Assessment of nitrogen dioxide concentrations and main sources in a medium-sized city in Latin America using geographic information systems

Studying atmospheric nitrogen dioxide (NO₂) concentrations in urban areas is crucial for assessing air quality and caring for the population’s health; however, the background of studies on this gas in medium-sized cities is scarce, highlighting a significant knowledge gap in the field, especially in Latin America. This study aims to assess the levels of NO₂ concentration in a medium-sized city in Argentina using passive samplers over six months. The Geographic Information Systems (GIS) was employed to analyse the spatial distribution of gas concentration using the Inverse Distance Weighting (IDW) interpolation method. Additionally, potential emission sources were evaluated by applying exploratory regression analysis. The study found that atmospheric concentrations of NO₂ generally exceeded the values established by the World Health Organization (WHO) of 10 µg/m³. The highest mean concentration (30.4 µg/m³) was determined near a national route and industrial areas. Correlation analysis between the NO₂ concentration at each site and possible emission sources suggests that industries are the main sources of this gas.