Document e71bQDzpMg6bOyM7ng2ZE415y

FINAL REPORT EpiMdeedmiicoalloDgye,pa2r2t0m-e3nWt-05 3M Company St. Paul, MN 55144 Date: May 3.2011 Title: Biomonitoring Assessment of the 3M Woodbury Northeast Landfill Remediation Project Study Start Date: September 1, 2010 Protocol Number N/A IRB Approval N/A Principal Investigator: Co-investigators: Geary W. Olsen, D.V.M., PhD." Barbara A. Gibson, M.D, MP.H.! DaviJd. Ehresman, B.S., MT (ASCP)* Diane C. Madsen, CMA-C' 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 Departmen, Mail Stop 236-1B22, St. Paul, MIN 55144 eons Summary There were 15 contingent workers (non-3M employees) who worked within the exclusion zone at the 3M Woodbury northeast landfill remediation project that had baseline and end-of-project `perfluorooctanoate (PFOA) and perfluorooctanesulfonate (PFOS) measurements. The duration of this project was approximately 4 months. An additional 7 contingent workers participated in either a baseline (n = 4) or end ofproject (n = 3) assessment; thus, a rend assessmentofthese 7 individuals was not possible. The 15 contingent workers with paired assessments showed no satistially significant increases ineithertheirmean PFOA or PFOS serum concentrations. These 15 workers" `mean baseline PFOA concentration was 3.8 ng/mL (95% C1 2.7 - 5.0).TheirmeanPFOS concentration was 13.1 ng/mL (95% C19.6 ~ 16.5). The mean concentration differences (end-ofproject minus baseline)were0.0 ng/mL (95% CI (-0.3-) 0.4, p = 0.97) for PFOA and -0.3 ng/mL (95% CI (1.1) ~0.4, p = 0.38) for PFOS. Conclusion: Based on the paired biomonitoring data of 15 contingent workers, there was no increase in serum PFOA or PFOS concentrations while working at the 3M Woodbury northeast landfill remediation project. comes Introduction Several remediation projects have been completed regarding legacy perfluorochenicals. These include the 3M Woodbury (primary) landfill remediation project, the 3M Cotuage Grove Building 15/73 demolition and disposal project, the 3M Cottage Grove Building 25re-roofproject, the 3M Cottage Grove DI/D2 and D9 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 work zones where `potential exposure to legacy perfluorochemicals (e.g, PFOS (perfluorooctanesulfonate) and PFOA (perfluorooctanoate) was possible, but duteo 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 POS, PFOA, and several clinical chemistries. The purpose of this report is to provide a descriptive analysis of the PFOA and PFOS serum concentrations (ng/mL) at baseline and end-of-project time periods for the 3M Woodbury northeast landfill remediation project. The duration of this project was approximately 4 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. Me 2. Clinical chemistries Clinical chemistries included alipid panel profile, blood glucose, BUN, creatinine, serum electrolytes, and liver enzyme tests (including alkaline phosphatase, AST, ALT, and total bilirubin). Fasting was noat requirement becauseofthe logisticsof collecting blood samples during various timesofthe day. Clinical chemistries were analyzed by Quest Diagnostics. Individual clinical chemistry analyses at baselineandat end-of-project were medically reviewed by Dr. Gibson, `Subjects were informed in writing that this examination program was not a 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 regardingtheir clinical chemistry test results shouldthe subject so desire. 3. Analytical measurementsofPFOA 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 directionof 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 randomizedpriorto the samples being delivered for analysis. The 3M Medical Department's Toxicology Laboratory was "blinded" to the identityofall 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 al. 2007). cpp `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 (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 quantitation were based on matrix matched extracted standard curves. A'S ul injection of 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 cvaluated using a quadratic regression model where the standards were weighted at 1x,andcach 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 renge of the assay. Extracted serum and aqueous blanks remained below the lower limitof 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 th clinical chemistries and the other letter provided baseline PFOA and PFOS concentrations. At end-of-project, two letters were again senttoeach participant. The first leter provided the individual's clinical chemistry results. The second letter compared baseline to end-of-project serum PFOA and PFOS concentrations. SM Comspasny Results A total of 22 contingent workers participated in biomonitoring for this remediation project (Table 1). Fifteen individuals had both baseline and end of project assessments. `Table 1. Distribution of workers by company and participation Company Baseline AVeEiCtOM 13 1 Briscoe Trucking ~~ 0 WKeosrttoecnh Consulting 50 Total __End-of-Project 9 1 1 61 Reasons for "no show" 4didnot show for end of project (Did not show for baseline) ((DOinde ndoitd snhotowshfoorwbfaosrelbiansee)line) It was not possible to determine whether the 7 individuals, without paired measurements as shown in Table 1, had increased serum PFOAor PROS concentrations atributable to working on the Woodbury northeast landfill remediation project. The 4 Veit workers that had only abaseline: assessment had PFOA concentrations comparable to thei9r Veit colleagues with paired measurements (3.0 ng/mL vs. 3.0 ng/mL, t = 0.08;p value = 0.94); however,these 4 workers had asignificantly higherbaseline PFOS concentration (21.3 ng/mL vs. 9.9 ng/mL, = 4.3, p = 0.01). Reason for this difference is unknown. The three workers assessed only at end of project worked for different employers. Two of these workers had prior work exposures with other 3M remediation sites. Their serum PFOA and PFOS concentrations were higher than the average of the 15 contingent workers with paired measurements. csPaipeny Tables 2 and 3 provide the measures of central tendency for the baseline and end-of-project PFOA and PFOS concentrationsforthe 15 subjects with paired measurements. Values are provided in ng/mL (parts-per-billion). There were no statistically significant differences between baseline and end of project measurements for these 15 contingent workers. Table 2. PFOA Baseline and End-of-Project Concentrations (ng/mL) Min Ol Baseline 13 24 End-of-Project 10 25 MedinQ3 35 48 35 46 Max MAerainthm9et5i%cCL 101 38 27-50 10 38 27-50 MeaGenome9t5r%iCc] 34 26-45 34 26:45 Table 3. PFOS Baseline and End-of-Project Concentrations (ng/mL) Min Ol Baseline 49 87 End-ofProject 35 03 MedianQ3 Max MAerainthm9e5t%icCL 120 181 290 131 96-165 122 156 282 128 95-160 MeGaenome9t5ri%cC 119 92-152 ILS 89-150 A matched-pair statistical analysis was performed (see Equation). The mean difference represeats the averageofthe sumofthe individual differences for the 15 subjects. There were no statistically significant mean matched-pair differences for PFOA or PFOS (Table 4). Equation. Mean Difference = Yi(end-of-project ~baseline)/15 2) 3M ComFpeansy `Table 4. Matched-pair Analysis Comparing Baseline to End-of-Project PFOA and PFOS concentration (ng/mL) MDiefafenrePnaciered PFOA (ng/mL) tratio pualue PROS (ng/ml) tratio p value Equation __00 0.04 097 203 090 038 `Table provides the statistically nonsignificant matched-pair differences by the 2 employers (Veit and Weston) for 14ofthese 15 contingent workers with paired assessments. `Table 5. Matched-pair Analysis Comparing Baseline to End-of-Project PFOA and PFOS Concentration (ng/mL) by Employer Mean Paired Difference PFOA (ng/ml) txatio pale PFOS (ng/mL) ratio p value Veit 00 Weston _-0. 012 2040 091 071 00 a2 100347 00927 Figures 1 and 2 provide another method to compare the baseline to end-of-project concentrations for PFOA and PFOS, respectively, for these 15 contingent workers. Data points near the diagonal identity line, wherxe = y, indicate no difference in concentrations between baseline (x) and end ofproject (y). The strong linear trend centered along the identity line is indicative of no change between the paired measurements. The R? was 0.93 for PFOA (Figure 1) and 0.95 for PFOS (Figure 2). The paired baseline and endofproject PFOA and PROS concentrations were compared between the 9 Veit employees and the Weston employees. The baseline mean PFOA and POS concentrations were higher among the Weston workers (PFOA baseline Weston = 5.3 ng/mL vs Veit METS = 30nginL, (= 17, p= 0.15; POS baseline Weston = 17.7ng/mLcompared 0 Veit 99 ng/mL= 2.1,p=0.09). The 5 Weston employees had worked at other 3M remediation projects. Discussion `Comparison of baseline 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 Woodbury northeast landfill remediation project. Given the fact that exposure potential during the course of the, landfill remediation project was unknown, the use of biomonitoring data allowed for ar assessment of the actual (unknown) exposure to PFOAor POS,or to materials that may degrade to them. The clinical chemistry data were not analyzed by paired statistics because the biomonitoring; data indicated there were no substantive differences in exposure to PFOA or POS between the baseline and end of project measurements. Potential exposure to any other materials was not known since only PFOA and PFOS were analyzed in the workers' serum. Conclusion Based on the paired biomonitordiantga of 15 contingent workers, there was no increase in serum PFOA or PFOS concentrations while working at the 3M Woodbury northeast landfill remediation project. References Ehresman DJ, Froehlich JW, Olsen GW, Chang SC, Butenhoff JL. 2007. Comparisonofhuman whole blood, plasma, and serum matrices for the determination of perfluorooctanesulfonate (PFOS), perfluorooctanoate (PFOA), and other fluorochemicals. Environ Res 103:176-184, Co-- mping Figure 1. Baseline (x axis) and End of Project (y axis) PFOA Concentrations (ng/mL) for 15 Contingent Workers, Woodbury NE Project. 20 hai [taemiy Liinnee | Su > Ea zw . 2 www 4 sm FROABasoine on) Ww cpamhpy FiCognutrineg2e.ntBWaosrekleinres,(xWaoxoids)buanrdyENnEdoPfrojPercotject (y axis) PFOS Concentrations (ng/mL) for 15 5 2 250 Emo Su Zuo olws s : ws a PFOSBaseline (ngind) mw