Impacts of urban emissions and air quality in São Paulo State, Brazil

Daily violations of air quality have an impact on urban populations and cause damage to the environment. Thus, the study evaluated the violations of the daily concentrations of SO 2 , NO 2 , and PM 10 , in regions of the State of São Paulo (SSP), based on the National Environment Council (CONAMA) resolution no 491/2018 and the World Health Organization (WHO - World Health Organization. (2016). Ambient air pollution: a global assessment of exposure and burden of disease.) criteria. Daily SO 2 , NO 2 , and PM 10 data from 6 air quality stations operated by Environmental Company of the State of São Paulo CETESB (1996–2011) were organized and submitted to quality control, with data faults (gaps) being identified. The imputation of data via spline proved satisfactory in filling in the gaps ( r > 0.7 and low values of Standard Error of the Estimate (SEE) and Root Mean Square Error (RMSE). The cluster analysis (CA) applied to SO 2 formed only one homogeneous group (G 1 ). Contrariwise, NO 2 and PM 10 formed two homogeneous groups (G 1 and G 2 ) each. The stations that showed the greatest similarity according to the CA were Cerqueira Cesar and Osasco. The cophenetic matrix generated for SO 2 (0.83), NO 2 (0.79), and PM 10 (0.77) indicate a satisfactory adjustment of the dendrograms. The exploratory statistics applied to groups G 1 and G 2 point to the high variability of outliers. The WHO criteria are more restrictive than CONAMA regarding daily violations, with a reduction in SO 2 and an increase in specific years for NO 2 and PM 10 . Such variability is due to the adoption of public policies by the SSP and the influence of meteorological systems, being confirmed by the Run test that indicated oscillations in the time series, mainly in PM 10 , and also recognized well-defined biannual cycles.