Correlation between precipitation over the Andralanitra landfill and PM2.5 and PM10 concentrations in the City of Antananarivo, Madagascar

Abstract

This study examines the correlation between particulate matter (PM2.5 and PM10) concentrations in the city of Antananarivo and precipitation over the constantly burning open landfill (Andralanitra), located 12 km from the city. Statistical analysis was conducted using daily PM2.5 and PM10 concentration data from air quality monitoring stations (November 2023 to October 2024) and daily precipitation data from the Andralanitra landfill. The results indicate a weak negative correlation between the daily concentrations of PM2.5 and PM10 and the daily precipitation levels. The correlation is stronger for PM10 than for PM2.5, likely due to the differences in particle size: PM10 particles are more affected by precipitation. Additionally, monthly precipitation levels at Andralanitra show a moderate negative correlation with the monthly concentrations of PM2.5 and PM10. Seasonal variations also influence the overall concentrations of PM, and an increase in precipitation intensity at Andralanitra leads to a reduction in the number of days considered polluted. These findings emphasize that air pollution caused by particulate matter (PM2.5 and PM10) is directly influenced by precipitation levels at Andralanitra.