Alicja Wolk Karolinska Institutet, Stockholm, Sweden

Transcription

1 Questionnaire-based estimates of long-term dietary exposure to polychlorinated biphenyles (PCBs) vs. serum biomarkers: implications for studies of fish/seafood intake Alicja Wolk Karolinska Institutet, Stockholm, Sweden 1

2 Outline Polychlorinated biphenyls (PCBs) Food sources of PCBs Determinants PCBs concentrations in serum Validation of FFQ-based PCBs estimates PCBs in serum vs. adipose tissue 2

3 Polychlorinated biphenyls (PCBs) 209 PCB congeners (of them 6-10 types are usually analyzed; PCB 153, a major and very stable PCB congener, has been shown to correlate to the total amount of PCBs) 90% is from food Half-life of PCBs in the body increases with increasing chlorination range: < 1 year to 71 years Phillips et al. Arch Environ Health

4 Food sources of PCBs in Sweden Foods Women Men Fish 68% 64% Dairy products 18% 19% Meat 9% 11% Other 5% 6% Data from the Swedish Mammography Cohort and the Cohort of Swedish Men 4

5 Determinants of PCBs concentrations in the body Age Sex BMI reproductive factors in women(parity and breast-feeding) decrease the body burden of PCBs Body weight change Geographic region Diet Food preparation methods mainly fatty fish removal of skin and fat 5

6 Mean serum PCB levels (ppb) by demographic characteristics and period of data collection (the Michigan Fisheater Cohort, n = 179) Tee et al. Environ. Health Perspect

7 Percentage change in concentrations of PCB congeners per unit change in age, BMI, and weight a in Swedish women NS, not significant, p > 0.05, n = 205 a change of geometric means (95%CI) was mutually adjusted for each other and region Wicklund Glynn et al. Environ. Health Perspect

8 Regional differences in serum PCB concentrations among elderly Swedish women a a geometric mean (95%CI) was mutually adjusted for age, BMI, and weight change b significance levels represent the overall test of differences in adjusted geometric means between the regions Wicklund Glynn et al. Environ. Health Perspect

9 PCB concentrations in serum/plasma in men from different countries Area-group (n) Mean age 153 PCB concentration Swedish men-general population(120) Sweden-moderate fish consumpt (7) Sweden-fishermen (11) Norway-referents (10) Norway-crab consumers (9) Germany-referents (34) Russia-refugees (22) Asia-refugees (21) 28 <40 Africa-refugees (24) USA-charter boat captains (100) Canada-ice fishers (25) no data 80 b ng/g lipid, median or mean 9

10 Serum PCB concentrations in Swedish women ( ) by fatty fish consumption a a geometric mean (95%CI) was mutually adjusted for region, age, BMI, and weight change b significance levels represent the overall test of differences in adjusted geometric means between consumption categories Wicklund Glynn et al. Environ. Health Perspect

11 Long-term mean fish consumption (A) and mean serum PCB level (B) by survey year (the Michigan Fisheater Cohort, n = 179) Tee et al. Environ. Health Perspect

12 Validation of FFQ-based PCBs estimates 12

13 Serum concentrations of PCBs in the group of 120 Swedish men (ng/g lipid) Substance Mean S.D. Median min max >LOQ PCB < PCB <2 < PCB < PCB < PCB PCB PCB PCB PCB < PCB ΣPCB Σdi-ortho PCB Σmono-ortho TEQ b b pg/g lipid Wicklund Glynn, Wolk et al. The Science of the Total Environment

14 Spearman rank correlation coefficients (r) between concentrations of PCB in serum (120 Swedish men) Substance PCB congeners (IUPAC no) b TEQ Σdi-orthoPCB PCB PCB PCB Σmono-orthoTEQ PCB PCB PCB Σdi-orthoPCB ΣPCB b Using WHO s toxic equivalent factors for dioxin-like PCB congener, the concentration of toxic equivalents (TEQ) was calculated for the monoortho PCB congeners PCB 105 (TEF=0.0001), PCB 118 (0.0001), PCB 156 (0.0005) and PCB 167 ( ). ΣPCB=sum of individual PCB congeners Wicklund Glynn, Wolk et al. The Science of the Total Environment

15 The linear relationships between concentrations of potential marker substances and other organochlorines a Marker Organochlorines R 2 Regression P-value substance coefficient PCB 153 ΣPCB ±0.04 <0.001 PCB 153 Σdi-ortho PCB ±0.03 <0.001 PCB 156 Σmono-ortho TEQ ±0.06 <0.001 a N=120. Regressions showed were those giving the best fit to the results of the dependent variable (y) Wicklund Glynn, Wolk et al. The Science of the Total Environment

16 Linear regressions for the relationship between concentrations of the marker substances PCB 153 and PCB r = 0.96 Wicklund Glynn, Wolk et al. The Science of the Total Environment

17 Linear regressions for the relationship between concentrations of the marker substances PCB 153 and di-ortho PCB r = 0.97 Wicklund Glynn, Wolk et al. The Science of the Total Environment

18 Box plots of the difference between each individual's observed and estimated concentration of ΣPCB and Σdi-ortho PCB (ΣDi) The lower and upper boundaries of the box give the 25th and the 75th percentiles. The line within the box indicates the median and the whiskers above and below the box gives the 10th and the 90th percentiles. ( ) Outliers Wicklund Glynn, Wolk et al. The Science of the Total Environment Namn Efternamn 18

19 Major characteristics of women in the validation and cohort study median (5th 95th percentile) Current (n = 201) Past 1997 (n= 142) Long-term 1997/ (n = 142) The Swedish Mammography Cohort 1997 (n = ) a Age (years) 66 (58 78) 57 (50 69) 61 (54 73) 59 (50 77) Weight (kg) 70 (55 92) 67 (54 86) 69 (56 90) 66 (52 88) Body mass index (kg/m 2 ) 26 (17 39) 25 (21 30) 25 (21 32) 24 (20 32) Energy intakes (kcal) 1680 ( ) 1701 ( ) 1735 ( ) 1683 ( ) FFQ-based PCB (ng/day) b 105 (48 200) 171 (78 348) 140 (82 249) 166 (71 372) Dietary PCB (ng/kg b.w./ day) b 1.6 ( ) 2.6 ( ) 2.1 ( ) 2.5 ( ) a The 1997 baseline cohort, excluding women with prevalent CVD, cancer, diabetes. b FFQ-based PCB (polychlorinated biphenyls B-153) exposure energy adjusted to the mean energy intake in the whole cohort. Bergkvist et al. Mol. Nutr. Food Res

20 Serum concentrations of lipids and individual PCB congeners (201 Swedish women ) Lipids (g/l) Median (5th-95th percentile) Mean Triglycerides 0.9 ( ) 1.0 Total cholesterol 3.4 ( ) 3.4 Phospholipids 2.6 ( ) 2.6 Total lipids 7.6 ( ) 7.6 Adjusted PCBs (ng/g lipid weight) (5.8 35) (26 111) (63 195) (5.8 18) (21 62) (46 130) 83 sumpcb 312 ( ) 337 PCBs, polychlorinated biphenyls Bergkvist et al. Mol. Nutr. Food Res

21 Spearman correlation coefficients (95% CI) between FFQ-based PCB and serum PCB 153 and PCBs (Swedish women ) PCB 153 PCBs Concurrent ( ) FFQ-based PCB estimates (n = 201) PCB a 0.24 ( ) ** 0.26 ( ) ** PCB b 0.29 ( ) ** 0.31 ( ) ** PCB c 0.41 ( ) ** 0.45 ( ) ** Past (1997) FFQ-based PCB estimates (n = 142) PCB a 0.21 ( ) * 0.22 ( ) * PCB b 0.23 ( ) * 0.26 ( ) * PCB c 0.34 ( ) * 0.38 ( ) * Long-term FFQ-based PCB estimates (n = 142) PCB a 0.23 ( ) * 0.25 ( ) * PCB b 0.29 ( ) ** 0.33 ( ) ** PCB c 0.42 ( ) ** 0.48 ( ) ** a FF) based CB-153 (ng/day) and serum polychlorinated biphenyls (PCBs, ng/g lipid). b FFQ-based CB-153 adjusted for body weight (ng/kg body weight/day) and serum PCB adjusted for age (ng/g lipid/age). c Additional adjustments for within-person variability interclass correlation of FFQ-based PCB (CB-153) estimates. * p value < 0.05; ** p value < Bergkvist et al. Mol. Nutr. Food Res

22 Scatter plot between concurrent FFQ-based PCB153 and serum PCBs ** r = 0.45 * adjusted for body weight and within-person variability ** adjusted for age * 22

23 PCBs in serum vs. adipose tissue 23

24 Levels of selected PCBs in female tissues, Belgium ( ) ND, < detection limit a Detection limit in adipose tissue: 1 ng g -1 lipid b Detection limit in serum: 10 ng g -1 lipid c Missing data derive from interferences in the GC-chromatogram Pauwels et al. Arch. Environ. Contam. Toxicol

25 Distribution pattern of PCB congeners in serum and adipose tissue (n = 44) Pauwels et al. Arch. Environ. Contam. Toxicol

26 PCB serum Correlation between PCB 153 and PCBs In serum r = 0.94 In adipose tissue r = 0.91 PCB 153 serum Pauwels et al. Arch. Environ. Contam. Toxicol

27 Conclusion Questionnaire-based estimates of long-term dietary exposure to PCB153 relatively well reflect serum concentration of PCB 27