en |
Determination of Total Potency Equivalent Concentration (Tpec) of Carcinogenic Polycyclic Aromatic Hydrocarbons (Cpahs) In Soils of Bodo-City
IWUOHA, G.N.; NWIGOO, J. & ONOJAKE, M.C.
Abstract
The aim of this paper is to report the determination of Total potency equivalent
concentration (TPEC) of Carcinogenic polycyclic aromatic hydrocarbons (cPAHs) in soil
samples from Bodo area in Ogoniland using the Toxicity Equivalent Factor (TEF) model. Gas
Chromatography GC HP 5870 with FID was used for analysis. Out of the seven cPAHs
investigated only three were detected. They are Benzo (a) Pyrene (BaP), Dibenzo (a, h)
anthracene and Indeno (1, 2, 3-cd) pyrene with soil concentrations of 19.06 mg/kg, 6.67 mg/kg
and 29.26 mg/kg respectively. Their correspondingly individual potency equivalent
concentrations in soil (mg/kg) are 19.06, 0.67 and 2.93 respectively. Benzo (k) Fluoranthene,
Benzo (a) Anthracene, Benzo (b) Fluoranthene and Chrysene was not detected. The calculated
TEQ or TPEC is 22.66mg/kg and this value by far exceeds the method B cleanup levels of BaP
value of 0.137mg/kg, it suggests a massively contaminated soil. TPEC is 226.6 times higher
than the method B and CAL-EPA risk-based cleanup value of 0.1mg/kg while Total cPAHs is
549.9 times higher than the risk-based cleanup value as indicated. This level of soil toxicity
with respect to BaP indicates that the area should be declared a no-go area for humans and
animals alike. We strongly recommend the application of Dispersion by Chemical Reaction
Technology, should be deployed immediately in this area for total detoxification and
decontamination of the area.
Keywords
TEQ; TEF; PEF; cPAHs; BaP; Bodo; risk assessment
|