Determination of Naphthalene Concentration in Gombe Urban Soils

Abstract

Petroleum hydrocarbon pollution of urban soils in advancing countries is on the rise as a result creating a public health concern. Urban soil pollution with hydrocarbons mostly originate from diverse anthropogenic sources including petroleum and petroleum products spills and uncontrolled disposal of spent oil in the environment. This study focused on the spectrophotometric analysis of naphthalene in thirty urban soils sampled from 10 urban sites with dissimilar anthropogenic pollution sources in Gombe metropolis. Spectrophotometric detection of naphthalene was optimized to enable the construction of a standard calibration curve using naphthalene standards and further applicability in determining naphthalene concentrations from prepared samples via automatic extrapolative determination. Naphthalene was detected optimally at 221.8 nm wavelength and further detection from soil samples produced significantly varied naphthalene concentrations from all the ten urban sites portraying 5.28 and 9.07 mg/kg as the lowest and highest naphthalene concentration loading from sites 4 and 6 respectively. However, naphthalene concentration levels in other sites were close with a range from 8.39 to 8.96 mg/kg and depicted significance from sites 4 and 6. Naphthalene concentrations in all the sites were high above the established allowable or intervention limits for urban soils. The naphthalene pollution is majorly attributed to human anthropogenic activities relating to the use of petroleum, petroleum products and derivatives. There is a need for regulatory policies and routine monitoring of urban sites with anthropogenic pollution sources that could overburden urban soils with petroleum hydrocarbons which are hazardous to humans and other receptors onsite.