Abstract

This study was carried out to investigate the level of lead in six edible vegetables from two popular markets and farms in Lagos metropolis. Total acid leaching digestion method was employed and determination of the lead was done by atomic absorption spectrophotometry (AAS). All the vegetables were analyzed in the forms in which they are normally consumed. The concentration of lead obtained ranged from 0.00 mg/kg ± 0.022 at Mushin –7.5 mg/kg ± 0.080 at Yaba for Celosia argentea; 0.00 mg/kg ± 0.002 at Mushin – 4.76 mg/kg ± 0.047 at Yaba forAmaranthus hybridus; 1.16 mg/kg ± 0.039 at Oba farm – 3.96 mg/kg ± 0.151 at Yaba for Telfaria occidentalis; 0.00 mg/kg ± 0.015 at Yaba – 9.820 mg/kg ± 0.036 at Idi-Araba for Vernonia amygdalina; 0.00 mg/kg ± 0.091 at Mushin – 3.99 mg/kg ± 0.173 at Oba farm for Talinum triangulare; 1.02 mg/kg ± 0.049 at Oba farm – 9.22mg/kg ± 0.088 at Mushin for Lactuca sativa. The mean concentrations of the metal were 3.01, 1.93, 3.00, 3.61, 2.26 and 3.76 mg/kg, respectively. Lead was detected in 80% of all analyzed vegetables with an overall mean concentration of 2.78 mg/kg, which is regarded as relatively high. This may be attributed to the proximity of farms and markets to roadsides, where there are vehicular emissions. Going by the tolerable weekly intake of 25 µg/kg.bw/wk for lead (an equivalence of 1.5 mg/person/week assuming a body weight of 60 kg), it can be concluded that, some Lagos residents may be prone to lead toxicity, considering the fact that, these vegetables are regarded as highly nutritious foods and are largely consumed in Nigeria.

Key words: Lead, vegetable, AAS, toxicity.