Impact of air-conditioning system disinfection on microbial contamination of passenger cars

AbstractAn automobile air-conditioning (AC) system can be a source of microbiological contamination in a driver ’s car. The aim of this study was to assess the level of microbial contamination before and after servicing of the automobile AC system, based on qualitative and quantitative analyses of bacteria and fungi isolated from the air, and to check the efficiency of different AC system cleaning methods i n the removal of microbial contaminants. The study was carried out in 35 randomly selected cars, equipped with AC systems. In each car tested, viable bioaerosol samples were taken using a single-stage MAS impactor before and after servicing the AC systems. Four methods were used to disinfect the air -conditioning installations in the vehicles examined: ozonisation, application of chemical disinfectant using ultrasounds, manual application of chemical disinfectant foam and simultaneous ozonisation and application of chemical disinfectant foam. The bacterial and fungal concentrations in air sampl es before AC servicing in cars were between 7.5 × 101 cfu/m3 and 2.0  × 103 cfu/m3 and 4.0  × 101 cfu/m3 and 5.0  × 102 cfu/m3, respectively. Regardless of the disinfection method, after the AC service, a decrease in microbial concentrations was observed. The highest disinfection efficiency was observed for two methods: ozonisation combined with manual application of the chemical disinfectant into the air-conditioning system and spraying of the chemical dis...
Source: Air Quality, Atmosphere and Health - Category: Environmental Health Source Type: research