Health and hygiene issues of swimming pools

Pool health and hygiene issues deal with the sources and types of pool water pollution. The main source of pollution is man. Substances causing pool water pollution include cellular detritus (exfoliated epithelia of skin, mucous membranes and hair), micro-organisms and various organic substances (sweat, urine, sebaceous and mucous secretions, residues of cosmetics, sunscreens, soaps, etc.)

Fecal pollution
Fecal pollution is the most common water pollution. Indicators include bacteria, viruses and protozoa.


 * Bacteria


 * enterococci - group D streptococci (fresh contamination);
 * coliform bacteria - enteropathogenic Escherichia coli;
 * sporulating clostridia - Clostridium perfringens.


 * Viruses


 * enteroviruses;
 * adenoviruses;
 * Hepatitis A viruses.


 * Protozoa


 * Giardia;
 * Cryptosporidium.

Sources of faecal pollution

 * Visitors of the pool;
 * Birds and rodents at outdoor pools;
 * Contaminated overflowing water

Microorganisms of non-fecal origin

 * Bacteria: Legionella spp., Pseudomonas spp., Mycobacterium spp., Staphylococcus aureus., Leptospira spp.
 * Viruses: papillomaviruses, adenoviruses.
 * Fungi: Trichophyton spp., Epidermophyton floccosum.
 * Protozoa: Naegleria fowleri, Acanthamoeba spp.

Chemical contamination of pool water

 * Disinfection and water treatment products


 * disinfectants and algicides;
 * residues of coagulants and pH adjusting agents;
 * by-products of water chlorination (chloramine, chlorates, chlorine gas, haloacetic acids, trihalomethanes).


 * Pollution of incoming water


 * Unwanted organic matter, carbon compounds, protozoa and microbes;
 * chemicals (industrial products, fertiliser and pesticide residues).


 * Chemical substances from which the pool visitor is a source


 * urine, sweat, sebaceous gland products;
 * residues of sunscreens, make-up, soaps, dust from body surface.

Factors influencing the risk associated with bathing

 * Route of exposure (inhalation, dermal contact and skin absorption);
 * length of stay in the pool water (degreasing and maceration of the skin, irritation of the skin by chemicals, formation of rashes, mechanically damaged skin - abrasions, rashes - facilitates the entry of infection);
 * medical condition (susceptible individuals - with reduced or impaired immunity);
 * visitor behaviour (initial showering before entering the pools).

Risks of accidents and drowning
Injuries and drowning are among the most common health risks associated with pool use.

Health risks associated with water temperature
Sudden or prolonged exposure to extreme temperatures can be associated with health problems in sensitive people.

Hot water (thermal baths) - drowsiness, fainting.

Cold in cooling pools (sauna 8-10 °C) - respiratory arrest, hypothermia, slow heart rate, muscle cramps or even loss of consciousness.

Exposure to these temperature extremes should be avoided by pregnant women and young children, people suffering from heart and circulatory diseases.

Risk of allergic diseases

 * associated with a visit of chlorinated swimming pools;
 * chlorine-based oxidants contribute to an increased risk of atopic diseases, (asthma or hay fever) - facilitate  transepithelial penetration of allergens;
 * risk mainly for pool staff, competitive swimmers.

Pool water control

 * The presence of people in the pool water represents a continuous introduction of microorganisms and a risk of transmission of infection between persons;
 * if the pool is in use and in operation, some health risk will always exist;
 * regular monitoring of the pool water quality is important.


 * Pollution indicators


 * Escherichia coli: indicator of faecal contamination;
 * colony count at 36 °C: total microbiological load of water;
 * Pseudomonas aeruginosa and Staphylococcus aureus: indicators of specific non-fecal contamination from bathers;
 * Legionella: opportunistic pathogen, indicator of the overall hygiene status of the water system;
 * Transparency, turbidity: an indicator of pool load and water treatment efficiency;
 * pH - optimum range (7.2-7.6);
 * bound chlorine, free chlorine;
 * oxidation-reduction potential (ORP).

Risk minimisation measures

 * Education of pool visitors;
 * technical measures aimed at reducing the number of microorganisms or the concentration of undesirable chemicals (water treatment, including disinfection, water recirculation, effective air ventilation);
 * proper training of operating personnel;
 * compliance with the operating rules.