Australian fires and perinatal health risks

This study is investigating risk of birth outcomes and perinatal mortality from fire-related PM_2.5. The interdisciplinary team is developing fire modeling methods to estimate PM_2.5 specifically from fires for Australia with improved fire emissions inventories and Lagrangian modeling.

Poster abstract for HEI Annual Conference 2022

Australian fires and perinatal health risks

Michelle L. Bell¹, Josh Warren¹, Loretta Mickley², Gavin Pereira³, Yuming Guo⁴, Jenny Fisher⁵

¹Yale University, New Haven, USA; ²Harvard University, Cambridge, USA; ³Curtin University, Perth, Australia; ⁴Monash University, Melbourne, Australia; ⁵University of Wollongong, Australia

Background and objectives: In recent years Australia has experienced unprecedented wildfires (often referred to as “bushfires” in Australia), resulting in severe air pollution across much of the continent. Prescribed burns, which are used for bushfire management, also produce extensive smoke. The importance of this challenge is growing as climate change is anticipated to make wildfires occur more frequently, burn hotter, and last longer. To date, studies on fire smoke and health are limited, but the growing literature indicates increased risk such as for hospital admissions and mortality. Our literature reviews on fire smoke found that birth outcomes and perinatal mortality are understudied, despite the importance of adverse pregnancy outcomes, which are linked to mortality and other health outcomes. Health impacts of fine particles (PM_2.5) from fire likely differ from those of PM_2.5 total mass, due to variation in chemical composition. In order to study fire-related PM_2.5 and health, advancements in exposure methodology are needed. The vast majority of studies assess exposure either with crude measures that compare wildfire periods or locations to those without wildfires or with air pollution measures that obscure differences by source. Atmospheric modeling of fire smoke can address these concerns but is limited by the existing fire emissions inventories, which can vary by an order of magnitude in many areas, including Australia. Further, some subpopulations may be at disproportionate risk from fire smoke. Aboriginal and Torres Strait Islander peoples generally have poorer health and lower life expectancy than non-Indigenous Australian populations. Evidence is needed on whether racial/ethnic minorities and those with low socioeconomic status have different exposure to and health responses from exposure to fire smoke. The study of birth outcomes in this context is critical as health disparities can begin early in life, and the Aboriginal and Torres Strait Islander populations have higher risk of adverse birth outcomes than non-indigenous persons.

Methods and approach: We are investigating risk of birth outcomes and perinatal mortality from fire-related PM_2.5. Our interdisciplinary team includes expertise in biostatistics, epidemiology, atmospheric science and fire modeling. We are developing fire modeling methods to estimate PM_2.5 specifically from fires for Australia with improved fire emissions inventories and Lagrangian modeling. We will estimate daily fire PM_2.5 (and non-fire PM_2.5 and PM_2.5 total mass) for 12 Australian cities for 2009-2010 at the community-level. Exposure estimates will be used to estimate risk of benchmark pregnancy outcomes (preterm birth, fetal growth restriction) and perinatal mortality. Results will provide evidence on health risks from fire PM_2.5, in comparison to PM_2.5 from other sources. We will assess disparities in exposure and in health response for potentially sensitive populations. Our results will aid more effective, targeted public health policy regarding the health impacts of fire smoke, including efforts to protect the most vulnerable.