Health effects of swimming pool disinfection
|Health effects of swimming pool disinfection |
Disinfectants that are used for swimming pool disinfection water can affect human health.
Free active chlorine
Hypochlorous acid (HOCl) and hypochlorite (OCl-) are the main components of free active chlorine. Swimming pool water has a high pH value and the amount of dissolved chlorine gas as free active chlorine is negligible. Free active chlorine hardly ever causes eye irritations. These only occur above concentrations of 20 mg/L. Dissolved chlorine and chlorine substances dehydrate hair and skin. The air above the pool contains chlorine gas concentrations between 0,01 and 0,1 mg/m3. These concentrations are far below the level that irritates respirational tracts. Through the formation of combined active chlorine, free active chlorine can cause irritation.
Combined active chlorine
Combined active chlorine is the generic term for reaction products produced by free active chlorine with organic and inorganic nitrogen pollutions. These pollutions are made of swimmers excretion products. Combined active chlorine is a complex mixture of partly unknown substances, such as chlorine ureum combinations, chloramines and chlorine kreatines.
Disinfection byproducts: chloroform
Some disinfection byproducts, such as trihalomethane chloroform, are suspected carcinogenic.
Effects of chloroform
Exposure to low concentrations of chloroform causes renal and liver defects. These can be demonstrated by enzymes in the blood which are indicators for renal- and liver functions. Epidemiological research shows there might be a relation between skin exposure to chlorinated organic substances and hypochlorite, and skin cancer. This relation has not been proved by laboratory animal testst. Long-term oral exposure of laboratory animals to chloroform through food caused liver cancer.
Health complaints of swimming pool attendants
Especially swimming pool attendants are exposed to swimming pool disinfection byproducts for a long period of time. Dutch research, carried out in 2001 by Abvakabo Nederland, concerned working conditions in swimming pools. Swimming pool attendants were interviewed. The research shows that a lot of employees suffer from forgetfulness, fatigue, chronic colds, voice problems, eye irritations, headache, sore throat, eczema and frontal sanus inflammation. Fertility problems are also mentioned. All problems are probably caused by working conditions. People work long hours in a warm, humid environment and are exposed to chemical substances. Swimming pool ventilation is often insufficient and volatile disinfection byproducts remain. If swimming pool attendants do not work, health problems vanish and a sense of health returns. Alternative disinfectants that produce less disinfection byproducts and improved ventilation can prevent or at least minimize problems.
Effects of exposure to swimming pool disinfectants and byproducts have been researched a couple of times. Competitive swimmers weekly spent many hours in swimming pools. During exercise their physical effort is large. Their inhalation is more deeply and more powerful than that of recreational swimmers. They inhale more air and absorb more chlorine products. Lung functions of swimmers decrease when they are swimming in pools that are disinfected by chlorine. Many competitive swimmers suffer from asthma. Complaints disappear when they swim in outdoor pools, because the wind removes gasses from the air above the pool. Children inhale more air per unit body than adults do. They relatively absorb more gaseous substances and the health risk for children is bigger. Swimming pools that are disinfected by chlorine gas can produce hydrochloric acid with sunlight. This causes the pH value to drop. when pH values drop below 3,6, swimmers can suffer from dental abrasion. Tooth enamel dissolves and the teeth become brittle and sensitive.
At low pH values in swimming pools, the teeth can be damaged