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.

Effects of the Irrigation with Treated Wastewaters on the Proximate Composition, Mineral, and Polyphenolic Profile of the Globe Artichoke Heads [Cynara cardunculus (L.)]

“…This could be due to the higher amount of irrigation water supplied (1850 and 950, for the main and the processing, respectively, vs. 350 m 3 ha −1 for the secondary) and, consequently, to a higher intake of minerals within the artichoke heads. These data are in agreement with results reported by Achah et al (2014) [49], who found a close relationship between iron content in the irrigation water and iron content of the vegetable samples. On the other hand, Al-Lahham et al (2007) [50] reported increased concentrations of manganese and iron in the soil correlated with the high concentrations of these minerals in the wastewater used for irrigation.…”

Irrigation with Treated Municipal Wastewater on Artichoke Crop: Assessment of Soil and Yield Heavy Metal Content and Human Risk

“…Plant storage organs, such as fruits and seeds, have low transpiration rates and do not accumulate heavy metals because they are largely phloem-loaded. The accumulation of heavy metals in agricultural soils through wastewater irrigation might not only result in soil contamination, but might also affect food quality and safety [15]. Adverse effects of soil and vegetables heavy metals contamination on human health have been widely reported [9,16,17].…”

Health Effects Associated with Wastewater Treatment, Reuse, and Disposal

“…Agricultural Reuse. Ackah et al (2014) investigated the burden of heavy metals in wastewater, soil and vegetable samples from a wastewater irrigated farm located at KorleBu, Accra, Ghana. Although those people who consumed vegetables from the study area were assumed to be safe, the sodium ratio indicated that the risk.…”