Multidisciplinary evaluation of an environmentally driven health risk: the case study of herring and dioxin(EVAHER)
HERC Seminar 25.10.2007, Mari Vanhatalo In collaboration with Samu Mäntyniemi
Department of Biological and Environmental SciencesUniversity of Helsinki
[email protected] Environmental and management group
http://www.helsinki.fi/science/fem/
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Content
Background Objectives and aims of the study Key personnel and participating institutes Methods Progress of the study and current results
Publication plan
Results
Relevance of the study in environmental research and
solving environmental problems
Background
Dioxins bioaccumulate in humans and wildlife due to their lipophilic
properties
are supertoxins
are merely environmental toxins ( .. a little amount as by-
product of industry)
For humans a major source of dioxin is food specifically through the consumption of fish, meat, and milk
products
Herring is the most important species of the commercial
fishery of Finland and the key species in the marine
ecosystem of the northern Baltic Sea
..
Dioxin may cause disturbances in humans Trade-off between cost and benefits of eating fish
Several causal dependencies behind the dioxin problem
are highly uncertain
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.. diluted by growth but persists at noticeably elevated levels even to adulthood ..
M.Vanhatalo
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Objectives and aims of the EVAHER study
1) to evaluate the uncertainty related to threshold values
of dioxin 2) to develop risk analysis models to assess current risks
caused by herring consumption 3) to evaluate the relative impacts of alternative ways to
manage the health risk caused by herring consumption 4) to educate one scientist to Bayesian analysis and to
the modeling of links between ecosystem health and
human health.
Personnel and institutes
Sakari Kuikka, coordinator (Professor, Fisheries Science,
UHel) Mari Vanhatalo, PhD student (Aquatic Science, UHel) Samu Mäntyniemi, PhD (biometry, Uhel) Other researchers :
Mr. Anssi Ahvonen, LicPhil, Mr. Jukka Pönni, MSc and Mr.
Pekka Vuorinen, PhD (Finnish Game and Fisheries
Research Institute),
Mr. Timo Assmuth, PhD and Mr. Heikki Peltonen PhD
(Finnish Environmental Institute)
Mr Jouni Tuomisto. PhD, Docent (National Public Health
Institute, Kuopio).
Methods
Bayesian approach Enables researcher to quantitatively integrate interpretation
of data with expert knowledge
- learning process
Bayesian probability is a formalism of knowledge that
allows us to reason under conditions of uncertainty Knowledge is combined and updated by using the rules of
probability calculus
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Why Bayesian approach: The importance of assessing the uncertainty
0
0.01
0.02
0.03
0.04
0 20 40 60 80 100 120 140 160 180 200
value of interest variable
pro
babili
ty
A
B
critical value (e.g. dioxin)
Influence diagram/mind map/probability model
Publication plan
The first analysis has been published (Spring 2007) in
Ambio Human Dietary Intake of Organochlorines from Baltic
Herring: Implications of Individual Fish Variability and
Fisheries Management. Ambio, Vol.36, No. 2/3
Next tasks: Would a maximum size for herring in the human diet
decrease the health risks ?
Paper 3) Variability of herring consumption among
consumers (and variability of exposure from other sources?)
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Would a maximum size for herring in the human diet decrease
the health risks? & Human Dietary Intake of Organochlorines from
Baltic Herring: Implications of Individual Fish Variability and
Fisheries Management.
Recommendation (Finnish Food Safety Agency): > 17cm ,
1-2 times per month
Consumers cannot choose size-selectively herring
individuals nowadays, because a major part of herring is
consumed in forms that obscure the original size.
What would be the risk from intake of smaller herring,
length ≤ 17cm (0-30g)?
EU SCF limit for all foodstuff of WHOtotal-TEq 840 pg wk-1
and limit of WHOtotal-TEq originating from herring is 275
pg WHOtotal-TEq wk-1
Results from first analysis (Kiljunen et al. 2007) show that
regulating the fishing is a far less effective way to
decrease the risk than regulating the consumption of
herring
Individual variability in dioxin content of herring
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Materials, data
90 herring individuals were collected from the Bothnian
Sea, northern Baltic, in June 2002. (Parmanne et al.) Human herring consumption frequencies were obtained
from the survey of the Finnish National Health Institute,
(J.Tuomisto et al) consumption classes 1,…,5 Classes are: 1, 2, 4, 8 or 20 times herring per month
The relative frequencies of age groups in catch in 2002
were calculated from herring population estimates
provided by the Finnish Game and Fisheries Research
Institute. (Jukka Pönni)
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0
0.02
0.04
0.06
0 5 10 15 20 25 30 35 40
pg WHO-TEq g-1
Re
lati
ve
pro
ba
bili
ty d
en
cit
y Status quo
1) Present F maintained
2) 50% increase in F
3) 100% increase in F
4) 50% decarease
Relative probability distribution of whole market herring WHO_total_TEq consentrations (pg g-1) estimated for present day (status quo 2002) and future fishing scenarios. Kiljunen et al. 2007, Ambio
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Results
0
0,1
0,2
0,3
0,4
0,5
0 500 1000 1500 2000
275 840
WHO-TEQtotal intake in decade in four main herring consumptions classes
0
0,1
0,2
0,3
0,4
0,5
0,6
0 500 1000 1500
275 840
ii) status quo
ii) status quoIi) status quo
i) small herring
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Results II
0
0,05
0,1
0,15
0,2
0,25
0,3
0 500 1000 1500
275 840
0
0,1
0,2
0,3
0,4
0,5
0,6
0 500 1000 1500
275840
WHO-TEQtotal intake
in one week (small
herring)
i) within 15 days
ii) within 40 weeks
(whole pregnancy
time)
in four main herring
consumptions classes
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Conclusions
Herring consumers cannot choose unless they don’t know
the herring size. It is possible to reduce the dioxin risk related to herring
consumption by the following means:
Sort herring size-selectively in food industry. The
information about the size of herring used should be passed
on to the consumer
Then it could be possible to reduce the dioxin risk by
regulating the consumption of herring by size, if consumers
could choose the small or bigger ones.
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Discussion
• Recommendation related to breast-feeding time?
• What is the true dioxin intake of fetus and the baby? And risk?– Different metabolism,
halftime– Related to different
responses (tooth enamel damage, chloracne, developm. dis. etc.)
– Dioxin extraction of the mother during pregnancy and breast-feeding
T.Vanhatalo
T.Vanhatalo
Future/continuation plan after EVAHER
• Paper 4) Partly included already in paper: The variance
of the dioxin content in the catch and on the markets.
• Paper 5) Uncertainties of the critical residue levels in
herring: sensitivity between individuals
• Paper 6) The overall management of risks.
Relevance of the study’s in environmental research and solving environmental problems
Offer methodological solutions to other fields of
environmental research and management
The study brings together multiple fields of research that
are dealing with the dioxin problem – integrative approach
increases the relevance of basic research in different
disciplines
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Thank you for your attention!
