Diagnóstico das condições da qualidade do ar interior, ventilação e conforto térmico de consultórios odontológicos em Aracaju

Abstract

Indoor air quality in healthcare settings, particularly in dental offices, presents a significant challenge due to the risk of exposure to biological and chemical contaminants in aerosols. This study aimed to assess the air quality conditions in public and private dental offices in Aracaju, SE, considering microbiological parameters, ventilation rates, and thermal comfort. The methodology involved measurements of temperature, relative humidity, and carbon dioxide (CO₂), in addition to the collection of bioaerosols (total bacteria, fungi, and Legionella) and condensed water samples from air-conditioning systems, in accordance with national and international standards (ABNT NBR 17037:2023; ABNT NBR 7256:2021; ISO 11731:2017). Ventilation was evaluated using the CO₂ decay method, and thermal comfort was assessed using the PMV and PPD indices (ISO 7730:2005). The results indicated that, in terms of microbial load, most offices met regulatory limits; however, office C1 (P1) exceeded the reference value for mesophilic bacteria (512 CFU/m³ versus the 500 CFU/m³ limit), indicating higher risk in areas near dental chairs. For fungi, all environments presented values well below the limit of 750 CFU/m³, posing no significant risk. Regarding ventilation, considerable heterogeneity was observed: C1 had a rate of only 12.79 m³/h/person, below the requirement of ABNT NBR 7256:2021, while C6 reached 96 m³/h/person; however, no office met the 126 m³/h/person recommended by ANSI/ASHRAE 241:2023. Similarly, in terms of air changes per hour (ACH), the environments did not fully meet the references of NBR 7256:2021 (2 ACH) and ASHRAE 170 (3 ACH), confirming insufficient air renewal relative to international standards. Regarding thermal comfort, some environments remained within or close to the acceptable zone of ISO 7730, but relevant extremes were identified: C4 experienced heat discomfort (PMV = +1.10; PPD = 30.47%) and C6 experienced cold discomfort (PMV = -0.97; PPD = 24.68%). These findings demonstrate that merely complying with the temperature range specified in NBR 7256:2021 (20–24 °C) does not guarantee adequate thermal comfort conditions. Concerning Legionella, no confirmed colonies were found; however, interpretation should be cautious due to methodological limitations such as fungal contamination of plates, absence of a biosafety cabinet, and the limited number of samples, which reduce the robustness of the conclusion of absence. It is concluded that the evaluated dental offices present significant inadequacies in terms of ventilation and thermal comfort, as well as critical points of bacterial contamination, reinforcing the need for preventive maintenance of air-conditioning systems, updates to Brazilian legislation including mesophilic bacterial load as a reference parameter, and the adoption of risk management plans and continuous environmental monitoring.