Healthy recreational waters


16 October 2003

Coastal waters
New WHO guidelines should make recreational waters safer

Recreational water activities can have substantial benefits to health and well-being. Swimming pools, beaches, lakes, rivers and spas provide environments for rest and relaxation, physical activity, exercise, pleasure and fun. Yet they also present risks to health. Polluted and unsafe recreational waters can lead to infections, exposure to chemicals, injuries and death.

New WHO Guidelines for safe recreational water environments are aimed at reducing bathing-related death and disability, and making beaches and recreational waters safer places to relax, exercise and have fun.

Recreational waters for positive health

Water-based recreational activities have long been recognized as having a positive influence on health and well-being. Since ancient times, bathing in mineral waters has been reputed to cure a variety of illnesses. While there have been few scientific studies of these postulated effects, there is no doubt of the benefits of warm water therapy in pain relief, joint mobility and relaxation.

These days, more and more people are taking up recreational activities in and around water, and these are an important part of leisure and tourism around the world. Swimming is recognized as one of the most beneficial forms of exercise and is also an important therapy for rehabilitation after operations such as hip replacements.

Hazards of recreational water use

Water-based recreation, however, can expose people to a variety of health risks, which vary according to the type of water, geographical location and local conditions. These are linked to physical, microbial and chemical hazards.

Physical hazards: drowning and injuries
Drowning is one of the unequivocal dangers of recreational water use. An estimated 400 000 people drown each year(1). In children, drowning is one of the leading causes of accidental deaths (more information on drowning).

Boys diving

Most cases of drowning are the result of drinking alcohol or poor supervision. In seas and rivers, tides and currents are also important hazards and can cause even strong swimmers to drown. In spas and pools, drowning can result from hair or body parts getting caught in inlets and outlets. The clarity of the water can also be a factor. In murky water, people may not see that someone needs help. Overcrowded swimming areas present a similar problem.

Water-based recreational activities can also result in a variety of injuries. Diving or jumping into waters of unknown depth can lead to serious injuries, including spinal injury, which may ultimately result in paraplegia or quadriplegia. Diving into shallow water is the most common cause of spinal injuries. More common, but usually less severe, are injuries arising from discarded glass, cans and needles on beaches or near bathing areas, or injuries from slipping on wet surfaces around pools.

Reducing the risk of drowning and injuries – some solutions

- Educate children and adults about the risks of water activities, including basic life saving and first aid techniques
- Supervise children and weak swimmers at all times in or near to swimming areas and water bodies
- Teach children to swim
- Keep beaches clean
- Install fencing around pools
- Display warnings and water safety instructions
- Improve pool design for safety

Reducing the risk of drowning and injuries – some solutions

:: Educate children and adults about the risks of water activities, including basic life saving and first aid techniques
:: Supervise children and weak swimmers at all times in or near to swimming areas and water bodies
:: Teach children to swim
:: Keep beaches clean
:: Install fencing around pools
:: Display warnings and water safety instructions
:: Improve pool design for safety.
 

Cryptosporidium oocysts
Cryptosporidium oocysts

Microbial hazards: infections
Millions of litres of raw or partially-treated sewage are pumped into seas every day, polluting the environment and resulting in an estimated 250 million cases of bathing-related gastroenteritis and upper respiratory disease each year. Pathogenic viruses and bacteria such as Escherichia coli O157 are commonly found in untreated sewage, rendering swimmers, surfers, and children, at risk from infection.

While the water quality in swimming pools and spas is generally well-monitored, there may be outbreaks of disease due to contamination. The majority of outbreaks are caused by viruses or bacteria linked to faecal contamination. An increasing number of infections are associated with protozoa such as Giardia and Cryptosporidium, which are resistant to commonly used pool disinfectants. Spas present particular risks and require particularly stringent monitoring, as the warm, nutrient-containing, aerobic waters provide an ideal habitat for bacteria to proliferate.

Reducing the risk of infections – some solutions

:: Employ effective sewage discharge procedures
:: Implement beach management and award schemes
:: Set international norms, standards and limits for microbial levels in seas, lakes and rivers
:: Apply appropriate levels of chlorine or other disinfectants to pools
:: Empty, disinfect and clean pools, and filter pool water in cases of accidental faecal release
:: Encourage pre-swim showering, toilet use and good hygienic behaviour at pools and spas
:: Monitor pH, disinfectant levels and other parameters frequently as part of a routine pool and spa maintenance schedule
:: Clean spas and spa filters regularly.
 

Chemical hazards
Chemical contamination of seas and rivers arises principally from direct waste discharge (e.g. industrial effluent) or chemical spills, and is typically local or regional in nature. Chemicals found in swimming pools and spas include those related to water treatment (disinfectants and their by-products), and those that come from swimmers (soap residues, cosmetics, suntan oil). Disinfectant by-products, such as chloroform, are produced from chemical reactions between the disinfectants and organic or inorganic material in the water. Little is known about the adverse effects of exposure to chemical contaminants, although there is concern about the possible long-term toxicological effects.

Reducing the risk of chemical exposure – some solutions

::Monitor and regulate industrial effluents
::Develop damage limitation action plans in the event of chemical spills
::Ensure good ventilation in rooms housing pools and spas
::Encourage pre-swim showering and good hygienic practices
::Monitor pH, disinfectant levels and other parameters frequently as part of a routine pool and spa maintenance schedule.
 

Tropical waters

Recreational waters in the tropics and subtropics pose special hazards, not just from some of the local aquatic or amphibious predators such as crocodiles, but also from a number of tropical diseases. First and foremost is schistosomiasis or bilharzia, a disease caused by parasitic worms. The complex life-cycle requires the parasites to spend part of their development inside aquatic snails found in freshwater lakes and streams. Infectious larvae are shed by the snails and penetrate the skin of people wading into or bathing in the water. The parasites then lodge as adults in people’s veins around the intestines and liver, or around the bladder. Children and adolescents are particularly vulnerable to schistosomiasis as they frequently play or bathe in unsafe water in hot tropical climates (more information on schistosomiasis).

Healthy recreational waters: WHO’s role

Girls in a swimming pool

The health aspects of recreational water use are attracting increasing attention by members of the public, concerned professionals, regulatory agencies, and the tourist industry. WHO’s principal role in improving the safety of recreational water environments is to develop, publish and help implement guidelines for use by national and local authorities. Based on a critical review of the available scientific evidence and representing views of world experts, the purpose of the guidelines is to ensure that recreational water environments are as safe as possible in order for the most people to get the maximum benefit.

Water is the essence of life. Without water, we cannot live for more than a few days. The desperate need to improve access to safe drinking water in many parts of the world means that the recreational role of water is not seen as a health priority. Yet children will play in water whether it is safe or not, and the use of water for relaxation, exercise and pleasure will continue to grow. It is essential, therefore, to ensure that recreational bathing becomes safer and healthier.

(1) This number includes accidental drowning and submersion, but excludes drowning due to floods, water and other transport accidents, assaults and suicide.

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