Where Does All the Residual Chlorine Go? Do You Know How Harmful Residual Chlorine in Tap Water Really Is?

Faced with increasingly serious water pollution problems, our tap water treatment process still uses the decades-old method of "sedimentation, filtration, and chlorine disinfection." Can you safely drink tap water treated with such a simple process?

1. What are the main methods of tap water disinfection and sterilization currently used?

A: In China, the current tap water purification method is chlorine sterilization; in developed countries and regions, the tap water purification methods are ultraviolet light and ozone technology sterilization.

2. What is chlorine?

A: Chlorine is a yellowish-green gas with a strong, suffocating odor and is toxic. It is a strong oxidizing agent, forming phosgene upon contact with carbon dioxide. Under high pressure, it can be liquefied into liquid chlorine, appearing as a white fumes in the air. It is highly soluble in water, alcohol, and ether; its aqueous solution is called hydrochloric acid.

3. Why is chlorine added to tap water?

A: Tap water should ideally be hygienic and safe drinking water. However, due to environmental pollution, bacteria and other harmful substances proliferate in the water. To inhibit and kill bacteria, chlorine is added during the water treatment process.

4. What are the harmful effects of chlorine on the human body?

A: Chlorine gas is seriously harmful to the human body. It can irritate the eyes, nose, throat, and upper respiratory tract. It can cause acute pulmonary edema and pneumonia. High concentrations can paralyze the respiratory center, leading to sudden death. Long-term inhalation of low concentrations of chlorine can cause chronic poisoning, resulting in the production of large amounts of free radicals in the body, accelerating aging. Major symptoms include rhinitis, chronic bronchitis, emphysema, cirrhosis, arteriosclerosis, and even cancer.

When heated, chlorine reacts with organic matter in water to produce carcinogenic substances such as chloroform.

5. What effect does water containing residual chlorine have on washing vegetables, fruits, and grains?

A: Chlorine destroys vitamins, minerals, and other nutrients in vegetables, fruits, and grains, severely affecting the body's absorption of nutrients.

6. How does residual chlorine enter the human body?

A: Chlorine in tap water is easily and quickly absorbed by any porous surface, such as skin, nostrils, mouth, lungs, hair, eyes, and oxidized surfaces like meat, fruits, and vegetables.

7. Why is residual chlorine easily absorbed through human skin?

A: Because the surface of human skin is covered with pores and sweat glands, residual chlorine can easily enter and be absorbed through these tiny pores upon contact with tap water.

8. What are the dangers of long-term bathing with water containing residual chlorine?

A: When bathing with tap water containing residual chlorine, 40% of the total chlorine in the bathroom is inhaled through the respiratory tract, and 30% is absorbed through the skin. This is 6-8 times the amount of chlorine normally ingested through drinking water. Mild effects include itching, and over time, the risk of cancer increases by 30% by middle age.

9. Why is it said that boiling tap water is more harmful?

A: Boiling tap water causes chlorine to react with organic matter in the water, producing carcinogenic substances such as chloroform. The amount of chloroform will increase 3-4 times compared to tap water. If residual chlorine is not removed, the coffee, tea, or soup we drink daily, after being heated and boiled, will have 3-4 times more carcinogens in our bodies.

10. What diseases can long-term consumption of water containing residual chlorine lead to?

A: Heart disease, coronary atherosclerosis, anemia, bladder cancer, liver cancer, rectal cancer, high blood pressure, and allergies.

11. What are the dangers of residual chlorine to children?

A: When bathing children with tap water, chlorine can cause dry, brittle, and split ends in their hair. It can also bleach the skin, cause peeling, and lead to intensely itchy skin allergies. When chlorine interacts with organic matter, such as sweat, it can easily form nitrogen trichloride in the surrounding air, which can easily damage the eyes and throat. Chlorine inhaled into the lungs can damage respiratory cells (Clara cells), leading to asthma and emphysema.

12. What are the dangers of residual chlorine to pregnant women?

A: Long-term consumption of tap water containing chlorine by pregnant women can affect the development of the fetus's heart and lungs, potentially leading to neonatal arrhythmia, heart failure, and functional lung disorders.

13. What are the dangers of residual chlorine to the elderly?

A: It can lead to atherosclerosis, heart failure, arteriosclerosis, heart disease, bladder cancer, liver cancer, rectal cancer, and high blood pressure.