still need to boil water to safely drink i
Not everywhere. Drinking water in the little town I live in in Norway is merely filtered and a little aluminium sulphate added to precipitate out the solids. You absolutely could have drunk the water before that treatment with no ill effects. That's because it comes from a lake high in the hills above any industrial or agricultural activity.
>That's because it comes from a lake high in the hills above any industrial or agricultural activity.
Half correct, but not completely correct..
I'm also assuming it remains very cold or even frozen for a huge portion of the year. The water is never getting to a temperature that allows much of the dangerous things to humans to grow. For example here in Texas you're apt to get amoebas in the 25-35C waters.
Also that high in the mountains you're probably getting water off mineral rock that's had very few interactions with the biosphere to accumulate wastes from animals.
You don't need industrial or agricultural activity to kill you.
Industrial and agricultural pollution are not the only potential pollutants in tap water. There are natural sources of viruses, bacteria, and parasites that exist.
Not everywhere. Drinking water in the little town I live in in Norway is merely filtered and a little aluminium sulphate added to precipitate out the solids. You absolutely could have drunk the water before that treatment with no ill effects. That's because it comes from a lake high in the hills above any industrial or agricultural activity.