Dating back to 1981, the regulatory context associated with swimming pools presupposes an update taking into account in particular the evolution of practices. Indeed, during the development of the French health regulations on public swimming pools, different types of pools such as whirlpool baths were almost non-existent and their specificities were not taken into account. To carry out this update, the ministries in charge of health and the environment asked the Agency to draw up an inventory of swimming pools with the aim of detecting any health risks.
The Agency’s work was carried out in two stages and focused on:
- regulated swimming pools (within the meaning of article D1332-1 of the public health code). These pools, intended for sports or leisure use, are supplied with water from the public distribution network. These are municipal swimming pools, hotels, campsites, vacation homes, lodges, etc. ;
- hot tubs,whether they are powered by water intended for human consumptionby of Seawater or by natural mineral water.
Expertise work has enabled identify the main chemical and microbiological hazards present in water, air and surfaces regulated swimming pools and whirlpools. The dangers have been described in particular according to the origin of the basin’s supply water.
Chemical hazards
The identified chemical hazards mainly come from substances formed by reaction of disinfectants (mainly chlorine) with organic matter brought in by swimmers. Among more than 400 substances listed in regulated swimming pools, only about ten were selected to carry out the health risk assessment, due to their toxicity and their high concentration in the water. The substances selected are the trichloraminethe trihalomethanesTHE haloacetic acids and the bromates.
According to the scenarios established and the populations observed (babies, children, athletes, workers, pregnant women), the study does not show any health risk concerning these substances, except for trichloramine which can cause respiratory and ocular disorders. among high-level swimmers, lifeguards and baby swimmers; dichloroacetic acid which could be responsible for adenoma and hepatocellular carcinoma in high level swimmers.
Microbiological hazards
The microbiological hazards have been analyzed and the pathogenic waterborne germs potentially found in regulated swimming pools have been listed. Although no epidemic has been identified to date in France, it appears that the microbiological risk is essentially linked to the lack of hygiene of swimmers.
These same pathogenic substances and germs can also be found in hot tubs. However, these basins have certain particularities which can modify the hierarchy of the dangers described and/or be the source of additional relevant dangers. These specificities relate to:
- high water temperature;
- the presence of bubbling devices;
- the low volume of water compared to the number of bathers frequenting these pools;
- a low water renewal rate compared to the rate of frequentation of these baths;
- fluctuating disinfectant concentration;
- increase in pH;
- inter-bather promiscuity.