Análise da qualidade microbiológica do ar de uma cooperativa de reciclagem no Oeste do Paraná

Abstract

This study aimed to evaluate the microbiological air quality of a recycling cooperative located in the city of Santa Helena/PR. Five data collections were carried out in April and June 2021, following the methodology of spontaneous sedimentation and using Petri dishes for cultivation of fungi (Dicloran Rosa Bengala Chloramphenicol Base Agar) and gram negative bacteria (Eosin Methylene Blue Agar) . The plates were placed open at ten different collection points inside and outside the cooperative for 30 minutes. After incubation, the colony forming units in each plate were quantified and the fungi and bacteria were isolated for further identification. For the molds, slides were prepared for visualization under an optical microscope (400x) and comparison of the structures with taxonomic keys. For the identification of bacteria, Bactray kits were used with isolated colonies with 24h of growth, diluted in sterile saline water. In order to make the population aware of the correct separation of solid waste, an educational booklet in digital format was prepared to be made available to students in the municipality, as well as identifying the main contaminated waste that reached the cooperative. In the quantification of gram negative bacteria in the indoor environment, collections 1, 2 and 3 exceeded the limit of 500 CFU m­³ of air, while in the outdoor environment, only collection 5 (627.76 CFU m­³) presented an average that did not comply with the legislation. For bacteria, the cooperative environment presented an I/E ratio greater than 1.5, indicating internal sources of contamination. Nine species of bacteria were identified, belonging to five genera (Acinetobacter sp., Klebsiella sp., Serratia sp., Shigella sp. and Stenotrophomonas sp.) in the indoor environment and five species in the outdoor environment, with a predominance of the genus Klebsiella sp. The fungus count exceeded the legal limits (750 CFU m­³) in the first, fourth and fifth collections with averages of 858.86 CFU m­³, 948.93 CFU m­³ and 956.21 CFU m­ ³ of air, respectively, and the environment is in accordance with the I/E ratio, indicating a greater amount of fungi in the cooperative's external environment. Thirteen genera of molds were identified in the indoor environment, with a predominance of Aspergillus sp., Rhizopus sp., and Eupenicillium sp. and in the external environment, 19 genera with prevalence of Aspergillus sp., Rhizopus sp., Eupenicillium sp., Trychophyton sp. and Mucor sp. The main contaminated waste that reaches the cooperative is poorly sanitized food packaging and sanitary waste. The results indicate a poor microbiological quality of indoor air in the cooperative analysis, with three samples with values higher than those recommended by applicable legislation.