Impact of a truck Driver's strike on air pollution levels in São Paulo

• Published in: Atmospheric environment (1994) 2021-02, Vol.246, p.118072, Article 118072
• Main Authors: Chiquetto, Júlio Barboza, Alvim, Débora Souza, Rozante, José Roberto, Faria, Marlon, Rozante, Vinícius, Gobo, João Paulo Assis
• Format: Article
• Language: English
• Subjects: Criteria pollutants; Diurnal cycle; Truck strike; Urban air pollution; Urban microenvironments; Vehicular emission
• ISSN: 1352-2310; 1873-2844
• DOI: 10.1016/j.atmosenv.2020.118072

From May 21st to 31st, 2018, a truck driver strike greatly decreased all vehicle activity in Brazil. We evaluated the concentrations of criteria pollutants in seven different microenvironments during this period in the São Paulo Megacity. Results were evaluated by violin plots, the Kruskal-Wallis test and diurnal cycles, comparing the year 2018 to an average of 4 previous years. Primary pollutants (CO and NO) decreased by 50% in 2018, predominantly in roadside (RDS) locations. NO2, PM10, and PM2.5 did not decrease as much, suggesting the relevance of secondary reactions and other sources (ex: fires). Ozone increased significantly (about 30–50%), possibly due to favourable atmospheric conditions (solar radiation) and changes in the NOx/VOCs ratio caused by the decrease in NO. Our findings help to better assess the role of vehicular emissions and provide insights on the impacts of interruption of activities (ex: during lockdowns) over air quality in metropolitan environments. [Display omitted] •We evaluated the impact of a truck driver strike on air pollution in São Paulo.•Primary pollutants (CO and NO) decreased by 50%, predominantly in roadside locations.•NO2, PM10, and PM2.5 showed mixed impacts while O3 increased by 30%.•Results help to understand the role of vehicular emissions in urban environments.•Secondary reactions and atmospheric conditions are key factors in restriction periods.