3 research outputs found
Characterizing the Movement of Per- and Polyfluoroalkyl Substances in an Avian Aquatic–Terrestrial Food Web
The movement of per- and polyfluoroalkyl substances (PFAS)
through
linked aquatic–terrestrial food webs is not well understood.
Tree swallows (Tachycineta bicolor)
in such systems may be exposed to PFAS from multiple abiotic and/or
biotic compartments. We show from fatty acid signatures and carbon
stable isotopes that tree swallow nestlings in southwestern Ontario
fed on both terrestrial and aquatic macroinvertebrates. The PFAS profiles
of air, terrestrial invertebrates, and swallows were dominated by
perfluorooctanesulfonic acid (PFOS). Short-chain perfluoroalkyl acids
(PFAAs) were largely restricted to air, surface water, and sediment,
and long-chain PFAAs were mainly found in aquatic invertebrates and
tree swallows. PFOS, multiple long-chain perfluorocarboxylic acids
[perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), perfluorotridecanoic
acid (PFTrDA)] and perfluorooctane sulfonamide precursors were estimated
to bioaccumulate from air to tree swallows. PFOS bioaccumulated from
air to terrestrial invertebrates, and PFOS, PFDA, and perfluorooctane
sulfonamidoacetic acids (FOSAAs) bioaccumulated from water to aquatic
invertebrates. PFOS showed biomagnification from both terrestrial
and aquatic invertebrates to tree swallows, and PFDA and FOSAAs were
also biomagnified from aquatic invertebrates to tree swallows. The
movement of PFAS through aquatic–terrestrial food webs appears
congener- and compartment-specific, challenging the understanding
of PFAS exposure routes for multiple species involved in these food
webs
Occurrence of Triclocarban and Triclosan in an Agro-ecosystem Following Application of Biosolids
Triclocarban
(TCC) and triclosan (TCS), two of the most commonly
used antimicrobial compounds, can be introduced into ecosystems by
applying wastewater treatment plant biosolids to agricultural fields.
Concentrations of TCC and TCS were measured in different trophic levels
within a terrestrial food web encompassing land-applied biosolids,
soil, earthworms (<i>Lumbricus</i>), deer mice (<i>Peromyscus maniculatus</i>), and eggs of European starlings
(<i>Sturnus vulgaris</i>) and American kestrels (<i>Falco sparverius</i>) at an experimental site amended with biosolids
for the previous 7 years. The samples from this site were compared
to the same types of samples from a reference (biosolids-free) agricultural
site. Inter-site comparisons showed that concentrations of both antimicrobials
were higher on the experimental site in the soil, earthworms, mice
(livers), and European starling eggs, but not American kestrel eggs,
compared to the control site. Inter-species comparisons on the experimental
site indicated significantly higher TCC concentrations in mice (TCC:
12.6–33.3 ng/g) and in starling eggs (TCC: 15.4–31.4
ng/g) than in kestrel eggs (TCC: 3.6 ng/g). Nesting success of kestrels
only was significantly lower on the experimental site compared to
the reference site due to nest abandonment. This study demonstrates
that biosolids-derived TCC and TCS are present throughout the terrestrial
food web, including secondary (e.g., starlings) and tertiary (i.e.,
kestrels) consumers, after repeated, long-term biosolids application
The Flame Retardant β‑1,2-Dibromo-4-(1,2-dibromoethyl)cyclohexane: Fate, Fertility, and Reproductive Success in American Kestrels (<i>Falco sparverius</i>)
Captive American kestrels (<i>Falco sparverius</i>) were
exposed via diet during reproduction to an environmentally relevant
concentration of β-1,2-dibromo-4-(1,2-dibromoethyl)Âcyclohexane
(β-TBECH). The β-TBECH isomer was injected into the food
source at a daily dosing concentration of 0.239 ng/g kestrel/day (22
pairs); control birds were exposed via diet to the safflower oil vehicle
only (24 pairs). Eight pairs in each group were exposed for four weeks
and sacrificed for tissue analysis; the remaining pairs completed
their breeding cycle, with exposure ceasing at the end of incubation
(82 days). α- and β-TBECH appeared to be rapidly metabolized
and/or eliminated from fat, liver, and plasma; both isomers and potential
hydroxylated metabolites of β-TBECH (plasma) were undetected.
Notwithstanding, compared to controls, pairs exposed to β-TBECH
laid fewer eggs (<i>p</i> = 0.019) and laid lighter eggs
(successful eggs: <i>p</i> = 0.009). Exposed pairs also
demonstrated poorer egg fertility (<i>p</i> = 0.035) although
testis mass and histology were similar among males. Reductions in
egg production and fertility resulted in decreased hatchling success
(<i>p</i> = 0.023). The β-TBECH-exposed pairs also
produced fewer males overall (<i>p</i> = 0.009), which occurred
concurrently with increased estradiols maternally deposited in eggs
(<i>p</i> = 0.039). These findings demonstrate that β-TBECH
may be detrimental for breeding in wild birds receiving similar exposure
levels