The Canadian air quality health index

Abstract

Air pollution can cause both short and long term impacts on human health. A new tool, the Air Quality Health Index, has been developed in Canada to provide the public with a real time indication of short term health risks associated with air pollution concentrations. The Air Quality Health Index (AQHI) builds upon existing indices of air pollution but differs by being based on a rigorous statistical link between mortality and air quality. The development of the AQHI in Canada was aided by recent advancements in health effects research, pollutant monitoring and reporting, weather and air quality prediction systems, efficient dissemination processes and political support. More heavily urbanized areas generally experience higher AQHI values than smaller communities. The AQHI is a function of three common air pollutants: ozone, nitrogen dioxide and PM2.5 (Particulate matter of maximum diameters 10 and 2.5 microns (millionths of a metre) respectively). It normally varies from 1 to 10, though it can occasionally rise above 10 during severe pollution episodes, such as thick wildfire smoke. The AQHI and its predicted maximum values for the next 24-36 h are provided to the public through various websites, with specific health advice provided for each of four AQHI health risk categories. The vulnerable population receives more cautious health advice than the general public. Promotion campaigns are used to explain the AQHI and encourage its use.