Air Quality Health Index

Air Quality Health Index La Cote air santé
Headquarters	Ottawa, Ontario, Canada
Established	2005
Website	http://www.airhealth.ca http://www.coteairsante.ca

The Air Quality Health Index or (AQHI) is a scale designed to help understand the impact of air quality on health. It is a health protection tool used to make decisions to reduce short-term exposure to air pollution by adjusting activity levels during increased levels of air pollution. The Air Quality Health Index also provides advice on how to improve air quality by proposing behavioral change to reduce the environmental footprint. This index pays particular attention to people who are sensitive to air pollution. It provides them with advice on how to protect their health during air quality levels associated with low, moderate, high and very high health risks.^[1]

History

Air quality in Canada has been historically been reported by the Air Quality Index in various provinces. Significantly, AQI values reflect air quality management objectives, which are based on the lowest achievable emissions rate, and not exclusively concern for human health. The AQHI was created with a different goal - to report on the specific health risks posed by air pollution. As such, the AQHI represents a paradigm shift in communicating air quality information to the public.

The Air Quality Health Index or "AQHI" is a federal program jointly coordinated by Health Canada and Environment Canada. However, the AQHI program would not be possible without the commitment and support of the provinces, municipalities and NGOs. From air quality monitoring to health risk communication and community engagement, local partners are responsible for the vast majority of work related to AQHI implementation.

The AQHI is being rolled out across Canada and replacing the AQI as the public face of air quality information.

Originally launched as a pilot project in the British Columbia Interior and Nova Scotia in 2005, it is currently implemented in 49 locations across Canada.^[2]

The AQHI

The Air Quality Health Index provides a number from 1 to 10+ to indicate the level of health risk associated with local air quality. Occasionally, when the amount of air pollution is abnormally high, the number may exceed 10. The AQHI provides a local air quality current value as well as a local air quality maximums forecast for today, tonight and tomorrow and provides associated health advice.

As it is now known that even low levels of air pollution can trigger discomfort for the sensitive population, the index has been developed as a continuum: The higher the number, the greater the health risk and need to take precautions. The index describes the level of health risk associated with this number as ‘low’, ‘moderate’, ‘high’ or ‘very high’, and suggests steps that can be taken to reduce exposure.

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How is the AQHI calculated?

The formulation of the AQHI is based on the observed relationship of Nitrogen Dioxide (NO₂), ground-level Ozone (O₃) and particulate matter (PM_2.5) with mortality from an analysis of several Canadian cities. Significantly, all three of these pollutants can pose health risks, even at low levels of exposure, especially among those with pre-existing health problems.

When developing the AQHI, Health Canada’s original analysis of health effects included five major air pollutants: particulate matter, ozone, and nitrogen dioxide (NO2), as well as sulphur dioxide (SO₂), and carbon monoxide (CO). The latter two pollutants provided little information in predicting health effects and were removed from the AQHI formulation.

The AQHI does not measure the effects of odour, pollen, dust, heat or humidity.

Who is at Risk

The AQHI is aimed towards two populations: 1. The “general” population; and 2. The “at-risk” populations. The later consists of children, the elderly and people with existing respiratory or cardiovascular conditions, such as those with asthma, and people suffering from diabetes, heart disease or lung disease.

Children are more vulnerable to air pollution: they have less-developed respiratory and defense systems. Because of their size, they inhale more air per kilogram of body weight than adults. Their elevated metabolic rate and young defense systems make them more susceptible to air pollution.

Seniors are also at a higher risk because of the weakening of the heart, lungs and immune system and increased likelihood of health problems such as heart and lung disease.

Exposure to air pollutants can cause a range of symptoms. People with lung or heart disease may experience increased frequency and/or severity of symptoms, and increased medication requirements. It is recommended that those susceptive should take greater precautions.^[5]

AQHI and Lifestyle

Environment Canada recommends looking for outdoor air quality by checking the AQHI in your community before heading off to work or play as well as to use the forecasts to plan activities, whether over the next hour or the next day. Seniors, parents, those with asthma, and people suffering from diabetes, heart or lung disease, can use the AQHI to assess the immediate risk air pollution poses on their health and take steps to lessen that risk. The AQHI is also recommended for healthy, fit and active people to consult to decide when it is best to exercise or work outdoor.

The best way for someone to use the AQHI is to regularly check the current index value, to pay attention to personal symptoms and self-calibrate to the reported current AQHI value. For example, if symptoms are experienced when the index is a 6, then precaution should be taken when the index is at a 6 or higher by following the corresponding health messages. Then, when an individual knows what number triggers health symptoms, to get in the habit of checking the maximum forecast to plan activities ahead of time.

The AQHI is easily accessible via the web: At http://www.arihealth.ca and http://www.weatheroffice.gc.ca/canada_e.html and The Weather Network.^[6] It is reported throughout the day on The Weather Network channel as well as the weather and traffic reports on local media.The AQHI is also available for download as a desktop widget for Windows and Mac, and iphone app, http://mirtchovski.com/code/AQHI.html. There are several news feeds and blogs dedicated to the AQHI: http://www.ec.gc.ca/cas-aqhi/default.asp?lang=En&n=C7B2359F-1.

External links

• http://www.airhealth.ca
• http://www.hc-sc.gc.ca/ewh-semt/air/out-ext/effe/health_effects-effets_sante-eng.php
• http://www.toronto.ca/health/airquality/aqhi/index.htm AQHI Available in 13 Languages
• http://mirtchovski.com/code/AQHI.html Flash AQHI Widget
• http://www.theweathernetwork.com/airquality/whatis

AQHI video

(http://picasaweb.google.com/lh/sredir?uname=thecleanairpartnership&target=ALBUM&id=5356080206208401857&authkey=Gv1sRgCNX_1c-16vqRgQE&feat=email)

Be Air Aware

• http://www.greennexxus.com/gnx.aspx?name=AA-home

Twitter

• http://twitter.com/#!/environmentca
• http://twitter.com/#!/environnementca

References