Introduction: Edible plants are the major source of diet, and their
contamination with toxic metals may result in catastrophic health
hazards. .
Aims: This study was conducted to analyse the heavy metal levels in
Amanranthus viridis, Celosia argentea, and Ocimum gratissimum grown
in selected farmlands around Lagos State University using Atomic
Absorption Spectrometers (AAS).
Materials and Methods: Dry ashing method was used to destroy the
organic matter to determine the content of the heavy metals. The level of
the following heavy metals (Lead (Pb), Copper (Cu), Iron (Fe) and
Chromium (Cr).) were determined in the soil and edible portion of the
vegetables.
Results:The results showed that the mean concentration of heavy
metals dry weight are: Cu(0.072± 0.014 mg/kg), Fe (0.761± 0.140 mg/kg)
Pb (0.006± 0.001 mg/kg) and Cr (0.008± 0.002 mg/kg) for Amaranthus
viridis,0.004± 0.002 mg/kg- Pb, 0.113± 0.158 mg/kg- Fe, 0.032± 0.003
mg/kg- Cu in Celocia argentea, 0.025± 0.004 mg/kg- Pb, 0.111±0.002
mg/kg Fe in Ocimum gratissimum were recorded in Sport center (site A).
The value of heavy metal contamination obtained from School gate (site
B) ranged from 0.072± 0.006 mg/kg- Pb to 0.742± 0.066 mg/kg- Fe in
Amaranthus viridis, 0.007± 0.0 mg/kg- Pb to 0.450± 0.111 mg/kg- Fe in
Celosia argentea, 0.030± 0.005mg/kg- Fe to 0.051± 0.044 mg/kg- Pb in
Ocimum gratissimum. The value of heavy metal contamination obtained
from PPL (site C) ranged from 0.037± 0.004 mg/kg -Cu to 0.559± 0.080
mg/kg- Fe in Amaranthus viridis, 0.011± 0.001 mg/kg Cr to 0.474± 0.151
mg/kg Fe in Celosia argentea, 0.007± 0.008 mg/kg Pb to 0.048± 0.017
mg/kg Fe in Ocimum gratissimum.
Conclusion: The levels of heavy metals determined in the analyzed
Vegetable samples were found to be below the permissible limits set by
World Health Organization, thus they are safe for human consumption.