Abstract:
Air pollution is increasingly recognized as a critical environmental and public health issue, particularly in rapidly urbanizing and industrializing regions like Rwanda. This study investigates the impact of meteorological factors on air pollution in Rwanda's Eastern Province, focusing on quantifying the relationship between these variables and the concentration levels of pollutants such as PM2.5, O3, and NO2. The relationship between air quality and meteorological factors were analyzed using variables such as temperature, humidity, wind speed, and rainfall significantly influencing the concentration and dispersion of pollutants in the atmosphere. Data on meteorological variables such as temperature, humidity, wind speed, and rainfall and air pollutants data were obtained from Rwanda Meteorological Agency and from the air quality monitoring stations in Nyagatare and Bugesera. The key findings showed that NO2 levels peaked at 24.22 µg/m³ in March and dropped to 21.85 µg/m³ in July, while PM2.5 concentrations were highest in August (25.12 µg/m³) and lowest in April (15.62 µg/m³). O3 concentrations followed a similar pattern, reaching 34.10 µg/m³ in July and declining to 20.02 µg/m³ in April. These findings suggest that reduced precipitation and increased sunlight during dry seasons contribute to higher pollutant levels, whereas wet conditions lower them. The results on meteorological factors, indicated that high relative humidity in April (83.97%) correlated with lower O3 and PM2.5 levels, while rainfall was associated with decreased pollutant concentrations. Wind speed influenced pollutant levels, with higher speeds in July linked to moderate pollutant levels and lower speeds in January associated with higher concentrations of NO2 and PM2.5. The predictions based on meteorological conditions revealed strong correlations between pollutant levels and weather factors. PM2.5 concentrations decreased with increased rainfall, while ozone levels were negatively correlated with relative humidity and rainfall. Temperature positively influenced ozone levels, highlighting the role of higher temperatures in enhancing photochemical reactions. NO2 levels showed a complex relationship with relative humidity, with both pollutant removal and accumulation observed under different conditions. The study suggests that strategies to mitigate air pollution in Rwanda should be tailored to seasonal variations, focusing on reducing emissions during the dry season and controlling O3 precursors throughout the year. Future research should explore the complex interactions between meteorological factors and secondary pollutants, particularly in different climatic regions of Rwanda, to enhance the effectiveness of air quality interventions
