Human Cancer Risk due to Heavy Metals in Soil and its Bioaccumulation in Earthworms in Punjab Pakistan

Abstract

Abstract Earthworms are considered as the intestine of the soil and play a key role as ecological engineers. The earthworms along with soil were sampled from different regions of Punjab. The soil and earthworm samples were digested using standard protocol and further heavy metal analysis was done through ICP-MS in central Hi-Tech Lab Government College University Faisalabad. The pollution index, bioaccumulation factor and health risk assessment, due to heavy metal contamination, was calculated. The data were subjected to regression analysis to find the relationship between abiotic factors and heavy metals, heavy metal concentration and its bioaccumulation. The highest pollution index was due to cadmium contamination in Bahawalnagar i.e.,4.5. The pollution index of heavy metals shows a trend Cd ≥ Pb ≥ Sr ≥ Fe ≥ Cu ≥ Mn ≥ Co ≥ Cr ≥ Zn ≥ Ni ≥ Ca. The highest bioaccumulation was of Calcium recorded in the region of Faisalabad i.e., 8.18 and lowest bioaccumulation was of Nickel recorded the region of Muzaffargarh is -2.58. The bioaccumulation of other heavy metals shows a trend Mn ≥ Cu ≥ Sr ≥ Zn ≥ Co ≥ Cr ≥ Cd ≥ Fe ≥ Pb ≥ Ni. The highest average daily dose (ADD) was of cadmium through ingestion of soil in Children was found in the region Bahawalnager is 0.002. The maximum hazard quotient (HQ) of was of cadmium through ingestion of soil in children was found in Bahawalnager is 1.13. The highest carcinogenic risk (CR) was due to lead through ingestion of soil in children, was found in the region Muzaffargarh showing 3 persons per 10000 at cancer risk. Most potent impact on BAF has been found of electrical conductivity, including cadmium, followed by moisture and total dissolved solids followed by pH followed by total suspended solids. The lead has negative relationship with BAF of strontium, manganese, cobalt, chromium and cadmium. This study provides an insight regarding bioaccumulation of heavy metals and bioremediation of the soil through earthworms in Punjab Pakistan.