LATEBREAKER
Science Communication & Media
Desirable properties of public health communication tools on ambient air quality from muti-pollutants for better interpretation Hwashin H. Shin* Hwashin Shin Hwashin H. Shin Patrick Brown Guowen Huang
Background: Adverse health effects of ambient air pollutants (AP) have been reported worldwide, and public health communication tools were introduced to mitigate AP-related health risks. The Air Quality Health Index (AQHI) considers AP-related health risks, whereas the Air Quality Index (AQI) considers air pollutant concentrations. Existing communication tools may be insensitive to unpredicted high AP concentrations (e.g., wildfires), and interpretations of the index levels are unclear.
Methods: To convert air quality of multiple pollutants to a simple metric, we consider three components of the metric: reference risk, levels (or scales), and between-level differences. The public communication metric should be: 1) determined by relative health risk attributable to real-time air quality; 2) based on relevant reference risk; 3) accounted for general population and vulnerable subpopulations; and 4) transparent and interpretable. The WHO global air quality guidelines offer thresholds and limits for key APs that pose public health risks, which can serve public health communication metrics as an international reference risk, not varying over country.
Results: Taking the WHO global air quality guidelines as the reference risk, we propose (N+1)-point levels (1 to N and N+), which can be determined based on linear or non-linear concentration-response function (CRF). Using Canadian data of 47 census divisions (60% of population), we demonstrate an example based on a linear CRF, where: N=10, reference risk N=5, and between-level difference indicates ±1.5% increases/decrease in relative risk. Overall this metric is responsive to Canadian wildfire events in the past years and interpretation of the level becomes clearer compared to the WHO guidelines.
Conclusions: If the three components (reference risk, levels and between-level differences) are used internationally, the public health communication tools would become more transparent and interpretable based on global standards.