Heavy Metals Seasonal Variation in Soil Near Jakara River, Kano State, Nigeria

Abstract

Many food crops have the potential to absorb substantial amounts of heavy metals while thriving in contaminated soil. Wastewater irrigation, excessive use of agrochemicals, air deposits and other anthropogenic activities stirring excessively around the Jakara River continue to stock the soil in the vicinity of the river with poisonous heavy metals. The food crops produced along the river remain the vehicle for transmitting those heavy metals to humans. The objective of the research is to determine the effect of season and location on the concentrations of Pb, Cd, Ni, Co, Cr and Hg in the soil around Jakara River. Composite soil samples were collected from Airport Road, Jaba and Kumantaka monthly for 12 months from January to December 2022. The soil samples were digested and subjected to heavy metals analysis using an atomic absorption spectrophotometer. The results revealed that Pb, Cd, Ni, Co and Cr are present in all the soil samples collected during the research period. The highest concentration of Pb was found in November, Cd in March, Ni and Co in December and Cr in October. Soil samples collected from Airport Road have the highest accumulation of Pb, Ni and Co and those collected from Jaba have the highest accumulation of Cd and Cr. The Cr content of soil samples collected from Jaba exceeded the WHO permissible limit.