Document KJdReLnoJX4VydMkGO3QmDwpX

FINAL REPORT Epidemiology, 220-3W-05 Medi3cMalCDoemppaarntyment St. Paul, MN 55144 Date: April 2, 2010 Title: Biomonitoring Assessmentofthe 3M Woodbury Landfill Remediation Project Study Start Date: August 26, 2009 Protocol Number N/A IRB Approval N/A Principal Investigator: Co-investigators: Geary W. Olsen, D.V.M,, Ph.D.' BDaarvbiadrJa. AE.hrGeisbmsaonn,, MB..SD..,,MMT.P.(HA.S"CP)? 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 Department, Mail Stop 236-1B-22, St. Paul, MN $5144. Summary Ei Atotal of 32 subjects who worked on the 3M Woodbury landfill remediation project had baseline and end-of-project perfluorooctanoate (PFOA) and perfluorooctanesulfonate (PFOS) measurements. The 32 subjects' baseline mean PFOA concentration was 4.6 ng/mL (95% C13.8 5.4) and their end-of-project mean PFOA concentration was 4.3 ng/mL (95 C1 3.=4 5.1). The baseline mean PFOS concentration was 15.5 ng/mL (95% C1 12.0 ~ 19.0) and the end-of-project mean PFOS concentration was 14.8 ng/mL. The mean concentration difference (baseline minus end-of-project) for PFOA was -0.35 ng/mL (p= 0.01). Likewise, the mean difference for PFOS was -0.67 ng/mL (p = 0.06). These counterintuitive findings are likely well-within the variation of the analytical measurements performed. Thus, there was no evidence ofa statistically significant increase in PFOA or PFOS concentrations from baseline to end-of-project measurements. Conclusion: Based on the paired biomonitoring data, there was no substantive occupational exposure to PFOA or PFOS while working on the 3M Woodbury landfill remediation project. Tan Introduction Several remediation projects were launched in 2009 regarding legacy perfluorochemicals. `These include the 3M Woodbury landfill remediation project, the 3M Cottage Grove Building 15/73 demolitiaondn disposal project, the 3M Cottage Grove Building 25re-roofproject, the 3M Cottage Grove D1/D2 excavation project, and the 3M Decatur Building 2/49 demolition and disposal project. For eachofthese projects baseline and end-of-project assessments were requiredof3M employees and contractor workers who entered specified work zones where. potential exposure to legacy perfluorochemicals (.g., PFOS (perfluorooctanesulfonate) and PFOA (perfluorooctanoate) was possible, but due to the uniqueness ofthe work the magnitude was unknown. Both baseline and end-of-project assessments required response to a medical questionnaire and blood (serum) measurementsof PFOS, PFOA, and several clinical chemistries. "The purposeofthis report is to provide adescriptive analysisofthe PFOA and PFOS serum concentrations (ng/mL) at baseline and end-of-project time periods for the 3M Woodbury landfill remediation project. Methods 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 Ei Clinical chemistries includead 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 becauseofthe logisticsofcollecting blood samples during various times ofthe 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 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 ifthey 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 Laboretoryunderthe directionofDave 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 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 al. 2007) hd `The methodusedtwo stable labeled internal 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 quantitation 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, andcachcurve had an ""R" value equaltoorgreaterthan 0.9998. Matrix spiked controls (QC samples) evaluated during this study ell 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 quanitation established at 1.0 ng/mL (lowest standard fitted on the standard curve used for ths project). 4. Communication After cach blood collection, individual letters were set to the participants describing their results. Inthe baseline assessments, two letters were sent. One referred to the clinical chemistarnditehse other letter provided baseline PFOA and PFOS concentrations. At end-ofproject, two letters were again sent to each participant, The first letter provided the individual's aPMCaocmepran1y clinical chemistry results. The second letter compared baseline to end-of-project serum PFOA and PFOS concentrations. Results `Table 1 provides the total number of individuals, by company, who were tested for PFOA and PFOS during the 3M Woodbury landfill remediation project. `Table 1. Distributionofworkers by company and participation Company Baseline 3M 2 AECOM 3 Bolander 18 Kortech Consulting 1 Metro Gravel 19 SKB 2 Weston s Total 68 End-of:Project 0 29 0 16 0 5 2 Reasonfor No End-of-Project Sample Leaveofabsence, other unknown DDiidd nnoott wwoorrkk aatt ssiittee ((nn == 91)) `Continued working on other projects Did not work at site (n= 3) Working at industrial landfill - test later All tested `The 20 SKB employees are involved with receiving wastes at the industrial landfill. These wastes have originated from the 3M Woodbury landfill, 3M Cottage Grove Building 25 re-roof project, Cottage Grove Building 15 demolition and disposal project, and the 3M Cottage Grove. DI/D2 excavation project. These SKB workers will be tested for their PFOA and PFOS concentrationsa the completionofthese four projects `Tables 2 and 3 provide the measuresofcentral tendencyforthe beseline and end-of- project PFOA and PFOS concentrations for those 32 subjects with paired measurements (baseline and end-of-project). Valuesare provided in ng/mL (parts-per-billion). 3PMaCoTmoplan1y `Table 2. PFOA Baseline and End-of-Project Concentrations (ng/mL) Arithmetic Min Ql MedianQ3 Max Mean 95%CI Baseline 07 31 40 65 104 46 38-54 End-ofProject07 28 34 S58 112 43 34-51 Geometric: Mem 95%CL 41 34-50 37 30-45 `Table 3. PFOS Baseline and End-of-Project Concentrations (ng/mL) Baseline Arithmetic Min Ol _ MedianQ3 Max Mem 95%Cl 28 102 153 185 592 155 120-190 End-ofProject 25 94 138 173 661 148 109-188 Geometric Mean 133 9150%6C-L164 124 99-154 Provided in Table 4 are the baseline and end-of-project arithmetic mean values for those companiesthathad or more employees. `Table 4. Baseline and End-of-Project Arithmetic Mean PFOA and PFOS Concentrations (ng/mL) by Company Company BoMletarnodeGrravel Weston standard deviation PFOA Baseline EndofProject 35067 3003) 5300) 4703) 5809) 62033) POS Baseline End-ofProject 138(44) 127(46) 168(122) 160(140) 192(61) 195012) sPwCaacmsop1 y Asthe data are paired samples, a matched-paired statistical analysis was performed where the mean value for the average ofthe sumofthe individual differences for all 32 subjects See Equation 1 Equation |. 2 Mean Difference = =(end-of-project - baseline)/32 Becauseofthe skewed PFOA and PFOS distributions, as seen in Tables 1 and 2, the mean differencesofthe natural logsofthe paired values were also determined. See Equation 2. Equation 2. Mean ="2i(In(ead-of-project value)) - (in(baseline value))/32 Results for Equation 1andEquation 2, and associated statisticsofthe mean differences ofthe paired comparisons, ar provided in Table or both PFOA and PFOS. c`Toanbcleent5r.atMiaotnch(endg-/pmaLi)r Analysis Comparing Baseline to End-of-Project PFOA and PFOS DMiefafnerPeanicreed PFOA (ng/ml) tratio pale PFOS (ng/ml) tratio _pvalue Equation] -03 EX 0009 07 193 0.06 For both PFOA and PFOS, there was adecrease in the meanofthe differences. In other words, the end-of-project PFOA and PFOS concentrations were less than the baseline au concentration (ng/mL) when analyzed as paired differences. This counterintuitive finding is likely well-within the variationofthe analytical measurements performed. Similar results were seen when the differences between the logs were analyzed. 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 on a log scale] The strong linear correlation centered along the diagonal is indicative ofno changes between the paired measurements. The RY was 0.93 for PFOA (Figure 1) and 0.98 for POS (Figure 2). Discussion Comparisonofbeseline and end-of-project serum concentrations of PFOA and PFOS provided eachworkeran excellent method to assess his/her exposure experience for the 3M `Woodbury landfill remediation project. Given the fact that exposure potential during the course of the landfill remediationprojectwas unknown, theuseofbiomonitoring data allowedforan assessmentofthe actual (unknown) exposure PFOA or PFOS, or to materials that may degrade to them. The clinical chemistry data were not analyzed by paired statisticsbecausethe biomonitoring dta indicated there were no substantive differences in exposure to PFOA or 'PFOS between the beseline and end-of-project measurements. Potential exposure to any other materials would notbe known since only PFOA and PFOS were analyzed in the workers" serum. Conclusion pit Basedon the paired biomonitoring data, there appearetd0 be no substantive occupational exposures to PFOA or PFOS for the 32 workers involved with the 3M Woodbury landfill remediation project. References Ehresman DJ, Froehlich JW, Olsen GW, Chang SC, ButenhoJfLf. 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, mrceomm GaFirguorven1.. ESMxWootodPbrureyLaFnOdARCoermeaendrsioarrts ij(9ocmn). || i o 3g i oF ! b+ eo cfioerm] BFoeurs2. 9E0r ech LFoongRsCRemoedtaionn Prrogc) E i le+m od | vy wn