Exposure and Effects of Perfluoroalkyl Substances in Tree Swallows Nesting in Minnesota and Wisconsin, USA

Abstract

The exposure and effects of perfluoroalkyl substances (PFASs) were studied at eight locations in Minnesota and Wisconsin between 2007 and 2011 using tree swallows (Tachycineta bicolor). Concentrations of PFASs were quantified as were reproductive success end points. The sample egg method was used wherein an egg sample is collected, and the hatching success of the remaining eggs in the nest is assessed. The association between PFAS exposure and reproductive success was assessed by site comparisons, logistic regression analysis, and multistate modeling, a technique not previously used in this context. There was a negative association between concentrations of perfluorooctane sulfonate (PFOS) in eggs and hatching success. The concentration at which effects became evident (150-200 ng/g wet weight) was far lower than effect levels found in laboratory feeding trials or egg-injection studies of other avian species. This discrepancy was likely because behavioral effects and other extrinsic factors are not accounted for in these laboratory studies and the possibility that tree swallows are unusually sensitive to PFASs. The results from multistate modeling and simple logistic regression analyses were nearly identical. Multistate modeling provides a better method to examine possible effects of additional covariates and assessment of models using Akaike information criteria analyses. There was a credible association between PFOS concentrations in plasma and eggs, so extrapolation between these two commonly sampled tissues can be performed.

Mechanistic modeling of insecticide risks to breeding birds in North American agroecosystems

“…Etterson et al [24] compared two versions of the parameterized MCnest model to field-based predictions of the number of broods per female produced in Illinois populations of Eastern meadowlark ( Sturnella magna ) and dickcissel ( Spiza americana ). The Markov algorithm behind MCnest has also been adapted for use as a multistate competing risks estimation model and has been applied to the problem of estimation of stressor effects on wild bird populations [53–55], including two cases exploring the effects of environmental contaminants [56,57]. Etterson [4] also showed how the framework could be further adapted to estimate acute mortality of contaminants in field trials when carcass scavenging and imperfect detection make inference difficult.…”

Organic contamination in tree swallow (Tachycineta bicolor) nestlings at United States and binational Great Lakes Areas of Concern

“…In addition, PCB concentrations in stomach contents of tree swallow nestlings from 1 site on the PCBcontaminated Housatonic River (MA, USA) varied from 5630 ng/g to 8800 ng/g wet weight over 3 yr [43] and were >50 times higher than the average diet concentration in the present study. [19]. Concentrations of perfluorinated compounds in tree swallow nestling plasma varied in Minnesota and Wisconsin from 14 ng/mL (North Bass Lake, a remote site in north central Wisconsin, USA) to 437 ng/mL (Pigs Eye Lake, MN, USA) [19] on the Mississippi River near the Twin Cities metro area.…”

“…Concentrations of both PBDEs [12,13] and perfluorinated compounds [14,15] have now been documented in biota, including birds; and reproductive and physiological effects have been reported in birds for both PBDEs [16,17] and perfluorinated compounds [18][19][20]. Exposure to these chemicals of concerns, however, needs to be quantified and accounted for so that effects of the listed contaminants can be correctly assessed, especially for bird or animal deformities and reproductive problems beneficial use impairment.…”

“…Exposure to these chemicals of concerns, however, needs to be quantified and accounted for so that effects of the listed contaminants can be correctly assessed, especially for bird or animal deformities and reproductive problems beneficial use impairment. Concentrations of both PBDEs [12,13] and perfluorinated compounds [14,15] have now been documented in biota, including birds; and reproductive and physiological effects have been reported in birds for both PBDEs [16,17] and perfluorinated compounds [18][19][20]. Comparative ranking among AOCs for PBDEs was recently reported for tree swallow eggs [4] but not for perfluorinated compounds.…”

Full Issue

“…Nevertheless, these results suggest that limiting intensive agricultural practice in proximity to forest reserves could help limit both nest predation and nest parasitism rates. Finally, we hope that the competing risks paradigm employed here (specifically modeling predictor variables for nest predation without excluding failures due to other causes) may be useful at other locations and potentially with other management and conservation questions (e.g., Jackson et al 2011, Johnson et al 2012, Custer et al 2014, to help identify and characterize anthropogenic risks to avian breeding success.…”