Modelagem de valores extremos na avaliação da qualidade do ar pós-rompimento da barragem em Brumadinho, MG

Abstract

Currently there are studies that indicate a significant increase in air pollution around the world, which can cause serious environmental damage and human health. Among the numerous factors that contribute to this increase, the mining activity has a relevant partition throughout the ore beneficiation process. In cases of accidents, such as the rupture of a tailings dam, these problems can be accentuated. In this sense, this work aimed to evaluate the air quality before and after the rupture of Dam I of the Córrego do Feijão Mine, in the municipality of Brumadinho (MG). For this, the extreme values methodology was applied to the series of maximums of total suspended particles (TSP) and particulate matter (PM10) is used, both in μg/m3

. For the adjustment of a model, two approaches of extreme values were used: Generalized Extreme Value Distribution (GEV) and Generalized Pareto Distribution (GPD). Furthermore, the parameters estimated for each model were obtained by the maximum likelihood method. Once the parameter estimates were obtained, the probabilities of exceeding the legal limit were calculated, in addition to the Value at Risk (VaR), to verify the air quality at the established standard levels. The results obtained showed high probabilities of exposure to pollutants, considering air quality standards, in both periods. However, the probability of higher PM10 concentrations decreased after the dam failure. For TSP concentrations, there was an increase in the probability of extreme occurrences.