Wildfire Smoke Exposure and Cancer- and Aging-Related Outcomes in the PLCO Cohort

Principal Investigator

Name
Shuguang Leng

Degrees
MBBS PhD

Institution
University of New Mexico HSC

Position Title
Associate Professor

Email
sleng@salud.unm.edu

About this CDAS Project

Study
PLCO (Learn more about this study)

Project ID
PLCO-2041

Initial CDAS Request Approval
Apr 28, 2026

Title
Wildfire Smoke Exposure and Cancer- and Aging-Related Outcomes in the PLCO Cohort

Summary
Wildfires have increased dramatically in frequency, duration, and intensity across the western United States and globally. Recent evidence indicates that wildfire smoke has stalled or reversed decades of progress in reducing ambient fine particulate matter (PM2.5) across much of the contiguous United States (CONUS). Since 2016, wildfire smoke has contributed approximately 1 µg/m³ to annual PM2.5 concentrations in the most affected regions. Wildfire emissions contain a complex mixture of fine particles, toxicants, and carcinogens that can adversely affect populations both near and far from fire sources.
Despite strong biological plausibility linking wildfire smoke exposure to carcinogenesis and disease progression, its impact on cancer incidence, survival, and mortality remains poorly understood. This knowledge gap is particularly important given the growing population of cancer survivors who may experience repeated wildfire smoke exposure over time.
We propose to leverage data from the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial to evaluate the effects of long-term wildfire smoke exposure on cancer incidence, cancer mortality, and survival. In addition, we will assess associations with non-cancer outcomes to capture broader aging-related impacts. We will investigate effect modification by individual-level factors (e.g., sex, smoking status, education, menopausal status), lifestyle factors (e.g., diet), environmental conditions (e.g., temperature, UV radiation, precipitation), and neighborhood-level socioeconomic context. Analyses will include all cancer sites.
This study will generate critical epidemiologic evidence on the long-term health impacts of wildfire smoke and inform public health strategies in an era of increasing wildfire activity.

Aims

Aim 1:
Evaluate the associations between wildfire smoke exposure and cancer-related outcomes, including overall and site-specific cancer incidence, mortality, and survival, and identify effect modifiers at both individual and neighborhood levels.
Aim 2:
Evaluate the associations between wildfire smoke exposure and aging-related outcomes and identify effect modifiers at both individual and neighborhood levels.
Aim 3:
Compare the relative potency of wildfire-derived PM2.5 versus PM2.5 from other sources (e.g., ambient PM2.5 from residential wood burning) in relation to overall and site-specific cancer- and aging-related outcomes.
Aim 4:
Evaluate differences in the chemical composition of wildfire-derived PM2.5 (e.g., organic carbon vs. elemental carbon) and assess their relative potency in relation to overall and site-specific cancer- and aging-related outcomes.

Collaborators

SHUGUANG LENG University of New Mexico