What is the Air Quality Health Index?

The Air Quality Health Index (AQHI) is a public health reporting tool, gauged on a scale from 1 to 10+ depending on the health risk. The lower the number, the lower the risk. The Index has corresponding health risk categories and provides advice on how to lower one's risk.

What does the Air Quality Health Index measure?

The AQHI measures the relative health risk against three common air pollutants known to harm human health: ground-level ozone, fine particulate matter, and nitrogen dioxide. All three can affect health, even with short-term exposure. Additionally, these pollutants can pose health risks at low levels of exposure - particularly among those with pre-existing health conditions.

Unlike other parts of the country, Alberta also considers pollutant concentrations that may sometimes go above the province's set thresholds for individual pollutants. These thresholds are applicable to ozone, fine particulates, nitrogen dioxide, sulphur dioxide, and carbon monoxide. In such cases, the AQHI value could be over-ridden with an appropriate "high" or "very high" risk rating depending on the level of any single pollutant. Additionally, community-based messaging for odour (sulphur dioxide) and visibility (fine particulate matter) is used if these concentrations exceed specified thresholds.

Who is most at risk?

People with existing respiratory or cardiovascular conditions: Those with existing respiratory conditions as well as those with cardiovascular conditions such as arrhythmia. People with diabetes also appear to be at greater risk. Air pollution can make it even more difficult for people to breathe and can make existing lung or heart-related symptoms worse.

Young children: Children tend to inhale relatively more air on a per-body weight basis than adults. Their elevated metabolic rate and young defense systems make them more susceptible to air pollution.

Those active outdoors: Athletes or individuals who undertake strenuous work outside tend to breathe deeper and more rapidly allowing more air pollution to enter the lungs.

How can you tell if someone is sensitive to air pollution?

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.

People who are otherwise healthy may have the following symptoms:

• irritated eyes
• increased mucus production in nose or throat
• cough
• difficulty breathing, especially during activity

By understanding how air pollution can affect health, people can better protect themselves and those they care for.

Suggestions for High AHQI

• Reduce or reschedule outdoor physical activities
• Monitor possible symptoms, such as difficulty breathing, coughing, irritated eyes
• Activate a personal health plan or consult a physician or health care provider

Adapted from:
Air Quality Health Index - Health Risks. Environment and Climate Change Canada (2020).