Lead and nutrient allocation in vegetables grown in soil from a battery site

Abstract

The steady growth of the Brazilian automotive industry and the resulting development of the battery market, which represent a large proportion of the lead (Pb) used in the country, have made battery recycling one of the main sources of Pb soil contamination in Brazil. Plants cultivated in Pb-contaminated soil can take up this metal, which can affect the plant's nutritional metabolism. The Pb can also be transferred into the edible parts of plants, thereby imposing threats to human health. This study was conducted to evaluate the concentration of Pb in edible parts of vegetables grown on soil contaminated by battery recycling activities. This study also investigated the effects of Pb on nutrient concentrations in plants. Plant species biomass, Pb concentration, and concentrations of macronutrients (P, K, Ca, Mg) and micronutrients (Fe, Mn, Zn, Cu) in plant parts were measured. The results showed that Pb concentrations in the edible parts of vegetables grown in contaminated soil were above the threshold acceptable for human consumption. Among the vegetables evaluated, only lettuce dry matter production was reduced because of the high concentration of Pb in soil. The presence of Pb altered the concentration of micronutrients in the edible parts of kale, carrots, and okra, stimulating higher Mn and Cu concentrations in these plants when cultivated in contaminated soil.