ANALYSIS OF HEAVY METALS IN DIFFERENT WINTER VEGETABLES FROM DIFFERENT REGIONS OF NARSINGDI DISTRICT

Abstract

Irrigation by water with industrial effluents, wholesale use of pesticides and resources and important urbanization result in heavy metal contamination in agricultural produces and thereby human health complicacies. Biomonitoring vegetables and their potential health risks involved are of prime importance for the time being. Concentration of heavy metals in six different vegetables species (helancha, malancha, red amaranth, cauliflower, Indian spinach and brinjal) collected from two different sites of Narsingdi District, adjoining Dhaka were measured by using the Atomic Absorbtion Spectrophotometer (AAS). Potential health risks of heavy metals to the local population via vegetables consumption were estimated. Variations in concentrations of heavy metals were recorded among studied vegetables species. In both the sites, the pattern of metals exhibited the following trend: Nickel > Lead > Chromium > Cadmium. The concentration of all metals was found to be higher in the traditional leafy vegetables as compared to cultivated vegetables. An exception was Indian spinach, the leafy vegetables, had higher Cd concentration than other vegetables studied in both the sites. Helancha and Malancha had the highest single factor pollution index (Pi) of most the heavy metals, except Indian spinach which had the highest Pi of Cd. The Pi of all metals analysed in the present study are above 1 or around 1 for the traditional vegetables (helancha and malancha), except Indian spinach. The sum of pollution index was also the highest in helancha (7.94), followed by malancha (5.98) and Indian spinach (5.94). The traditional vegetables had also the highest metal pollution index (0.43 in helancha and 0.35 in malancha). Accordingly, helancha and malancha had higher hazard quotients for Pb, Cr and Ni, while Indian spinach had higher Cd hazard quotient than other vegetables. The hazard quotient of Ni analyzed in helancha and malancha traditional vegetables is higher than 1.0. However, Indian spinach vegetables along with helancha and malancha, from both the sites can be highly hazardous for children. Continuous monitoring of heavy metal status in vegetables should be enforced all over Bangladesh for health concern of peoples of all ages.