Airborne Fungus and Bacteria Concentrations in Houses with Indoor Pets

Abstract

Airborne fungus and bacteria concentrations were measured in the living rooms of 25 households with indoor pets (PET) and 35 households without indoor pets (NOPET) in summer and autumn. Room temperature and humidity were also measured at the same time. A questionnaire asked the residents about the length of time the room was ventilated per day, how frequently the room was cleaned, daily duration of air conditioning, and so on. Room temperature ranged from 28 to 30°C in summer and from 17 to 20°C in autumn. Air humidity was 50 to 70% in both seasons. High concentrations of airborne fungus (0.07-0.09 CFU/l) and bacteria (0.27-0.35 CPU/l) were found in PET compared with NOPET households (0.02-0.05 CPU/l in fungus, 0.13-0.15 CPU/l in bacteria). However, high concentrations of fungus and bacteria were not always observed in all the PET houses; rather, high concentrations were frequently found in PET houses that were cleaned infrequently or in which the rooms were less well ventilated than in other PET or NOPET houses.