A ventilação e a fumaça ambiental de cigarros — um estudo sobre a influência das condições meteorológicas na qualidade do ar de ambientes fechados

Abstract

Environmental tobacco smoke (ETS) is a major contributor to indoor air concentrations and exposure to particles. Tobacco and hospitality industries maintain ventilation as a solution for this problem, but studies indicate that it is not the appropriate solution. In this research, the influence of meteorological conditions on natural ventilation and, therefore, on indoor air quality of places where smoking is allowed was studied. In order to access this influence, a building airflow model and a model for predicting pollutant concentrations from smoking were used. Simulated concentrations were submitted to risk assessment. It was evidenced that wind velocity and temperature are the meteorological variables that have more influence on natural ventilation. Winter is the season with tendency to higher flow rates and, consequently, to better indoor air quality, due to lower temperatures. It was also evidenced that even high flow rates do not reduce life risk imposed by ETS to the acceptable level: this reduction demands very high flow rates, unacceptable in terms of comfort. When estimated the wind velocity that would induce these flow rates, it was verified that winds of the order of thousands kilometers per hour would be necessary for that. It was concluded that ventilation does not solve the problem imposed by ETS on indoor environments and that the only viable solution is the prohibition of smoking.