Comstock Images/Comstock/Getty Images

Since 1904, chlorine has been used in U.S. drinking water supplies to disinfect pathogens, kill bacteria and protect us from being infected by contaminated organisms. Chlorine is also used in swimming pools to eliminate dangerous bacteria in the pool water. Although chlorine is intended to protect people from infections, scientific research indicates that taking in too much chlorine can pose serious health risks.


If you stay in a swimming pool, hot tub, shower or other body of water filled with chlorine for an extended period of time, too much chlorine will be absorbed by your skin and you will notice some immediate effects. As the excessive amount of chlorine enters your skin pores and flows into your blood stream, you might experience irritated skin, itchy rashes, a very weak pulse, numbness in the limbs, nausea, heart palpitations or extreme dizziness.

Digestive Problems

Many dangerous health risks can develop as a consequence of drinking chlorinated water. For instance, drinking too much chlorine can impair the digestive track of your body. The high chlorine rates destroy intestinal flora, which can inhibit the ability of your digestive system to effectively absorb and process nutrients. As a result, your body might not absorb and benefit from the minerals, vitamins and fats that you take in, thus making the body more vulnerable to infections.


Although chlorine is used to kill bacteria and clean our drinking water, chlorine is still a poison; thus, many scientists and medical researchers agree that drinking an excessive amount of chlorine can cause severe health problems. For instance, Hypothyroidism Diet Info states that drinking chlorine can interfere with the thyroid's processes, leading to the development of hypothyroidism. The thyroid gland, which is in the neck, helps control the rate of protein production and regulate hormone levels. If you drink too much chlorinated water, the chlorine can block the iodine receptors that reside in the thyroid gland and reduce the iodine-containing hormone production levels in the body.


Many scientific studies and research projects have established a direct relationship between drinking excessive chlorine for long periods of time and the development of various cancers. For example, a study at Oak Ridge Associated Universities found that drinking high amounts of chlorinated water for over 15 years significantly increases the chances of developing colon cancer. According to the "Journal of the National Cancer Institute," drinking chlorinated water over extended periods can also increase your risk of developing bladder cancer by up to 80 percent. Further, a 1992 study by the Medical College of Wisconsin found that bladder and rectal cancers are linked to the digestion of excessive amounts of chlorinated water.

Other Effects

An excessive surplus of chlorine in the blood stream can kill proteins and beneficial bacteria in the body, which diminishes the strength of your immune system and makes your body more susceptible to infections. Additionally, taking in too much chlorine can result in lung and respiratory problems that can make breathing more difficult and that can result in throat or lung infections. The American Medical Association also reports that absorbing too much chlorine can cause or exacerbate asthma and allergy problems.