Document jBqLZjeZ1bK1LKGkBVX4M0B0p

3M ComPpagaeny| FINAL REPORT EpiMdeedmiicoalloDgye,pa2r2t0m-e3nWt-05 3M Company St. Paul, MN 55144 Date: December 15, 2009 Title: Biomonitoring Assessmentof the Cottage Grove Building 25Re-Roof Project Study Start Date: September 1, 2009 Protocol Number N/A IRB Approval N/A Principal Investigator: Co-investigators: Geary W. Olsen, D.V.M., Ph.D! Barbara A. Gibson, M.D, MPH.' David J. Ehresman, B.S., MT (ASCP)? Diane C. Madsen, CMA-C' Study Director: Carol A. Ley, MD, MP.H. 1. 2. Corporate Occupational Toxicology Laboratory, MTeodxicAisnsem,tM&ediCcoamlplDeApsasrutrmaenncte,,2M2e0d-i6cWa-l0D8e,paStr. tPmaeunlt,,MMaNil55S1t4o4p 236-1B-22, St. Paul, MN 55144 3M ComPpaagney2 Summary A totalof 37 subjects, who worked on the 3M Cottage Grove Building 25re-toofproject, had baseline and end-of-project serum clinical chemistry and perfluorochemcial (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 25re-roof project. Introduction Several remediation projects were launched in 2009 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 eachofthese 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 (e.g. PFOS (perfluorooctanesulfonate) and PFOA (perfluorooctanoate) was possible but due to the uniquenessofthe 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 ofthis report s to provide a descriptive analysisof the PFOA and PFOS serum concentrations (ng/mL) at baseline and end of-project time periods for the 3M Cottage Grove Building 25 re-roof project. Methods 3M ComPpagaeny 1. Informed consent `The purposeofthe 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 arequirement because of the logisticsofcollecting 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 s0 desire. 3. Analytical measurements of PFOA 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 ofDave Ehresman. Medical Department personnel collected 3M ComPpagaeny blood samples that were processed to provide serum samples for analysis. These samples were assigned unique identification numbers and randomizedpriorto 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 2 100 ul. sample size and utilized Waters (Milford, MA) Oasis hydrophilic-lipophilic balance (HLB) 3.0m cartridges (Ehresman et al. 2007). `The method used two stable labeled intemal standards for quantitation. The internal standards used were adual labeled PFOS where two *0 molecules were included in the sulfonate group (internal 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. A'S uL injectionofthe 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 1/x, and each curve had an *"R" value equal to or greater than 0.9998. Matrix spiked controls (QC samples) evaluated during this study all had acceptable results "with-in" their previously established ranges. Matrix`matched dilutions were used for samples requiring dilution to bring the samples into the linear rangeofthe assay. Extracted serum and aqueous blanks remained below the lower limit of 3M ComPpagaensy 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'sclinical chemistry results. The second letter compared baseline to end-of-project serum PFOA and PFOS concentrations. Results A totalof 37 3M employees and contract workers had paired baseline and end-of-project assessments. Six subjects had baseline assessments but did not participate in end-of-project assessments. One subject worked on both the Building 25 re-roof project and the Building 15/73 demolition and disposal project and remained on the 15/73 project after the completionofhis assignment on there-roof project. His results are not included herein because they could be confounded by other PFOA and PFOS workplace exposure at Cottage Grove. Table! and Table 2 (below) provide the measuresofcentral tendency for baseline and end-of-project PFOA and PFOS concentrations for the 37 subjects with paired measurements. Values are provided in ng/mL (parts-per-billion). To convert to parts-per-million, divide the values by 1,000. Table 1. PFOA Baseline and End-of-Project Concentrations (ng/mL) Arithmetic Min Ql Medi Q3 Max Mean 95%Cl Baseline 10 32 50 161 2750 340 98-581 Endof-Project <1.0 29 49 140 2650 326 07-555 3M ComPpagaeny Geometric Mean 95%Cl 78 47-130 83 50-138 Table 2. PFOS Baseline and End-of-Project Concenirations (ng/mL) Baseline Arithmetic Min 47 Ql 148 Medi Q3 19.6 30.0 Max Mean 95%Cl 3170 49.1 222-761 End-of-Projectd7 148 220 337 2970 498 232-765 MeGaenome9t5r%icCl 242 171-343 252 178-356 As the data are paired samples, a matched-paired statistical analysis was performed where the mean value was determined for the average ofthe sumofthe individual differences for the 37 subjects. See Equation I. Equation 1 Mean Difference = X7(end-of:project --baseline5)7 Because of the skewed PFOA and PFO distributions, as seen in Tables 1 and 2, the mean differencesof the natural logs of the paired values were also determined. See Equation 2. Equation 2. Mean 7 = Z(Inend-of projet value) - (n(baseline valu))57 3M ComPpaagney? Results for Equation | and Equation 2, and associated statisticsofthe 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. palue PFOS (ng/mL) tratio _p value Equation I-14 EE] 0.04 +07 0.94 083 Equation 2_+0.012 +0.57 011 40.039 2.04 097 "The only statistically significant difference was a decrease in the meanofthe differences for PFOA (Equation 1). In other words, the end-of-project PFOA concentration was statistically significantly less than the baseline PFOA concentration (ng/mL) when analyzed as paired differences. This counterintuitive finding is likely well-within the variationof the analytical measurements performed. Figures 1 and 2 provide another method to compare the baseline to end-of-project concentrations for PFOA and PFOS, respectively. [Note: These figures are graphed in log scale.) The strong linear correlation centered along the diagonal is indicative of no changes between the paired measurements. The R? values for both figures are 0.997, indicativeofstrong linearity between baseline and end-of-project concentrations (i.., no differences between the individual's end-of:project and baseline concentrations). 3M ComPpagaeny3 Discussion Comparison of baseline and end-of-project serum concentrations ofPFOA and PFOS. provided each worker an excellent method to assess his/her exposure experience for the 3M Cottage Grove Building 25 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 courseofthere-roofproject was unknown, the useof biomonitoring data allowed for an assessment the actual exposure. Because the biomonitoring data indicated there were no substantive differences in exposure to PFOA or PFOS between baseline and end-ofproject, the clinical chemistry data were therefore not analyzed in aggregate by paired statistics Potential exposure to any other materials would not be known since only PFOA and PFOS were analyzed in the workers' serum. Conclusion Based on the biomonitoring data, there appeared to be no substantive occupational exposures to PFOA or POS for the 37 total 3M and contract workers involved with the 3M Cottage Grove Building 25re-roofproject. 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 (PFOS), perfluorooctanoate (PFOA), and other fluorochemicals. Environ Res 103:176-184. 3M Comfpsan]y wo EFB igue 1. CatiageGoveRn eRoofPC rojet ) i " i= oe : " 3 3 | he w - semen) SMCaFmpoatnoy JE Fo eemot sty o_o ii L Jv ful 2 . | em ss -er)-