Every year, the European Commission publishes a report on bathing water quality, which is issued before the start of the next bathing season. In the 2021 report, 255 (97.7 %) of the 261 Austrian bathing sites were rated "excellent", 4 bathing sites (1.5 %) were rated "good", and one bathing site (0.4 %) was rated "sufficient". One bathing site was not assessed due to a still too short data series.

Report: European bathing water quality 2021

Interactive bathing water map Europe

Bath dermatitis

Higher water temperatures are not only pleasant for humans, water snails can also reproduce better in them - and in the water snails also cercariae, microscopic parasites that can lead to itching and rashes in humans, to so-called bath dermatitis.

Cercariae (fork-tailed larvae) are larvae of sucking worms. They develop in aquatic snails and are subsequently excreted in large quantities. They are found in both freshwater and saltwater, mainly in shallow shorelines. In water, they survive only one day, so they must enter waterfowl quickly to complete their development cycle. Humans are only "unintentionally" infested; the parasites die quickly in the skin. However, they can trigger an immune reaction that leads to itching and skin rashes, bath dermatitis.

The initial infection is often asymptomatic (= without signs of illness) and remains undetected. If symptoms occur, they are usually mild and quickly subside. However, if a person is infected several times by cercariae, itching, redness and wheals may occur, some of them severe. In most cases, bath dermatitis subsides after one to two weeks at the most.

The presence of cercariae does not mean that the water quality is poor. Suitable water snails must be present for the formation of cercariae to occur at all. In Austria, the occurrence of bath dermatitis was first described in the late 1960s; since then, cercariae associated with cases of bath dermatitis have been documented in individual water bodies in all provinces. Chlorinated water, e.g., in a public swimming pool or outdoor pool, does not pose a risk for bathing dermatitis.

Algae bloom

Dogs are usually not allowed at bathing areas. When it is hot, however, dog owners are happy to allow their four-legged friends to cool off. However, caution is advised in some pools, ponds, etc: High water temperatures can cause a rapid proliferation of cyanobacteria, known as "algal blooms." Cyanobacteria can form toxins (poisons) which can be fatal for dogs, e.g. if they lick the algae blooms out of their fur. The rotting "bloom material" on the shore, which some dogs eat, also poses a danger.

Cyanobacteria, colloquially called "blue-green algae", are not true algae, but bacteria and natural components of surface waters. They can proliferate en masse, especially in over-fertilized waters. Signs of cyanobacteria in the water are:

• bluish-green turbidity of the water
• streaking
• "algae carpets" on the water surface ("pea soup")
• limited visibility depth of less than 1 meter

If a water body is suspected of showing an accumulation of cyanobacteria, water samples can be tested for cyanobacterial toxins at our facility for a fee.