Multidisciplinary study of chemical and biological factors related to Pb accumulation in sorghum crops grown in contaminated soils and their toxicological implications

• Pb concentrations in soils were above the permitted levels.
• Sorghum did not show any toxicological risk for direct consumption.
• Sorghum was demonstrated as a potential phytostabilizator of lead for phytoremediation.

In this study, the content of Pb, the physico-chemical and biological parameters in soils, and the metal transfer to vegetative and reproductive Sorghum bicolor plants were evaluated along with their relationship with the toxicological risk of crop consumption. To carry this out, soil and sorghum samples at different growth stages were collected near to a former battery recycling plant. The results showed that the concentrations of Pb in soils at several sites were above the maximum permissible levels. Metal bioavailability was not directly related to the pH, OM% or EC, while no association between metals and the different genera of fungi was observed. Sorghum crops accumulated Pb mainly in the roots in all of the growth stages, and therefore presented low levels of Pb in aerial parts without toxicological risk due to direct consumption. Taken together, our results revealed that sorghum could be employed as a potential phytostabilizator of lead in soils associated with crop production. However, further studies are necessary to extend these findings.

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