## 2 Materials and Methods
### Pollution and Health Risk Assessment
#### 2.4.2 Plant Bioaccumulation of Major and Trace Elements  
To assess the environmental risk of chemicals, the bioaccumulation factor (BFi) of major and trace elements was calculated according to Equation (8), as it helps to determine the potential for the toxic or potential toxic elements to accumulate in the food chain and ultimately affect human and animal health. \[\text{BFi}=\frac{\text{C}_{i}\text{plant}}{\text{C}_{i}\text{soil}} \tag{8}\]  
where C_i plant_ refers to the concentration of element \(i\) in plant section (leaf and grain), and C_i soil_ is the same element content in the soil. A BFi > 1 indicates that the plant has a higher potential to accumulate the element (the plant is called \"accumulator\"), while 1 < BFi suggests that the plant is less likely to accumulate the element (the plant is called \"excluder\"), and when BFi = 1, it indicates the soil metal contents (the plant is called \"indicator\") [47,48]. _Human health risk assessment_ is a very important process that involves assessing the potential impact of a hazard on the health of people and even the communities they belong to. Due to agricultural practices that cause environmental damage (especially the irrational use of chemical fertilizers, pesticides, amendments, mismanagement of agricultural land use, and the lack of tree planting to optimize soil protection against water and wind erosion, by which a large amount of dust full of toxicants is released into the air and body of water) and industrial activities, which release polluting particles into the atmosphere, in the Lower Danube Basin, heavy metal and other contaminant exposure is an actual concern. The dust dispersed from the surface of the agricultural soils in the vicinity of the TUL (GL), SEN (GL), and VAD (BR) villages is thus inhaled, swallowed, or even deposited on the surface of the skin, generating health risks for the inhabitants, children being the most exposed. For the study area, there is less information about soil and crop contamination with toxic or potentially toxic elements, and less is known about the non-carcinogenic and carcinogenic risks to which the population of adults and children is exposed during their lifetime. To assess the potential health risk of contaminants, the analytical data for soil elemental composition (Csoil) and also the reference values and equations given by [49,50] and [51] were used (see Equations (9)-(11)). The chronic daily intake (CDI) for toxic element exposure is estimated by the CDI for ingestion (CDIingestion), dermal contact (CDIdermal), and inhalation (CDI inhalation). The equations employed in this regard are as follows:  
\[\text{CDI}_{\text{ingestion}}=\frac{\text{Csoil}\times\text{IngR}\times\text{ EF}\times\text{ED}}{\text{BW}\times\text{ATnc}}\times\text{CF} \tag{9}\]  
\[\text{CDI}_{\text{dermal}}=\frac{\text{Csoil}\times\text{SA}\times\text{AF} \times\text{ABS}\times\text{EF}\times\text{ED}}{\text{BW}\times\text{ATnc}} \times\text{CF} \tag{10}\]  
\[\text{CDI}_{\text{inhalation}}=\frac{\text{Csoil}\times\text{InhR}\times\text{ ET}\times\text{ED}}{\text{EF}\times\text{BW}\times\text{ATnc}} \tag{11}\]  
where the parameters of non-carcinogenic and carcinogenic health risks and their reference values are presented in Table 3.  
The hazard quotient (HQJ) provides information on the non-carcinogenic risk of element \(i\) through chronic daily intake of toxic elements (CDI) relative to the chronic reference dose of element \(i\) (RfDi, mg kg\({}^{-1}\) day\({}^{-1}\))--Equation (12).