A Multi-Pollutant Air Quality Health Index (AQHI) Based on Short-Term Respiratory Effects in Stockholm

Abstract

TPS 681: Short-term health effects of air pollutants 1, Exhibition Hall, Ground floor, August 26, 2019, 3:00 PM - 4:30 PM Background/Aim: In this study, an Air Quality Health Index (AQHI) is introduced to capture the health risks associated with multi-pollutant exposure. The index is intended for public information regarding the expected health risks associated with current or forecasted concentrations of pollutants and pollen. Methods: The AQHI is based on an epidemiological study of daily emergency department visits for asthma (AEDV) and urban background concentrations of NOx, O3, PM10 and birch pollen in Stockholm. The index is calculated as: AQHI = ∑(i=1…p) [100 (e^βiXi-1)] where the beta-coefficient (βi) represents the increase in AEDV per 1 µg m-3 increase of each individual air pollutant (Xi). For birch pollen it is the increase per one pollen per cubic meter. The beta-coefficients are based on all age groups, and the exposure window is lag01 (mean of same day and yesterday). Results: The epidemiological analysis showed per 10 µg m-3 increase an increase in AEDV of 0.5%, 0.3% and 2.5% for NOx, O3 and PM10, respectively. For birch pollen, the increase was 0.26% per 10 pollen m-3. The AQHI increase associated with NOx exhibits an even distribution throughout the year, except for a decrease during the summer due to less traffic. O3 contributes to an increase in AQHI during the spring. PM10 reaches a peak during early spring due to road dust suspension and pollen also peak during the late spring/early summer. Total monthly mean AQHI during 2015–2017 varied between 4 and 9%, with a peak value of 16%. Based on daily mean values, the most important risk contribution during the study period is from PM10 with 2.9%, followed by O3 with 2.0%. Conclusion: An AQHI based on asthma emergency department visits can provide the overall daily adverse risks of exposure to air pollutants and pollen especially for people suffering from respiratory diseases.