Major and Trace Element Accumulation in Soils and Crops (Wheat, Corn, Sunflower) around Steel Industry in the Lower Danube Basin and Associated Ecological and Health Risks

The study aimed to evaluate for the first time the degree of contamination of soil and crops with major and trace elements (Cd, Co, Cr, Cu, Ni, Pb, Zn, F, Na, Mg, Si, P, Cl, Fe, Al) in agricultural lands situated in the Lower Danube Basin, Galati and Braila counties (SE Romania), impacted by the steel industry. Soil samples, as well as leaves and seeds of wheat, corn, and sunflower, were collected from two depths in 11 different sites. Along with elemental and mineralogical analyses, performed by HR-CS AAS, PIGE, SEM-EDX, and ATR-FTIR, the soil pH, texture, organic matter, electric conductivity, and CaCO3 content were investigated. The results showed that the levels of Cr (83.27-383.10 mg kg-1), Cu (17.11-68.15 mg kg-1), Ni (30.16-55.66 mg kg-1), and F (319-544 mg kg-1) in soil exceeded the Romanian regulations for sensitive use of the land. Igeo, EF, PI, and PERI pollution indices indicate that the soil is moderate to highly contaminated with Cr, Ni, and Cu, while the CSI and mERMQ indices suggested a relatively low risk for metal contamination. The elemental concentrations in plant tissues and bioaccumulation factors (BFs) provide valuable insights into the soil-plant relationship, health risks, and the selectivity of plant compartments for different elements. Thus, the results revealed that the wheat plants tended to exclude the bioaccumulation of particular elements in their tissues, while exhibiting a different bioaccumulation pattern for Zn and Cu. In the case of corn, most BFs were below one, indicating a limited phytoaccumulation capacity. However, exceptions were observed for Cd, Zn, and Cu with the sunflower BFs indicating higher bioconcentration of these elements in leaves and seeds compared to other elements. Chromium (Cr) contributes to non-carcinogenic dermal contact and ingestion hazards, children being more susceptible to the adverse effects of this contaminant.