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FINAL REPORT Epidemiology 220-6W-08 Medical Department 3M Company St. Paul, MN 55144 Date: July 14,2010 Title: Biomonitoring Assessmentofthe 3M Cottage Grove D1/D2 Remediation Project Study Start Date: February 1, 2010 Protocol Number N/A IRB Approval N/A CoP-riinncviepsatligInavteosrtsig:ator: GBaerabrayraW.A.OlGsiebns,onD,.VM..MD.,, PMh..PD..H!." David J. Ehresman, B.S., MT (ASCP)* Diane C. Madsen, CMA-C' Study Director: Carol A. Ley, M.D, MPH. 1. 2. CToorxpiocroaltoegyOcLcaubpoartaitoonrayl, TMeodxicAisnsem,tM&ediCcoamlplDeApsasrutrmaenncte,,2M2e0d-i6cWa-l0D8e,pSatr.tPmaeunlt,,MMaNil55S1t4op4 236-1B-22, St. Paul, MN 55144. 3M ComPpaagney? Summary A totalof36 subjects worked on the 3M Cottage Grove DI/D2 remediation project. `Twenty-four (67%) subjects had baseline and endofproject perfluorooctanoate (PFOA) and perfluorooctanesulfonate (PFOS) measurements. Twelve (33%) subjects had only endofproject measurements. The 24 subjects' mean baseline PFOA concentration was 4.6 ng/mL (95% C1 3.6 ~5.5) and mean end of project PFOA concentration was 5.2 ng/mL (95 C1 3.8 - 6.6). Their mean baseline PFOS concentration was 15.6 ng/mL (95% CI 12.7 ~ 18.5) and mean end ofproject PFOS concentration was 17.2 ng/mL (95% C1 12.7 ~ 21.7). The mean paired concentration difference (baseline minus endofproject) for PFOA was +0.7 ng/mL (p = 0.17). Likewise, the `mean paired difference for PFOS was +1.6 ng/mL (p = 0.32). Of the 24 individuals with paired `measurements, there was only 1 person who had a substantive increase in PFOA and PFOS concentrations at endofproject (17.8 ng/mL and 56.0 ng/mL) over baseline (7.0 ng/mL and 19.6 ng/mL), respectively. Potential exposures for this individual may have come from the DI/D2 remediation siteoran independent laboratory setting. Of the 12 individuals with only end of project measurements, their mean PFOA and PFOS concentrations were similar to those who also had a paired baseline measurement. Conclusion: Based on the paired biomonitoring data, and excluding 1 individual whose exposure could have occurred elsewhere, there were no substantive increases in PFOA or PFOS concentrations while working on the 3M Cottage Grove. DI/D2 remediation project. 3M ComPpiapensy Introduction Several remediation projects were launched in 2009 regarding legacy perfluorochemicals. `These included the 3M Woodbury landfill remediation project, the 3M Cottage Grove Buildings 15 and 73 demolition and disposal project (hereafter referred to as only Building 15), the 3M Cottage Grove Building 25re-roof project, the 3M Cottage Grove DI/D2 remediation project, and the 3M Decatur Building 2/49 demolition and disposal project. For each of 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 (c.g. PFOA (perfluorooctanoate) and PFOS (perfluorooctanesulfonate)) was possible, but due to the uniqueness of the work the magnitude was unknown. Both baseline and end of project assessments required a worker's response to a medical questionnaire and collection of blood for serum measurements of PFOA and PFOS, and analysisofseveral clinical chemistries. The purposeofthis report is to provide adescriptive analysis of the PFOA and PFOS serum concentrations (ng/mL) at baseline and endofproject time periods for the 3M Cottage Grove DI/D2 remediation project. Methods 3M Comipadny 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 endofproject 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 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 ofproject were medically reviewed by Dr. Gibson. Subjects were informed in writing that this examination program was nota full `medical `check-up.' Values outofreference 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 subject so desire 3. Analytical measurements ofPFOA and PFOS Serum samples were analyzed for PFOA and POS by state-of-the-art high performance liquid chromatography mass spectrometry methods by the 3M Medical Department's Toxicology Laboratory under the directionof Dave Ehresman. Medical Department personnel collected 3M ComPpagaeny5 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-lipophilic balance (HLB) 3.0mL cartridges (Ehresman et a. 2007). `The method used two stable labeled intemal standards for quantitation. The internal standards used were a dual labeled PFOS where two '*O 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. A'S ul injectionofthe sample cluate 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. Matrixmatched dilutions were used for samples requiring dilution to bring the samples into the linear range of the assay. Extracted serum and aqueous blanks remained below the lower limit of Capes 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 end of 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 of36 individuals participated in the D1/D2 remediation project: 24 (67%) had baseline and end of project assessments and 12 (33%) hadonlyan end ofproject measurement performed. Ofthe 24 baseline assessments that were conducted, 17 (71%) used their 3M `Woodbury end of project measurement (conducted on December 4, 2009) as their baseline assessment for the D1/D2 project. Five (21%) used their 3M Woodbury landfill remediation `baseline assessment (conducted either on August 26, 2009 or September 14, 2009) as their baseline assessment for the DI/D2 project. These individuals did not work on the 3M `Woodbury landfill remediation project; thus their 3M Woodbury baseline assessment was sufficient for the 3M Cottage Grove D1/D2 project. Two (8%) individuals had an initial baseline assessment specific for the D1/D2 remediation project. MOT "Table 1 provides the total numberof individuals, by company, who were tested for PFOA and PFOS during the 3M Woodbury landfill remediation project. Table 1. Distribution of Workers by Company Company Bolander MWeetsrtoonGravel Other Total Baseline 10 57 2 2 End-of-Project 14 154 3 36 Figures 1 through 4 compare the baseline to end-of-project concentrations for PFOA and PFOS, respectively. [Note: These figures are graphed on a log scale.] A strong linear relation centered along the displayed diagonal line, termed the identity line where y =x, is indicative of no change between the paired measurements. For the 24 individuals with paired serum `measurements for PFOA (Figure 1) and PFOS (Figure 3), it can be readily seen that only | individual had a substantive increase in serum PFOA and PFOS concentrations over baseline. `The R? was 0.47 for PFOA (Figure 1) and 0.45 for PFOS (Figure 3). Because this individual was a Weston employee, it is not certain whether the exposure occurred at the D1/D2 excavation site or elsewhere (i.e., in the laboratory). Therefore, the following results will be analyzed by both including (n = 24) and excluding (n = 23) this individual. Removalofthis individual, leaving 23 paired samples, resulted in R% of 0.90 for PFOA (Figure 2) and 0.91 for PFOS (Figure 4). Tables 2a (n = 24) and 2b (n = 23) provide the measuresofcentral tendency for the baseline and end-of-project PFOA concentrations for those subjects with paired measurements (baseline and end-of-project). Values are provided in ng/mL (parts-per-billion). MOT `Table 2a. PFOA Baseline and Endof Project Concentrations (ng/mL), N = 24 Paired Samples Arithmetic Geometric: Min Ql MedianQ3 Max Mean 95%Cl Mean 95% CL Baseline 20 30 42 55 112 46 36-55 41 34-50 EndofProject 20 35 43 59 178 52 38-66 46 38-56 Table 2b. PFOA Baseline and Endof Project Concentrations (ng/mL), N = 23 Paired Samples Arithmetic Geometric Min Ql MedianQ3 Max Mean 95%CI Mean 95%Cl Baseline 20 29 41 55 112 44 35-54 40 34-49 EndofProject 20 35 43 56 101 47 39-55 43 37-51 `Tables 3a (n = 24) and 3b (n= 23) provide the measuresofcentral tendency for the baseline and end of project PFOS concentrations for those subjects with paired measurements (baseline and end-of-project). Table 3a. PFOS Baseline and End of Project Concentrations (ng/mL), N = 24 Paired Samples Baseline Min Ql 42 99 Arithmetic Geometric MedianQ3 Max Mean 95%Cl Mean 95% CL 156 200 298 156 127-185 141 115-173 EndofProje4c7t 98 161 220 560 172 127-217 148 116-187 3M ComPpaagneyd Table 3b. PFOS Baseline and End of Project Concentrations (ng/mL), N = 23 Paired Samples --Bas-- eline Arithmetic Geometric: M4i2n Q7l2 Me1d50ian2Q031 M2a9x8 M1e5a4n 9152%4C-l1_85__Me13a9n 9152%-C1l72 EndofProject 47 9.6159 206 303 155 125-185 139 113-173 Because the data were paired samples, a matched-paired statistical analysis was performed where the mean difference is the averageofthe sum of the individual differences for the 24 (or 23) subjects. See Equation 1. Equation 1. x Mean Difference = aY(end of project ~ baseline24) Becauseofthe skewed PFOS distribution, in particular, as seen in Table 3, the mean differences of the natural logs of the paired values were also determined. See Equation 2. Equation 2 Mean = [X[(In(endofproject value)) ~(In(baseline value))24] Io Results for Equation 1 and Equation 2, and associated statisticsof the mean differences ofthe paired comparisons, are provided in Tables 4a and 4b for both PFOA and PFOS. 3M CoPmagpean1y0 Table 4a. Matched-pair Analysis Comparing Baseline to End of Project PFOA and PFOS Concentration (ng/mL), N = 24 Paired Samples DMiefafenrePnaicreed PFOA (ng/mL) t-ratio palue. PFOS (ng/ml) t-ratio pyalue Equation 1 +0.7 140 017 +16 101 032 Equation2__+0.11 219 004 +005 083 041 TCaonbcleent4rba.tiMoantc(hnegd/-mpLa)i,rNAn=al2y3siPsaiCroedmpSaarmpilnegs.Baseline to End of Project PFOA and PFOS Mean Paired Difference PFOA (ng/mL) tratio p value PFOS (ng/mL) tratio __pvalue Equation] +02 141 017 00 017 087 Equation2__0.0 205 005 0.04 010 092 Only when the logs ofPFOA were taken limited for the n = 23 subjects was there a statistically significant increase in the meanofthe paired differences as seen in Equation 2 in Table 4b. The difference between endofproject and baseline PFOA log concenirations was. negative (-0.07) indicating a decrease in concentrations from baseline to endofproject. However, the difference is slight given the analytical variabilityofthe measurements. A similar situation was seen for PFOS in Table 4b but this finding was not statistically significant `There 12 individuals who only had an endofproject assessments. Their mean PFOA and PFOS concentrations were compared to the 24 (and 23) subjects who had bothbaselineand end of project measurements to determineifthey had different concentrations at endofproject. The `mean serum PFOA and PFOS concentrations at end of project were not statistically significantly different between these two groups although the 12 individuals, who did not have baseline 3M CoPmapgaenly assessments, had higher mean values for both PFOA (Tables Sa and Sb) and PFOS (Tables 6a and 6b) at end of project. Table Sa. Endof Project Arithmetic Means of Serum PFOA Concentrations (ng/mL) Among. DI/D2 Subjects With and Without Baseline Assessments, N = 24 Paired Samples Had baseline assessment? _N__ Mean 95%CI ___tstatistic _p value Yes 24 52 38-66 052 061 No 1265 13-116 Table Sb. EndofProject Arithmetic Meansof Serum PFOA Concentrations (ng/mL) Among DI/D2 Subjects With and Without Baseline Assessments, N = 23 Paired Samples Had baseline assessment? N Mean 95% Cl t-statistic p value Yes 23 47 39-55 076 0.46 No 265 13-116 Table 6a. End of Project Arithmetic Means of Serum PFOS Concentrations (ng/mL) Among DI/D2 Subjects With and Without Baseline Assessments, N = 24 Paired Samples. Had baseline assessment? N_ Mean 95%Cl __tstatistic _p value Yes 24172 125-186-040 0.69 No 12188 127-217 Mcp "Table 6b. End of Project Arithmetic Means of Serum PFOS Concentrations (ng/mL) Among DI/D2 Subjects With and Without Baseline Assessments, N = 23 Paired Samples Hod baseline assessment? _N__ Mean 95%CI __tstatisic value Yes 23 155 125-186 091 037 No 2 188 116-260 Discussion `Comparison of baseline and endof project serum concentrationsof PFOA and PFOS provided cach worker an excellent method to assess his/her exposure experience for the 3M Cottage Grove DI/D2 remediation project. Given the fact that exposure potential during the courseofthe remediation project was unknown, the use of biomonitoring data allowed for an assessmentofthe actual, yet unknown, exposure to PFOA or PFO, or to materials that may degradeto them. Only 1ofthe 24 D1/D2 remediation subjects had a substantive increase in serum concentrations over baseline. Because this individual was a Weston employee, itis not known where the increased exposure to PFOA and PFOS might have occurred. Because of minimum differences between baseline and endofproject PFOA and PFOS measurements for 23 ofthe 24 subjects with paired measuremetns, the clinical chemistry data were therefore not analyzed by paired statistics. MGW Conclusion Based on paired biomonitoring dat, there was no substantive change in PFOA or PFOS serum concentrations for those workers involved with the 3M Cottage Grove DI/D2 remediation project except for 1 worker whose sourceof exposure could have been eithera the ste and/or at other employer-related locations. can References Ehresman DJ, Froehlich JW, Olsen GW, Chang SC, ButenhofJLf. 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. 3MCoTmapgaensy Subs ForeP.og tyCGomIoRgeelethrPts w 3 z2 a5 A mw PFOABaseline ogd) 3M CoPmapacnty Fp at Go DiRerasn: `BaseinevsEndofProjectPFOAConcentaions ng)forN=23PairedSamples. me 3 HS Po 0 w mw PFOABaseine fngnl) _-- figae3. 3M CotageGroveD102RemedaPiroogent `Baseinevs.Endof ProjectFOSConcentrations nil) or N=24 PeedSaves. Sno P :. ne sae ERE Fig CoteGaveDYO2RemediatPiroent _c--d 10. 3 :. BaseioePOS gin)