Poluição atmosférica no interior do Paraná: variações espaço-temporais e suas relações com fontes industriais e veiculares

Abstract

Continuous air quality monitoring is essential for supporting public policies aimed at protecting human health. However, most studies focus on large urban centers. This study analyzed atmospheric pollutants measured at fixed monitoring stations installed in six municipalities in the state of Paraná, Brazil: five urban environments (Cascavel, Foz do Iguaçu, Londrina, Maringá, and Ponta Grossa) and one industrial site associated with oil shale extraction in São Mateus do Sul, over the period 2017–2019. Concentrations of NOX, NO2, CO, O3, SO2 and PM10 were evaluated using descriptive statistics, diurnal cycles, and spatial occurrence probability, relating them to surrounding characteristics, such as vehicular traffic and industrial activities. The results revealed high temporal variability in pollutant concentrations, primarily associated with vehicular traffic in urban areas and atmospheric stability conditions, with the influence of some physical barriers that hinder pollutant dispersion. The industrial station recorded the highest mean SO2 concentration (15.46 μg/m³), whereas the urban areas showed the highest mean concentrations of NOX and CO (38.33 μg/m³ and 0.91 mg/m³, respectively), strongly impacted by on-road vehicle emissions. Diurnal cycles showed primary peaks of NOX, NO2, and CO at night and secondary peaks in the morning, following the daily traffic patterns and also reflecting periods of periods of greater atmospheric stability. O3 reached its maximum concentration in the afternoon (14:00–15:00), when NOX concentrations decrease and solar radiation is more intense for photochemical formation. Secondary nighttime peaks of O3 suggest contributions from regional transport. PM10 concentrations were highest at night, a period marked by increased atmospheric stability. The spatial occurrence probability analysis demonstrated a strong association of NOX and CO with areas of higher vehicle traffic. O3 showed occurrence patterns associated with strong northern winds, highlighting its relationship with regional transport, particularly from biomass burning in northern and west-central Brazil. PM10 showed a combined influence of local industrial activities and vehicle traffic. Overall, the results indicate higher SO2 emissions in the industrial site and a strong influence of urban mobility on NOX, NO2, and CO levels, demonstrating the need for site-specific air quality management strategies to reduce emissions and mitigate impacts on public health. Additionally, reducing regional pollution from biomass burning requires coordinated national and international efforts across South America.