quinta-feira, novembro 17, 2011

POLLUTANTS IN SWIMMING POOLS

 
The water in public swimming pools contains microorganisms and unwanted substances, which derive from the skin and excretion products of swimmers. Swimmers cause many pollutants to enter the water, such as bacteria from saliva, excretion products, pollution from swimwear, skin tissue, sebum, sweat, nose and throat saliva, hairs, cosmetics and ammonia (NH3).

Vouching for clean swimming pool water through constant refreshment is often too expensive. Furthermore, this does not solve the problem of pollutants that remain on swimming pool walls. The water is recicled, causing pollutant and pathogen concentrations to increase. Microorganisms will multiply and this causes the risks of contagion to increase.

DISSOLVED POLLUTANTS
 
Swimming pool water contains dissolved pollutants, such as urine and sweat and other excretion products of swimmers. Sweat and urine largely consist of water, ammonia and ureum. These substances also contain kreatine, kreatinine and amino acids. The components of sweat and urine are not harmful for human health. However, when these products react with disinfectants in the water, such as chlorine, unwanted reaction products can be formed which consist mainly of chloramines.

The water can contain dissolved pollutants that derive from disinfectants and cleansing agents that are used to clean swimming pools. Dissolved pollutants are largely removed by oxidation. This means that pollutants are decomposed by chemicals. Substances that are not or partly decomposed during the oxidation process and oxidation products are removed from the circulation system by gradual refreshment of swimming pool water.
 
HEALTH EFFECTS OF SWIMMING POOL POLLUTANTS
 
Swimmers are susceptive to pathogenic microorganisms in swimming pool water. As a result of cooling and water uptake, the resistance of the mucous membranes of swimmers can weaken, causing them to become more susceptive to pathogens in swimming pool water and air, and even to pathogens that are present in their own bodies. Microorganisms that enter the water through excretion by swimmers can cause a large variety of conditions. Most pathogenic microorganisms cause diarrhoea or skin rashes. Certain microorganisms can cause serious symptoms, such as paralysis, brain inflammation, heart inflammation, jaundice, fevers, vomiting, diarrhoea and respirational or eye infections.

Pathogenic mciroorganisms that can be found in swimming pool water are bacteria, viruses and parasitic protozoa. Young children, elderly people and people with damaged immune systems are more susceptive to infections caused by these species and will fall ill more easily. People that have an untreated form of cancer may also suffer from lower resistance to waterborne diseases. Not every person that is infected will fall ill, but hen or she can still cause contagion of other people.

In developing countries, the number of people with damaged immune systems is increasing, as a result of an increase in the number of AIDS patients in the last 20 years.

Fonte: Lenntech