Exposure to fine particulate matter (PM2.5) during landscape fire events and the risk of cardiorespiratory emergency department attendances: a time-series study in Perth, Western Australia

Adeleh Shirangi; Ting Lin; Ivana Iva Nova; Grace Yun; Grant J Williamson; Peter Franklin; Le Jian; Rowena Burch; Ashraf Dewan; Bradley Santos; Nathan Eaton; Jianguo Xiao

doi:10.1136/jech-2021-218229

Exposure to fine particulate matter (PM2.5) during landscape fire events and the risk of cardiorespiratory emergency department attendances: a time-series study in Perth, Western Australia

J Epidemiol Community Health. 2022 Jul 19:jech-2021-218229. doi: 10.1136/jech-2021-218229. Online ahead of print.

Authors

Adeleh Shirangi^{1

2

3}, Ting Lin⁴, Ivana Iva Nova⁵, Grace Yun⁴, Grant J Williamson⁶, Peter Franklin⁷, Le Jian⁴, Rowena Burch⁴, Ashraf Dewan⁵, Bradley Santos⁸, Nathan Eaton⁹, Jianguo Xiao⁴

Affiliations

¹ Epidemiology Branch, Department of Health, Government of Western Australia, East Perth, WA, Australia shirangi.adeleh@curtin.edu.au a.shirangi@murdoch.edu.au.
² School of Population Health, Curtin University, Bentley, WA, Australia.
³ College of Arts, Business, Law, and Social Sciences, Murdoch University, Murdoch, WA, Australia.
⁴ Epidemiology Branch, Department of Health, Government of Western Australia, East Perth, WA, Australia.
⁵ Department of Spatial Sciences, School of Earth Sciences, Curtin University, Bentley, WA, Australia.
⁶ School of Natural Sciences, University of Tasmania, Hobart, Tasmania, Australia.
⁷ School of Population Health, University of Western Australia, Crawley, WA, Australia.
⁸ Environmental Prediction Services - Severe Weather, Bureau of Meteorology (WA Office), West Perth, WA, Australia.
⁹ NGIS, West Perth, WA, Australia.

PMID: 35853664
DOI: 10.1136/jech-2021-218229

Abstract

Background: Landscape fires (LFs) are the main source of elevated particulate matter (PM_2.5) in Australian cities and towns. This study examined the associations between daily exposure to fine PM_2.5 during LF events and daily emergency department attendances (EDA) for all causes, respiratory and cardiovascular outcomes.

Methods: Daily PM_2.5 was estimated using a model that included PM_2.5 measurements on the previous day, remotely sensed aerosols and fires, hand-drawn tracing of smoke plumes from satellite images, fire danger ratings and the atmosphere venting index. Daily PM_2.5 was then categorised as high (≥99th percentile), medium (96th-98th percentile) and low (≤95th percentile). Daily EDA for all-cause and cardiorespiratory conditions were obtained from the Western Australian Emergency Department Data Collection. We used population-based cohort time-series multivariate regressions with 95% CIs to assess modelled daily PM_2.5 and EDA associations from 2015 to 2017. We estimated the lag-specific associations and cumulative risk ratios (RR) at lags of 0-3 days, adjusted for sociodemographic factors, weather and time.

Results: All-cause EDA and overall cardiovascular presentations increased on all lagged days and up to 5% (RR 1.05, 95% CI 1.03 to 1.06) and 7% (RR 1.07, 95% CI 1.01 to 1.12), respectively, at the high level. High-level exposure was also associated with increased acute lower respiratory tract infections at 1 (RR 1.19, 95% CI 1.10 to 1.29) and 3 (RR 1.17, 95% CI 1.10 to 1.23) days lags and transient ischaemic attacks at 1 day (RR 1.25, 95% CI 1.02 to 1.53) and 2 (RR 1.20, 95% CI 1.01 to 1.42) days lag.

Conclusions: Exposure to PM_2.5 concentrations during LFs was associated with an increased risk of all-cause EDA, overall EDA cardiovascular diseases, acute respiratory tract infections and transient ischaemic attacks.

Keywords: air pollution; epidemiology; public health.