CONTAMINATION OF CULTIVATED VEGETABLES BY HEAVY ELEMENTS FROM FLOODED ARABLE SOIL: HUMAN EXPOSURE

Abstract

The consumption of vegetables is one of the most important pathways for heavy elements to harm human health. Direct deposition of contaminants from the atmosphere onto plant surfaces and accumulation of heavy elements in flooded arable soil are of great concern because of the potential health risk to the local population. Thus, the present study was carried out to analyse distribution and soil-plant transfer of Pb, Cd, As, Co, Cr, Ni, Cu, Mn and Fe in potato, carrot, celery, parsnip and onion in order to evaluate their potential effects on human health. Total content of heavy elements in 26 vegetable samples collected from different flooded fields was analysed by atomic absorption spectrometry with a graphite furnace (AASGF) after microwave digestion of the analysed samples. Average concentrations of lead (Pb) and cadmium (Cd) in some of the investigated vegetable samples were higher than maximum allowable concentrations set by EC/Serbian regulation. On the other hand, arsenic (As) was not detected in any of the analysed samples. Accumulation and translocation of analysed elements were varied from element to element as well as among selected vegetable crops. The results showed that the parsnip had highest uptake for the most analysed elements (Fe (107 mg/kg) ˃ Mn (6.98 mg/kg)˃ Cu (1.94 mg/kg)˃Ni (0.34 mg/kg)˃ Pb (0.13 mg/kg) compared with the other investigated crops. The bioaccumulation factor (BA) for analysed elements in different vegetables was found in order of Cd (0.08)˃Fe(0.07)˃Cu (0.06)˃Pb (0.01)=Ni˃Mn (0.001), indicating that analysed crops are categorized as excluder (BA<1). The total health risk associated with the consumption of investigated vegetables grown in studied flooded arable soil was assessed using target hazard quotient (THQ). The THQ values estimated for investigated crops were notably below the safe limit of 1, except for Mn (2.10) and Fe (11.65).