Geology topics

Annette Trowbridge

Publications and source records attributed to Annette Trowbridge.

3 recordsLinked to original sources

USGS2013

Exposure and effects of perfluoroalkyl substances in tree swallows nesting in Minnesota and Wisconsin, USA

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.

Minnesota;Wisconsin↗

USGS2013

Perfluorinated compound concentrations in great blue heron eggs near St. Paul, Minnesota, USA, in 1993 and 2010-2011

A great blue heron (Ardea herodias) colony on Pig's Eye Island on the Mississippi River near St. Paul, Minnesota, USA, is located near several potential perfluorinated compound (PFC) sources. The PFC concentrations in great blue heron eggs reported from a 1993 collection from the Pig's Eye colony were among the highest measured in bird eggs worldwide. The objective of this investigation was to determine whether PFC concentrations in great blue heron eggs at the Pig's Eye colony have changed since 1993. Total PFC concentrations in great blue heron eggs collected at the Pig's Eye colony in 2010 and 2011 (geometric mean = 340 and 492 ng/g wet wt) were 60% lower than the 1993 collection (1,015 ng/g wet wt). Among PFCs, perfluoroalkyl sulfonate concentrations were lower and perfluoroalkyl carboxylate concentrations were higher in the 2010 and 2011 collections. Two of 20 (10%) of the eggs analyzed from Pig's Eye in 2010 and 2011 were >1,000 ng PFCs/g wet weight and the maximum PFC value (2,506 ng PFCs/g wet wt) measured in 2010 and 2011 was among the highest PFC concentration reported in bird eggs. These high concentrations are at levels associated with physiological and neurological effects in birds.

Minnesota↗

USGS2010

Perfluorinated compounds and polybrominated diphenyl ethers in great blue heron eggs from three colonies on the Mississippi River, Minnesota

Archived Great Blue Heron (Ardea herodias) eggs (N = 16) collected in 1993 from three colonies on the Mississippi River in Minnesota were analyzed in 2007 for perfluorinated compounds (PFCs) and polybrominated diphenyl ethers (PBDEs). One of the three colonies, Pig's Eye, was located near a presumed source of PFCs. Based on a multivariate analysis, the pattern of nine PFC concentrations differed significantly between Pig's Eye and the upriver (P = 0.002) and downriver (P = 0.02) colonies; but not between the upriver and downriver colonies (P = 0.25). Mean concentrations of perfluorooctane sulfonate (PFOS), a major PFC compound, were significantly higher at the Pig's Eye colony (geometric mean = 940 ng/g wet weight) than at upriver (60 ng/g wet weight) and downriver (131 ng/g wet weight) colonies. Perfluorooctane sulfonate concentrations from the Pig's Eye colony are among the highest reported in bird eggs. Concentrations of PFOS in Great Blue Heron eggs from Pig's Eye were well below the toxicity thresholds estimated for Bobwhite Quail (Colinus virginianus) and Mallards (Anas platyrhynchos), but within the toxicity threshold estimated for White Leghorn Chickens (Gallus domesticus). The pattern of six PBDE congener concentrations did not differ among the three colonies (P = 0.08). Total PBDE concentrations, however, were significantly greater (P = 0.03) at Pig's Eye (geometric mean = 142 ng/g wet weight) than the upriver colony (13 ng/g wet weight). Polybrominated diphenyl ether concentrations in two of six Great Blue Heron eggs from the Pig's Eye colony were within levels associated with altered reproductive behavior in American Kestrels (Falco sparverius).

Minnesota↗