Seasonal Variations of PM2.5 Concentration across the Cities of the Niger Delta Region, Nigeria

Abstract

Fine particulate matter PM2.5 has attracted much attention both scientific and public, due to its effects on human health. This study used remotely sensed PM2.5 to analyze the seasonal variation of PM2.5 concentration across the cities of the Niger delta region of Nigeria. PM2.5 data that was used for this study was Aerosol Optical Depth (AOD), it was acquired from remotely sensed satellite data from National Aeronautics and Space Administration (NASA’s) earth observing system data and information system, PM2.5 concentration data were obtained from 2001 to 2015 and two-way ANOVA was employed to analyze the seasonal variation of PM2.5 concentration. The ANOVA result showed that PM2.5 concentration in the Niger delta varied from season to season, and that PM2.5 is significantly higher in the dry season 20.72 µg/m3 than in the rainy season 17.27 µg/m3 across the cities of the Niger delta with Yenagoa having the highest concentration in dry season (25.5 µg/m3) with standard deviation of (9.3 µg/m3) and Calabar having the highest concentration in rainy season (23.4 µg/m3) with standard deviation of (18.4 µg/m3). This means that there is a wide variation in PM2.5 concentration over the years across the cities. The effect of PM2.5 concentration is higher in dry season than in rainy season across the region, and all the state capitals have annual mean values of PM2.5 above the WHO guideline value of 10 µg/m. PM2.5 concentration is increasing with years especially as a result of the illegal refining activities, gas and oil pipeline bombing and gas flaring activities, this implies that PM2.5 concentration will continue to increase in the dry season more than in the rainy season. This situation can lead to adverse health and environmental health effects such as hospital admissions, asthma, cardiovascular or lung disease including premature death on human beings with continuous exposure.