Patterns related to pollutant concentrations in the Metropolitan Area of Belo Horizonte, Brazil

Air pollution from human and industrial activities has been a major concern in recent years. Among the various pollutants found in the atmosphere, particulate matter (PM) and ozone (O3) show significant occurrences, with high concentrations in urban centers frequently associated with environmental and public health problems. Therefore, this study uses the analysis of variance (ANOVA) technique and Tukey's test to investigate patterns related to the variability of maximum daily O3 concentrations and mean daily concentrations of PM with a diameter less than 10 mu m (PM10), registered between 2007 and 2012 through six sites in the Metropolitan Area of Belo Horizonte, Brazil. To this end, the data were analyzed using ANOVA arranged in a factorial scheme (6 x 4 x 2) with four repetitions per treatment, followed by Tukey's test. In the ANOVA and Tukey's test, the first factor (A) represents the six air quality monitoring stations, the second (B) represents the seasons, and the third (C), the measurements carried out during working days and weekends. Seasonal variability patterns show higher concentrations of O3 in spring and of PM10 in winter. The values were 22.9 and 35.32% higher than the annual averages of O3 and PM10 concentrations, respectively. The mean values for working days and weekends showed different patterns for the two pollutants. PM10 concentrations were 11% higher during working days when compared to weekends. The O3 weekend effect was found only in one of the stations. The profiles of vehicular and industrial emissions have been identified as a potential factor leading to these results.