New isotopic evidence of lead contamination in wheat grain from atmospheric fallout

Abstract

Crops could accumulate trace metals by soil-root transfer and foliar uptake from atmospheric fallout, and an accurate assessment of pollution sources is a prerequisite for preventing heavy metal pollution in agricultural products. In this study, we examined Pb isotope rates to trace the sources of Pb in wheat grain grown in suburbs. Results showed that, even in zones with scarcely any air pollution spots, atmospheric fallout was still a considerable source of Pb accumulation in wheat. The concentration of Pb in wheat grain has poor correlation with that in farm soil. The Pb concentration in wheat grains with dust in bran coat was significantly higher than that in wheat grains, which indicates that Pb may accumulate by foliar uptake. The Pb isotope rate has obvious differences between the soil and atmospheric fallout, and scatter ratio is significantly closer between the wheat grain and atmospheric fallout. Atmospheric fallout is a more significant source of Pb concentration in wheat grains than in soil. As far as we know, this is the first study on the main sources of lead in grain crop (wheat) samples with isotope. This study aims to improve our understanding of the translocation of foliar-absorbed metals to nonexposed parts of plants.

Lead smelting alters wheat flour heavy metal concentrations and health risks

“…This implies that total soil Pb should not be used as a predictor for wheat Pb accumulation in these soils. Earlier research suggested that, in areas where atmospheric Pb deposition occurs, wheat grain Pb is mainly attributed to leaf absorption of Pb particulates (Douay et al., 2008; Ma, Liu, Hu, et al., 2019; Ma, Liu, Jin, et al., 2019; Yang et al., 2015). The Pb atmospheric deposition in the study area was previously determined to be ∼100 mg (m 2 30 d) −1 , which is much greater than “cleaner” areas (Qiu et al., 2016).…”

“…Unsafe heavy metal concentrations in wheat grain, with respect to human consumption, have been reported (Douay et al, 2008;Huang et al, 2008;Li et al, 2020b;Liu et al, 2017;Liu, Cui, et al, 2020;Ma et al, 2015;Rezapour et al, 2019). Because wheat is an important worldwide food source (Senapati & Semenov, 2020;Wu et al, 2020), elevated heavy metal concentrations in wheat grain imply that human health may be adversely affected.…”

“…However, most of the past research focused on heavy metal accumulation in wheat grain has compared wheat grain heavy metal concentrations with recommended safe levels (e.g., Douay et al, 2008;Li et al, 2020b;Liu, Cui, et al, 2020;Ma et al, 2015;Xing et al, 2016). Recently, the HQ method has been used for health risk assessments from food consumption (e.g., Chen et al, 2018;Huang et al, 2008;Kang et al, 2018;Sharma et al, 2018).…”

Accumulation, transfer, and potential sources of mercury in the soil-wheat system under field conditions over the Loess Plateau, northwest China

“…Cu, Zn, Pb, and Cd exhibited good correlations between grains and soils, soils and roots with the exception of Zn in grains and soils. It has been known that generally these elements in wheats came mainly from soils (Wang et al, 2012b;Çıçek et al, 2013;Wahsha et al, 2014;Safari et al, 2015) although few studies reported that Pb accumulation in wheat samples was mainly contributed by atmospheric deposition, rather than the contaminated soil (Yang et al, 2015). The significant correlations for Hg were only found between soils and roots, stems and leaves, and leaves and shells.…”

A Study Concerning the Lead Contamination of some Food Products Marketed in Romania During 2017-2019

“…The toxicity of metals is the result of their binding to important enzyme systems in the animal cell or to certain components of the cell membrane. Human exposure to potentially toxic metals is mainly through food (4,7,9,10,12,20,21,30). Potentially toxic metals end up in food in multiple ways: along with raw materials, following treatments applied in agriculture, during processing, storage and transport, from auxiliary materials, from water used in technological processes, etc.…”