Avaliação da qualidade microbiológica do ar em biblioteca de uma universidade pública federal

Abstract

Largely conditioned environments such as libraries and public archives are permanently subject to an important concentration of microorganisms in indoor air, as they have a favorable natural environment for the propagation of bacteria and fungi, which are transported through the dust internal files, the large movement of people and the ventilation air (BORREGO, et al., 2012). According to the World Health Organization (World Health Organization, WHO) air quality in indoor environment has a wide variety of pollutants that can be associated with various diseases and syndromes (WHO, 1988). Considering the global concern with climate-controlled environments related to ill health, the Ministry of Health (MOH), through the proposed ordinance GM / MS n °. 3.523/98, which were certain standards of air quality in air-conditioned environments, as well as its monitoring (MS, 1998). The aim of this study was to evaluate the microbiological quality of air in a public library Higher Education. To determine the microbiological profile in local search (hall and top floor ) used the technique of passive sampling by spontaneous sedimentation, which involves exposing Petri plates containing solid medium. The culture media were used: Potato Dextrose Agar (PDA) supplemented with antibiotics (tetracycline) to the total counts of fungi, mannitol agar for the isolation of Staphylococcus sp; Nutrient Agar and MacConkey agar for isolation of Enterobacteriaceae (Gram-negative bacilli). A total of 24 plates were used for each medium, and 03 for each sample. The plates were exposed for 30 minutes during the morning (8:30 h) and afternoon (17:00 h), in triplicate, with a (15 days) repetition, totaling 96 samples. First, fungi and bacteria (CFU) were visualized and quantified macroscopically and the results presented in CFU/m3 air. The results showed that the total count of microorganisms in the lobby and upper floor ranged 3-1508 CFU/m3 for bacteria and 377-871 CFU/m3 for fungi. The site has contributed to greater amount of MO (UFC) was the lobby with 1508 CFU/m3 for bacteria and fungi 871 CFU/m3 , being above the level recommended by ANVISA (≤ 750 CFU/ m3 ). In superior floor the maximum values found were 649 CFU/m3 (bacteria) and 337 CFU/m3 (fungi) and is therefore within the maximum values recommended by ANVISA, although the concentration of fungi is close to acceptable. Among the isolated bacteria, Staphylococcus coagulase negative cocci (S. capitis, S. epidermidis, S. hominis, S. haemolyticus) were the species present in the samples, but was not the presence of S. aureus (coagulase positive). As for Gram negative enterobacteria were observed the following: Klebsiella pneumoniae, Leclercia adecarboxylata and Sphingomonas paucimobilis. Finally, the data obtained in this study demonstrate the presence of MOs (bacteria) that are potentially pathogenic, so a study covering the other dependencies of the library as well as at different times could accurately assess the microbiological quality of air.