Impact of Industrial Effluents on Accumulation, Translocation of Zinc and Antioxidant Activity in Radish (Raphanus sativus L.): A Laboratory Study

Abstract

Industrial effluents are often used to grow crops, including vegetables. Wastewaters contain not only organic matter and other nutrients but also heavy metals, which contribute to soil pollution and their further accumulation in vegetables. For this reason, a laboratory experiment was performed to assess zinc accumulation and translocation in the following chain: industrial effluents–soil–parts of radish (Raphanus sativus L.). The industrial effluents contained zinc in a concentration similar to its maximum permissible level in irrigation water (Effluent 1) and about 40 times higher than the established level (Effluent 2). Zinc concentrations in effluents, soil, and radish were determined by inductively coupled plasma optical emission spectrometry. The contamination factor, bioconcentration factor, translocation factor, and estimated daily intake of zinc were calculated. The antioxidant activity and the phenol content in radish biomass were also determined. The levels of zinc in different parts of radish ranged between 37.76 and 588 mg/kg dry weight and followed the order: non-edible roots of radish ≥ leaves ≥ edible roots. Zinc content in the edible and non-edible parts of radish irrigated with Effluent 2 was up to 5 times higher than the maximum permissible value of 117 mg/kg dry weight established by the Ministry of Health of the Russian Federation. The values of bioconcentration factors varied from 0.33 to 2.44 for radish roots, and the maximum bioaccumulation capacity was revealed for the control plants. According to this work, the values of the estimated daily intake of zinc were lower than the safe daily dietary intake established for zinc by World Health Organization.