Abstract:
Various heavy metals have been reported as dangerous agents to the human health and wildlife when they
occur in the environment at high concentrations. Cadmium (Cd) and lead (Pb) compounds are classified as
hazardous metals. In this study, concentrations of Cd and Pb were investigated in cultivated and
uncultivated lands of both upland and lowland areas at two depths (0-15 cm, 15-30 cm) in soils of
Anuradhapura district. The design was Completely Randomized Design (CRD) in three factor factorial with
three replicates. Total Cd and Pb and available cadmium and lead in the soils were determined. In addition
other soil properties such as total organic carbon (TOC), microbial biomass carbon (MBC), water soluble
carbon (WSC), and permanganate oxidizable carbon (POC) were also measured. Cd was not detected
(detection limit 0.02 mg/kg) in any of the samples. The total Pb and available Pb ranged between 1.61 to
11.72 mg/ kg and 0.982 to 7.202 mg/kg, respectively. Total Pb and available Pb did not show any
significant difference with elevation, land-use and depth. As the maximum permissible level of soil Pb is
150-300 mg/kg, according to European Community standard, values of the tested soils are safe in terms
of Pb hazard. Total Pb and available Pb showed a highly negative correlation with distance from main
road. Both total and available Pb showed weak negative correlations with TOC and water soluble carbon
whereas both total and available Pb showed significant negative correlation at 95% confidence level with
MBC.
