What can environmental monitoring tell us about human exposure to dioxins?about human exposure to dioxins?

Niklas JohanssonNiklas Johansson

Swedish EPA and

Karolinska Institutet

2012-11-09Naturvårdsverket | Swedish Environmental Protection Agency

1

What are ”dioxins”?What are dioxins ?

• Chemically, ”dioxins” are polychlorinated dibenzo-p dioxins (PCDDs) polychlorinated dibenzofuransp-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) (together: PCDD/Fs)

F d i t ti ll l C th t b• Formed unintentionally only. Can thus not be banned, just restricted

• The total number of PCDD/Fs is 210 but only 17 of these have the specific toxicological profile that characterises the most toxic congener: TCDDcharacterises the most toxic congener: TCDD

What are ”dioxins”What are dioxins

• In addition, there are 12 dioxin-like PCBs (DL-PCBs) that also have been shown to act via the )same toxicological mechanism as TCDD

• Toxic equivalence factors (TEFs) are used toToxic equivalence factors (TEFs) are used to calculate toxic equivalence concentrations (TEQs) of dioxins and DL-PCBs.

• Current internationally accepted TEF scheme: van den Berg et al., 2006 (WHO 2005)

• NB: A number of different TEF schemes have been applied since the 1980s (I-TEF, WHO-TEF, etc )etc.)

Some implications of persistencySo e p cat o s o pe s ste cy

Slow break down but also slow reactions with• Slow break down but also slow reactions with biological systems. Thus, toxic effects will be chronic rather than acutechronic rather than acute

• Ample time to be transported and redistributed in the environmentthe environment

• Long time until positive changes from actions can be observed in the environmentbe observed in the environment

Toxicology of dioxinsToxicology of dioxins

• Important effects for human risk assessment of dioxins are developmental, cancer and immunological effects

Tolerable daily intake TDITolerable daily intake, TDI

• TDI of dioxins and DL-PCBs for humans should represent long-term intake with no risk of negative ff t f h h ltheffects of human health.

• The TDI generally applied within the EU is currently 2 pg TEQ/kg b wcurrently 2 pg TEQ/kg b.w.

Estimated daily intake of dioxins, ypg TEQ/kg b.w.

C t A M i t kCountry Age Mean intake The Netherlands 40 1.1The Netherlands 10 1.5The Netherlands 10 1.5The Netherlands 2 2.8Italy 13-94 2.28

Italy 7-12 3.37Italy 0-6 5.34

P R China 18-45 0.15-0.96

Japan 17-72 0.79-1.06pUSA >80 1.9USA 0-1 42Egypt - 6.04-6.68

Finnish fishermen and general gpopulation in the late 1990s

I Fi l d t th d f 1990' fi h l tiIn Finland at the end of 1990's, fishermen versus average population

500 average men

400

TEQ

, fat average women

fishermen

200

300

OPC

DD

/F-T

100

200

WH

O

00 10 20 30 40 50 60 70 80 90

(D t f J T i t KTL)age (Data from J. Tuomisto, KTL)

Environmental monitoring ofEnvironmental monitoring of contaminants

• Purpose: checking the state of the environment• Purpose: checking the state of the environment and to study trends −how well environmental objectives are metj−detect new environmental issues

• Often carried out as multidisciplinary programmesOften carried out as multidisciplinary programmes of recurring, systematic studies that reveal the state of the environment.

Recurring environmental monitoringRecurring environmental monitoring of contaminants in biota

• Systematic approach in order to reduce biological variation −Standardised with respect to sampling method,

time, site, species, sex, age, developmental stage organ etcstage, organ etc.

−Collect contextual information on a number of physical, chemical and biological variablesp y , g

−Analysis of several contaminants and other compounds

−Analysis of other variables that can add to the characterisation of the samples.

Environmental monitoring ofEnvironmental monitoring of contaminants

Recurrent monitoring in background areasDetection of temporal trends p

In grids and or transects including possible sources. Identification and quantification of affected areasIdentification and quantification of affected areas

Emission control Control the effect of emission reducing actionsControl the effect of emission reducing actions taken at point sources

ScreeningScreening

Bio-banking

Dioxins in Baltic Proper Guillemots p

ng TEQ/g fat

Dioxins in Baltic Proper Guillemots p

0 50,5

ng TEQ/g w.w.

01969 1974 1978 1982 1986 1990 1995 1999 2003 2007 2011

Dioxins and DL PCBs in BalticDioxins and DL-PCBs in Baltic Proper Guillemots p

ng TEQ/g fat

Dioxins in human milk

30

35

20

25

30ng TEQ/g fat

15

20

5

10

01972 1989 1996 2000 2006

Dioxins and DL-PCBs in human milk

50556065

Dioxins

35404550 DL-PCBng TEQ/g fat

20253035

5101520

05

1972 1989 1996 2000 2006

My fishmongery g

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Information given: species (also scientificInformation given: species (also scientific name), catchment area, eco-labelling …

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Representativity and relevance of analytical results for the exposure assessment

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Where to take samples?Where to take samples?

400

300

400+ 20 %

kg fw

)

200

300

- 74 %B (μ

g/k

100

74 %

um P

CB

0Anterior Middle Tail

S

Anterior Middle Tail muscle muscle musclePart of the fish analysed (n=2)

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Spatial trendsSpatial trends

Often found in gradient studies and expressed• Often found in gradient studies and expressed as coast-open sea- and north-south gradients

G di f ibl• Gradient from possible sources−Active point sources−Contaminated sediments

Pattern analysisPattern analysis

A l t d ti t f DDE/DDT• An elevated quotient of DDE/DDT reveals recent emission of DDT

• Different patterns of dioxins indicate different sources

• Differences between biological and non-bi l i l lbiological samples

Ratio individual PCB congeners between residents in flats in buildings with and without PCB

Important information fromImportant information from environmental monitoring

• Temporal trends

• Pattern analysis−SourcesSources

Exposure routes−MetabolismMetabolism

QuotientsRecent emission?Recent emission?

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Important information fromImportant information from environmental monitoring, cont.

• Spatial trends, facilitated by standardisation−Sources

• Co-variation of compoundsCo variation of compounds−Temporal−Common sources?Common sources?

• Relative contribution to total exposure from different exposure routesdifferent exposure routes

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ConclusionsConclusions

Information on temporal and spatial trends of• Information on temporal and spatial trends of contaminants in biota could improve the general assessment of contaminants in foodassessment of contaminants in food

• Borders could be overcome as we have a win-win situationsituation

• To accomplish this we need to further harmonise food and environmental monitoringfood- and environmental monitoring

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