In many parts of the world where water is scarce, a large number of people harvest rainwater to drink and cook with it. Some even solely depend on it when they're trying to live off the grid. However, the question of whether drinking rainwater is safe is usually not considered in these instances.
You should always ensure that your health won't be affected when you drink rainwater because of the elements it's exposed to, making it unsuitable for drinking and cooking purposes. The main reason behind this is that when you drink water, it permeates throughout your body and acts as a cleaning agent by removing toxins and other harmful elements.
Directly drinking water
You should always be cautious when drinking rainwater, especially if you are going to drink it as is, without purifying or filtering it. If you live around factories or other industrial zones, it might be very dangerous to drink rainwater as is. This is because the pollution generated by these factories might cause acid rain that may be poisonous and lead to death.
This also applies if you live in a place that has experienced a volcanic eruption or has a lot of volcanic activity. Particles from the volcano are present in these areas and can poison the rainwater in them. Besides these direct air pollutants, there are other normal areas that may have unsafe rainwater that may need filtering or purification before drinking.
This is caused by general bacteria, viruses and parasites. These pollutants can become airborne and cause diseases like diarrhea and cholera. Diarrhea and cholera caused by these pollutants can be very intense and cause you a lot of pain.
Another major determining factor of whether rainwater is safe to drink is the method used in its harvesting. For example, if the water is harvested directly from the sky, it may be safe to drink without purification. If the water was harvested using gutters or another method that involves a roof, it could be unsafe.
This is because roofs are usually paint coated which has hazardous chemicals that pose a risk to your health. Metal gutters also may have rust on them and that makes drinking water harvested from these risky or outright unsafe. PVC gutters may also leak dangerous chemicals due to being exposed to the sun and make it dangerous to drink rainwater.
If you also use plants to harvest rainwater, you need to ensure that they are not poisonous or have any dead insects or any other contaminants. For example, if you want to use big leaves to harvest water into your bucket, you should ensure that they aren't poisonous.
Making rainwater safe to drink
You can make rainwater safe by filtering it using a coffee filter or clean t-shirt to remove most contaminants. To remove the bacteria, you can boil the water and add a little bit of bleach in it. Putting water purification pills in your water will also kill contaminants like bacteria, parasites and viruses.
Before drinking rainwater, you should take general precautions like personally checking your water. Be sure that your water doesn't have any visible contaminants and also do your best to eliminate those that aren't visible. Even if you are in an emergency situation, you should take all the necessary measures to make your water safe.
You can even use your t-shirt to filter the water or buy water purification pills beforehand and keep them for whenever you could get caught up in a crisis. When you follow those steps, you will be able to drink rainwater without putting yourself at the risk of getting health problems.