Assessment of noise and ozone levels in a small industrial urban area

Abstract

Monitoring environmental parameters in urban centers has become a critical step for health risk assessment. In this study, conducted in the industrial park of Mirandela (Portugal), an environmental monitoring system consisting of a meteorological station, a class 1 smart sound sensor and three reference optical gas analyzers were deployed to measure noise levels, tropospheric ozone concentrations, carbon monoxide, and nitrogen oxides, during winter and spring of 2019. The interdependence among all variables was evaluated, and legal compliance was assessed according to the European Union (EU) target values for ozone. Higher concentrations of nitrogen oxides and carbon monoxide were observed during rush hours, while ozone concentrations increased as a consequence of the emissions of primary pollutants after sunrise reaching their maximum values at about 13:00 to 14:00h. Regarding the Accumulated Ozone Exposure (AOT), both target values set by the EU for AOT40 vegetation and forest have been exceeded. For AOT60, the observed values were below target; however, the threshold for NET60 was exceeded even before the end of 2019. Noise levels were higher during rush hours, because of higher traffic intensity; however, noise level indicators (Lden, Ln) remained within the legal limits. It was possible to realize that urban traffic is the most relevant source of noise and local air pollution. These results can be used to define strategies that may improve the environmental performance of the studied industrial park.