Evaluation of the transfer of soil arsenic to maize crops in suburban areas of San Luis Potosi, Mexico

- The soil pH was negatively correlated with the accumulated As in each plant part.
- Fe and Mn had a significant correlation (P = 0.5) with the As translocation factors.
- As(V) was the main species found in soil aqueous leachate and maize crop.
- MTA showed a decrement in As level with distance increment to the irrigation source.
- Inorganic As was the predominant form in edible plant parts for livestock.

The presence of arsenic (As) in agricultural food products is a matter of concern because it can cause adverse health effects at low concentrations. Agricultural-product intake constitutes a principal source for As exposure in humans. In this study, the contribution of the chemical-soil parameters in As accumulation and translocation in the maize crop from a mining area of San Luis Potosi was evaluated. The total arsenic concentration and arsenic speciation were determined by HG-AFS and IC-HG-AFS, respectively. The data analysis was conducted by cluster analysis (CA) and principal component analysis (PCA). The soil pH presented a negative correlation with the accumulated As in each maize plant part, and parameters such as iron (Fe) and manganese (Mn) presented a higher correlation with the As translocation in maize. Thus, the metabolic stress in maize may induce organic acid exudation leading a higher As bioavailability. A high As inorganic/organic ratio in edible maize plant tissues suggests a substantial risk of poisoning by this metalloid. Careful attention to the chemical changes in the rhizosphere of the agricultural zones that can affect As transfer through the food chain could reduce the As-intoxication risk of maize consumers.