Potential toxic metals (PTMs) contamination in agricultural soils and foodstuffs with associated source identification and model uncertainty

The research aimed to find out physiochemical properties, metal concentration, sources of metals using statistical analyses, and positive matrix factorization (PMF) model using 315 soil and 250 foodstuff samples (25 species) in Jhenidah as well as Kushtia district, Bangladesh. The range of Pb, Cd, As, Cu, Ni and Cr contents (mg/kg) in soils were found to be 0.97-114.72, 0.11-7.51, 1.07-23.38, 0.89-122.91, 0.91-77.32 and 0.7-23.03 mg/kg, respectively, whereas those in foodstuff samples were found to be 0.46-11.48, 0.30-11.54, 0.47-9.21, 0.20-3.59, 0.001-1.76, and 0.27-5.93 mg/kg, respectively. PMF model revealed that Cu (81.4%) in the study area soils were predominantly contributed by vehicular fuel combustion, Cr (84.9%) was primarily of natural origin, Pb (73%) resulted from traffic emissions, Cd (74.3%), and As (63.4%) mainly came from agricultural practices while Ni (70.9%) was dominated as industrial pollution. EF > 1.5 of Cu, As, and Pb suggesting mild contamination; however, soils from all the studied sites revealed moderate potential ecological risk. Cr recorded BCF values of >1 in the majority of the examined crops, suggesting higher uptake of Cr than other metals. Cr, Ni, As, and Pb showed cancer risks from food intake and risk values were greater than the threshold range (10^-4), suggesting potential cancer risks.