2026-10-10T19:07:53Z https://api.figshare.com/v2/oai

oai:figshare.com:article/34033383 2026-09-30T15:14:01Z category_7 category_15 category_21 category_24 category_272 category_734 category_64 category_106 category_122 portal_63 item_type_6 month_year_09_2026

Carbonaceous Components Underlying Wildfire Smoke PM_2.5-Associated Mortality in Older U.S. Adults Zhihao Jin (10110168) Ke Xu (134879) Hua Hao (3539054) Meng Qi (142397) Gonzalo A. Ferrada (21532929) Joshua S. Fu (2152939) Noah Scovronick (6938234) Howard H. Chang (605905) Alvaro Alonso (211735) Kyle Steenland (158852) Yang Liu (4829) Medicine Neuroscience Biotechnology Evolutionary Biology Environmental Sciences not elsewhere classified Biological Sciences not elsewhere classified Cancer Science Policy Mental Health substantial spatial heterogeneity stronger among black 2002 – 2019 major carbonaceous components 752 medicare beneficiaries carbonaceous fraction accounting 3 </ sup per 1 μg 076 – 1 027 – 1 5 </ sub smoke carbonaceous components term mortality effects carbonaceous fraction carbonaceous matter term exposure eligible beneficiaries resolved evidence resolution estimates remains scarce range scale racial groups linked annual impact assessment hazard ratios geographic regions Wildland fire activity has increased in the U.S., elevating population exposure to smoke-derived fine particulate matter (PM_2.5). Emerging studies suggest higher toxicity per unit mass for PM_2.5 from wildfire smoke. However, source-resolved evidence on long-term mortality effects of major carbonaceous components in smoke PM_2.5 remains scarce. We linked annual, high-resolution estimates of smoke and non-smoke PM_2.5 mass and carbonaceous matter to 77,470,752 Medicare beneficiaries during 2002–2019 and fit stratified Cox models. Long-term exposure to smoke PM_2.5 mass and its carbonaceous fraction were associated with higher all-cause mortality risk per unit mass than their non-smoke counterparts. Per 1 μg/m³ increase, hazard ratios were 1.032 (95% CI: 1.027–1.037) for smoke PM_2.5 mass and 1.087 (1.076–1.098) for smoke carbonaceous components. On the interquartile-range scale, the association was larger for non-smoke PM_2.5 than for smoke PM_2.5, whereas smoke carbon remained more strongly associated with mortality. Associations were stronger among Black and other racial groups and Medicaid-eligible beneficiaries. Substantial spatial heterogeneity was observed across empirical smoke regimes and geographic regions. The associations correspond to 22,420 annual deaths attributable to smoke PM_2.5, with the carbonaceous fraction accounting for most of this burden. These findings support strengthening wildfire smoke health-impact assessment and mitigation as climate change increases population exposure to wildfire smoke. 2026-09-30T00:00:00Z Text Journal contribution 10.1021/acs.est.6c07219.s001 https://figshare.com/articles/journal_contribution/Carbonaceous_Components_Underlying_Wildfire_Smoke_PM_sub_2_5_sub_-Associated_Mortality_in_Older_U_S_Adults/34033383 CC BY-NC 4.0