Analysis of Particle Pollution in Residential Urban Area of Port Harcourt, Nigeria

Abstract

Particle pollution poses serious public health concern because of its potential to find its route into human lungs thereby causing respiratory diseases and cancer. This paper analyses various aspect of particulate matter including seasonal variation, Particulate matter based AQI, particulate matter exceedances and empirical modelling for seasonal prediction of PM2.5 and PM10 concentration. The study was carried out in Woji, a residential urban area of Port Harcourt, Nigeria, between May and December 2018. The Particulate matter concentrations were monitored with particulate monitor while meteorological variables were also monitored with Misol weather station. The 24-hour average PM10 concentration for dry and wet seasons were 139.6 μg/m³ and 97 μg/m³ respectively. These concentrations are below USEPA 24-hr standard (PM10 = 150 μg/m³) while the 24-hour average PM2.5 concentrations of 46.1μg/m³ for dry season exceeded daily limit (PM2.5 = 35 μg/m³) but was below the limit in wet season with concentration of 29.1 μg/m³. The study area experienced daily PM2.5 and PM10 exceedances of 33.3% and 19.7% respectively for the study period. Also, the PM based AQI were unhealthy to all residents for 13%, unhealthy to the sensitive group for 20%, moderate for 62% and good for 5% of the monitoring period. PM2.5 and PM10 pollution prediction model were developed for dry and wet season with a high correlation coefficient of 0.98 and 0.97 respectively at (P < 0.001).The seasonal variation of PM concentration revealed that PM10 and PM2.5 concentration varied from season to season, with significantly higher concentration in dry season than in wet season. The air quality of Woji Port Harcourt was better in wet season than in dry season due to the scavenging mechanism of rainfall. Also, PM exceedances were higher in dry season than wet season due to high atmospheric stability associated with low wind speed in dry season.