Air Pollution

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Air Pollution Health Effects Progress on
Environment and Health Indicators
Canadian Context and Current Initiatives
Presentation by
Sabit Çakmak, Ph.D. Biostatistics and
Epidemiology Division, Health Canada.
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Outline

• What are indicators?
• Why do we need them?
• Criteria for indicator selection
• Indicator initiatives in Canada
• Air Quality as an example is the science strong
  enough to make the links to health?
• Current monitoring program in Canada
• Conclusions

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What are Indicators?

• Indicators
• measures that provide information on trends in
  the condition of a phenomenon
• Environmental indicators
• selected key measures which represent or
  summarize a significant aspect of the state of
  the environment.
• focus is on
• trends in the state of the environment,
• stresses on the environment,
• responses or actions to prevent or reduce these
  stresses.

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Why do we Need Indicators?

• Identify Hazards and Risks
• Tools for decision making and policy development
• Tools for setting and evaluating program
  objectives
• Tool to inform Canadian Public of environmental/
  health issues in a non-technical, easy to
  understand way
• To respond to right of the Canadian public to
  know the state of their environment

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Criteria for Indicator Selection

• Relevant to issue
• Representative of the issue
• Scientifically credible and transparent
• Sensitive to change over time
• Supported by reliable data
• Easily understood by intended users
• Cause-effect links / predictive
• Useful and relevant to decision-makers

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Canadian Indicator Initiatives
International Indicators
Environment Canada Indicator Series
Statistics Canada Natural Capital Accounts
National Roundtable on Environment and Economy
Sectoral Indicators (Forestry, Agriculture,
Transportation)
EMAN Nature Watch
Regional Transboundary
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Commitments to Childrens Environmental Health
Indicators

• Commission for Environmental Cooperation
• G8 Environment Ministers
• Health and Environment Ministers of the Americas
• World Summit on Sustainable Development

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An Example Air Quality

• Constructing an Environment/Health indicator
  series linking air quality and health
• Total kilometers driven (driving forces)
• Emissions of air pollutants (pressure)
• Ambient concentrations of air pollution , i.e. ,
  concentration of PM2.5, PM10,ozone etc. (state)
• Population exposure to pollution in excess of
  maximum acceptable levels (exposure)
• Population mortality/morbidity due to respiratory
  or cardiovascular disease (effect)
• Agreements, initiatives, and programs (action).

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Driving Force - Transportation
Total Kilometers Traveled
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State - Ambient Concentrations
Concentration of PM2.5 (ug/m3) calculated using
the Canada-wide Standards for 1998 to 2000 (TEOM
stations).
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Toronto Non-Accidental Mortality 1980-1994
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Toronto Cardio-respiratory Hospitalization
1980-1994
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Pollutant Specific Contribution to
Non-Accidental Mortality in 11 Canadian Cities
1980-1991 Evaluated at Mean Concentrations
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Effect of Pollution Episode on Mortality
(London, England)
500
2500
Deaths
450
2000
400
Particulate Matter (
1500
PM
Total Deaths Per Day
350
1000
300
500
250
m
g/m3
200
0
0
2
4
6
8
10
)
December, 1952
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Trends in Air Pollution
(Toronto, 1980-
1994)
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Number of Deaths
Particulate Matter (µg/m3)
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Ontario Respiratory Hospital Admissions
and Summertime Ground Level Ozone
120
118
116
114
Respiratory Admissions Per Day
112
110
108
20
30
40
50
60
70
80
90
Ozone (1 hour maximum - ppb)
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Accountability

• What assurances do we have that if we spend
  billions of dollars on improving air quality,
  population health will also improve?
• Not sufficient to demonstrate that air quality
  has improved
• Things can change over time
• Nature of pollution could change
• Size and nature of at risk groups could change

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Environmental Health Indicatorfor Air Quality

• Air pollution only accounts for a small
  percentage of population health effects
• Population health statistics (HALE) are too
  insensitive to changes in air quality
• Need to directly assess relation between air
  quality and health over time using same studies
  and analytical methods used to identify air
  quality as a health hazard

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What the Indicator Should Be

• Directly (causally) related to air quality
• Sensitive to changes in air quality
• Represent (at least) general population
• Sub-indicators on specific groups (infants)
• Data inputs must be readily available
• Extensive temporal and spatial coverage
• Geographically representative
• All of Canada
• Regions or cities within the country
• Comparable internationally

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Proposed EHI Mortality Particulate Matter

• Causal link between daily mortality counts and PM
  is well established
• Statistically link daily variations in the number
  of deaths and daily levels of PM using time
  series methods
• Controlling for temporal trends and weather

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26 European cities or regions
13 Canadian cities
Shenyang
90 U.S. cities, counties or regions

Beijing

7 Korean cities

Mexico City
Bangkok

Brisbane
Sao Paulo


Sydney
Santiago


Melbourne

Christchurch

Location of studies of air pollution and mortality
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EHI Mortality Fine Particles

• Mortality represents major component of
  population health
• Death certificates universally maintained
• Major Canadian cities have air pollution data
• Long time series have been established
• Aggregated at city, regional, or national level
• Statistical agencies could maintain EHI

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Trend in PM2.5 in Toronto
1980 1985 1990 1995
Time
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of Deaths Attributable to PM2.5 Exposure in
Toronto, 1980-1995 _at_ 18 mg/m3
1980 1985 1990 1995
Time
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Environmental Health Indicator for Ambient Air
Quality
1980 1985 1990 1995
Time
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Limitations

• Mortality due to short-term pollution exposure
  may not represent all population health effects

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Ground Level Ozone and Infant Respiratory Health
Daily Number of Admissions
Ozone (ppb)
Days After Pollution Episode
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Extensions

• Include hospital admissions and ER visits
• Be wary of changes in health care utilization
• National cohort studies (NPHS) used to assess
  long-term exposure effects
• Longevity
• Development of disease
• Need to know latency period
• Extend EHI to multiple pollutants
• O3, CO, NO2, SO2

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Monitoring Program

• Successful indicator program has a robust,
  reliable, consistent monitoring program in place
• In Canada we have an ambient air quality
  monitoring program run by Environment Canada
  National Air Pollution Surveillance network
• 271 stations in 163 cities distributed across
  Canada

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Conclusions

• Indicators provide a useful tool to link science
  to policy
• For air quality, the science is advanced enough
  to provide useful indicators
• Indicators show that although the state of air
  quality in Canada is generally good and
  improving, health effects from poor air quality
  are still observed
• More people die and are admitted to hospital for
  heart and lung problems on days of high air
  pollution.
• People do not live as long in cities with high
  air pollution
• In Canada we do have a sufficient ambient air
  quality monitoring network for credible indicator
  development