[Occurrence of bacteria from the Legionella genus in cooling water systems].

Results of Legionella bacteria study in water samples from industrial cooling water systems and air-conditioner systems were presented. Legionella pneumophila was detected in 32,4%. of 518 examined water samples collected from 1998 to 2006. The most dangerous Legionella pneumophila sg 1 was detected in 11.3% of all positive samples. The high number (more than 10(4) jtk/l) of isolated Legionella bacteria was determinated in 60% of water samples taken from cooling waters systems and 33% of samples of waters related with air-conditioning that is alarming. High pollution requires immediate intervention (installations cleaning and disinfection). Data indicated real health risk connected with Legionella pollution of cooling water. Creation of low regulations which will put the obligation of cooling water systems monitoring of Legionella bacteria occurrence and taking preventive measures is necessary.