ANSES publishes its recommendations for whirlpool baths and pools

For several years now, water-based recreational activities have become increasingly popular and are intended for a wide range of individuals of all ages. Today many sector players offer a wide variety of recreational and sporting activities involving water, including conventional swimming pools, artificial bathing sites and whirlpool baths (Jacuzzis).  In addition to the development of these activities, our understanding of the chemicals and pathogens that may occur in swimming pool water has also grown, requiring that the regulations for conventional swimming pools be updated and the creation of a regulatory framework suited to new water-based recreational practices. 

To do this, the ministries of health and ecology asked ANSES in 2006 to assess the health risks associated with recreational water. Today the Agency issues a collective expert assessment report on the health risks found in the water and air of whirlpool baths (Jacuzzis). This is its most recent publication in the cycle of expertise work undertaken on this topic since 2006, and follows on from its reports on regulated swimming pools (2010) artificial bathing sites (2009).

What are the risks associated with whirlpool baths?

The chemical compounds and microbiological agents found in the water and air of whirlpool baths are identical to those described in ANSES's expert report on regulated swimming pools (trihalomethanes, trichloramine, Legionella pneumophilla, Pseudomonas aeruginosa, Staphyloccocus aureus, etc.), regardless of the origin of the water supplied to the pool.  

However, whirlpool baths have certain characteristics (low water volume, high proportion of bathers compared to the volume of water, sporadic use, close proximity of bathers, bubble aeration of the water, fluctuating concentrations of disinfectant, high water temperature) which may change the ranking of these hazards. 

Similarly, when the water supplying the pool is different from that used for human consumption, the ranking of hazards also changes.  

In addition, due to the layout of whirlpool baths and how they function, certain specific hazards exist: 

• the high water temperature in these pools can promote the development of micro-organisms, amplify the dynamics of water disinfection products, and may intensify the formation of disinfection by-products;
• the high water temperature combined with the water bubbles promotes the volatilisation of volatile and semi-volatile disinfection by-products;
• the specificities of the hydraulic systems used (including nozzles and bends) create conditions which promote the development of biofilms.

Agency recommendations

Considering these different points, the Agency has listed various measures to implement in order to reduce possible health risks for bathers and personnel: 

• recommend that bathers wash thoroughly before entering the pool area;
• improve pool layout and ensure proper upkeep of the premises;
• provide adequate treatment of the pool water;
• improve water quality management by closely monitoring chlorination by-products (trihalomethanes, chloramines), total organic carbon, and microbial pathogens (Staphylococcus, Pseudomonas aeruginosa, etc.);
• improve air quality management through trichloramine monitoring.

The Agency also recommends:

• a "reference" water temperature of 32-33°C with a mandatory upper limit of 36°C;
• limiting baths to 15 minutes;
• prohibiting whirlpool bath access to children under 10 years of age due to the average pool depth and average height of children;

In addition, the Agency highly discourages the use of certain materials for the construction of whirlpool baths (wood) and certain practices associated with them (such as the addition of chocolate, milk, etc. to the water).