Document 2RxraEM9zD4xbyoK0zM1JExD5

FINAL REPORT Epidemiology, 220-6W-08 Medical Department 3M Company St. Paul, MN 55144 Date: January 30,2013 "Title: Biomonitoring Assessmentofthe Cottage Grove Building 25 Phase It Re-Roof Project Study Start Date: September 1, 2000 Protocol Number N/A IRB Approval N/A 3MPaCgoemp1 aonfy Principal Investigator. Covinvestigators Geary W. Olsen, D.V.M., PhD." Barbara A. Gibson, MD, 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 236-1B-22, St. Paul, MN $5144 3MPaCgoem2p0an1y8 Summary A total of 28 subjects, who worked on the 3M Cottage Grove Building 25 Phase I reroof project, had baseline and end-of-project serum clinical chemistry and perfluoroalkyl (PFOA and PFOS) measurements. There were no statistically significant increases in paired PFOA and PFOS concentrations when the end-of-project values were compared to baseline assessments. Conclusion: Based on the biomonitoring data, there was no substantive occupational exposure to PFOA or PFOS while working on the 3M Cottage Grove Building 25 Phase If re-roof project. Introduction Several remediation projects have been completed regarding legacy perfluorochemicals `These included the 3M Cottage Grove Building 15/73 demolition and disposal project, the 3M Woodbury landfill remediation project, the Decatur Building 2/49 demolition and disposal project, and the 3M Cottage Grove Building 25 re-roof project. For eachof these projects, baseline and end-of-project assessments were requiredof 3M employees and contractor workers who entered specified work zones where potential exposure to legacy perfluorochemicals [PFOS (perfluorooctanesulfonate) and PFOA (perfluorooctanoate)] was possible but due to the uniqueness of the work the magnitude was unknown. Both baseline and end-of-project assessments required response to a medical questionnaire and blood (serum) measurements of PFOS, PFOA, and several clinical chemistries. The purpose of this report is to providae descriptive analysis of the PFOA and PFOS serum concentrations (ng/mL) at baseline and endof-project time periods for the 3M Cottage Grove Building 25 Phase IIre-roofproject.The project began in mid-September 2011 and concluded by mid-December 2011 3MPaCgoemp3a0n8y Methods 1. Informed consent The purposeof 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 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 not a requirement becauseof the logistics of collecting blood samples. during various times of the 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 physician if they had abnormal test results However, questions could be directed to Dr. Gibson regarding their clinical chemistry test results should the subjectsodesire. 3MPaCgoem4paonfy 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-up was based on a 100 uL. sample size and utilized Waters (Milford, MA) Oasis hydrophilic-Tipophilic balance (HLB) 3.0m. cartridges (Ehresman et al. 2007) "The method used two stable labeled internal standards for quantitation. The internal standards 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 quantitations were based on matrix matched extracted standard curves AS ul injectionof the 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 3MPaCgoempSaofny an "R"" value equal to or greater than 0.9998, Matrix spiked controls (QC samples) evaluated during this study all had acceptable results "within" their previously established ranges. Matrixmatched dilutions were used for samples requiring dilution to bring the samples into the finear rangeofthe 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 project). 4. Communication After each blood collection, individual letters 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 letter provided baseline PFOA and PFOS concentrations. At the endof-project, two letters were again sent to each participant. The first letter provided the individual's clinical chemistry results. The second letter compared baseline to end-of-project serum PFOA and PFOS concentrations. Results A total of 28 3M employees and contract workers had paired baseline and end-of-project assessments. Ten subjects had baseline assessments but did not participate in end-of:project assessments. Table] and Table 2 (below) provide the measuresofcentral tendency for baseline and end-of-project PFOA and PFOS concentrations for the 28 subjects with paired measurements. Values are provided in ng/mL (parts-per-billion) 3MPaCgoemGpoafny Table 1. PFOA Baseline and End-of-Project Concentrations (ng/mL) Arithmetic Min Ql MedianQ3 Max Mean 95%CI Baseline <10 20 31 60 1150 91 07-175 End-ofProject <10 23 28 55 1090 89 10-169 Geometric Mean 95%Cl 47 32-67 40 27-60 `Table 2. PFOS Baseline and End-of-Project Concentrations (ng/mL) Baseline Arithmetic Min _ Ql Median Q3 Max Mean 95%Cl 34 72 133 182 2250 220 61-379 End-of-Proje2c9t 57 120 185 2000 200 59-341 Geometric: Mean 95% CI 150 112-200 117 83-166 As the data are paired samples, a matched-paired statistical analysis was performed where the mean value was determined for the average of the sum of the individual differences for the 28 subjects. See Equation | Equation I Mean Difference =S(end-ofprojec -baseline)'28 Becauseof the skewed PFOA and PFOS distributions, as seen in Tables 1 and 2, the mean differences of the natural logs of the paired values were also determined. See Equation 2 Equation 2. Mean =Siento project value-) (In(baseline value))/28 3MPaCgoempTaorny Results for Equation 1 and Equation 2, and associated statisticsof the mean differences ofthe paired comparisons, are provided in Table 3 (below) for both PFOA and PFOS. `Table 3. Matched-pair Analysis Comparing Baseline to End-of-Project PFOA and PFOS. concentration (ng/mL) Mean Paired Difference PFOA (ng/mL) t-ratio p value POS (ng/mL) ratio p value Equation I-02 07 024 20 22 002 Equation 2 _+0.04 +12 088 01 34 0001 `The only statistically significant difference was a decrease in the mean of the differences for PFOS (Equations | and 2). In other words, the end-of-project PFOS concentration was statistically significantly less than the baseline PFOS concentration (ng/mL) when analyzed as paired differences. Discussion 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 Cottage Grove Building 25 Phase Il re-roof project. Historically, Building 25 has had the potential for both exposures, but primarily PFOS and its related chemistries. Given the fact that exposure potential during the courseof there-roofproject was unknown, the use of biomonitoring data allowed for an assessment the actual exposure. Because the biomonitoring data indicated there were no substantive differences in any increase in exposure to PFOA or PFOS between baseline and end-of-project, the clinical chemistry data were therefore not 3MPaCgoem$panfy analyzed in aggregate by paired statistics. Potential exposuretoany other materials would not be known since only PFOA and PFOS were analyzed in the workers" serum. Conclusion Based on the biomonitoring data, there was no substantive occupational exposures 10 PFOA or PFOS for the 28 total 3M and contract workers involved with the 3M Cottage Grove Building 25 Phase Il re-roof project References Ehresman DJ, Froehlich JW, Olsen GW, Chang SC, Butenhoff JL. 2007. Comparison of human whole blood, plasma, and serum matrices for the determination of perfluorooctanesulfonate (PFO), perfluorooctanoate (PFOA), and other fluorochemicals Environ Res 103:176-184.