If you are looking into your own water filtration system, a good first step is to understand the possible pollutants that can exist in your tap water. There are five main categories of pollutants that can be found in your water.
Water Pollutant Categories
Pathogens consist of bacteria, viruses and parasites. They can be spread through water, contact with animals, contaminated food and contaminated pools.
Bacteria is killed by chlorine when it is added to our water supply, and therefore bacteria is not usually a problem with tap water. The majority of viruses found in water are also handled by the water utilities in the USA. Parasites however are a challenge to eliminate.
The most common parasites found in water are giardia and cryptosporidium because they are difficult to kill, even with chlorine. They can cause gastrointestinal illness (e.g. diarrhea, cramps, vomiting), and can be dangerous for people with impaired immune systems.
2. Toxic Minerals
Many types of minerals form an essential part of our healthy diet and are even good to have in water. However ingesting toxic minerals can lead to a number of health difficulties. Low doses of toxic minerals taken over a period of many years can cause disorders in our kidneys, bones, blood, immune system and nervous system.
Toxic minerals that can be found in water include: mercury, nitrate, arsenic, lead, fluoride, aluminum, copper, cadmium, asbestos, barium, chromium, nitrite, selenium and silver.
You definitely want to avoid cadmium, lead and mercury. Asbestos-cement water pipes are used to deliver the water to most of the homes in the USA, which means you will find asbestos in most tap water.
Water treatment plants reduce the high levels of toxic minerals, however there is controversy on whether these limits are truly safe in the long term.
3. Organic Chemicals
The long list of organic chemicals that have been found in water supplies include pesticides, herbicides, preservatives, fuels, and synthetic fertilizer.
Volatile Organic Chemicals (VOCs) are dangerous because they are absorbed through our skin when we take a bath or a shower. If strong amounts of VOCs are in your tap water, it will be dangerous to your health, even if you don’t drink it.
A known problem that occurs when chlorine is added to our water system, is that it can combine with the organic chemicals to form a pollutant called trihalomethanes (THMs). THMs have been reported to increase the risk of cancer.
4. Radioactive Substances
Natural radioactive substances can occur in water supplies near a mining operation. Man-made radioactive substances occur from nuclear power plants, nuclear weapons facilities, or anything that may have a nuclear power source nearby.
The most dangerous is radon, which is reported to cause cancer. It escapes from the earth’s crust, and can dissolve in groundwater. It is mainly only a problem when the water is not exposed to air, as it dissipates rapidly. The danger lies in inhaling it.
A granulated activated carbon filter can remove radon from water. However if you happen to know that you have a problem with radon in your water, it may be entering the house through the basement and it would be wise to look into eliminating all airborne radon as well as filtering your water.
Fluoride and Chlorine are the most well known additives. Due to the proven threat of Chlorine combining with organic chemicals to form toxic chemicals known as THMs, some public water systems have stopped using chlorine and use chloramines instead, which form fewer THMs. However chloramines form other compounds and the long term health risks are not yet known.
To see a comparison of some of the under sink water filters on the market that greatly help with reducing water pollutants view our Under Sink Water Filter Comparison Chart .