| Abstrakt: |
Summary: In order to evaluate bacterial and fungal contamination, the authors used a qualitative and quantitative procedure and investigated 47 air conditioning and humidifying units. Air samples were studied using Biotest RCS biocollector (1606 liters on 6 different selective media), whilst dust samples were analysed after spreading 10 mg onto fungal media. Selective research ofLegionella and fungi were performed using water filtrates and specific media. Even though, the most frequently identified species were quite common environmental fungi, mainlyPenicillium, Alternaria andAspergillus fumigatus (36 out of 47 collections), the health effects of intense exposure to these common moulds are not really known.Staphylococcus aureus was identified 6 times and thermophilic actinomyces species (A. candidus) once. From the quantitative analysis a significant relationship was found between some risk factors and airborne contamination. Indeed bacteria and fungi number depends on the humidifying system (steam or washer), efficiency of secondary filters, relative humidity percentage (< or >60%), installation maintenance, industrial activity and complaints of people at risk. The presence of air recycling and biocide use seems only to have an influence on fungal flora. Having determined a global risk score for each air conditioning unit, the authors underline the fact that bacterial and fungal airborne contamination increases with score. Moreover, for a global, metrological, medical and technical evaluation, a multidisciplinary approach has proved itself to be indispensable. |
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