Contribution of Coal to the Bioavailability of PAHs in Environmental Samples

The contributory role of impure carbon in Okobo coal to the levels of polycyclic aromatic compounds (PAHs) in some environmental samples viz; water, soil and cassava samples were investigated. Bioavailability of the 16 USEPA priority PAHs was estimated, using GCMS after confirmation of high impure carbon load (> 80%) as unveiled by EDS analysis. The nearness in tPAHs of the coal (0.3781 ppm) and the values reported for their vicinity environmental samples including the harmonized cassava sample (0.2398 ppm) > soil sample (0.2331 ppm) > water sample (0.1151 ppm) are indications of direct impact from coal deposit. Water samples used for control experiment (> 10 km from the coal field) is totally void of PAH while the control cassava and soil samples gave 0.0398 and 0.0422 ppm respectively. Fascinating among the findings is the dominancy of four membered ring PAHs (Chrysene) in all the samples and coal diagnosis revealed mixed contributory sources, majorly of petrogenic origin. Values are however within the threshold limit prescribed by existing legislation except for the possibilities of bioaccumulation.