Ozone Formation Potential and Toxicity Potential of VOCs emissions from a Nigerian petroleum products depot

Abstract

Abstract: Emissions of volatile organic compounds (VOCs) are major causes of tropospheric ozone and aerosol pollutions. This research provided information on ozone formation potential (OFP) and toxicity potential (TP) resulting from VOCs emission from a Nigeria petroleum depot. In this work, speciated VOCs were provided on basis of updated emissions within and around the depot. The observed concentration of individual VOCs and maximum incremental reactivity (MIR) coefficient were applied to assess the OFP of individual VOC in the ambient atmosphere. Major aromatic VOCs species were considered at various locations. The total OFP in the atmosphere of the depot is 1522.42 μg O3/m3. Toluene specie was revealed to be major contributor to OFP with 71.47% while others species were in descending order of benzene (9.16%), m-xylene (8.41%), ethyl benzene (3.98%), p-xylene (3.51%) and o-xylene (3.46%). The TP levels of aerosols pollutions were also reported with respect to locations. The Slop tank area had the highest OFP and TP level. An assessment of TP level and OFP suggests that occupants of some location within the depot are exposed to unhealthy air conditions. The study established that OFP and TP have a relationship within the atmosphere of the depot with respect to location. It is recommended that aggressive controlled measures of VOCs sources should be adopted within the petroleum depot as a way of curtailing the impact of tropospheric ozone and aerosol pollutions.