title: Uptake of heavy metals by some edible vegetables irrigated using wastewater: a preliminary study in Accra, Ghana.
abstract: The heavy metals (Fe, Zn, Pb, Ni, Cr, Co, and Cd) burden in wastewater, soil, and vegetable samples from a wastewater irrigated farm located at KorleBu, Accra has been investigated. Flame atomic absorption spectrometry after microwave digestion using a combination of HNO3, HCl, and H2O2 (for water), and HNO3 and HCl (for soil and vegetables). The mean concentrations (in milligrams per kilogram) of heavy metals in the soil samples were in the order of Fe (171 ± 5.22) > Zn (36.06 ± 4.54) > Pb (33.35 ± 35.62) > Ni (6.31 ± 8.15) > Cr (3.40 ± 3.63) > Co (1.36 ± 0.31) > Cd (0.43 ± 0.24), while the vegetables were in the order of Fe (183.11 ± 161.2) > Zn (5.38 ± 3.50) > Ni (3.52 ± 1.27) > Pb (2.49 ± 1.81) > Cr (1.46 ± 0.51) > Co (0.66 ± 0.25) > Cd (0.36 ± 0.15). The bioconcentration factors suggest environmental monitoring for the heavy metals as follows: Cd (0.828), Cr (0.431), Ni (0.558), Co (0.485), and Fe (1.067). Estimated daily intakes were very low for both children and adults except Fe (0.767 mg/kg/day) in children. The population that consume vegetables from the study area were, however, estimated to be safe based on the results obtained from the health risk index, which were all < <1. The sodium absorption ratio according to FAO (1985) classifications indicate that the wastewater in the study area is unsuitable for irrigation purposes.
authors.affiliation: Nuclear Chemistry and Environmental Research Institute, National Nuclear Research Institute, P.O. Box LG 80, Legon, Accra, Ghana, mikeackah@ymail.com.
authors.forename: Michael
authors.initials: M
authors.lastname: Ackah
authors.forename: Alfred Kwablah
authors.initials: AK
authors.lastname: Anim
authors.forename: Eva Tabuaa
authors.initials: ET
authors.lastname: Gyamfi
authors.forename: Nafisatu
authors.initials: N
authors.lastname: Zakaria
authors.forename: John
authors.initials: J
authors.lastname: Hanson
authors.forename: Delali
authors.initials: D
authors.lastname: Tulasi
authors.forename: Sheriff
authors.initials: S
authors.lastname: Enti-Brown
authors.forename: Esther
authors.initials: E
authors.lastname: Saah-Nyarko
authors.forename: Nash Owusu
authors.initials: NO
authors.lastname: Bentil
authors.forename: Juliet
authors.initials: J
authors.lastname: Osei
mesh_terms: D057914:Agricultural Irrigation / Q000379:methods*; D004784:Environmental Monitoring; D005506:Food Contamination / Q000032:analysis*; D005869:Ghana; D019216:Metals, Heavy / Q000032:analysis*; D014675:Vegetables / Q000737:chemistry*; D062065:Wastewater / Q000737:chemistry* / Q000706:statistics & numerical data; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D019216:Metals, Heavy; D062065:Wastewater; D014874:Water Pollutants, Chemical