Comparative Analysis of Heavy Metals in Talinum triangulare (Water Leaf) Grown in Industrial, Residential and Commercial Area of Lagos State, Nigeria

Abstract:

This study was conducted to determine the concentration of heavy metals (copper (Cu), zinc (Zn), magnesium (Mg), calcium (Ca), lead (Pb), cadmium (Cd), chromium (Cu) and iron (Fe)) in Talinum triangulare (water leaf plant) and soil collected from commercial, residential, and industrial sites of Lagos State. The heavy metals present in water leaf and soil were analyzed using Inductively Coupled Plasma–Optical Emission Spectrometer (Agillent 710 Axial). The results showed that Zn, Mg, Pb, Fe, Cr, Cu from all sites were within the safe limit. However, calcium in Talinum triangulare was detected highest in commercial site (2971.850±116.319 mg/kg) and least in residential site (1416.05±40.659 mg/kg). Cadmium concentration was highest in industrial site (0.58±0.33 mg/kg) and least in residential and commercial (0.50±0.00 mg/kg). Calcium in all the sites was beyond the WHO/FAO, and Food and Nutrition recommended dietary intake of 1000 mg/kg. Enrichment factor (EF) showed moderate enrichments of all metals (except Cr and Cu) in the soil across the sites. EF of Cr and Cu respectively at industrial site were significant and extremely high. The Igeo value of Ca (2.52) at Commercial site indicated moderate contamination, Igeo values of Mg (3.82,3.61) at Industrial and residential sites implied heavily contaminated while the Igeo values of Ca (4.58, 5.01) from industrial and residential sites indicated extremely contaminated. The Water leaf plants from all the sites are still safe for consumption but high calcium contamination in the vegetable could cause health problem. However, water leaf plants from these sites can be suggested in conditions of calcium deficiencies.