Increased risk for lead exposure in children through consumption of produce grown in urban soils

Abstract Childhood Pb exposure is associated with a multitude of poor health outcomes. In food-insecure areas, growing fresh produce in backyard gardens or on vacant industrial properties is seen as options for parents. The question arises, could Pb accumulate in consumable tissues of common produce when grown in metals-rich soils at concentrations that would pose a risk to children. This study investigated factors contributing to the accumulation of Pb in consumable tissues of nine common produce crops grown in metals-rich soils from backyard gardens and a former industrial property. Pb in consumable tissues was directly quantified at concentrations less than 1 μg g−1 via X-ray fluorescence (XRF) using protocols specifically developed for use in plant matrices. The accumulation of Pb in prepared raw consumable tissues in three Pb-rich soils was the greatest in modified taproot crops (mean Pb of 11.8 ± 14.6 μg g−1; turnip, beetroot, radish, carrot), with lesser concentrations in fruits (mean Pb of 2.0 ± 3.0 μg g−1; tomato, pepper), and potatoes (mean Pb of 0.7 ± 1.1 μg g−1). An exposure risk evaluation using the USDFA IRL for Pb indicates that consumption of less than 1 g of certain produce grown in this study, including produce grown in garden soils from residential properties, drastically increases the risk of Pb exposure in children. This study further indicates the proportion of Pb contributed to the daily body burden in children from food is far greater than previously understood, and in all modeled cases, the contribution of Pb from food on a daily basis far outweighs the contribution of Pb from drinking water. For an average child, after addressing over-riding soil/dust impacts, addressing food quality is critical to minimizing Pb exposure.