Multicriteria selection of human health scenarios

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Multi-criteria selection of human health
scenarios due to private consumption
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Boundary conditions of the Risk Problem
Of the 145 substances included, 78 have already
been risk assessed, 63 are on the EU priority
list but have not yet been subjected to a
thorough risk assessment, 4 substances are top
scores in the Danish NIR, but not included in
the four EU priority lists of substances.
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• The System Model for the private consumption
  scenario
• Problem Specification Model (PSM)
• Problem Tree mapping 195 single sub-problems to
  be addressed in the household risk scenario
• Scenario Composition Model (SCM)
• Selection of fraction of sub-problems considered
  the most important ones
• biased by data availability
• Criteria Model (CM)
• Approximating sub-problems by criteria
• usage and toxicity category data
• Scenario Selection Model (SSM)
• Criteria data values are used as input parameters
  in order to identify the most problematic
  substance/-s and derived from this the most
  serious circumstances for risk assessment

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Problem Specification Model (PSM)
Qualitative model
Problem Tree mapping 195 single sub-problems as
part of the household risk scenario
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Scenario Composition Model
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Criteria Model
Ordinal model for each sub problem
Toxicity criteria approximations Cr1 quantified
by R20,R23,R26 (harmful, toxic and very toxic
by inhalation), Cr2 by R22,R25,R28 (harmful,
toxic and very toxic by oral intake), Cr3 by
R39, R48 (danger of very serious irreversible
effects, danger of serious damage to health by
prolonged exposure) and Cr4 by R45,R46 (may
cause cancer, may cause heritable genetic
damage)
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Scenario Selection Model
Ordinal model for risk level
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Hasse Diagram including only realised positions
in the Event Space, i.e. the 145 VOC and semi-VOC
substances
Cr(1, 2, 3, 4, 5, 6, 7, 8, 9,10)
0,0,0,0,1,1,1,1,1,1
Cr(1, 2, 3, 4, 5, 6, 7, 8, 9,10)
1,1,1,1,0,1,1,1,1,1
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Substances closest related to the top ranked
substance (Id 94, benzene) represent the set of
highest concern substances
Substances one of the priority lists, but have
not yet been risk assessed Substances not on
the EU priority list
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Hasse Diagram visualising the Event Space
constructed based on the Cr1 to Cr10 Grey circle
represents non-realised objects, the numbered
white circles the 145 VOCs and semi-VOCs
Ids representing groups of equivalent
substances Id 1(29), Id 6 (2), Id 9 (12), Id 10
(3), Id 13 (6),Id 15 (3), Id 16 (2), Id 18 (5),
Id 19 (2)Id 35 (5), Id 36 (6), Id 47 (2), Id 49
(2), Id 60 (2), Id 68 (5), Id 102 (2)
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Probability distribution of ranking levels for
each single substance
All criteria equally important
Cr3-Cr4 gt Cr1-Cr2 gt Cr5-Cr19
Cr1-Cr4 gt Cr 5-Cr10
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Mean Ranking Estimate for the individual
substances
All criteria equally important
Cr1-Cr4 gt Cr 5-Cr10
Cr3-Cr4 gt Cr1-Cr2 gt Cr5-Cr19
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Some simple observations concerning the test
scenario

• The majority of the 145 substances are ranked in
  the lower of the risk scenario ranking
• i.e. having criteria values of 1 on less than
  50 of the ten criteria
• 57 of the 145 substances have no or little
  relevance in relation to indoor exposure
  sources
• 28 chemicals of the 78 risk assessed chemicals at
  EU level, and 30 of 63 the not yet risk assessed
  chemical, have no criteria values of 1 on the
  exposure estimator criteria, Cr5 to Cr10, for
  private consumption in households

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Additional facts!

• The absolute top candidate, i.e. highest risk
  chemical, is benzene
• Except for 2-butoxyethanol and ethylbenzene, all
  top candidates are have positive scores on the
  chronic toxicity criteria
• Two top candidates, i.e. solvent naphta and
  stoddard solvent, are not on the EU priority
  lists of chemicals.
• These are examples of top scores in the Danish
  emission inventory with an indicated high
  frequency of use in private household conditions
  having criteria values of 1 on all exposure
  estimator criteria except for Cr5, personal use.
  Both are acute toxic by inhalation, Cr1, and show
  potential for chronic and irreversible health
  effects, Cr3.
• Two top candidates, i.e. 2-butoxyethanol and
  ethylbenzene, have not been subjected to RA at EU
  level but are on the priority lists.
• These substances show no chronic toxicity related
  to Cr3 and Cr4. Both substances have a high
  frequency of use in terms of consumer product
  categories.

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The methodological Approach

• The System Model
• increases awareness of boundary conditions of the
  risk problems
• hypothesis driven approach
• Ignorance
• increases awareness uncertainty induced by
• delimitations of the problem three
• approximation of sub-problems by criteria
• increases awareness data availability and
  aggregation level of the scenario description
• The Multi Criteria Ranking model
• Input parameters / criteria values are binary
• thus only able to take one out of two possible
  values as high or low
• which makes it possible to define an Event Space
  that includes all possible criteria data values
• . which makes it possible to identify substances
  that have the same criteria data value
  combination
• the possibility of defining relative criteria
  importance prior to object ranking
• the ability of quantifying multi-attribute
  uncertainty

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Thanks!