The Full Picture

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The Air Quality Health Index:

using Canadian Earth observations

for health protection from air pollution

Dave Henderson, Policy Advisor, Air Issues and Sean Daley, Program Officer, Business Policy,

Meteorological Service of Canada, Environment Canada; David M. Stieb, Medical Epidemiologist,

Healthy Environments and Consumer Safety Branch, Health Canada

xtensive studies around the world have linked air pollution

to a variety of adverse health effects including premature

mortality, and both respiratory and cardiovascular morbid-

ity. These studies also indicated that certain populations are more

vulnerable to those adverse health effects, namely children, the

elderly, and people with pre-existing cardio-respiratory disease.

Individuals who exercise or do strenuous activities outdoors are

also more susceptible to the negative effects of air pollution.

For nearly three decades Canadians have relied on an Air Quality

Index (AQI) to inform them of measured and forecast air pollution

conditions. It is recognized that these indices are inadequate for

personal health protection because they are:

• Based on thresholds which imply a safe level of single pollutant

concentrations and can not convey that adverse health effects can

be experienced by sensitive members of the population at rela-

tively low pollutant concentrations

• Not designed to reflect a realistic assessment of the mixture of

gases and particles that we breathe

• Inconsistently applied and communicated across Canada, resulting

in the absence of a true national picture of daily air quality, which

limits national media exposure and comparability for travelling.

The move toward an Air Quality Health Index

Health Canada (HC) and Environment Canada (EC) collaborated

with national air quality stakeholders representing health and envi-

ronmental expertise from provinces, municipalities and

non-governmental organizations. Together they developed a national,

health-based approach to presenting air quality information to

Canadians.

Modelled after the successful, Canadian-developed index for ultra-

violet radiation (UV index), the Air Quality Health Index (AQHI)

was designed to provide Canadians with local air quality informa-

tion and forecasts combined with health and environmental

messages, on a daily basis. The AQHI is a personal communications

tool designed to increase public awareness of air quality as a commu-

nity health issue in Canada.

The index follows the principles established by the Group on Earth

Observations (GEO), as it combines observations and information

across sectors to provide a value-added product to society; in this

case information related to human health. The index

will be used to enable Canadians to take appropriate

measures to protect their health in response to changing

air quality conditions and to help motivate them to take

actions to reduce emissions.

The science of the AQHI

As an alternative to linking air quality information to

air pollution standards or guidelines, the AQHI is

founded on the statistical analyses of mortality risks

associated with air pollution for ten large Canadian cites.

Through exhaustive analyses of the 20-year, day-to-day

health impact of air pollution for each location, Health

Canada analysts developed a new health-based formu-

lation derived from mortality statistics. This

The Air Quality Health Index provides Canadians with local air

quality information and forecasts combined with health and

environmental messages

Air Quality Health Index

Source: Environment Canada, 2007

OCIETAL

ENEFIT

REAS

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EALTH