PROFILE COMPOSITION AND RISK EVALUATION OF PAHS IN BOREHOLE WATER FROM AMASSOMA, BAYELSA STATE, NIGERIA

Abstract

Water is an essential and indispensable natural resource. The most important to human endeavors, ecosystem and all living things. Thus, this study was carried out to determine the levels of concentration of sixteen (16) priority pollutants (PAHs) in borehole water from Amassoma, Bayelsa state. The PAH concentrations in the borehole water samples was performed using GC–MS method. The total PAHs concentration ranged from 0.003 – 0.364mg/l with a mean value of 0.132mg/l. Dibenzo(a,h)anthracene had the highest individual PAH concentration of 0.164mg/l. PAH accumulation in the environment and Toxic equivalency factor (TEF) used to estimate relative toxicity of a PAH compared to that of BaP, principal component analysis and pearson’s correlation was employed. Pearson correlation matrice analysis reveals a positive correlation between the PAHs; this could indicate a common source for some of the PAHs, however, some were negatively correlated with each other. This behavior could indicate non-point source. Six principal component accounting for 88% of the entire variance were extracted. A comparative analysis of PAHs concentrations in the water samples with maximum allowable concentration (MAC) standards revealed that the results obtained in this study were within the permissible levels except for Ind(1,2,3-cd) P and DbahA, however, carcinogen PAHs present in the water of the Amassoma axis, Nun River may pose a threat to human health. PAH fingerprint ratios for determining both petrogenic and pyrogenic (pyrolytic) PAH accumulation such as (Ant/(Ant+Phe), BaA/(BaA+Chr), and ∑▒〖LMW/∑▒HMW〗) ratios was employed. The PAH diagnostic ratio indicates that within the Amassoma Town was of mixed ratios, petroleum (petrogenic) and combustion (pyrogenic) sources and grass/wood/straw combustion sources. This is a clarion call on policy makers and necessary regulatory authorities to step up.