Evaluation of Residues in Hen Eggs After Exposure of Laying Hens to Water Containing Per‐ and Polyfluoroalkyl Substances

Abstract

Per‐ and polyfluoroalkyl substances (PFAS) have been used in aqueous film‐forming foams used in firefighting, resulting in soil and groundwater contamination and leading to human exposure via animal products grown in contaminated areas. The present study reports the relationship between PFAS intake by hens and the PFAS concentrations in the edible parts of eggs. Laying hens were exposed via drinking water to different concentrations of 4 PFAS compounds (perfluorooctane sulfonate [PFOS], perfluorohexane sulfonate [PFHxS], perfluorooctanoic acid [PFOA], and perfluorohexanoic acid) over 61 d. Egg PFAS residues were assessed for a further 30 d after exposure ceased. The target concentrations of PFAS were 0, 0.3, 3, 30, and 300 µg/L for the treatment groups T1–T5, respectively; and PFAS residues were determined from the eggs collected every second day. There was a linear correlation between the PFAS concentrations in the drinking water of hens and those detected in the egg, which could be useful in estimating PFAS concentrations in the egg by measuring water concentrations. Exposure of hens to drinking water with PFAS concentrations below the Australian Government Department of Health limits (PFOS and PFHxS, 0.07 µg/L; PFOA, 0.56 µg/L), and with no other sources of PFAS exposure, is unlikely to result in egg PFAS concentrations that would exceed the 10% limit set by Food Standards Australia New Zealand for human consumption. Environ Toxicol Chem 2021;40:735–743. © 2020 SETAC

Transfer of Per- and Polyfluoroalkyl Substances (PFAS) from Feed into the Eggs of Laying Hens. Part 1: Analytical Results Including a Modified Total Oxidizable Precursor Assay

“…These data are in line with other studies that also described the majority of PFAS to be located in the yolk rather than in the albumen. 69,73,77 A potential explanation for these differences was recently given by Wang et al, 73 who found differences in the binding energies of PFAS to the main components of the respective fractions. The binding abilities of the investigated PFAAs were higher for lipoproteins and proteins in egg yolk than for the ovalbumin proteins in albumen.…”

“…Hence, the results indicate that FOSA, FOSAA, MeFOSAA, and EtFOSAA represent the significant C8 TOP assay precursors in the feed. In the egg yolk samples, differences between 77 who performed a similar study with hens and with PFAS administration via drinking water. They described a plateau phase that was reached after ∼12−24 d for PFOS, PFHxS, and PFOA.…”

Transfer of Per- and Polyfluoroalkyl Substances (PFAS) from Feed into the Eggs of Laying Hens. Part 2: Toxicokinetic Results Including the Role of Precursors

“…The lack of adverse effects on hens' health and performance are consistent with the transfer study on commercial laying hens of Wilson and co-workers. 42 Due to the lack of clinical impact of treatment on health and productivity even from the highest tested exposure level of 300 μg PFAA/L, there are no obvious external signs of PFAS exposure for owners of laying hens. 42 PFAS Concentrations in the Diet.…”

“…42 Due to the lack of clinical impact of treatment on health and productivity even from the highest tested exposure level of 300 μg PFAA/L, there are no obvious external signs of PFAS exposure for owners of laying hens. 42 PFAS Concentrations in the Diet. Table 1 shows the PFAS concentrations of the contaminated feed components barley and hay as well as the daily mean PFAS dose.…”

“…The calculated feed-to-egg transfer rates (defined as amount in eggs/amount ingested, called "transfer factor" against convention in their article) were 1.1 (PFOS), 0.7 (PFHxS), 0.5 (PFOA), and <0.005 (PFHxA). 42 The present study provides the data of PFAA accumulation in laying hens' tissues and blood plasma obtained from the feeding trial as well as the feed-to-egg transfer data including the yolk excretion half-lives of PFAAs and FOSA derivatives, which were calculated by toxicokinetic modeling. Furthermore, this is the first study quantifying the transfer of FOSA derivatives into hens' eggs after ingestion with feed.…”