Caracterização de material particulado em ar interno de pizzarias com fornos à lenha

Abstract

Indoor air quality can be affected by the presence of atmospheric pollutants, among they highlights the particles such us atmospheric particulate matter (PM), black carbon (BC), brown carbon (BrC) and bioaerosols. Thus, this work aimed to characterize the concentration of these pollutants in indoor environments of pizzerias that have wood oven as fuel for cooking food in the city of Londrina, Paraná. The measure the concentration of particles in number and mass, the equipment operated in the internal environments of the kitchens during the preparation of the pizzas and recorded the concentrations every 1 minute. For the bioaerosols sampling (bacteria and fungi), the was performed in a period of 5 minutes for each group of microorganisms and the collections were made in triplicate. The sampling were carried out on 3 different days for Pizzerias 1 (P1) and 3 (P3) and 2 days for Pizzeria 2 (P2). After the incubation time, it was made the counts of the Colony Forming Units (CFU) and a cultural characterization. For bacterial colonies, morphotinctorial characterization was also performed and for fungal colonies the. Based on the data collected, the analysis of colonies diversity was carried out through the construction of dendrograms. The number concentrations of particles (NP0.3 – NP1.0) were higher in P2, whilefor coarse particles (NP2.5 – NP12) were in P3. P2 showed a higher concentration of PM1.0 and PM2.5, while for PM10 it was in P3, with average concentration of 212.8  190.1 μg m-3. For BC and BrC the concentrations in the pizzerias ranged from 0.09 - 42.9 μg m-3 and 0.48 - 29.4 μg m-3, respectively, with the higher concentrations for both in P3, place that remained closed for great time of the sampling. The potential inhaled doses were for MP2.5 and BC, 1.29 μg/Kg.h and 0.15 μg/Kg. h. For bioaerosols, it was found that P1 presented the highest diversity of bacteria, while P3 the lowest, however with the highest average concentration (1540 ± 554 CFU m-3). In relation to fungi, P3 presented a greater diversity, while P2 presented a smaller one. Similar genera of fungi were identified, with Aspergillus spp. the predominant genus in P1, followed by Penicillium spp., and Cladosphialophora spp.. In summary, P3 presented the highest concentrations of coarse particles, BC, BrC and the highest concentration of fungi, which could be because the only opening (door) in the pizza preparation environment remains closed the greater part of the time. On average, the concentrations of PM2.5, BC, BrC, bacteria and fungi in kitchens were 29.6, 3.0, 2.8 μg m-3, 876, and 1261 CFU m-3, with a mean ratio BrC/MP2.5 of 0.06; ratio it that can be considered a tracer of this source for BrC. Finally, the concentrations of PM and fungi found in kitchens indicate a polluted environment, with levels above of those recommended by national and international guidelines and that an adequate kitchen design that also considers this aspect is important to minimize this problem.