2026-03-11 カリフォルニア大学サンディエゴ校(UCSD)
＜関連情報＞
- https://today.ucsd.edu/story/california-communities-recovery-time-between-wildfire-smoke-events-is-shrinking
- https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2025GH001389
煙波間の回復期間の短縮：カリフォルニア州における時空間分析（2006～2020年） Shorter Recovery Periods Between Smoke Waves: A Spatio-Temporal Analysis in California (2006–2020)
Caitlin G. Jones-Ngo, Chen Chen, Rosana Aguilera, Miriam E. Marlier, Tarik Benmarhnia
GeoHealth Published: 11 March 2026
DOI:https://doi.org/10.1029/2025GH001389
Abstract
The increasing frequency of wildfires in California, fueled by climate change through hotter, drier conditions, poses uncertain public health risks due to repeated wildfire smoke exposure. This study explores the “recovery period,” the time between smoke waves, which may offer respite from smoke impacts, including health risks and adaptation demands. We examine trends in wildfire smoke wave frequency, duration, and recovery periods in California from 2006 to 2020, aiming to assess repeated exposures and develop a framework to evaluate associated health risks via recovery periods. We define a smoke wave as two or more consecutive days with wildfire-specific fine particulate matter (PM2.5) > 1 μg/m3, at the census tract level. Recovery periods are calculated as the days between smoke waves, ending with the first wave of 2021. We also examine community characteristics such as income, race, and education. From 2006 to 2010 to 2016–2020, we observed a 60% reduction in recovery periods, an 85% increase in smoke events, and longer durations. Spatial variability was substantial across census tracts, with the greatest reductions in recovery periods in Southern and Central Valley regions. Northern California, with the shortest recovery periods, showed minimal changes. Communities with higher proportions of minority race groups, single female householders, and lower incomes experienced the largest reductions in recovery period length. This study introduces a framework to assess the repeated impacts of smoke waves, highlighting changing spatio-temporal patterns. Incorporating recovery periods into health risk assessments can guide public health strategies to address compounding risks from wildfire smoke.
Plain Language Summary
Wildfires in California are becoming more frequent due to climate change, but the risks of repeated exposure to smoke are not well understood. This study examines the “recovery period,” the time between smoke waves when air quality improves. We aimed to understand how often smoke waves occur, how long they last, and how much time people have to recover. Using data from 2006 to 2020, we explored how smoke wave patterns differ across communities, considering factors like race, ethnicity, and socioeconomic conditions. Our findings show that recovery periods have shortened by 60% and the number of smoke events has increased by 85%. Areas in Southern and Central California saw the largest reductions in recovery periods, while Northern California, which already had the shortest recovery times, saw minimal changes. We also found that communities with higher proportions of racial minorities, lower household incomes, and more single female-headed households experienced the greatest reductions in recovery periods. This study introduces a new approach to understanding the repeated health effects of wildfire smoke and provides insights that can inform public health strategies to address the growing risks from increasingly frequent wildfires.
