Polycyclic aromatic hydrocarbons in air from industrial areas in Lagos and Ogun states, Nigeria

Abstract

There is currently scarce information on the occurrence and distributions of Polycyclic Aromatic Hydrocarbons (PAHs) in the air from industrial estates in Nigeria. Hence, the present study aims to evaluate the extent and sources of pollution of polycyclic aromatic hydrocarbons in the air from some industrial estates in Lagos and Ogun States, Nigeria. Ten air samples have been collected from the industrial estates in Lagos (Ogba and Ilupeju) and ten from Ogun (Agbara and Ota) between October and November, 2014, using low volume air sampler. Also five further air samples have been collected from Epe town, located in the outskirts of Lagos, where there are no industrial activities to serve as control. The concentrations and distributions of 20 target Polycyclic Aromatic Hydrocarbons (PAHs) in the air samples have been determined by gas chromatography-mass spectrometry. The concentration of ∑20PAHs ranged from 89.20 to 96.48 ng/m3 (with an average of 92.84 ng/m3) and 72.52 to 142.91 ng/m3 (with an average of 107.72 ng/m3) in the air samples from Lagos and Ogun industrial estates, respectively. The air from the control site has a total ∑20PAHs concentration of 19.55 ng/m3 (9.78 ng/m3 in average). When compared with global data, these values show that the air samples have been moderately polluted. PAHs in most air samples are mainly from pyrolytic sources, which may have resulted from diesel fuel combustion and high vehicular emissions, typical of industrial activities in the area.