Diurnal variation of air quality in Port Harcourt City Local Government Area, Rivers State

Abstract

An investigation to assess the diurnal variation in ambient air quality in selected areas of Port Harcourt City Local Government Area (PHALGA) was carried out. Five sample sites (Borokiri, Lagos Bus-Stop, Mile One, Old GRA and Amadi roundabout) were purposively chosen to cover the major zones that make up the Local Government Area. The portable Aeroqual 200/300 series and Aeroqual PM2.5/10 were used for the determination of gases and particulate matter respectively. The assessment was carried out morning and evening (in each visit), twice monthly for two months (November and December 2019). The results obtained (Mean±SD) in μg/m3for morning/evening are, Ozone (0.063±0.017/0.039±0.022), Methane (13.80±4.54/ 9.75±5.67), Carbon Monoxide (0.080±0.051/0.094±0.043), Carbon Dioxide (840.450±181.293/836.300±303.929), Ammonia (0.120±0.011/ 0.100±0.031), Hydrogen Sulphide (0.044±0.015/ 0.028±0.020), Volatile Organic Carbon (8.715±1.704/ 9.850±5.021),PM10 (0.052±0.009/ 0.024±0.007). The observed results showed a significant variation between morning and evening values but both fell within the permissible limits of the World Health Organization, United States Environmental Protection Agency and National Environmental Standards and Regulations Enforcement Agency (NESREA) meaning that the air in Port Harcourt Local Government Area is relatively free of pollutants. However, it is recommended that air quality monitoring should be carried out periodically and extensively to forestall a possible health hazard in the case of a relapse of the present status into a full-blown pollution