Is rain the cleanest water or the dirtiest water when it is falling down?

Question

well you have to think about all of the polution in the air it gets while fall ing so is it still the cleanest?

Answer 1

I think it may still be cleaner.

Answer 2

I say dirtiest b/c raindrops need a CCN ( Cloud Condensation Nuclei) to form in the first place.  A CCN is usually a particle of some pollutant such as smoke.  The water condenses onto  the particle and passes along it's Kholer Curve and eventually becomes a raindrop!

Answer 3

This is an interesting question because, in order to rain, the moisture in the atmosphere has to condensate into water droplets that need to further condensate into small drops big enough to be pulled down by gravity.

The problem is: in order to go from gas to liquid, water needs to give away energy in form of heat. But the water molecule doesn't have enough mass in order to dissipate heat. It has to meet a small particle of dust, smoke - just anything, in order to condensate. That's the reason why in some place aircraft 'seed' the clouds with e.g. silver chroride in order to create rain. This is also the reason you can see morning dew or frost on the tree leaves. To become liquid or solid, water needs to give away energy.

So, the rain water is 'polluted.' But how much and does it affect us in some way? The only alternative would then be to drink only pure distilled water. But what's the point? Our body is supposed to be able to handle a lot of dust and bacteries. In fact, our digestive system needs a lot of bacteries in order to function. Recent surveys worldwide show that if various allergies are becoming more and more common is that we live in a too much antiseptic environment. A bit of dirt now and then is good for us.

Answer 4

You have a whole hydro logic cycle thing going on here. in which the oceans moisture evaporates, condenses into drops, falls from the sky an eventually returns to the ocean and just repeats that whole process. The air gets to it, and by the time it reaches us, its not exactly healthy to drink like sink water, which is just as bad.

its safer for someone collecting water from rain to boil it excessively. That gets rid of all the unclean harmful stuff n it.