Seasonal variability of particulate matter pollutants in Abuja, Nigeria

This study examines the seasonal variability of particulate matter (PM₂.₅ and PM₁₀) in Abuja, Nigeria, from January 2021 to December 2022, using high-resolution data from PurpleAir sensors. It analyzes spatiotemporal trends, meteorological influences, PM₂.₅/PM₁₀ ratios as source indicators, and air quality using the US EPA AQI. Descriptive statistics, correlation analysis, and time-series visualization were applied across dry and wet seasons. Results revealed significantly higher PM levels during the dry season (December–March), with mean PM₂.₅ and PM₁₀ concentrations exceeding WHO limits by up to 2.8 and 2.3 times, respectively. Rainfall showed a strong negative correlation with PM (r = –0.71), while traffic emissions and biomass burning were major contributors. The average PM₂.₅/PM₁₀ ratio (0.54) suggests dominance of coarse particles from dust and construction activities. Chronic exposure to these particulates poses serious public health risks. This study provides one of the first long-term, fine-scale analyses of PM dynamics in Abuja using calibrated low-cost sensors, offering essential baseline data for air quality management. Strengthening emission control, promoting green infrastructure, and integrating real-time monitoring into policy frameworks are strongly recommended.