12 Most Common Drinking Water Contaminants

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Common Drinking Water Contaminants

Accessing pure drinking water is becoming difficult day by day. Drinking unclean and contaminated water can cause severe illnesses including diarrhea, stomach pain, headache, and kidney failure. Also, waterborne diseases lead to death in certain cases.

There are a lot of chemicals and substances present in the water that affects its quality. Many of these bacteria and organisms do not affect human health. However, the harmful chemicals need to be removed by various methods, and hence, clean drinking water is obtained.

Let’s have a look at some of the most common drinking water contaminants that are dangerous for health.

1. Chlorine

The presence of chlorine in water is very common. It is used as a water disinfectant as it helps in killing many pathogens. But, when chlorine mixes with the organic compounds, the byproducts obtained are not good for health.

Trihalomethane and Haloacetic acids are common byproducts that form during this mixing. Both of these chemicals increase the risk of cancer and hence, water containing these is not suitable for drinking. Following are the common symptoms that may be seen if water containing chlorine is consumed:

  • Sore throat
  • Skin and eye irritation
  • Cough
  • Difficulty in breathing

2. Lead

Lead pipes are commonly used everywhere. These pipes corrode and lead is mixed in water making it fatal. Lead is a toxic metal that has severe effects on human health.

Drinking water containing lead can have different side effects on adults and kids. The common reaction observed among kids is the brain’s improper functioning, which further leads to learning disability.

In adults, exposure to lead can cause nausea and other issues related to the reproductive system.

Although lead has its smell, its presence does not affect the taste and smell of water.

3. Arsenic

Underground water usually contains Arsenic. It is an element that is found in the Earth’s crust. A small percentage of arsenic is also found in the air. Groundwater that is not properly treated contains traces of arsenic.

The presence of arsenic in drinking water also increases the chance of cancer and heart diseases.

4. Nitrate

A high amount of nitrate in drinking water is considered unsafe. According to various health standards, 10mg/L or less nitrate does not cause any harm.

If it is more than 10mg/L, it needs to be treated as it can have poisonous effects on human health. Mostly, kids and infants suffer more through water-containing nitrate.

The presence of nitrate in the human body lowers the level of oxygen causing respiratory and breathing issues. Nitrate can also cause blue baby disease in infants, leading to death.

5. Copper

The water lines and piping are made from copper. As they become old, copper starts releasing from the pipes and gets mixed into the water.

When used for longer, this contaminated water can cause many serious illnesses. A small quantity of copper does not cause any serious issue, but if the amount is increased, this can be fatal.

Therefore, the copper pipes should be well-maintained and replaced when needed to keep your drinking water safe and clean.

6. Fluoride

Although fluoride is still a major ingredient of toothpaste, a larger quantity of fluoride is not good for health. High levels of fluoride can cause muscle and joint pains.

There is no doubt that fluoride has many benefits for dental health, but it is not suitable for drinking purposes.

To get rid of fluoride in drinking water, filters are installed which serve the purpose. In the case of high levels of fluorides, the reverse osmosis method needs to be implemented.

7. Perfluorooctanoic acid

Commonly known as PFOA, Perfluorooctanoic acid is another dangerous chemical that is not considered good for health. Therefore, water containing PFOA is never recommended for drinking unless it is properly treated.

This water contaminant can cause cholesterol levels to rise and increase kidney cancer risk. This chemical cannot be removed through ordinary filtration methods. High technologies are used to treat this type of contamination.

8. Mercury

Drinking water containing mercury can affect the kidneys. Health organizations do not recommend to consume water having mercury.

The industrial wastes contain mercury and if not properly discarded, it gets mixed with water. Inorganic mercury is comparatively safer than organic mercury.

9. Micro-organisms

Some of the water-borne bacteria are not harmful. However, there are some bacteria, viruses, pathogens, and parasites that need to be eliminated to make the water suitable for drinking.

Certain tests are performed to confirm the presence of microorganisms in water. The presence of coliform bacteria is a sign that other harmful viruses and bacteria are also present in the water.

10. Perchlorate

This is another common contaminant that is mostly present in public drinking water systems. This is a toxic chemical and people who are exposed to this chemical are at a high risk of many serious health problems.

Reverse osmosis filters are used for the removal of this contamination. It can damage the brain functioning in children and is also not safe for pregnant women as it can also affect the unborn kids as well.

11. Manganese

Going down the list, we have manganese which is another naturally occurring chemical and is found in underground water. Although a small quantity of manganese is considered beneficial for human health, high levels can have opposite reactions.

Also, if present in larger quantities can be easily detected by its distinctive smell. Sometimes, it also changes the color of the water.

12. Radioactive chemicals

Uranium, Radon, and Radium are common radioactive chemicals found in water. Exposure to these harsh contaminants can cause kidney, skin, lung, and liver cancer.

These substances are mostly found in underground water and cannot be removed through boiling.

There are multiple filtration systems depending on the type of contaminant present in your water. Before installing a purification system, proper testing is required.


Apart from these common drinking water contaminants, many other contaminants and pollutants found in water make it unsafe for drinking. Aluminum, ammonia, chloramine, and chromium are also hazardous water contaminants that are not suitable for health.

Since the world is struggling for clean drinking water, it is recommended to get a whole-house filtrations system installed that provides pure drinking water free from contaminants and also does not take away the essential minerals from the water.

Jeremy Lee is a researcher and part-time blogger who has a passion to discover cutting-edge technologies related to water filtration. He knows the importance of purified water in our lives and started this blog aiming to provide the best product reviews, buying guides, and other useful information related to water. When not working, he loves to spend time with his beloved wife and two kids.