Ambient Air Quality NEPM

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Ambient Air Quality NEPM

• By
• Dr Tom Beer
• CSIRO Atmospheric Research
• CSIRO Environmental Risk Network

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National Environment Protection Council

• Set up under IGAE
• Council of Governments
• Implement National Environmental Protection
  Measures(NEPM)

(www.ephc.gov.au)
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National Environment Protection Measures

• Desired environmental outcome
• Reason for the proposed measure
• Environmental impact of not making the measure
• Statement of alternative methods
• Economic and social impact
• Address regional environmental differences
• Timetable

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Ambient Air Quality NEPM

• Started in mid-1996
• Direction by a Project Team of regulators from
  States and Commonwealth
• Desired outcomeProtect human health well-being

• Deal with six criteria pollutants
• nitrogen dioxide
• sulfur dioxide
• carbon monoxide
• ozone
• particulate matter
• lead

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NEPM - 1998
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Ambient Air Quality NEPM
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Exposure Assessment

• Number of people
• Air concentration
• Duration of exposure
• Used monitoring data plus ABS statistics
• Metric - Population exposed(person-events)
• Extreme value metricPopulation affected(persons)

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Exposure Assessment
P exp(-kc) and exp (-kc-b)
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Exposure - a complex problem.

• Objective - a first approximation
• Problem simplified to OUTDOOR, AMBIENT
  AIR Population stays still (residential
  census) Current pollution levels (1993 - 1995)

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Exposure assessment methodology

• Define regional boundary (around populated area)
• Spatial interpolation of pollution data
• Map population data onto a 1km x 1km grid
• Combine pollution population
• Assess exposure to varying levels of pollution
• Compute total exposure.

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Air Pollution
Population
Exposure
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ExposureModelResults
of person-events/year ( 24-hr average
visibility lt 30 km )
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Alternative exposure metrics(extreme value
metric)

• Population affected computed fromANNUAL
  MAXIMUM CONCENTRATIONS,POPULATION DENSITY
• Gives an independent measure of exposure.

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Exposure assessment - results
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Exposure assessment - results
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Health Risk Assessment

• Risk, during a given time, of the scenarios
  under consideration is the union of a set of
  consequences and their associated probabilities
  (Beer Ziolkowski, 1995)
• Time - 1993 to 1995
• Scenarios - air quality measurements
• Consequences - health end-points
• Probabilities - calculated using exposure and
  dose-response information

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Health Risk Assessment

• University of Wollongong/CSIRO
• Population-based, non-cancer assessment
• Health end-points for 6 criteria pollutants
• Exposure assessment (average value of k)plus
  dose-response
• Dose-response approximated by concentration-respon
  se, based on proportion of people displaying
  symptoms
• Total number of symptomatic people
• Normalise by dividing by total population

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Quantitative Health Risk Assessment
Peak Concentration NOEL 1/k
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Health Risk Calculations
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Notional NEPM - Air QualityJuly 1997
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Standards - Issues

• Numerical valuePrecautionary Principle
  approach NOEL/(Safety Factor)Risk based
  approach Undetermined
• Averaging timeStatistical equivalence
• Allowed exceedances

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Statistical equivalence
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CSIRO Concerns

• Nitrogen Dioxide1 year standard protects
  vegetation
• Ozone4 hour standard set on medical experiments
  over 6-8 hours
• Sulfur Dioxide1-day standard 0.15ppm
  statistically equiv.
• Lead - Air is only one of many pathways

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Notional NEPM - July 1997

• Desired environmental outcome
• Protection of human health well-being
• Definitions
• Goal
• Standard
• Protocol

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Draft NEPM - December 1997
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Future Research Needs

• ABS Census data is static - people move
• Australians indoors 95 of the time
• Fixed monitoring station data - only a first
  approximation
• NOEL contentious
• Concentration-response curves
• Dose-response, individual variability
• Exposure and health - same dose measure

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Indoor/Outdoor relationships

• Effective concentrationWeighted sum of indoor
  and outdoor0.95 Indoor 0.05 Outdoor
• Effective concentrationas a ratio of
  outdoor0.95 (Indoor/Outdoor) 0.05

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Indoor/Outdoor relationships
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Future Air Quality NEPM

• Stakeholder agreement
• Collaborative, interactive consultancies
• Transparent basis for the use of science
• Adequate time-lines

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Discussion of issues

• The NEPM process
• Setting standards
• The results of the 1998 NEPM
• Data requirements
• Exposure assessment
• Health risk assessment

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Issues The NEPM Process

• Stakeholder agreement
• Collaborative, interactive consultancies
• Transparent basis for the use of science
• Adequate time-lines

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IssuesSetting standards

• Numerical valuePrecautionary Principle
  approach NOEL/(Safety Factor)Risk based
  approach Undetermined
• Choice of averaging time
• Allowed exceedances

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IssuesData requirements(NEPM Monitoring
Protocol)

• Previous lack of national standards in data
  storage and data quality control
• Need nationally consistent databases and
  software.
• Need improved spatial coverage
• Need travel/trip data, indoor/outdoor data.

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Issues - Exposure assessment

• Validate estimates using different methods
• Modelling can be used as a sophisticated
  interpolation method to estimate time variations
  in concentration
• Implement roadside, indoor and in-vehicle
  models.

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IssuesHealth risk assessment

• No agreed health end-points
• Uncertainty in LOEL values
• No agreed acceptable level of risk, or method to
  obtain it.
• Shape of concentration-response

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Future Research Needs

• ABS Census data is static - people move
• Australians indoors 95 of the time
• Fixed monitoring station data - only a first
  approximation
• Dose-response, individual variability
• Exposure and health - same dose measure

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NEPM Ambient Air Quality NEPC actions

• Establish A Peer Review Committee.
• Risk assessment taskforce to report within 3
  years.
• Reviews ofparticle standard start by 2001SO2
  and O3 - start by 2003NEPM in 2005.
• Monitor PM2.5

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NEPM Ambient Air Quality PM2.5
Issues Paper (The need for a PM2.5
Standard) Discussion Paper (Setting a PM2.5
Standard) Technical paper on exposure and risk
characterisation Technical paper on
monitoring Impact Statement for draft
variation NEPM variation (www.ephc.gov.au)
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NEPM Ambient Air Quality PM2.5 Standard
July 2003 Monitoring to start in 2004 Fine
particle NEPM in force 2005