Map of Simcoe Muskoka

Environment

Air Quality Health Index

Health Canada and Environment Canada developed the Air Quality Health Index (AQHI) as a public information tool to help Canadians protect their health from the negative effects of air pollution. The AQHI is a scale that goes from 1 to 10+ and represents the increased risk of death based on the level of three pollutants (PM2.5, O3, and NO2) in the ambient air. This scale is then sub-divided into four health risk categories (see table below).

INDEX

HEALTH RISK

HEALTH MESSAGES

At Risk Population*

General Population*

1-3

Low

Enjoy your usual outdoor activities.

Ideal air quality for outdoor activities.

4-6

Moderate

Consider reducing or rescheduling strenuous activities outdoors if you are experiencing symptoms.

No need to modify your usual outdoor activities unless you experience symptoms such as coughing and throat irritation.

7-10

High

Reduce or reschedule strenuous activities outdoors. Children and the elderly should also take it easy.

Consider reducing or rescheduling strenuous activities outdoors if you experience symptoms such as coughing and throat irritation.

Above 10

Very High

Avoid strenuous activities outdoors. Children and the elderly should also avoid outdoor physical exertion.

Reduce or reschedule strenuous activities outdoors, especially if you experience symptoms such as coughing and throat irritation.

*People with heart and breathing problems are at greater risk. Follow your doctor’s usual advice about exercising and managing your condition.

Adapted from Environment Canada:
http://www.ec.gc.ca/cas-aqhi/default.asp?lang=En&n=79A8041B-1

The ambient air monitoring station in Barrie is the only one in Simcoe Muskoka that collects hourly data on all three pollutants needed to calculate the AQHI.

In Barrie in 2015, the vast majority (96.8%) of monitored hours had ‘low risk’ AQHI readings and all of the remaining monitored hours (3.2%) were considered ‘moderate risk’. In 2015 there were no monitored hours with a ‘high risk’ AQHI. There haven’t been any monitored hours with a ‘very high risk’ reading in Barrie since 2001. There was a significant increasing trend for the per cent of hours with ‘low risk’ readings from 2003 to 2011, with an average annual increase of 1.7% (0.8%, 2.5%) per year; however, from 2011 to 2015 the trend for the per cent of hours in the ‘low risk’ AQHI range has been flat, with no significant increases or decreases. 

140605_AQHI_YearlyTrend

Between 2003 and 2014 the per cent of monitored hours with AQHI readings of ‘moderate risk’ or higher (i.e. 4 and above) at the Barrie station correlated strongly with the age-standardized rate of emergency department visits related to Asthma for Simcoe Muskoka as a whole. The correlation coefficient for these eleven oberservations was 0.93 (where a perfect correlation is 1.00). While correlation doesn’t imply causation, it does provide some evidence of improved health outcomes related to improved air quality and also provides additional validation of the AQHI as an indicator of health risk associated with outdoor air pollution.

140605_AQHI_vs_Asthma_Trend