Mortality risk attributable to wildfire-related PM2·5 pollution: a global time series study in 749 locations

Abstract

Background Many regions of the world are now facing more frequent and unprecedentedly large wildfires. However, the association between wildfire-related PM 2•5 and mortality has not been well characterised. We aimed to comprehensively assess the association between short-term exposure to wildfire-related PM 2•5 and mortality across various regions of the world.Methods For this time series study, data on daily counts of deaths for all causes, cardiovascular causes, and respiratory causes were collected from 749 cities in 43 countries and regions during 2000-16. Daily concentrations of wildfirerelated PM 2•5 were estimated using the three-dimensional chemical transport model GEOS-Chem at a 0•25° × 0•25° resolution. The association between wildfire-related PM 2•5 exposure and mortality was examined using a quasi-Poisson time series model in each city considering both the current-day and lag effects, and the effect estimates were then pooled using a random-effects meta-analysis. Based on these pooled effect estimates, the population attributable fraction and relative risk (RR) of annual mortality due to acute wildfire-related PM 2•5 exposure was calculated.Findings 65•6 million all-cause deaths, 15•1 million cardiovascular deaths, and 6•8 million respiratory deaths were included in our analyses. The pooled RRs of mortality associated with each 10 µg/m³ increase in the 3-day moving average (lag 0-2 days) of wildfire-related PM 2•5 exposure were 1•019 (95% CI 1•016-1•022) for all-cause mortality, 1•017 (1•012-1•021) for cardiovascular mortality, and 1•019 (1•013-1•025) for respiratory mortality. Overall, 0•62% (95% CI 0•48-0•75) of all-cause deaths, 0•55% (0•43-0•67) of cardiovascular deaths, and 0•64% (0•50-0•78) of respiratory deaths were annually attributable to the acute impacts of wildfire-related PM 2•5 exposure during the study period.Interpretation Short-term exposure to wildfire-related PM 2•5 was associated with increased risk of mortality. Urgent action is needed to reduce health risks from the increasing wildfires.

Climate Change Related Depression, Anxiety and Stress Symptoms Perceived by Medical Students

“…As assessed by international collaborations such as the Lancet Countdown on health and climate change [ 2 ], climate change has drastic consequences on human physical and mental health. Impairment of physical health associated with rising mean temperature is, for instance, reflected in heat-related deaths [ 3 ], adverse somatic effects of increased exposure to wildfires [ 4 ] and droughts [ 5 ], the spread of vector-borne diseases [ 6 ], and the growing number of humans affected by food insecurity and undernutrition [ 7 ]. Known effects on mental health are the psychological suffering arising from natural disasters associated with climate change [ 8 ] and the direct effects of rising temperature on mental well-being.…”

A scoping review on the health effects of smoke haze from vegetation and peatland fires in Southeast Asia: Issues with study approaches and interpretation

“…Eight HBE studies [ 40 , 41 , 47 , 87 – 89 , 104 , 105 ] and 15 HRA studies [ 29 , 48 , 59 , 60 , 68 , 71 – 74 , 91 – 96 ] examined the health effects of long-term exposure. Ten EPI studies [ 32 , 52 , 56 , 58 , 63 , 66 , 67 , 82 , 101 , 102 ], 11 HBE studies [ 19 , 40 , 41 , 47 , 86 – 89 , 104 – 106 ], and two EPI- and HBE-combined studies [ 107 , 108 ] assessed mortality as a health endpoint; 35 EPI studies assessed morbidity [ 32 , 44 – 46 , 49 – 51 , 53 – 57 , 61 , 62 , 64 – 66 , 69 , 70 , 75 – 81 , 83 – 85 ,…”

Somatic symptoms, psychological distress and trauma after disasters: lessons from the 2014 Hazelwood mine fire and 2019-20 Black Summer bushfires

“…Bushfires, particularly those of extended scale and duration, cause significant physical and mental illhealth (2). Globally, between 2000 and 2016, over 33,000 deaths were attributable to bushfire smoke exposure (3). The psychological sequelae of bushfire exposure may persist, increasing the risk of mental disorders for years after the event (4).…”