Variation in PFAA concentrations and egg parameters throughout the egg-laying sequence in a free-living songbird (the great tit, Parus major): Implications for biomonitoring studies

To further characterize avian toxicity to environmental levels of select per‐ and poly‐fluoroalkyl substances (PFAS), we established species‐ and tissue‐specific PFAS chronic toxicity values (CTVs) associated with a lowest‐observable–adverse effect level (LOAEL) threshold previously established for northern bobwhite quail (Colinus virginianus) chronically orally exposed via drinking water to either perfluorooctane sulfonate (PFOS) or a simple PFAS mixture. Aided by advances in analytical techniques, the novel avian oral PFAS CTVs reported in the present study are lower than the previously reported toxicity reference values (TRVs) estimated for birds chronically exposed via feed. Thus, current avian PFOS TRVs may not be fully protective of wild avian populations at PFAS‐impacted sites. Also, likely due to differences in bioavailability, bioaccessibility, and toxicokinetics among individual PFAS between oral exposure types, we found higher bioaccumulation factors in all assessed tissues from birds exposed via water versus feed. Thus, we propose that future characterization of chemical toxicity due to ingestion exposure initially include a full examination of all probable sources of oral exposure for the most accurate derivation of TRVs and a more complete picture of ecological risk. The avian PFAS LOAEL CTVs established in the present study can be modified with the use of uncertainty factors to derive site‐specific avian TRVs for ecological risk assessment at PFAS‐impacted sites. From differences observed in the behavior of PFOS when administered as either a single chemical or part of a binary mixture with perfluorohexane sulfonate (PFHxS), we verified that PFOS was absorbed and distributed differently when coadministered with PFHxS and that PFOS likely interacted with PFHxS differently among tissues, helping to explain the differences observed in avian toxicity between exposures. Environ Toxicol Chem 2021;40:899–909. © 2020 SETAC

Section: Resultsmentioning

confidence: 85%

Species‐ and Tissue‐Specific Avian Chronic Toxicity Values for Perfluorooctane Sulfonate (PFOS) and a Binary Mixture of PFOS and Perfluorohexane Sulfonate

Dennis

Subbiah

Karnjanapiboonwong

et al. 2021

“…These complexes are then transferred via the blood to the ovary and into the eggs (Yoo et al 2009; Vicente et al 2015). Because heavier eggs presumably have higher lipoprotein concentrations, they might contain higher PFOS concentrations (Lasters et al 2019). Considering that the weight of yellow‐legged gull eggs declines with laying order (marked decrease between the second and the third egg; Rubolini et al 2011), the decrease in concentrations of PFOS and other long‐chain PFAAs in the final egg laid might suggest a decrease in female body burden of these contaminants or a lower rate of maternal transfer.…”

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

“…For example, previous studies have demonstrated that PFOS concentrations decreased with order in the laying sequence in eggs of the Audouin's gull (Larus audouini; Vicente et al 2015) and the great tit (Parus major; Lasters et al 2019), but no clear trends were found for other PFAAs. Moreover, previous studies have suggested limited variation among females in the amount of PFAAs deposited in their eggs (Lasters et al 2019). Assessing the within-and among-clutch variation in contaminant concentrations might help in planning for biomonitoring studies (Pastor et al 1995).…”

Section: Introductionmentioning

confidence: 99%

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Within‐ and Among‐Clutch Variation of Yolk Perfluoroalkyl Acids in a Seabird from the Northern Adriatic Sea

Parolini

Cappelli

Felice

et al. 2020

Perfluoroalkyl substances (PFAS) are surface‐active agents used in diverse industrial and commercial applications. They contaminate both freshwater and marine ecosystems, are highly persistent, and accumulate through trophic transfer. Seabirds are exposed to environmental contaminants due to their high trophic position in food webs and relatively long lifespan. We measured levels of 10 perfluoroalkyl acids (PFAAs) in egg yolks of yellow‐legged gulls (Larus michahellis) breeding in the northern Adriatic Sea (Northeast Italy). We examined variations in PFAAs within clutches (between eggs of different laying order) and among clutches. Perfluorooctane sulfonate (PFOS) was the most abundant yolk PFAA (mean = 42.0 ng/g wet wt), followed by perfluorooctanoic acid (PFOA; 3.8 ng/g wet wt) and perfluorododecanoic acid (PFDoDa; 2.8 ng/g wet wt). The ∑PFAAs averaged 57.4 ng/g wet weight, ranging between 26.5 and 115.0 ng/g wet weight. The PFAA levels varied substantially among clutches (0.29–0.79 of the total variation), whereas the effects of laying order were considerably weaker (0.01–0.13). Egg‐laying order effects were detected for ∑PFAAs, PFOS, perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), perfluoroundecanoic acid (PFUnA), and PFDoDa, whereby the last‐laid eggs exhibited lower PFAA concentrations than early‐laid eggs. Our results indicate that seagulls from the northern Adriatic basin deposit measurable amounts of PFAAs in their eggs. The large among‐clutches differences in PFAAs suggest that exposure of yellow‐legged gull females to these compounds is highly variable. Environ Toxicol Chem 2021;40:744–753. © 2020 SETAC

“…Concentrations of PFASs in juvenile birds may be due to residual exposure from maternal transfer from adult to egg (Newsted et al 2007). However, the contribution of PFASs in the egg from the mother varies widely between individuals (Gebbink and Letcher 2012) and will change as a function of the egg‐laying order (Lasters et al 2019), although as Procellariforms invariably lay only one egg, the latter may not be a factor. Overall, diet is the primary pathway of PFAS exposure in juvenile birds after they are hatched (Letcher et al 2010; Custer et al 2012, 2019).…”

Section: Introductionmentioning

confidence: 99%

Correlations between Per‐ and Polyfluoroalkyl Substances and Body Morphometrics in Fledgling Shearwaters Impacted by Plastic Consumption from a Remote Pacific Island

Szabo

Lavers

Shimeta

et al. 2020

We investigated the concentrations of 45 per‐ and polyfluoroalkyl substances (PFASs) in fledgling flesh‐footed shearwater (Ardenna carneipes; n = 33) and wedge‐tailed shearwater (A. pacifica; n = 9) livers via liquid chromatography–tandem mass spectrometry and their relationship to body morphometrics and ingested plastic mass recorded in 2019 on Lord Howe Island (NSW, Australia). Sixteen PFASs were detected, of which perfluorooctanesulfonate (PFOS) was the dominant compound, detected in 100% of birds (1.34–13.4 ng/g wet wt). Long‐chain perfluorocarboxylic acids, including perfluorodecanoic acid (PFDA; <0.04–0.79 ng/g wet wt) and perfluorotridecanoic acid (PFTrDA; <0.05–1.6 ng/g wet wt) were detected in >50% of birds. There was a positive correlation between PFDA and PFTrDA concentrations and wing chord length (Rs = 0.36, p = 0.0204; Rs = 0.44, p = 0.0037, respectively), and between PFDA concentrations and total body mass (Rs = 0.33, p = 0.032), suggesting that these compounds may impact shearwater fledgling morphometrics. Plastic was present in the intestinal tract of 79% of individuals (<7.6 g), although there was no correlation between PFAS concentrations and plastic mass, indicating that ingested plastic is not the likely primary exposure source. The widespread occurrence of PFASs in fledgling marine birds from a relatively pristine location in the Southern Hemisphere suggests that further studies in adult shearwaters and other marine birds are warranted to investigate whether there are any long‐term physiological effects on bird species. Environ Toxicol Chem 2021;40:799–810. © 2020 SETAC