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How does chlorine affect the human body?
Last reviewed: 03.07.2025

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Chlorine is best known to us as a substance used to treat water. The characteristic unpleasant smell and the fact that chlorine is used to wipe door handles, floors and toilets – that’s all we know about chlorine. How does chlorine actually affect the human body? Why do we need to treat surfaces with it and throw it into water? When does chlorine become dangerous?
A few words about the history of chlorine
This microelement – chlorine – was discovered in 1774 by Carl Scheele, a chemist and a Swede by nationality. He was conducting chemical experiments with hydrochloric acid and suddenly smelled a smell that reminded him of the familiar smell of aqua regia. Make no mistake, Carl Scheele was not a fan of alcohol. Aqua regia was the name of a solvent that contained nitric and hydrochloric acid, capable of dissolving even an apartment key or a wife’s gold ring.
The scientist became wary and continued to conduct experiments. He isolated a green-yellow gas from the obtained substance and began to study its effect on other gases and liquids. This is how chlorine was obtained - a complex substance that Scheele, and then his colleague Davy, called chlorin (green-yellow in Greek). This name has survived to this day in the USA and England, and in our country it has become shorter and more understandable - chlorine. This name was also established thanks to the famous French chemist Gay-Lussac, whose experiments are studied in physics lessons by today's schoolchildren. This microelement took its rightful place in the periodic table under the atomic number 17.
What is chlorine?
This is a substance, a macroelement that enters our body with mineral salts, calcium, magnesium, sodium, potassium and other microelements. The first and simplest source of chlorine is rock salt, which was used by our ancient ancestors. Chlorine in rock salt helped to keep fish and killed game safe and sound. Salt as a source of chlorine, necessary for humans, was mined back in the times described by the ancient Greek historian Herodotus, who lived around 425 BC.
Chlorine is found not only in store packaging, but also in our blood, bones, intercellular fluid, and the largest organ of our body – skin. Just as it enters the body, chlorine can also be excreted. About 90% of chlorine is excreted with decay products – urine and sweat.
Why does a person need chlorine?
Have you heard how often on TV or, less often, in the clinic, doctors talk about the acid-base balance? Advertising has buzzed everyone's ears about it. So, the acid-base balance of the body is the exchange of sodium, chlorine and potassium. It's very simple. All three of these elements must be in the intercellular fluid, blood and bones (what we wrote about above). Their ratio (doses) must be correct. If this correspondence is violated, a person begins to get sick. If the chlorine exchange in the body is disrupted, this immediately affects well-being: swelling of the arms, legs, face may appear, the heart begins to work intermittently, and the pressure jumps up and down.
All metabolic processes that are supported by chlorine and other necessary macroelements are called osmoregulation. Thanks to osmoregulation, a person maintains normal blood pressure, fluids and salts are excreted well, and the ratio and amount of useful substances in the body are regulated. It is chlorine that scientists call an active osmotically macroelement, since it is a constant participant in all these processes.
Chlorine is an element that is needed for good digestion. It helps secrete gastric juice, and thanks to chlorine, a good appetite is formed. If a person has increased gastric acidity, which leads to heartburn, the body needs more chloride because its consumption increases. If a person suffers from gastrointestinal diseases, more chlorine is needed because the need for it increases.
Another useful role of chlorine is to help a person retain water in tissues, that is, not to allow the body to become dehydrated, to lose moisture. Chlorine can also help remove toxins from tissues, helps the blood stay healthy, ensuring the good condition of blood cells - erythrocytes.
Sources of chlorine
Almost the entire daily norm – namely 90% of chlorine – enters the human body when it salts food, that is, with salt. There is very little chlorine in food, perhaps a lot only in bread or cheese. Most chlorine enters the human body with chlorinated water. If a person drinks tap water, there may even be an excess of chlorine. An interesting fact: although people are divided into vegetarians and meat eaters, neither of them has a shortage or excess of chlorine due to the choice of food. Even if people do not salt food or salt it little, modern technologies suggest increased doses of chlorides in the composition of the products themselves.
Name | chlorine content |
---|---|
Rye bread | 1025 |
Cheese | 880 |
White bread | 621 |
Butter | 330 |
Pork kidneys | 184 |
Pollock fish | 165 |
Capelin fish | 165 |
Hake fish | 165 |
Fat cottage cheese | 152 |
White mushrooms | 151 |
Cow's milk, 3.2% | 110 |
Kefir, 3.2% | 110 |
Egg | 106 |
Low-fat milk | 106 |
Oatmeal | 69 |
Beet | 58 |
Rice | 54 |
Potato | 38 |
Carrot | 36 |
Peas | 35 |
Cabbage | 24 |
Pears | 11 |
Apples | 5 |
How much chlorine do we need per day?
For healthy people, 4,000-6,000 milligrams of chlorine per day is enough. But it should be taken into account that this includes chlorine, which is contained in ready-made food, and in water, and in the salt that we throw into dishes. The maximum dose of chlorine - 7,000 milligrams - will still not harm a person, but such doses cannot be consumed constantly - there will be an excess of chlorine. If a person is hot, actively plays sports and sweats (and chlorine is excreted with decay products), more chlorine is needed. As with diseases of the digestive tract.
The chlorine requirement for children in milligrams is from 300 mg at the age of up to 3 months to 2300 mg at the age of 18 years. More detailed children's doses of chlorides can be considered in the table.
floor | 0-3 months | 4-6 months | 7-12 months | 1-2 years | 2-3 years |
---|---|---|---|---|---|
boys | 300 | 450 | 550 | 800 | 800 |
girls | 300 | 450 | 550 | 800 | 800 |
Preschoolers | Junior school | Middle school | Teenage |
---|---|---|---|
3-7 years | 7-11 years | 11-14 years old | 14-18 years old |
1100 | 1700 | 1900 | 2300 |
What are the risks of chlorine deficiency for a person?
If there is not enough chlorine in the body, its acid-base balance and carbohydrate metabolism are disrupted. A person may lose hair and crumble teeth, the skin ages and wrinkles sharply. Dehydration may occur, in which the mouth dries out, a person may feel sick, vomit, and the urination process is disrupted. The kidneys and gastrointestinal tract can no longer function normally, which disrupts the work of other organs. A lack of chlorides in the body can lead to a loss of strength, balance and appetite. Such people begin to complain of drowsiness, memory lapses, and the inability to concentrate.
As it turned out as a result of experiments conducted by scientists at the Max Planck Institute for Neurobiology in 2012, chlorides are necessary for the normal functioning of nerve cells. Experiments on mice showed that a lack of chlorides in the body can lead to overexcitation of nerve cells and the aggravation of such dangerous diseases as epilepsy.
Low-salt or salt-free diets, especially long ones, more than a week, can cause a lack of chlorine in the body. The state of health with a lack of chlorine worsens even more if a person previously suffered from hypertension or poor kidney function.
A person can reduce the concentration of chlorine in the body when he takes medications without a doctor's supervision. These can be laxatives, which lead to dehydration, diuretics (water pills), corticosteroids (steroid hormones produced by the adrenal cortex). If there is too little chlorine in the body and its amount is rapidly lost, a person can fall into a coma and even die.
What are the dangers of excess chlorine in the human body?
Dr. Price of the Saginaw Clinic writes that chlorine is the leading killer of our time, preventing one disease but causing another. He links chlorination of water to a general decline in health. "After chlorination of water began in 1904, the modern epidemic of heart disease, cancer and dementia began," says Dr. Price. Or is it?
On the one hand, unpurified water causes – how much would you think – up to 80% of all diseases in the world. If we drink unpurified water, the aging process occurs a third faster than if we drank purified water. That's how important it is to correctly follow just one point of our diet – drink normal water. And it is usually purified with chlorine. Is this right?
Scientists from Finland and the USA have proven through research that liver cancer and kidney tumors in 2% of cases occur due to excessively chlorinated drinking water. This is not such a large percentage compared to diseases of the immune system – due to the increased chlorine content, our immune system suffers in 80% of cases, and with constant drinking of chlorinated water, all internal organs suffer.
For example, with increased doses of chlorides obtained from drinking water, a person often begins to suffer from bronchitis and pneumonia - the respiratory organs suffer first of all. But water continues to be chlorinated, although it has long been proven that chlorine today does not destroy all harmful microorganisms - most of them remain alive and well, continuing to poison our body with toxins. These toxins, interacting with chlorine, can cause disorders at the genetic level.
Our body can be affected not only by water solutions, but also by chlorine vapors. They are more dangerous. It is very good that the trend of chlorinating clothes and bedding, which was previously used in everyday life, has ceased today. Chlorine vapors, which a person inhales in high concentrations, can cause a burn of the mucous membrane of the esophagus and throat, disrupt the respiratory rate, although such situations are rare. Risk groups include people working in hazardous industries, in the chemical industry, in the textile industry, as well as in work with cellulose and pharmaceuticals. Chronic diseases of the respiratory and digestive organs among such people are not uncommon.
Symptoms of Excess Chlorine
- Chest pain
- Acrid dry cough
- Irritation of the mucous membrane of the throat
- Dry mouth
- Diarrhea
- Lacrimation
- Soreness and dryness in the eyes
- Headaches (often severe)
- Heartburn
- Nausea
- Violation of gas formation
- Heaviness in the stomach area
- Frequent colds with high fever
- Pulmonary edema
Excess chlorine can be caused not only by a large dose of salt or chlorinated water that you drink, but also by regular showering. If you often take a hot shower with excess chlorine, then a person receives a much larger dose of chlorine through the skin than with drinking chlorinated water. And the amount of toxins that enter the blood with such bathing increases by 10-20 times.
Water can be purified from chlorine in several ways. First of all, throw activated carbon into it for 15-30 minutes. Or, as a last resort, boil and let the water stand for 24 hours – but this method is less effective, and, in addition, when boiling, all useful substances are destroyed in water, primarily mineral salts.
Chlorine must be present in the body, but its doses must be controlled so that your health always remains at its best.