If you are drinking tap water, the answer to that question is 300+ chemicals and pollutants, according to research from the Environmental Working Group. Among these contaminants are:
Volatile Organic Chemicals
(VOCs) such as pesticides, herbicides and other chemicals. These chemicals are found in most municipal water sources and even in well and other sources due to agricultural run-off and contamination. Research links certain VOCs to damage in the reproductive system, liver, kidneys and more.
Metals like lead and mercury are found in some water sources and have been linked to many health problems.
Endocrine Disrupting Chemicals
These chemicals may mimic or interfere with the normal hormones in the body and they are being found in increasing amounts in the water supply.
Once you know what you need to remove, it’s much easier to choose the best water filter option for your family. So what are the options for those of us not interested in drinking a chemical cocktail every time we are thirsty? There are options for every home and every budget. From filters that just take out the basics like Chlorine to ones that remove all contaminants and remineralize the water!
I've tried a couple dozen of the thousands of options available and share my experience here. This is from my own experience and I have not tried every option. This is also not medical or scientific advice and I’d encourage you to always do your own research and test your own water quality to find your best solution.