DOI: 10.5061/dryad.573n5tbjq
title: Data from: Bioaccumulation of perfluorooctane sulfonic acid (PFOS) and oxidative stress in snapping turtles in New York, USA

description: Perfluorooctane sulfonic acid (PFOS) is an anthropogenic chemical found in
 aqueous film-forming foams (AFFFs) and many consumer products. Despite its
 environmental ubiquity and persistence, little is known about the effects
 of PFOS on stress levels in wild animals. Here, we examined PFOS
 bioaccumulation and correlations between PFOS exposure and oxidative
 stress in snapping turtles (Chelydra serpentina) downstream of Griffiss
 Air Force Base in Rome, New York, a known source of AFFF contamination.
 Maximum concentrations of PFOS were extrapolated as 41.7 ppb and 498 ppb
 in water and turtle samples, respectively; in comparison, the proposed
 United States national advisory concentration of PFOS in drinking water is
 currently 0.00002 ppb. PFOS concentrations declined with distance
 downstream from the base and were lower in other local water bodies.
 Indices of oxidative stress were positively correlated with plasma PFOS
 concentrations in snapping turtles. These data illuminate the potential
 for bioaccumulation and increasing oxidative stress levels associated with
 PFOS contamination in a wild population of aquatic turtles.
description: On 6 October 2020, water samples were collected for PFAS analysis
 from six locations: one 5 km upstream of the contamination point in
 Sixmile Creek, four 0–1500 m downstream of the contamination point in
 Sixmile Creek, and one in the Erie Canal, 2,250 m downstream of the
 contamination point. Stream water samples (30 mL, collected in
 triple-rinsed Falcon centrifuge tubes) were stored at −20o °C until
 analysis. Twenty-nine blood samples were collected from
 snapping turtles between June and September of 2021. Turtle sampling
 locations included three sites downstream of the contamination point in
 Sixmile Creek, one site at Stony Creek Pond adjacent to a Department of
 Defense Fuel Depot fuel storage facility, which was also known to have
 PFAS contamination, and three control sites (Delta Lake, South Otselic
 Fish Hatchery, and Camroden Pond) with no known PFAS contamination.
 Snapping turtles were captured in hoop nets, and Tomahawk traps baited
 with tuna. Traps were checked within 24 hours after baiting. Captured
 turtles were weighed, and sex was determined by the shape and position of
 the cloaca. Blood samples (~ 0.1 mL) were taken from the dorsal cervical
 vessels into heparinized tubes and stored on ice until centrifugation.
 Plasma was stored at −80 °C until analysis. Turtles were sampled within 10
 min after they were removed from the traps and were released at the point
 of capture immediately after sampling.
 <strong>PFAS quantification</strong><br>
 Methods for the extraction of PFAS from water and plasma samples were
 modified from Taniyasu et al. (2005) and the EPA’s Method 537.1 (Shoemaker
 and Tettenhorst 2020). All samples were prepared and analyzed in
 duplicate. To prepare water samples for analysis, 10 mL samples were first
 spiked with the internal standard for PFOS [sodium
 perfluoro-1-[^<sub>13</sub>^C<sub>4</sub>]-octane
 sulfonate (MPFOS); purity &gt; 98%; Sigma-Aldrich] at a concentration
 of 16 ng/mL and then passed through conditioned Oasis WAX (6 cc, 150 mg,
 30 µm) solid-phase extraction cartridges (Wellington Laboratories) at a
 rate of 1 drop/s. WAX cartridges were conditioned by washing columns with
 2 mL of 100% HPLC-grade acetonitrile (Sigma-Aldrich) followed by 2 mL of
 water. After samples were added, the cartridges were washed with 3 mL of
 20 mM ammonium acetate followed by 3 mL of 100% methanol. Target analytes
 were eluted with 3 mL of 2% ammonium hydroxide in methanol and collected
 into conical polypropylene test tubes. The eluate was evaporated using a
 TurboVap concentrator with compressed air. One hundred µL of 60:40 water:
 acetonitrile solution was added to the test tube residues for
 reconstitution before HPLC/MS/MS analysis. To prepare plasma samples for
 analysis, turtle plasma (25µL) was transferred to a centrifuge tube with
 100% acetonitrile (75µL) and 0.22 µg/mL MPFOS internal standard solution
 (10µL) for a final concentration of 20 ng/mL. After centrifugation, the
 supernatant (approximately 50 µL) was extracted and filtered through a
 conditioned 0.45-micron sample filter-tipped syringe (using the
 conditioning methods described above) with distilled water (50µL) into a
 conical vial within a glass chromatography vial.
 <strong>LC/MS/MS analysis and
 quantification</strong><br> Analysis of PFOS was performed
 using an ultra-high-performance liquid chromatograph and mass spectrometer
 (LC/MS/MS), Thermo Vanquish HPLC LTQ-XL ion trap mass spectrometer,
 operated in the electrospray negative ionization mode (electrospray
 needle: 4.5 kV; capillary: 275 °C). Five µL of sample extracts were
 injected into an Accucore Vanquish C18 30 × 2.1 mm column (ThermoFisher;
 upper-pressure limit 1000.0 bar; 1.50 µm particle size; 2.1 mm diameter).
 At a flow of 0.250 mL/min and pressure of approximately 4600 psi (divert
 valve set to source), the flow gradient was started at 60% 95:5 water:
 acetonitrile and 40% 5:95 water: acetonitrile, increased to 70% 5:95
 water: acetonitrile at 3 min, then returned to the starting condition at
 5.3 min. Due to the limitations of the ion trap in detecting the expected
 m/z 80 product ion, PFOS, and MPFOS were detected using the ion current
 obtained from the deprotonated molecule, m/z 499 and m/z 503,
 respectively. Calibration curves were created separately for water and
 plasma analysis. Analytical standards for PFOS (purity &gt; 85%) were
 purchased from Sigma-Aldrich. For water samples, a curve was created from
 six standard samples prepared at 0.8, 4, 8, 40, 80, and 160 ng/mL of the
 PFOS standard, diluted in a 60:40 solution of water: acetonitrile with
 MPFOS internal standard (R2 = 0.988). For plasma samples, a calibration
 curve was created from six standard samples prepared at 0.4, 1.6, 8, 40,
 and 80 ng/mL of the PFOS standard, diluted in a 60:40 solution of water:
 acetonitrile with MPFOS internal standard (R2 = 0.974). Internal standards
 were maintained at concentrations of 16 ng/mL and 20 ng/mL MPFOS for water
 and plasma, respectively. Concentrations of PFOS in each sample were
 quantified based on the ratio of the response of the analytical standard
 concentrations to internal standard concentrations. Quality control
 samples were not run with these analyses.
 <strong>Oxidative stress
 measurements</strong><br> Oxidative stress levels in turtle
 plasma from Sixmile Creek were measured using the Arbor Assays DetectX®
 DNA Damage ELISA Kit (K059), following the manufacturer’s guidelines for
 plasma. The DNA Damage assay measures DNA and RNA deoxidized guanosine
 species, specifically 8-hydroxy-2′-deoxyguanosine (8-OHdG), which is a
 marker of oxidative stress. Plasma samples were diluted in a 1:8 ratio and
 run in duplicate. The endpoint absorbance values at 450 nm were read on a
 Bio‐Rad Benchmark Plus Microplate Spectrophotometer. Raw data were
 converted to DNA damage levels using the MyAssays (www.myassays.com)
 calculator tools designed specifically for these assays.
description: # Data from: Bioaccumulation of perfluorooctane sulfonic acid (PFOS) and
 oxidative stress in snapping turtles in New York, USA
 [https://doi.org/10.5061/dryad.573n5tbjq](https://doi.org/10.5061/dryad.573n5tbjq) ## Description of the data and file structure This dataset includes the sampling location, sex, weight, PFOS concentration, and 8-OHdG concentration of snapping turtles sampled in this study. NAs represent values that are not determined. ### Files and variables #### File: PFOS_data_Turtles.txt **Description:**  ##### Variables * Site: Sampling site; sites correspond to the map (Fig. 1) within the paper * Treatment: Control = sites with no known PFOS contamination; contaminated = sites in Sixmile Creek with known PFOS contamination; intermediate = a Department of Defense fuel storage facility with putative PFOS contamination. * sex: Sex of captured tu, rtles * weight (g): Weight of captured turtles (g) * Distance from base in Six-Mile Creek: Downstream distance (m) in Six-Mile Creek from the Griffiss Air Force Base * PFOS (ppb): Concentration of PFOS in turtle plasma * 8-OHdG (pg/mL): Concentration of 8-hydroxy-2′-deoxyguanosine (8-OHdG),  a marker of oxidative stress, in turtles of Sixmile Creek  ## Access information Other publicly accessible locations of the data: * NA Data was derived from the following sources: * NA