摘要:We report results of environmental microbiological sampling in an office building whose occupants referred different symptoms ascribable to the air conditioning system. Legionella pneumophila serogroup 1 was detected in water samples drawn from the cooling tower with counts that ranged from 1.4 x105 to 1.5x107 CFU/L. This biological agent is classified in the second risk group according to Italian law (D.Lgs. 626/94), consequently proper control measures in order to re-establish acceptable hygienic environment conditions and to assure healthy workplace are needed.