Trend Air Quality Index Levels during Dry and Raining Season in Selected Markets in Ilorin Metropolis, Kwara State, Nigeria

Air quality is a vital determinant of public health, yet urban markets in Nigeria remain poorly studied despite their heavy pollution loads from commercial activities. Hence, the objective of this paper was to assess the trend of air quality index (AQI) levels during dry (November–December 2024) and raining (May–June 2025) seasons in selected markets of Ilorin metropolis, Kwara State, Nigeria using appropriate standard techniques and compared to NESREA standard. Findings showed that the dominant pollutant, with dry season concentrations averaging 43–80 µg/m³, far above the NESREA 24-hour standard of 40 µg/m³. Corresponding AQI values during the dry season frequently fell within “unhealthy” to “very unhealthy” categories, especially in high-density markets such as Ipata, Oja-Oba, and mandate. In contrast, rainy season concentrations (17–37 µg/m³) reflected improved air quality, with AQI values mostly ranging from “good” to “moderate,” though occasional spikes were recorded during peak trading and festive periods. The study concludes that Ilorin’s markets experience significant air quality deterioration, particularly in the dry season, posing risks to traders, customers, and residents. It recommends improved waste management, restrictions on open burning, adoption of cleaner energy sources, and continuous AQI monitoring to safeguard public health and support sustainable market environments