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FINAL REPORT Epidemiology, 220-6W-08 Medical Department 3M Company St. Paul, MIN 55144 Date: December 14, 2011 Title: Biomonitoring Assessment of the 3M Oakdale Landfill Remediation Project Study Start Date Protocol Number N/A IRB Approval N/A Principal Investigator: Co-investigators: Geary W. Olsen, D.VM., PhD." Barbara A. Gibson, M.D., MPH." DavidJ. Ehresman, B.S., MT (ASCP)* Study Director Carol A. Ley, MD. MPH. 1. Corporate Occupational Medicine, Medical Department, 220-6W-08, St. Paul, MN 55144 2. Toxicology Laboratory, Tox Assmt & Compl Assurance, Medical Department, Mail Stop 236-1B22, St Paul, MN 55144 Summary Mew Atotal of 11 contingent workers (non-3M employees) entered the exclusion zoneofthe 3M `Oakdale landfill remediation project and therefore participated in biomonitoring. The duration of this project was approximately months. All 11 contingent workers had baseline and end of project measurements for serum concentrationsofperfluorooctanoate (PFOA) and perfluorooctanesulfonate (PFOS). These 11 workers' mean baseline serum PFOA concentration was 4.9 ng/mL (95% CI 3.4 -- 6.5; range 1.8 ~ 10.1), Their mean baseline PFOS concentration was 12.2 ng/mL (95% CI 8.1 - 16.3). `The mean serum concentration differences (end-of-project minus baseline) were -0.6 ng/mL (95% CI (10) (0.2), p= 0.006) for PFOA and -0.4 ng/mL (95% CI (-1.5) ~ (0:8), p= 049) for PFOS. Conclusion: Based on the paired biomonitoring data of 11 contingent workers, there was no increase in serum PFOA or PFOS concentrations while working at the 3M Oakdale landfill remediation project. my Introduction Several remediation projects have been completed regarding legacy perfluorochemicals. `These include the 3M Woodbury primary and northeast landfill remediation projects, the 3M Cottage Grove Building 15/73 demolition and disposal project, the 3M Cottage Grove Building 25 re-roof project, the 3M Cottage Grove D1/D2 and DO excavation projects, and the 3M Decatur Building 2/49 demolition and disposal project. For each of these projects, baseline and end of project assessments were required of 3M employees and contractor workers who entered specified exclusion zones. These zones were defined as where potential exposure to legacy perfluorochemicals (e.g, PFOS (perfluorooctanesulfonate) and PFOA (perfluorooctanoate) was possible, but due to the uniqueness of the work, the magnitude of exposure was unknown. Both baseline and end of project assessments required responses to a medical questionnaire and blood (serum) measurements of PFOS, PFOA, and several clinical chemistries. The purposeofthis report is to provide a descriptive analysisofthe PFOA and PFOS serum concentrations (ng/mL) at baseline and end-of-project time periods for the 3M Oakdale landfill remediation project. The durationofthis project was approximately months. Methods 1. Informed consent "The purpose of the project was explained in an Informed Consent. Subjects read and signed this informed consent at both baseline and end of project assessments. Subjects were informed they could not work on this specific project without such compliance. 2. Clinical chemistries Me Clinical chemistries included a lipid panel profile, blood glucose, BUN, creatinine, serum electrolytes, and liver enzyme tests (including alkaline phosphatase, AST, ALT, and total bilirubin) Fasting was nota requirement because of the logistics of collecting blood samples during various timesofthe day. Clinical chemistries were analyzed by Quest Diagnostics. Individual clinical chemistry analyses at baseline and at end-of-project were medically reviewed by Dr. Gibson Subjects were informed in writing that this examination program was nota full medical check-up." Values out of reference range were indicated with a notation for the subjects to follow up with their primary care physicianifthey had abnormal test results. However, questions could be directed to Dr. Gibson regarding their clinical chemistry test results should the subject so desire. 3. Analytical measurements ofPFOA and PFOS Serum samples were analyzed for PFOA and PFOS by state-of-the-art high performance liquid chromatography mass spectrometry methods by the 3M Medical Department's Toxicology Laboratory under the direction of Dave Ehresman Medical Department personnel collected blood samples that were processed to provide serum samples for analysis. These samples were assigned unique identification numbers and randomized prior to the samples being delivered for analysis. The 3M Medical Department's Toxicology Laboratory was "blinded" to the identity of all samples received for analysis Sample extractions were performed using solid phase extraction (SPE) technique. The extraction and sample clean-upwasbased on a 100 uL sample size and utilized Waters (Milford, MA) Oasis hydrophilic-Tipophilic balance (HLB) 3 0mL cartridges (Ehresman et al. 2007) `The method used two stable labeled intemal standards for quaniitation. The internal sMtOandards used were a dual labeled PFOS where two '*0 molecules were included in the sulfonate group intemal standard, >99% purity, synthesized by Research Triangle Institute, Research Triangle Park, NC) and a dual labeled PFOA molecule, where the carboxyl and alpha carbons were labeled with C stable isotope (greater than 97%, provided by DuPont, Wilmington, DE). All quantitation were based on matrix matched extracted standard curves A'S ul injection ofthe sample eluate was introduced into the High Pressure Liquid Chromatograph (HPLC) which was directly interfaced into the triple quadrupole mass spectrometer (Applied Biosystems/MDS-Sciex Instrument Corporation, Forest City, CA). Standard curves covered the range from 1.0- 150 ng/mL. Standard curves were evaluated using a quadratic regression model where the standards were weighted at 1x, and each curve had an "R'" value equal to or greater than 0.9998. Matix spiked controls (QC samples) evaluated during this study all had acceptable results "within" their previously established ranges. Matrix-matched dilutions were used for samples requiring dilution to bring the samples into the linear rangeof the assay. Extracted serum and `aqueous blanks remained below the lower limit of quantitation established at 1.0 ng/mL (lowest standard fitted on the standard curve used for this projec). +. Communication After each blood collection, individual leters were sent to the participants describing their results. In the baseline assessments, two letters were sent. One referred to the clinical chemistries and the other leter provided baseline PFOA and PFOS concentrations. At end of project, two letters were again sent to each participant. The firs letter provided the individuals clinical chemistry results. The second letter compared baseline to end of project serum PFOA and PFOS concentrations. Mw Results A total of 11 contingent workers participated in a biomonitoring assessment for the Oakdale landfill remediation project because oftheirentry into the exclusion zone. An undetermined number ofother individuals worked on this project but did not enter the exclusion zone; therefore they were not tested. These individuals were primarily truck drivers who hauled landfill material away to be disposedofin an industrial landfill in Rosemount, MN. `Tables 1 and 2 provide the measures of central tendency for the baseline and end-of-project PFOA and PFOS serum concentrations for the 11 subjects with paired measurements (baseline and end-of-project). Values are provided in ng/mL (parts-per-billion) `Table 1. PFOA Baseline and End-of-Project Serum Concentrations (ng/mL) Baseline Min Ql 18 33 MedianQ3 39 63 Arithmetic Max Mean 95%CI 101 49 34-65 End-of-Project 20 29 40 S53 85 43 30-57 `Table 2. PFOS Baseline and End-of-Project Concentrations (ng/mL) Baseline Min Ql 28 85 Arithmetic Median Q3 Max Mean 95%CI 115 184 220 122 81-163 End-of-Project 39 76 100 168 221 118 82-118 My As the data were paired samples, a matched-paired statistical analysis was performed (see Equation). The mean difference represents the averageofthe sumofthe individual differences for the 11 subjects Equation. Mean Difference = X1(end-ofproject baseline) 1 There was a statistically significant change (decrease)of-0.6 ng/mL PFOA between baseline and end of project (95% C1 (-1.0)~ (0.2). p< 0.006). There was no statistically significant change in PFOS concentrations between baseline and end of project (mean difference -0.4 ng/mL; 95% C1 (-1.5) (08); p=049). Figures 1 and 2 provide another method to compare the baseline to end of project concentrations for PFOA and PFOS, respectively, for these 11 contingent workers. Data points near the diagonal identity line, where x = y, indicates no difference in concentrations between baseline (x) and end of project (4). As seen in both Figures 1 and 2, the majority of data arenear the identity line. This indicates concentrations measured at endofproject approximated those at baseline given the analytical variabilityofthe measurements Discussion Me Comparisonofbaseline and end of project serum concentrations of PFOA and PFOS provided each worker an excellent method to assess his/her exposure experience for the 3M Oakdale landfill remediation project. Given the fact that exposure potential during the course of this project was unknown, the useof biomonitoring data allowed for an assessmentof the exposure to PFOA or PFOS, or to materials that may degrade to them. Matched pair analyses did not indicate any substantive. exposure during the course of his project to PFOA or PFOS. The clinical chemistry data were therefore. not analyzed by paired statistics because the biomonitoring data indicated there were no substantivedifferences in exposure to PFOA or PFOS between the baseline and end-of-project measurements. Potential exposureto other materials was not known because only PFOA and PFOS were analyzed in the workers" serum Conclusion Based on paired biomonitoring data of 11 contingent workers who entered the exclusion zone, there was no increase in serum PFOA or PFOS concentrations while working at the Oakdale landfill remediation project. References Ehresman DJ, Froehlich JW, Olsen GW, Chang SC, ButenhoJfLf. 2007. Comparisonof human whole blood, plasma, and serum matrices for the determination of perfluorooctanesulfonate (PFOS), perfluorooctanoate (PFOA), and other fluorochemicals. Environ Res 103:176-184 Coppaen] Figure 1. Baseline and Endof Project PFOA Serum Concentrations (ng/mL), Oakdale Landfill Remediation Project 12.0 _100 z Fogo I 2 60 Z3g 35 a0 20 0.0 00 4. . Co : . dentlyLine 20 40 60 80 100 120 Baseline PFOA (ng/mL) Cohmhpaon Figure 2. Baseline and End of Project PFOS Serum Concentrations (ng/mL), Oakdale Landfill Remediation Project 250 o 200 entity Lin 23 . giso iS100 .- z oS 50 . 00 00 50 100 150 200 250 Baseline PFOS (ng/mL)