Concentrations, dietary exposure, and human health risk assessment of heavy metals in market vegetables of Peshawar, Pakistan

The present study was carried out to assess heavy metal concentrations in ready-to-eat vegetables (RTEs) collected from open markets. Samples of RTEs including lettuce, coriander, and carrot were collected from five different local markets of Peshawar, Pakistan including Industrial estate, Board, Agriculture University, Firdos, and Hashtnaghri on four different dates, i.e., 21st March, 04th April, 19th April, and 05th May, 2016. The samples were analyzed through atomic absorption spectrophotometer to see the amount of heavy metals present in them. The elements studied were cadmium (Cd), chromium (Cr), copper (Cu), nickel (Ni), and lead (Pb). Maximum Cd, Cr, Cu, Ni, and Pb concentrations in samples collected from different markets were 0.68, 5.28, 12.31, 7.61, and 25.04 mg kg(-1), respectively, whereas maximum Cd, Cr, Cu, Ni, and Pb concentrations in RTEs collected at different dates were 0.59, 4.08, 14.85, 7.23, and 21.97 mg kg(-1), respectively. The mean Cd, Cr, and Pb concentrations exceeded the permissible limits, while Cu and Ni were found within the limits set by FAO/WHO in all studied RTEs. The daily dietary intake and hazard quotient (HQ) showed great variations. The HQ was found > 1 for Pb in all studied vegetables, while it was < 1 for Cd, Cr, Cu, and Ni with few exceptions. It can be concluded from the study that heavy metal concentrations were above the permissible toxicity levels and their continuous consumption may cause several health issues.