BISPHENOL A IN URINE SAMPLES OF THE GERMAN ENVIRONMENTAL SPECIMEN BANK FROM 1995 TO 2009: A RETROSPECTIVE EXPOSURE ASSESSMENT

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1 BISPHENOL A IN URINE SAMPLES OF THE GERMAN ENVIRONMENTAL SPECIMEN BANK FROM 1995 TO 2009: A RETROSPECTIVE EXPOSURE ASSESSMENT H.M. Koch 1, M. Kolossa-Gehring 2, C. Schröter-Kermani 2, J. Angerer 1, T. Brüning 1 1) Institute for Prevention and Occupational Medicine of the German Social Accident Insurance Institute of the Ruhr-University Bochum (IPA) Bochum, Germany 2) Federal Environment Agency (UBA) Berlin, Germany

2 Introduction Bisphenol A (BPA) 2,2-Bis-(4-hydroxyphenyl)-propan Use Polycarbonate Epoxy Resins (BADGE) Antioxidant in PVC (0,5%) Thermal paper Dental-Composites Toxicology Xenoestrogen / Endocrine Disruptor TDI (EFSA): 50 µg/kg b.w./day (liver weight changes) controversial discussion on lowdose reprotoxic effects

3 Metabolism / Biomarkers fast conjugation (close to 100%) fast elimination in urine detection of high free BPA indicates external contamination! < 24 h Dekant W, Völkel W. Toxicol Appl Pharmacol 228(1): (2008)

4 Analytical Approach on-line LC/LC-MS/MS method with and without enzymatic deconjugation (free + total BPA) free BPA to check sample integrity/contamination isotope dilution quantification LOQ of 0.05 µg/l limited manual sample handling; no preconcentration and/or derivatization; direct injection of urine laboratory blanks < LOQ highly sensitive, specific and robust 4

5 Analytica Approach On-line LC/LC-MS/MS: Valve position A: matrix separation, pre-concentration Analytical column MS-MS Pump 2 A waste Auto- sampler Pump 1 RAM-Phase Koch HM, Gonzalez-Reche LM and Angerer J: J Chromatogr B, 784 (1), (2003).

6 Analytica Approach On-line LC/LC-MS/MS: Pump 2 Analytical column MS-MS Valve position B: backflush chrom. separation MS-MS BA waste Auto- sampler Pump 1 RAM-Phase Koch HM, Gonzalez-Reche LM and Angerer J: J Chromatogr B, 784 (1), (2003).

7 Study Population: German Environmental Specimen Bank Collection and storage of human specimens since the early 80s Our subset : 600 urine samples from 1995 to 2009 students (age range years) 30m and 30f per year 24 h urine samples with full info on: 24hr urine volume body weight etc. 7

8 Description of the ESB study population (main study) Sampling year Subjects (m/f) Age mean (range) 24h urine volume mean (range) Creatinine mean (range) (30/30) 24.4 ( ) 1579 ( ) ( ) (30/30) 25.3 ( ) 1492 ( ) ( ) (30/30) 24.8 ( ) 1624 ( ) ( ) (30/30) 24.1 ( ) 1740 ( ) ( ) (30/30) 23.5 ( ) 1754 ( ) ( ) (30/30) 24.0 ( ) 1821 ( ) ( ) (30/30) 24.5 ( ) 1880 ( ) ( ) (30/30) 24.7 ( ) 1877 ( ) ( ) (30/30) 23.8 ( ) 2076 ( ) ( ) (30/30) 23.6 ( ) 2081 ( ) ( ) total 600 (300/300) 24.3 ( ) 1790 ( ) ( ) male ( ) 1786 ( ) ( ) female ( ) 1794 ( ) ( ) 8

9 Pilot study on 60 urine samples from 1988 and

10 Pilot study: free BPA as indicator of contamination 99,9 60 urine samples from 1988 and 2008 Total BPA Free BPA relativ ve cumulative frequency [%] Median (in µg/l) 1.18 < LOQ Max (in µg/l) N>LOQ 98% 10% 1 0, total BPA [in µg/l]

11 Pilot study: free BPA as indicator of contamination relativ ve cumulative frequency [%] 99, urine samples from 1988 and no indication of external contamination (pre-analytical phase) no indication of degradation of conjugates (due to storage) 0,95 (0,10) 3,3 (0,14) 2,9 (0,10) 2,0 (0,11) ,5 (0,24) 8,5 (0,11) , total BPA [in µg/l]

12 Main Study: 600 urine samples from 1995 to

13 Main study: total BPA from 1995 to 2009 (in µg/l) hr-urine samples (300m/300f) geom metric mean BPA [µg/l L] BPA in urine 24h-urine volume hr urine volume [ml] year 13

14 Main study: total BPA from 1995 to 2009 (µg/g crea) to otal BPA [µg/g crea] 4,00 3,50 3,00 2,50 2,00 1,50 1,00 0,50 0, years 14

15 Main study: total BPA from 1995 to 2009 (µg/g crea) to otal BPA [µg/g crea] 4,00 3,50 3,00 2,50 2,00 1,50 1,00 0,50 0, years geo Mean females geo Mean males geo Mean all 15

16 Main study: daily BPA intake [in µg/kg b.w./day] BPA daily intake (in µg/kg b.w./day) hr urine samples 24 hr urine volume BPA in µg/l daily BPA intake [µg/kg/day] (without any need for adjustments) median year 16

17 Main study: daily BPA intake [in µg/kg b.w./day] percentile arith. mean BPA daily intake (in µg/kg b.w./day) median year 17

18 Main study: daily BPA intake [in µg/kg b.w./day] BPA daily intake (in µg/kg b.w./day) all females males year 18

19 Main study: daily BPA intake [in µg/kg b.w./day] n Geometric mean total Median 95 th (95% conf. interval) percentile ( ) male ( ) Range female ( ) TDI (EFSA): 50 µg/kg/day 19

20 Comparison: BPA vs. some Phthalates 10 daily intake [µg/kg bw/ /d] median 1 Bisphenol A 0, DEHP DnBP DiBP DiNP M.Wittassek, G.A. Wiesmüller, H.M. Koch, R. Eckard, L. Dobler, D. Helm, J. Müller, J. Angerer and Ch. Schlüter: Internal phthalate exposure over the last two decades A retrospective human biomonitoring study Int. J. Hyg. Environ. Health 210(3-4): (2007) 20

21 Comparison: BPA in other HBM studies Study years n age total BPA in µg/l in µg/g creatinine NHANES > (13.2) 2.05 (9.32) Health Canada (7.30) 1.49 (6.83) ESB (this study) (6.34) 1.81 (6.39) 21

22 What about BPA in Blood/Plasma? 22

23 Total, free and conjugated BPA in 60 ESB plasma samples total BPA free BPA conjugated BPA median < LOQ (0.05) < LOQ (0.05) < LOQ (0.05) 95. percentile maximum

24 Total BPA in urine vs. total BPA in plasma (from 60 matching urine-plasma pairs) BPA in plasma[µg/l L] total BPA (total) in urine [µg/l] 24

25 Summary sensitive and robust analytical method (LOQ=0.05µg/L; blank < LOQ) measurement of BPA in 24hr-urine samples (ESB) small decline of µg/l values: ~ 2 µg/l (1995) to 1.4 µg/l (2009) however: increase in 24hr-urine volume (creatinine corrected values rather stable) daily intake in µg/kg b.w./day: no trend; stable daily intakes ( , German students; yrs) median: ~ µg/kg b.w./day; 95th percentile: ~ 0.17 µg/kg. b.w./day no differences between m/f plasma/blood handeled/interpreted VERY carefully 25

26 BISPHENOL A IN URINE SAMPLES OF THE GERMAN ENVIRONMENTAL SPECIMEN BANK FROM 1995 TO 2009: A RETROSPECTIVE EXPOSURE ASSESSMENT H.M. Koch 1, M. Kolossa-Gehring 2, C. Schröter-Kermani 2, J. Angerer 1, T. Brüning 1 1) Institute for Prevention and Occupational Medicine of the German Social Accident Insurance Institute of the Ruhr-University Bochum (IPA) Bochum, Germany 2) Federal Environment Agency (UBA) Berlin, Germany The findings and conclusions in this presentation are those of the authors and do not necessarily represent the views of the German Federal Environment Agency (UBA) or the German Social Accident Insurance (DGUV). The authors declare that they have no competing financial interests.