Investigations of Heavy Metals Concentrations in Leaves of Telfairia occidentalis Hook. F. (Fluted Pumpkin) in Nigeria

摘要

Investigations of heavy metals concentrations in leaves of Telfairia occidentalis Hook. F. (fluted pumpkin) within farmlands in Ibeno Coastal Area, Niger Delta, Nigeria was conducted using atomic absorption with a Unicam 939 spectrophotometer. The mean concentrations in mg.kg(-1) of the heavy metals in leaves of Telfairia occidentalis were in descending order of: dry season Mn (7.73+/-3.06) > Fe (5.93+/-1.28) > V (0.16+/-0.26) > Co (0.10+/-0.01) > Cd (0.21+/-0.16) > Zn (0.03+/-0.02) > Ni (0.02+/-0.01) > Pb (0.02+/-0.01), and wet season Mn (7.75+/-3.76) > Fe (5.96+/-4.07) > V (0.21+/-0.09) > Cd (0.19+/-0.06) > Zn (0.11+/-0.07) > Pb (0.09+/-0.15) > Co (0.05+/-0.03) > Ni (0.03+/-0.06). The concentrations of the heavy metals were higher in the wet season compared to the dry season. The mean concentrations of Cd (0.205 and 0.1699) mg.kg(-1), Mn (7.729 and 7.7531) mg.kg(-1), and Fe (5.93 and 5.955) mg.kg(-1) in dry and wet seasons, respectively, exceeded WHO maximum limits of (0.1 mg.kg(-1)), (6.0 mg.kg(-1)), and (4.8 mg.kg(-1)). Heavy metal contamination in agricultural soils may lead to the disorder of soil functionality and retardation of plant growth, and influence human health through a contaminated food chain. The elevated metals levels indicated the consequences of oil-related activities as well as other sources of anthropogenic contaminants in the study area. The pollution implications of these heavy metals together with their associated health hazards on humans, farm animals, and economic crops have been discussed based on the results, international standards, controls, and available related literatures.