The Relevance of Soil for Human Exposure to Dioxins

Transcription

1 The Relevance of Soil for Human Exposure to Dioxins Frank NEUGEBAUER, Nina LOHMANN, Olaf PAEPKE Eurofins GfA Lab Service GmbH, Hamburg, Germany

2 PCDDF: Toxicology, Importance and Sources 2

3 Dioxins (PCDD/F) Dioxins is the common name for two groups of polyhalogenated aromatics O O Cl x O Cl y Cl x x,y = 0...4; x+y>0 Cl y x,y = 0...4; x+y>0 Polychlorinated Dibenzo-(p)-dioxins (PCDD) 75 possible congeners 7 toxic congeners (2,3,7,8 chlorosubstitution) Polychlorinated Dibenzofurans (PCDF) 135 possible congeners 10 toxic congeners (2,3,7,8 chlorosubstitution)

4 TEQ-Scheme: toxicity evaluation Substance LD 50 [µg/kg] Tetanus toxine 0,0001 Botulism toxine 0,0003 Diphthery toxine 0,3 2,3,7,8-Tetrachlordibenzo-p-dioxin 1 Saxitoxin (mussel toxin) 8,9 Aflatoxin B 1 (Mycotoxin) 10 Kurare (pflanzl. Alcaloid mixture) 500 Strychnine (plant alcaloid) 500 Nikotin (Alcaloid of the tobacco plant) 1000 Natrium cyanide 9800 (Source: VIS Bayern 2005) 4

5 Toxicity Equivalent Factors (TEF) acc. to WHO 1998 / 2005 Highest toxicity Lowest toxicity 5

6 Toxicity EQuivalents (TEQ) calculation All results in pg/g Compound Result WHO-TEFs Single TEQ Tetra-CDD 0,31 1 0, Penta-CDD 0,64 1 0, Hexa-CDD 0,16 0,1 0, Hexa-CDD 0,5 0,1 0, Hexa-CDD 0,33 0,1 0, Hepta-CDD 4,7 0,01 0, Octa-CDD 25 0,0001 0, Tetra-CDF 2,22 0,1 0, Penta-CDF 0,34 0,05 0, Penta-CDF 0,34 0,5 0, Hexa-CDF 0,12 0,1 0, Hexa-CDF 0,07 0,1 0, Hexa-CDF n.d. 0, Hexa-CDF 0,11 0,1 0, Hepta-CDF 0,28 0,01 0, Hepta-CDF n.d. 0, Octa-CDF 1,92 0,0001 0, : multiplication with TEF 2: addition to TEQ WHO-TEQ 1,5 6

7 Exposure Pathways of Dioxins Emission Incineration Industry Chlorine Industry deposition Environment Rain/deposition Dump Sites/Sludge bioaccumulation Beef, cow milk/-products Pork/ -products Chicken/ -products Food Thermal Metal Process Plants, gras Fish/ -products Car Exhaust Soil / Water Humans Vegetables 95% 7

8 PCDD/F intake by humans Intake of PCDD/F Occupational Accidental Environmental (background) Food consumption 95% (mainly fat-containing food of animal origin) EU legislation on food Example: raw milk 2,5 pg TEQWHO05 / g fat Example: eggs 2,5 pg TEQWHO05 / g fat EU: daily intake at about 1 pg / kg b.w. * d Recommendations (e.g. WHO, SCF): ADI 2 pg / kg b.w. * d 8

9 Importance of Soil? Now, where is the influence of soil? Intake of PCDD/F via soil Direct route of exposure: Inhalation of air particulates Ingestion of contaminated soil Dermal absorption Indirect route of exposure: food Via plants Via animals (meat, milk, eggs) 9

10 SOIL Typical and elevated PCDD/F concentrations 10

11 Soil, PCDD/F background values and influence of use / origin, Germany Soil Type n German Regions ("Länder") averaged concentration means (ng I-TEQ/kg) averaged 90% percentiles Farmland 498 1,5 3 Grassland 260 3,4 7,8 Forest, top layer 70 10,8 41,5 Forest, soil 186 3,5 16,6 summarized, after LABO 2003 *) Soil Type n Bavaria Concentration median (ng BGA-TEQ/kg) maximum Farmland 41 0,24 ND -18 Grassland 27 0,6 ND - 18 Forest, top layer ND - 50 Forest, soil 30 0,8 ND - 17 Green spaces 30 1 ND - 13 Fiedler 1998 *) «Bund/Länder-Arbeitsgemeinschaft Bodenschutz» (LABO) 2003 (collection of all available, partially older, data)

12 TEQ (PCDD/PCDF only) in Sediment and Soils from EU Member States, ng /kg d. m. Sediment Soil Background, Urban Any Type, Pasture, Rural Austria Belgium Finland Germany Greece 2-45 Ireland Italy Luxembourg Netherlands Spain Sweden U. Kingdom Fiedler et al.,

13 Examples for elevated soil levels Values in TEQ, pg/g Taiwan PCP Production some 1,000,000 Vietnam Agent Orange *) about 1,000,000 Seveso TCP Production some 100,000 **) Germany Herbicide Production some 100,000 USA Horse Arena some 100,000 Germany Metal Reclamation some 10,000 Japan MWI vicinity some 1,000 UK Fly ash pathways some 1,000 *) Former air base **) values given in g/m2 13

14 SOIL Legislation 14

15 Soil guideline concentrations (TEQ, ng/kg d.m.) Germany (recommendations BLAG 1992; BBodSchV 1999) < 5 Target concentration for agricultural use and decontamination 5 40 limited agricultural use (plants, grazing limited) > 40 research on origin; no agricultural use > 100 measures to be taken on children playgrounds > 1000 measures to be taken in residential areas > 10,000 measures to be taken independent of the location The Netherlands 1 Agricultural farming 10 Dairy farming Sweden 10 Sensitive uses 250 Non-sensitive uses Japan

16 SOIL-HUMAN: direct intake 16

17 Direct Intake: Ingestion of soil Soil ingestion in children and adults of the same family Children: mg/day Adults: mg/day (Davis et al., 2005; based on titanium as tracer) 0,14 0,12 0,1 Daily Intake (g/day) 0,08 0,06 0,04 0, to 1 1 to 2 2 to 3 3 to 4 4 to 5 5 to 6 6 to 7 Age group (years) 17

18 Ingestion of soil by humans - calculation Assumption: Soil intake 0.1 g/d Soil contamination 10 ng TEQ / kg (elevated background) Body weights: toddler 12 kg; adult 70 kg Resulting intake: 1 pg TEQ / day = pg / kg BW * d for toddlers = pg / kg BW * d for adults Limited relevance regarding livelong ADI of 2 pg TEQ/kg body weight*d Regulation Germany: soil exchange on >100 ng TEQ / kg = 0.83 pg / kg BW * d for toddlers??? 18

19 SOIL-HUMAN: indirect intake via food 19

20 Indirect intake SOIL-PLANT-FOOD Plants 20

21 Comparison of Dioxin Concentrations (ng TEQ / kg d.m.) in Food Plants, Corresponding Soil (0-25 cm) and Deposition (TEQ, m 2 /d) Lettuce Endive Kale Soil Deposition MURL,

22 Increase of PCDD/PCDF in Carrots depending of Soil Concentration Field Investigation Marsberg Krause et al.,

23 Transfer factors soil green plants Hembrock-Heger,

24 SOIL-ANIMAL-FOOD flooding areas 24

25 Effects of Flooding on PCDD/F: River systems UK 1998/99 Grazing of milk producing cows on contaminated pastures resulted in contaminated milk. Samples were taken from farms with floodplain pastures and nearby control farms. Milk from flooded prone location: significant higher PCDD/F values for dioxins than from control sites. Food Standard Agency, UK, 1998f.; Dowding et al

26 SOIL-ANIMAL-FOOD Ingestion of soil by animals and biological availability of PCDD/F 26

27 Uptake of Soil by Grazing Animals, Overview Animal Uptake Reference Cow 6-14% of d. m. Healey, 1968 Cow % of d.m. Mayland et al., 1975 Cow 1-18 % of d.m. Thornton & Abrahams, 1983 Cow 1-2 % of d.m. Berende, 1990 Sheep % of d.m. Field & Purves, 1964 Sheep 75 kg/animal and year McGrath et al., 1982 Sheep 8% EFSA 2011 Sheep max. 30 % of d.m. Smith et al Cow, Pig max. 20 % of d.m. Edwards,2003; Gummow et al., 2006 Pig % of d.m. Fries et al Chicken* max. 50 % of d.m. Serpe 2013 * free ranged 27

28 Soil ingestion by animals alongside feed intake - Difficult to estimate! - Different methods - Animal group (e.g. ruminants, poultry) and species dependency - General climate and latitude dependency - Local/regional climate dependency - Season dependency - Pasture abundance and quality - Density of grazing animals - median: 6%; maxima up to 50%! (G. Brambilla, Chemosphere 2014, in press; EFSA 2011) 28

29 Dioxins on Soil: bioavailability PCDD/F bound to soil are Not as bioavailable to animals as feeding stuff, where PCDD/F are dissolved in fat Relative to feeding stuff available to about 40% for TCDD Partially less bioavailable (fly ash 30%, soil down to 20%) (Fries 1987, 1990) 29

30 SOIL-ANIMAL-FOOD Calculation of soil contribution using the buffalo milk incident, Italy

31 Italy, Campania region Buffalo raising in farms For milk production Original Mozzarella cheese from Buffalo milk Illegal waste burning Open fires PCDD/F formation Air transport of PCDD/F and PCB to feed growing, grazing and living areas Analytical program Buffalo milk Cow milk, sheep milk Animal feed (simple, compound) Soil picture: Wikipedia, modified 31

32 PCDD/F data PCDD/F-TEQ (WHO1998), incl. buffalo milk cow milk sheep milk basic feed other feed soil n = pg/g fat pg/g fat pg/g fat ng/kg 12% w.w. ng/kg 12% w.w. ng/kg dry average 2,89 1,80 4,25 1,06 0,17 1,49 median 1,41 1,07 2,79 0,17 0,10 1,05 s.d. 5,22 1,73 4,20 4,97 0,17 1,61 min 0,21 0,39 0,28 0,05 0,05 0,89 max 87,00 8,98 12,90 60,40 0,76 12,80 5%-quantile 0,37 0,53 0,29 0,06 0,06 0,92 95%-quantile 8,64 4,81 11,10 2,80 0,53 3,20 EU action limit (*) ,5 0,5 n/a % samples above EU action levels 38,8% 22,8% 55,0% 22,0% 9,8% n/a EU maximum limit (*) ,75 0,75 n/a % samples above EU maximum limit 26,6% 17,5% 50,0% 18,3% 1,6% n/a (*) food: action levels/maximum levels; feeding stuff: action threshold/maximum contents, for feeding stuff compared to limits for "plant origin" and "compound" since details are partially unknown (Neugebauer, 2009) 32

33 From soil to milk: conditions for example calculation - Feed consumption per day: 16 kg, e.g. grass - Adhering soil: 6 % (conservative) = 0,96 kg - Bioavailability in soil 40% (TetraCDD) - Milk production: 8 kg / d - Milk fat content: 8,5 % Soil, assumed pattern - Carry over rates (COR): Literature average / Brambilla TetraCDF 0, PentaCDF 0, PentaCDF 0, HexaCDF 0, HexaCDF 0, HexaCDF 0, HexaCDF 0, HeptaCDF 1, HeptaCDF 0,765 OctaCDF 3, TetraCDD 0, PentaCDD 0, HexaCDD 0, HexaCDD 0, HexaCDD 0, HeptaCDD 2,485 OctaCDD 12,35 WHO(2005) PCDD/F TEQ excl. LOQ 0,1855 WHO(2005) PCDD/F TEQ incl. LOQ 0,963 33

34 From soil to milk: Example calculation Calculation examples: TEQ-Values (WHOTEF05) soil milk transfer ng TEQ/kg soil ng TEQ/d available carryover: COR (cow) ng TEQ/d ng TEQ/kg milk ng TEQ/kg fat factor milk:soil median soil Naples 0,96 0,37 Brambilla 08 0,17 0,02 0,26 0,27 10 ng TEQ/kg soil Naples 9,47 3,64 Brambilla08 1,63 0,20 2,40 0,25 + COR: average literature 9,47 3,64 average COR 0,83 0,10 1,22 0,13 + soil intake: 20% 9,47 12,12 Brambilla08 5,45 0,68 8,01 0,85 + soil 20% / 6kg/d / 7,5% fat 9,47 12,12 Brambilla08 5,45 0,91 12,11 1,28 other pattern: Bien Hoa Brambilla

35 From soil to milk: details of calculation for one scenario calculation soil milk 10 ng/kg ITEQ TEF TEF WHOTEF 05 COR cow (Brambilla 2008) WHOTEF WHOTEF ng TEQ/kg ng TEQ/d ng TEQ/kg ng TEQ/kg ng/kg soil soil available ng TEQ/d milk fat 2378-TetraCDF 5,00 0,1 0,1 0,4999 0,6399 0,028 0,0182 0,0023 0, PentaCDF 4,41 0,03 0,03 0,1323 0,1693 0,049 0,0083 0,0010 0, PentaCDF 5,98 0,3 0,3 1,7945 2,2969 0,631 1,4503 0,1813 2, HexaCDF 8,43 0,1 0,1 0,8435 1,0797 0,467 0,5044 0,0631 0, HexaCDF 6,23 0,1 0,1 0,6226 0,7970 0,460 0,3664 0,0458 0, HexaCDF 1,86 0,1 0,1 0,1864 0,2386 0,125 0,0299 0,0037 0, HexaCDF 9,44 0,1 0,1 0,9442 1,2085 0,407 0,4917 0,0615 0, HeptaCDF 40,16 0,01 0,01 0,4016 0,5141 0,107 0,0550 0,0069 0, HeptaCDF 4,70 0,01 0,01 0,0470 0,0601 0,135 0,0081 0,0010 0,012 OctaCDF 49,17 0,0003 0,0003 0,0148 0,0189 0,020 0,0004 0,0000 0, TetraCDD 0, ,7557 0,9673 0,562 0,5438 0,0680 0, PentaCDD 1, ,7934 2,2955 0,597 1,3702 0,1713 2, HexaCDD 3,41 0,1 0,1 0,3407 0,4361 0,416 0,1812 0,0226 0, HexaCDD 3,71 0,1 0,1 0,3708 0,4746 0,520 0,2468 0,0309 0, HexaCDD 3,27 0,1 0,1 0,3266 0,4181 0,293 0,1226 0,0153 0, HeptaCDD 35,30 0,01 0,01 0,3530 0,4518 0,113 0,0509 0,0064 0,075 OctaCDD 150,93 0,0003 0,0003 0,0453 0,0580 0,014 0,0008 0, ,0012 TEQ 9,47 9,47 12,12 Brambilla08 5,45 0,68 8,01 Milk : Soil 0,85 35

36 Transfer of Dioxins by Consumption of Poultry and Products SOIL-ANIMAL-FOOD: poultry 36

37 Sources of Dioxins in Eggs: contribution of different origins Cage hens Feed 41 % 11 % 24 % Free range hens Feed Worms and insects Herbs, grasses, vegetables, leavings from kitchen gardens 24 % Food Worms Herbs Soil Soil G. Schoeters, R. Hoogenboom,

38 Soil vs. PCDD/F in Eggs EU limit value eggs: 2.5 G. Schoeters, R. Hoogenboom,

39 Discussion and conclusions 39

40 Take Home The contamination of soil DOES contribute sometimes significantly to the overall dioxin burden of humans This burden is especially important for producing meat or food, especially by raising and nourishing animals Care has to be taken especially for single cases due to high variability in contributingfactors Environmental legislation and feed/food legislation will have to merge further in order to consider the whole picture

41 Thank you for your attention!