Detection o f Ni. Cd, and Cu in green leafy vegetables collected from different cultivation areaS in and around Colombo District, Sri Lanka

Abstract

AttachedF iv e ty p es o f g r ee n le a fy v eg eta b les [“K ankun” (Ip o m o e a a q u a tic n ), “MukilmlvVetinfl'’ (A /te rn a n th era se ssilis), “T liam p ala” (A tn a ra n th iis viridis), “Nivithi” (Basel/a alba), and "Koliila leaver" (Lasia spinosa)] were randomly collected from si ; diffeien t.lo ca tio n s (W ellam pitiya, K o lon n aw a, Kt>tlnw«. Piliyandala, Bandaragama, and Kahathuduwa) in and around Colombo District, Sri Lanka, and subjected In analysis o f three heavy metals [nickel (Ni), cadmium (Cd), and copper (Cu)] by atomic absorption speclromeliy. Roils from green leafy vegetable cultivation lands and litigated wafer were also tested. The average concentrations o f heavy melals Ni, Cd, and Cu in soils were 51.5 ±45.5, 1.4±1.1, and 66 .5 ± 5 9 .5 m g kg-1, respectively. I he highest Ni contamination was detected in the irrigated water samples from Wellampitiya (2.02 m g L-1) followed by K olon naw a (1 .0 2 m g L“ ') and K ahathuduwa (0.25 m g L ') areas. This has exceeded (lie WHO/FAO guideline (0.2 m g L-1).' However, Cd and Cu contents in all tested irrigated water samples were w ell below the detection limits. Significant differences were observed in N i, Cd, and Cu levels, between both production sites and green leafy vegetables analyzed (P < 0 .0 5 ). The mean ciincenlralions^mg kg-1, dry weight basis) o f heavy metals id all green leafy vegetable samples collected from six areas varied as 0.23±0.15 for Cd, 12.60±9.01 for Cu, and 7.62 ±8.41 for Ni. Maximum N i, Cd, and Cu contaminations were found in the green leafy vegetables collected fitttn Kolonnawa area. Am ong the green leafy vegetables analyzed, “Kohila leaves” have (lie highest tendency to accumulate N i, Cd, and Cu from the environment.