Chlorine: Antiseptic or Cancer Provoker?
Chlor (Cl)
The daily requirement of the human body for chlorine is about 1.6–2 g. The minimum requirement for chlorine is about 800 mg per day. An infant receives the necessary amount of chlorine through breast milk, which contains 11 mmol/L of chlorine.
A typical diet contains an excess amount of chlorine – 7–10 g. The majority of chlorine (up to 90%) is obtained by adults from table salt. About 4 g of chlorine is obtained from bread and 1.5–4.6 g from table salt.
Chlorine accumulates in visceral tissue, skin, and skeletal muscles. In the stomach and skeleton of humans, the chlorine content is three times higher than in other organs and tissues. In cells, 10–15% of total chlorine is accumulated, of which 1/3 to 1/2 is in erythrocytes.
Chlorine is primarily absorbed in the large intestine. The absorption and excretion of chlorine are closely related to sodium ions and bicarbonates, to a lesser extent – to mineralocorticoids and the activity of Na+/K+–ATPase.
Chlorine is excreted from the body mainly through urine (90–95%), feces (4–8%), and through the skin (up to 2%). Chlorine excretion is associated with sodium and potassium ions, and reciprocally – with HCO3– (acid-base balance).
In the stomach, chloride ions create a favorable environment for the action of proteolytic enzymes in gastric juice; it is a component of hydrochloric acid produced by the stomach, necessary for the digestion of most food products. Chlorine is important for the formation of blood plasma, acts as an activator of certain enzymes, and plays a significant role in maintaining the acid-base balance of blood. It participates in all biochemical reactions that occur with the involvement of sodium.
Chlorine also plays an important role in the body by maintaining normal fluid balance. It is often assumed that consuming the recommended daily allowance of sodium automatically includes the chlorine requirement. However, recent findings suggest that this is not always the case.
The main manifestation of chlorine excess is growth inhibition.
Chlorination for water disinfection was recognized as a panacea in the 1820s by European doctors concerned about the extremely high mortality rates due to emerging epidemics. Free chlorine in water oxidizes and kills microorganisms; however, it also interacts with other substances, forming toxic compounds.
The use of disinfected (chlorinated) drinking water, as well as visiting indoor swimming pools, may lead to allergic reactions associated with chlorine exposure. Children who regularly use indoor pools for swimming may also be more prone to developing asthma – chlorine used in pools for water purification can increase the risk sixfold. This occurs because the by-products of chlorination contaminate the air in the pool area, irritating the airways and lungs, making them more susceptible to allergens.