Document XOKebxE0VRokEZXwzLX89GJqR

3PMagCeomopfa1ny0 FINAL REPORT Epidemiology, 220-6W-08 Medical Department 3M Company St. Paul, MN 55144 Date: April 20,2013 Title: Perfluoroalkyl Biomonitoring Assessment of SKB Environmental Employees Study Start Date: August 26, 2009 Protocol Number N/A IRB Approval N/A Principal Investigator Co-investigators: Geary W. Olsen, D.VM., PhD! DBeatvsyidJD.. EBhurcehrsemra,n,DBO.,S.MMPTH(.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 55144 Summary 3PMagCeom2p0a0n1y0 Atotal of 16 SKB Environmental employees who worked on 3M remediation projects had baseline and end-of-project perfluoroalkyl (PFOA and PFOS) measurements as well as clinical chemistries analyzed. There were no statistically significant mean increases in PFOA and PFOS concentrations when the end-of-project values were compared to paired baseline assessments. The mean decreases in PFOA and PFOS concentrations observed were consistent with the known pharmacokinetics of PFOA and PFOS. Conclusion: Based on the biomonitoring data, there was no substantive occupational exposure to PFOA or PFOS for SKB Environmental employees while working on the various 3M remediation projects. Introduction Several 3M remediation projects have been completed in Minnesota regarding legacy perfluoroalkyls. These projects have included the 3M Cottage Grove Building 15/73 demolition and disposal project, the 3M Woodbury landfill remediation project, the 3M Oakdale landfill remediation project, the 3M Cottage GroveBuilding25 re-roof project, and the 3M Cottage Grove D1/D2, D9, and East Cove remediation projects. 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 [PFOS (perfluorooctanesulfonate) and PFOA (perfluorooctanoate)] was possible but due to the uniquenessofthe work the magnitude of exposure was unknown. Both baseline and end-ofproject assessments required response toamedical questionnaire and blood (serum) measurements of PFOS, PFOA, and several clinical chemistries. 3PMagCeom3p0a0n1y0 Waste material from these 3M remediation projects was hauled by SKB Environmental and subsequently deposited in the SKB Environmental industrial landfill operations located in Rosemount, Minnesota. The SKB Environmental Rosemount facility is a state-of-the-art disposal facility for industrial, mixed-municipal solid waste incinerator ash, and construction and demolition debris. Specifics about the SKB Environmental Rosemount facility can be found at http://www. skbine. com/our-locations/rosemount-disposal. html. As occurred with other 3M perfluoroalkyl remediation projects, SKB Environmental employees with potential exposure to 3M material obtained baseline and end-of-project measurements of POS, PFOA, and several clinical chemistries. SKB Environmental employees conducted their baseline assessments in the summer 2009. End-of-project assessments were. completed in February 2013 after SKB Environmental completed its industrial landfill operations related to 3M's remediation projects. "The purpose of this report is to provide a descriptive analyosftihse PFOA and PFOS. serum concentrations (ng/mL) at baseline and end-of-project time periods for SKB Environmental employees who participated in its industrial disposal activities regarding 3M remediation materials 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. 2. Clinical chemistries 3PMaCgoempdoafn1y0 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 logisticsofcollecting blood samples during various timesof 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. Buehrer. 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. Buehrer regarding their clinical chemistry test results should the subject 50 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 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 prior tothe samples being delivered for analysis. The 3M Medical Department's Toxicology Laboratory was "blinded to the idenity 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) 3.0mL cartridges (Ehresman et al. 2007) 3PMagCeomSpoafn1y0 `The method used two stable labeled intemal standards for quantitation. The intemal 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 A'S 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 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 "within" their previously established ranges. Matrix matched dilutions were used for samples requiring dilution to bring the samples into the finear rangeof the assay. Extracted serum and aqueous blanks remained below the lower limit of quantitation established at 1.0 ng/mL. (lowest standard fied on the standard curve used for this project). +. 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 frst leter provided the 3PMagCeoGmopfan1y0 individual's clinical chemistry results. The second letter compared baseline to end-of-project serum PFOA and PFOS concentrations. Results Sixteen SKB Environmental employees had paired baseline and end-of-project assessments. Nine SKB Environmental employees had baseline assessments but did not participate in end-of-project assessments as they had left the company. Table 1 and Table 2 (below) provide the measuresofcentral tendency for baseline and end-of-project PFOA and PFOS concentrations for the 16 subjects with paired measurements. Values are provided in ng/mL (parts-per-billion) `Table 1. PFOA Baseline and End-of-Project Concentrations (ng/mL) Arithmetic Min QI Median Q3 Max Mean 95%CI Baseline 19 30 44 S790 45 34-56 End-of-Project 1020 29 30 71 32 24-4 Geometric: Mean 95%CI 41 32-52 29 20-37 `Table 2. PFOS Baseline and End-of-Project Concentrations (ng/mL) Baseline Arithmetic Min Ql Median Q3 Max Mean 95%Cl___ 64 03 158 220 3L1 167 123-210 End-of-Project 116 36 101 164 262 116 83-150 Geometric Mean 95% CL 147 110-195 99 72-137 3PMagCeompoafn1y0 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 16 subjects. See Equation | Equation I. Mean Difference = (end-of-project -baseline1)6 Becauseof the 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 ==[(n(end-of-project value)) ~ (In(baseline value)1)6 Results for Equation 1 and Equation 2, and associated statisticsof the mean differences of the paired comparisons, are provided in Table 3 (below) for both PFOA and PFOS. `CToanbcleent3r.atMiaotncshe(dn-gp/amiLr)Analysis Comparing Baseline to End-of-Project PFOA and PFOS Mean Paired Difference PFOA (ng/mL) t-atio p value POS (ng/mL) ratio p value Equation I-13 35 0002 50 53 <00001 Equation? 036 53 <0.0001 039 66 <00001 Statistically significant differences were observed for a decrease in the meanof the differences for PFOA and PFOS (Equations 1 and 2). In other words, the end-of-project PFOA and PFOS concentrations were statistically significantly less than their respective baseline concentrations. (ng/mL) when analyzed as paired differences. 3PMagCeomSpoafn1y0 Assuming there was no occupational exposure in this study, the percent of end-of-project concentrations measured for arithmetic means (Table 1 and 2) that could be attributable to PFOA and PFOS as a consequenceofpharmmacokinetics was 56% for PFOA and 86% for PFOS (Table 4). This calculation assumes serum elimination half-livesof 3.5 years for PFOA and 4.8 years for PFOS (Olsen et al. 2007). The amountoffollow-up time from baseline to endofproject in this SKB Environmental biomonitoring project was 3.4 years except for | individual `whose time was slightly longer (3.5 years). `OTcacbulre 4B.asPeedrcoenntSaegreuomfEElnidm-ionfa-tPiroonjeHcatlfP-lFiOveAs afnordPPFFOOAS (S3e.r5uymeaCrosn)caenndtrPatFiOoSns(E4.x8peyecatres)d.toSee Olsen etal. (2007) Mean (ng/mL) CMheaannge(nagt/ml) Baseline' End-of-Project' EMxepaenct(endg/mL) CMheaannge(%O)bserved Change' Based on Expected" PFOA 4s a3 22 56 PFOS 167 51 59 56 a See Tables 1and2 b. Mean baseline value minus mean end-of-project value from Tables 1 and 2 c. Absent any backgroundoroccupational exposure this is the Mean Baseline Value (ng/mL) x ProportionofHal-ife in Study x 0.5 years. For PFOA the proportion was estimated as 3.4 years/3. years For PFOS the proportion was estimated as 3.4 years/4.$ years. d. (Column 2 divided by Column 3) x 100 Discussion 3PMaCgoempOaarn1y0 Comparisonofbaseline and end-of-project serum concentrations of PFOA and PFOS provided each SKB Environmental employee an excellent method to assess his/her exposure experience to the various 3M remediation projects. Given the fact that exposure potential during the course of the remediation project was unknown, the useof biomonitoring data allowed for an assessment the actual exposure. The above data (Table 4) show that the decrease in PFOS concentration between baseline and end-of-project could be largely (86%) attributed to its known phamacokinetics (Olsen etal. 2007). Its possible that the 56% decrease observed for PFOA may be the consequence of its known pharmacokinetics (Olsen et al. 2007) coupled with an underlying low background (nonoccupational) levelof exposure to PFOA (Bartell et al, 2012). `These calculations do not suggest there were any substantive occupational exposures for SKB Environmental employees during the courseoftheir work on the 3M perfluoroalkyl remediation projects. 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 analyzed in aggregate by paired statistics. Potential exposure to any other material would not be known since only PFOA and PFOS were analyzed in the workers' serum, Conclusion Based on the biomonitoring data, there were no substantive occupational exposures 10 PFOA or PFOSforthe 16 SKB Environmental employees involved in the hauling and industrial landfill disposalofmaterials from the 3M remediation projects P3aMgeCo0m0pa1n0y References Bartell SM (2012) Biase in half-life estimates using log concentration regression in the presence of background exposures and potential solutions. J Expo Sci Environ Epiodemiol 22:299-303 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 Olsen GW, Burris JM, Ehresman DJ, Froehlich JW, Seacat AM, Butenhoff JL, Zobel LR. (2007) Half-life of serum elimination of perfluorooctaneusulfonate, perfluorohexanesulfonate, and perfluorooctanoate in retired fluorochemical production workers. Environ Health Perspect 115:1298-1305