Levels of Polycyclic Aromatic Hydrocarbons (PAHs) in Sediments from Dadin Kowa Dam, Gombe State, Nigeria

Abstract

The large class of organic compounds known as polycyclic aromatic hydrocarbons (PAHs) contains two or more fused aromatic (benzene) rings. The burning of agricultural waste and incomplete combustion or pyrolysis of organic material (i.e., emissions from cars, home heating, or cooking) are the two main anthropogenic sources of emissions. Humans may encounter PAHs through inhalation, dermal exposure, or eating food that has been contaminated. According to epidemiological studies, PAHs are linked to poorer lung function, worsening asthma, cancer, higher rates of obstructive lung diseases, and cardiovascular diseases. This raised questions and called for investigation and awareness of the risks posed by these pollutants. Herein, sediment was collected from Dadin Kowa Dam, Gombe State, Nigeria, during the dry and rainy seasons for assessing the levels of polycyclic aromatic hydrocarbon (PAH) residues. The collected samples were extracted, cleaned up, and analyzed for the presence of PAHs using GC-MS equipped with a flame ionization detector. The result shows that concentrations of all the PAHs studied in the sediment samples during the dry season ranged from 6.40E-01 to 1.09E +00 mg/kg, while during the rainy season they ranged from 4.60E+01 to 5.42E +01 mg/kg. The rainy season showed the highest total concentration of all the PAHs studied when compared to the dry season. The result from the diagnostic ratio showed the ratios of Ant/(Ant + Phe) ranged from 0.40-0.52; 0.33-0.58 Fla/(Fla + Pyr); and 0.08-0.5 BaA/(BaA + Chr). Generally, the findings of this work proved that pyrogenic inputs contributed to PAH contamination in the sediment from the study area. The result from the mean effect medium quotient (m-ERM-q) in the sediment samples ranged from 4.52E-05 to 1.41E+01 for both seasons, with a mean value of 5.13E-02.