Toxic Potential of Carcinogenic Polycyclic Aromatic Hydrocarbons (cPAHs) and Heavy Metal in Crude Oil from Gokana Area, Rivers State, Nigeria

摘要

This article is focused on ascertaining the toxic potentials of heavy metals andthe levels of PAHs and cPAHs in crude oil samples from Gokana area and using the data todetermine the carcinogenicity (toxicity) of the cPAHs in the crude oil. All the cPAHs namely;benzo (a) pyrene, benzo (a) Anthracene, benzo (b) Fluoranthene, chrysene, benzo (k)fluoranthene, dibenzo (a, h) perylene and indeno (1,2,3-cd) pyrene were detected at variousconcentration in mg/l as 1597.88, 46.97, 4219.99, 1498.04, 1220.41,831.82 and 1106.20respectively. The total concentration of cPAHs is 10,474.34 mg/l which represent 41.83% ofthe total PAHs (tPAHs) in the crude oil sample. Using BaP as baseline standard (0.0007 mg/l)to correlate the (toxicity) carcinogenicity of the cPAHs, we found out that the crude oilsample is many thousands of folds significantly and exceedingly (toxic) carcinogenic. Theorder of concentration of heavy metal (Fe > Ni > Cr > Cu > Cd = Pb = Zn) in the crude oilsample did not reflect their actual toxic potential as only nickel and chromium exceeded themaximum effluents limits. Considerable caution should be applied in exploration, exposureand distribution of the crude oil through protected and well maintained pipelines to avoid thepossible release of PAHs as well as nickel and chromium toxicity to soil, water andinhabitants of Gokana area.