SPATIAL DISTRIBUTION OF POTENTIALLY TOXIC ELEMENTS AND PHYSICOCHEMICAL PROPERTIES OF SOILS AT A MILITARY SHOOTING RANGE IN BUNI YADI, YOBE STATE, NIGERIA

Military shooting ranges may receive inputs of metal containing ammunition, which can contribute to the localized accumulation of trace elements in soil. This study evaluated selected physicochemical properties and concentrations of lead (Pb), cadmium (Cd), chromium (Cr), arsenic (As) and copper (Cu) in soils from the 27 Task Force Military Brigade Shooting Range in Buni Yadi, Yobe State, Nigeria. Twelve independent soil samples were collected, comprising three samples from each of three distances from the main shooting point (200 m, 100 m and 50 m) and three samples from a control location approximately 1 km away from the main shorting range. Soil pH, electrical conductivity (EC), bulk density, water-holding capacity, total nitrogen and temperature were assessed, while trace element concentrations were determined using atomic absorption spectrophotometry (AAS). Soil pH ranged from 5.7 to 6.4, and EC ranged from 1.975 to 1.997 mS/cm. Point C (50 m) had the highest mean concentrations of all five elements. Lead concentrations ranged from 24.45 ± 0.07 mg/kg in the control soil to 205.53 ± 0.03 mg/kg at Point C, while cadmium concentrations ranged from 0.30 ± 0.01 to 3.01 ± 0.03 mg/kg. Relative enrichment at Point C compared with the control was 8.41-fold for Pb, 10.03-fold for Cd, 1.36-fold for Cr, 3.46-fold for As and 1.64-fold for Cu. These findings indicate localized enrichment, particularly of Pb and Cd, and highlight the need for continued monitoring and further investigation of element mobility and bioavailability