‘Breathing Fire’: Impact of Prolonged Bushfire Smoke Exposure in People with Severe Asthma

Abstract

Wildfires are increasing and cause health effects. The immediate and ongoing health impacts of prolonged wildfire smoke exposure in severe asthma are unknown. This longitudinal study examined the experiences and health impacts of prolonged wildfire (bushfire) smoke exposure in adults with severe asthma during the 2019/2020 Australian bushfire period. Participants from Eastern/Southern Australia who had previously enrolled in an asthma registry completed a questionnaire survey regarding symptoms, asthma attacks, quality of life and smoke exposure mitigation during the bushfires and in the months following exposure. Daily individualized exposure to bushfire particulate matter (PM2.5) was estimated by geolocation and validated modelling. Respondents (n = 240) had a median age of 63 years, 60% were female and 92% had severe asthma. They experienced prolonged intense PM2.5 exposure (mean PM2.5 32.5 μg/m3 on 55 bushfire days). Most (83%) of the participants experienced symptoms during the bushfire period, including: breathlessness (57%); wheeze/whistling chest (53%); and cough (50%). A total of 44% required oral corticosteroid treatment for an asthma attack and 65% reported reduced capacity to participate in usual activities. About half of the participants received information/advice regarding asthma management (45%) and smoke exposure minimization strategies (52%). Most of the participants stayed indoors (88%) and kept the windows/doors shut when inside (93%), but this did not clearly mitigate the symptoms. Following the bushfire period, 65% of the participants reported persistent asthma symptoms. Monoclonal antibody use for asthma was associated with a reduced risk of persistent symptoms. Intense and prolonged PM2.5 exposure during the 2019/2020 bushfires was associated with acute and persistent symptoms among people with severe asthma. There are opportunities to improve the exposure mitigation strategies and communicate these to people with severe asthma.

The impact of prolonged landscape fire smoke exposure on women with asthma in Australia

“…During the fire period, participants were exposed to a median daily average PM 2.5 of 16.6 μg/m 3 and median peak PM 2.5 of 104.6 μg/m 3 , exceeding the World Health Organization (WHO) 24-hour air quality guideline (15 μg/m 3 ) [46]. Although there is mounting evidence supporting an association between landscape fire smoke related PM 2.5 and respiratory symptoms in the general population, and in adults and children with asthma [10,12,13,47], the impact of prolonged landscape fire smoke exposure on women with asthma has been reported only in one study [11], and none reporting on pregnant or breastfeeding women with asthma. Our findings demonstrate a significant impact of prolonged exposure to landscape fire smoke on the physical and mental health of women with asthma, including pregnant and breastfeeding women, with most participants reporting at least one physical symptom.…”

“…Following review of relevant literature and investigator/stakeholder input, a study-specific close ended item survey was designed to capture health outcome(s) experienced, and health seeking behaviour(s), during the landscape fire period [11,13,[28][29][30][31]. A template of the tool was prepared using REDCap (Research Electronic Data Capture) to capture survey responses [32].…”

“…Three-hundred-and-fifteen (82%) participants reported symptoms during the fire period. The most prevalent Maximum consecutive fire days 11 (11,11) symptoms were cough (57%), eye irritation/watery eyes (56%), throat irritation/dry throat (53%), and wheeze or whistling chest (50%). Two in five (41%) participants reported symptoms after the fire period (i.e.…”

“…An association between landscape fire smoke and respiratory morbidity has been reported in multiple studies [3,[8][9][10]. A study of the impact of prolonged landscape fire smoke exposure in people with severe asthma indicated that 83% of people with severe asthma reported symptoms during the fire period and 65% reported persistent asthma symptoms months after exposure had ceased [11]. Furthermore, studies in Australia found that people with asthma were more likely to report respiratory symptoms and healthcare utilisation, including the use of corticosteroid medications, hospital admission and emergency presentations during the fire period compared to people without asthma [12,13].…”

The impact of the 2019/2020 Australian landscape fires on infant feeding and contaminants in breast milk in women with asthma

“…The survey, results of which are reported elsewhere [ 34 ], collected information on general and asthma-specific symptoms, risk mitigation strategies and sources of information utilised during the fire period by mothers with asthma; the data relating to infant/toddler feeding is presented herein. A template of the tool was developed using REDCap (Research Electronic Data Capture) to capture the survey responses [ 35 , 36 ]. The survey commenced on the 19 th of May 2020 and closed on the 2 nd of December 2020.…”