Polycyclic Hydrocarbons (Pahs) in Ghana Cocoa Beans

The concentration of polycyclic aromatic hydrocarbons (PAHs) in cocoa beans from six regions of Ghana was investigated. Thirty-six (36) samples of cocoa beans were randomly collected from farming communities in each of the six regions during the lean and major seasons. The samples were air-dried for two days to prevent hydrolysis and degradation and stored in amber glass bottles. The PAHs were extracted using the Soxhlet extraction method and analysed using gas chromatography (GC). With PAHS, even though cocoa farmers in these regions were not found drying the beans with heat generated from locally manufactured ovens, some levels of polycyclic aromatic hydrocarbons were detected in all the thirty-six farms visited. The regions from which the cocoa bean samples were obtained include: Western, Ashanti, Eastern, Central, Volta and Brong-Ahafo regions. Only one farm in the Western Region recorded two carcinogenic polycyclic aromatic hydrocarbons, Benzo[a]Flourenthene, and Dibenzo[a]anthracene at low levels (BDL - 4.80 ± 10.00 ng/kg) and (BDL - 15.50 ± 40.00 ng/kg) respectively. Pyrene (49.90 ± 90.00 - 578.90 ± 650.00 ng/kg) and Flourenthene (113.60 ±180.00 - 620.80 ± 390.00 ng/kg) were however present in all the cocoa samples collected from the 36 farms. The presence of these polycyclic aromatic hydrocarbons was thought to have originated from vehicular emissions, as that particular cocoa bean samples were found being dried in close proximity to roads within their communities. The results obtained for the PAHs in the cocoa beans were compared with the WHO/FAO permissible levels. The results obtained were for four PAHs, namely: pyrene, fluoranthene, benzo[k]fluoranthene and dibenz[a,h]anthracene, in the cocoa beans from all the six regions were found to be lower than the WHO/FAO permissible levels. However, benzo[k]fluoranthene and dibenz[a,h]anthracene were not detected in the cocoa beans from five of the regions.