Trends in air quality and hospital admissions due to respiratory diseases since the standstill of an industrial plant in Brazil

At the end of 2015, the rupture of an iron ore tailings dam resulted in the standstill of a pelletizing plant in the city of Anchieta, southeastern Brazil. Despite the negative environmental impact due to the dam rupture, the pelletizing plant standstill has provided a valuable opportunity for the assessment of the changes in local air quality. This work presents a statistical analysis of the spatial and temporal patterns of PM10, PM2.5, SO2, NO2, and O-3, between 2012 and 2018, aiming to identify the trends in the air quality since the pelletizing plant standstill. This work also shows the analysis of the short-term and long-term exposures and the exceedances of the local air quality standards (AQS), as well as the study of the directional patterns of the pollutants associated with the prevailing winds. Since 2016, a meaningful improvement in the air quality of Anchieta was observed, coinciding with the pelletizing plant standstill. Since then, PM10 annual averages have decreased between 10 and 30%, while SO2 annual averages have decreased between 38 and 64%, depending on the monitoring station, which has led to a significant reduction in the exceedances of the AQS thresholds for these pollutants. Besides, the results suggest, qualitatively, a strong influence of the industrial emissions on the health of the Anchieta's population. The restart of the pelletizing plant production is expected in 2020; nevertheless, the results suggest the need for major improvements in the pollution control systems of the pelletizing plant before its resumption.