Determining how gavaging laying hens with lead (Pb) effects lead concentration in table eggs, bone, blood, and liver

Previous research has demonstrated that lead (Pb²⁺, for the remainder of the paper referred to as Pb) and other heavy metals are present in table eggs from backyard birds. While the source of Pb exposure is unknown, exposure to the environment via the foraging behavior of backyard poultry is likely a significant factor. A longitudinal cohort study was conducted to better understand how oral Pb consumption correlates with Pb concentration in table eggs and other physiological compartments (i.e. bone, blood, and liver). In order of absolute mean concentration, Pb was most present in bone (226.24 ppb experimental vs. 31.00 ppb control), blood (14.47 ppb experimental vs 0.27 ppb control), liver (11.24 ppb experimental vs 0.75 ppb control), and egg (1.17 ppb experimental vs 0.06 ppb control). The low concentration of Pb in table eggs implies that Pb preferentially accumulates in other tissue aside from the egg. While this study showed that eggs have the lowest overall tropism for Pb, the presence of Pb in other tissues demonstrates a public health risk when chickens are orally exposed to Pb via oral consumption.