Asian Journal of Research in Biochemistry

This study evaluated the concentrations, sources and health risk of polycyclic aromatic hydrocarbons in the blood of middle-aged pregnant women residing in Onne, Rivers State Nigeria. Twenty pregnant women within the age range of 18 – 35 years were involved in this study. The method of EPA 8270 using Gas Chromatography - Mass Spectrometry System was used to determine PAHs in the blood samples obtained from the pregnant women. The PAHs detected in the pregnant women and their mean concentrations were as follows: Acenaphthylene (0.019 ± 0.006 mgkg^-1), Acenaphthene (0.019 ± 0.006 mgkg^-1), Fluorene (0.030 ± 0.009 mgkg^-1), Phenanthrene (0.031 ± 0.009 mgkg^-1), Anthracene (0.039 ± 0.012 mgkg^-1), Fluoranthene (0.065 ± 0.020 mgkg^-1), Pyrene (0.047 ± 0.014 mgkg^-1), Benzo(a)anthracene (0.048 ± 0.015 mgkg^-1), Chrysene (0.041 ± 0.013 mgkg^-1), Benzo(b)fluoranthene  (0.037 ± 0.011 mgkg^-1), Benzo(k)fluoranthene (0.029 ± 0.009 mgkg^-1). The diagnostic ratios for LMWPAHs (low molecular weight PAHs)/HMWPAHs (high molecular weight PAHs), Fla(fuoranthene)/(Fla+Pyr) (fuoranthene+pyrene), BaA(benzo(a)anthracene/(BaA + Chr (chrysene), and Ant(anthracene)/(Ant+Phe) (phenanthrene) were 0.517, 0.580, 0.539 and 0.557 respectively. The pregnant women between the age range of 31-35 years showed higher loads of carcinogenic PAHs than non - carcinogenic PAHs, while the pregnant women between the ages of 18 - 24 and 25-30 years showed higher loads of non- carcinogenic PAHs than carcinogenic PAHs. In conclusion, the findings revealed elevated maternal blood serum concentrations of high molecular weight PAHs, particularly fluoranthene, benzo[a]anthracene, pyrene, and chrysene. The presence of these PAHs suggests multiple sources of exposure, including pyrogenic and combustion-related origins. Additionally, older pregnant women were found to carry a higher risk of cancer due to greater exposure to carcinogenic PAHs compared to their younger counterparts.