Work Package 1: results from questionnaire and overview of tools for chemical assessment

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Work Package 1- results from questionnaire and
overview of tools for chemical assessment
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WP1 Questionnaire

• Work in progress

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Background

• WP1 aims to gather information on approaches for
  protecting the environment from radioactive and
  non-radioactive substances
• Questionnaires were used to help gather
  information
• Two questionnaires were developed-
• regulatory/advisory bodies
• industry

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Main areas where a response was invited

• The questionnaire covered the following issues-
• Protection goals
• Methodology
• Criteria (thresholds)
• Future changes in regulation
• Comparison of radionuclide and chemical
  regulation

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Questionnaire responses
34 questionnaire responses received (23/03/07)
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Protection goals for radionuclides
Typically protection of ecosystems pollution
prevention protection of animals, plants and
diversity the aquatic environment Some more
specific e.g. species at population level -
some at individual level maintenance of
habitats with reasonable species populations
aspirational
Many respondents focussed on risks to health and
workers. Protection of flora and fauna to be
considered or general duty to protect
Technically measurable
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Protection goals for chemicals

• Aspirational aims also feature in legislation
  but accompanying technical guidance usually
  translates these into more tangible measurement
  endpoints
• Implicit protection goal is protection of
  populations rather than individuals
• Ecological function features in soil thresholds
  but not aquatic (entirely structural protection)
• May also consider risks from secondary poisoning
  (biomagnification) and risks to operation of
  wastewater treatment plants

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Tools used in Chemical Risk Assessment
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Structure of presentation

• Overarching principles of chemical risk
  assessment
• Examples of risk assessment schemes
• Examples of tools
• How do these schemes and tools link to assessment
  of radioactive substances?
• Conclusions

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Types of risk assessment
Retrospective
Prospective

• Anticipates possible risks
• Imaginary exposure scenario e.g. standard
  application regime, standard receiving
  environment
• Risk mitigation through release, approved uses

• Contaminants already present
• Site-specific
• Focus is on classification, remediation or
  abatement

RISK ASSESSMENT
e.g. New Chemicals, Pesticide Approval
e.g. ERA of contaminated land
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A generic framework for risk assessment
Problem Formulation
Effects Assessment
Exposure Assessment
Risk Characterisation
Risk Management
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Tools

• Exposure
• Emission-estimating tools
• dispersion models
• food chain models
• run-off models
• leaching models
• soil/cropping models

• Effects
• QSARs
• Biotic Ligand Model
• Data analysis (bioassays)
• SSDs

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Examples of chemical risk assessment schemes

• RETROSPECTIVE
• UK (?)Part IIa Environmental Risk Assessment for
  Contaminated Soils
• IPPC Directive

• PROSPECTIVE
• New and Existing Industrial Chemicals
• Biocides Directive
• Pesticides - Plant Protection Product Directive

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1. Industrial chemicals
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Industrial chemicals and biocides

• The EU Technical Guidance Document (TGD) for risk
  assessment provides technical detail for
  undertaking risk assessments required for-
• new substances (Directive 93/67)
• priority existing substances (Regulation 1488/94)
• biocides (Directive 98/8)

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Risk assessment of industrial chemicals and
biocides

• Requires understanding of exposure and effects
• Basic minimum data set required to undertake
  assessment
• Encourages use of additional data where available
  to refine the assessment for existing substances
• Provides option to refine exposure and effects if
  adverse risk indicated

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Risk assessment of industrial chemicals and
biocides

• TGD is supported by EUSES
• Computer-based models which predict environmental
  concentrations and effect concentrations based on
  available data
• Models cover
• emission estimates
• environmental distribution models for various
  environmental scales
• food chain modelling
• species sensitivity distributions

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ERA of contaminated land
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ERA of contaminated land

• Part IIa of Environment Act requires Local
  Authorities to classify designated sites (nature
  reserves etc) that might be at risk from chemical
  contamination
• May be requirement to clean up where unacceptable
  risk
• Scheme at advanced stage of development (EA with
  Conservation Agencies)

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ERA framework - overview
EXIT
CONCEPTUAL SITE MODEL
Tier 0
PROBLEM FORMULATION
Tier 1
SCREENING ASSESSMENT - compare chemical
contamination with SSVs
EXIT
DETAILED ASSESSMENT - assess evidence for
adverse effects
EXIT
Tier 2
Tier 3
CAUSE-EFFECT
EXIT
DETERMINE
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ERA Tools

• Use of SSVs (effectively chemical thresholds) as
  a screening tool
• compare monitored concs with SSV (equivalent to
  PEC/PNEC)
• need to consider background concentrations
• consider factors that affect availability (e.g.
  OC, pH)
• Suite of biological methods - are there impacts?
• ecological surveys
• bioassays
• models to predict risks from biomagnification?
• Tools to link impacts to causes under
  consideration

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Links to radioactive substances

• Assessment of environmental impact of radioactive
  substances involves a similar generic risk
  assessment approach
• Tools required to undertake such assessments are
  often similar, e.g. determination of contaminant
  exposure
• However there are some differences

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How do approaches for chemicals and radionuclides
compare?
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Conclusions

• Chemical risk assessment invariably involves
  exposure and effect assessment
• Typically a tiered approach
• to allow for risk assessment to be refined
• to structure use of different lines of evidence
• Numerous tools are available to help at each
  stage of the risk assessment process
• For large risk assessment schemes, technical
  guidance advises choice of which tool is to be
  used
• Similarities between the risk assessment of
  radioactive and chemical substances indicate need
  for some common tools but fundamental differences
  e.g. risks from external irradiation call for
  other tools in addition