Characteristics of wheat root-stem-seed enrichment of soil heavy metals and health risk evaluation in a field of north Henan Province

This paper is the result of environmental geological survey engineering.

Objective Heavy metals in farmland soil can be absorbed by crops through the root system and migrate to the seeds, causing safety problems of agricultural products and affecting human health, and the safety evaluation and utilisation of contaminated land is related to the ecological security of the national resources, so it is of great importance to explore the premise of heavy metal pollution in the soil, and to further study the heavy metal migration and conversion in the soil-crop-human body system. Therefore, under the premise of exploring soil heavy metal pollution, it is of great significance to further study the heavy metal migration and conversion in the soil-crop-body system.

Methods This study focused on a specific area in northern Henan Province, where soil and wheat were collected simultaneously. The heavy metal concentrations in different parts of the wheat were analyzed, and an edibility safety rating was conducted for the wheat grains. A human health risk model was then used to assess the non-carcinogenic risks posed by heavy metals in edible wheat grains to human health.

Results The distribution patterns of Cd, Ni, Pb, As, Cu, and Hg in different parts of wheat plants are as follows: roots > stems > seeds; for Zn, the order is seeds > roots > stems. Wheat seeds exhibit high accumulation coefficients for Zn, Cu, and Cd, and Cd shows relatively high accumulation coefficients in roots, stems, and seeds; The areas with high Ni, Cd, Cu, and Zn concentrations in seeds are closely correlated with the distribution of heavy metals in the soil; after comparing the Cd, As, and Pb levels in wheat seeds at study sites with food contaminant limit values, the exceedance rates at these sites were 20.4%, 0.67%, and 12.9%, respectively.

Conclusions There is a significant correlation between the levels of certain heavy metals in wheat grains and heavy metals in the soil. Consuming locally grown wheat poses no apparent non-carcinogenic risk to adults, but carries a certain non-carcinogenic risk to children. Further follow-up studies are needed to monitor populations that consume these crops over the long term.