Toronto gets serious about air quality

Jul 9 2007

Residents in Toronto, Canada will soon have a new way of testing the air quality in their city.

The Air Quality Health Index (AQHI), which was unveiled this week will test and rate the current air quality for pollution using a rating system of 1 to 10+ which will forecast the air-related health risk for the coming day.

The AQHI is aimed at those who are most vulnerable to air pollution, children, the elderly and people with heart or breathing problems such as asthma.

The AQHI will in effect give those people the opportunity to modify their activities should pollution levels reach a point were they would be affected.

The AQHI works on a risk scale and is the result of a partnership between the City of Toronto, and provincial and federal government.

It has already been successfully tested in Halifax and Vancouver and the 18-month Toronto pilot is the first in Ontario.

Environment Canada advises those with a moderate risk to reduce outdoor physical exertion or reschedule activities to times when the index is lower than moderate; this would not apply to the general population.

Should the rating reach the top 10+, the advice then suggests that children, the elderly, and people with heart or breathing problems avoid physical exertion outdoors and the general population is advised to reduce or reschedule strenuous outdoor activities.

The AQHI will enable individuals to assess their own health risk based on symptoms they experience, even if they have no known health problems; when they realise which AQHI rating triggers their symptoms they can use it to forecast and plan outdoor activities.

The new index is different from the current Air Quality Index in that it offers separate recommendations for healthy people and those with breathing problems; it is reached by combining readings of ozone at ground level, nitrogen dioxide and particulate matter.

The original system looks for six common pollutants and rates them on a scale and the pollutant with the highest level becomes the AQI reading.

Dr. David McKeown, Toronto's medical officer of health, has endorsed the index saying thousands of hospital admissions and an estimated 1,600 premature deaths each year are due to air quality issues.

Dr. McKeown says the AQHI will offer timely and accurate information on air pollution health risks and how to minimize them and will be particularly useful to vulnerable individuals, such as seniors and those with asthma.

It is also hoped the AQHI will encourage people to reduce emissions on days when air quality is poor and lead to a better understanding of the impacts of air pollution.

Toronto is Canada's largest city and the sixth largest government and has a diverse population of around 2.6 million people.