Bioavailability of arsenic, cadmium, iron and zinc in leafy vegetables amended with urban particulate matter suspension
Correspondence to Jiřina Száková,
Department of Agroenvironmental Chemistry and Plant Nutrition,
Czech University of Life Sciences,
165 21 Prague 6, Czech Republic.
Urban particulate matter (PM) can affect green plants either via deposition on the above-ground biomass, where the contaminants can penetrate the leaf surface, or indirectly via soil–root interaction. This experiment assessed the potential risk of PM-derived risk elements contained in vegetables. The bioavailable portions of arsenic (As), cadmium (Cd), iron (Fe), and zinc (Zn) in leafy vegetables amended by PM via soil and/or foliar application were investigated in a model pot experiment, in which lettuce and chard were cultivated.
By using the physiologically based extraction test simulating in vitro human digestive processes in the stomach and small intestine, the bioavailable portions of toxic elements from PM-amended plant biomass were extracted. Extractable portions of elements by a simulated gastric solution from biomass decreased for lettuce in the order Zn > Cd > As > Fe; while for chard, the order was As > Zn > Cd > Fe. No significant effects of PM physical fractions or soil were observed.
Although the bioavailable element portions in the PM samples were lower compared to plants, the bioavailable element contents in foliar PM-amended plant leaves exceeded the control and soil PM amendment levels, even after biomass washing.