Ambient dioxin exposure and incidence of lymphoid malignancies in large prospective US cohorts of female nurses

Jie Chen; Jaime E Hart; Trang VoPham; Elise G Elliott; Rena R Jones; Mary H Ward; Francine Laden; Brenda M Birmann

doi:10.1016/j.jhazmat.2025.139115

Ambient dioxin exposure and incidence of lymphoid malignancies in large prospective US cohorts of female nurses

J Hazard Mater. 2025 Jun 30:495:139115. doi: 10.1016/j.jhazmat.2025.139115. Online ahead of print.

Authors

Jie Chen¹, Jaime E Hart², Trang VoPham³, Elise G Elliott⁴, Rena R Jones⁵, Mary H Ward⁵, Francine Laden⁶, Brenda M Birmann⁷

Affiliations

¹ Department of Environmental Health, Harvard T. H. Chan School of Public Health, Boston, MA, USA; Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA. Electronic address: jiechen@hsph.harvard.edu.
² Department of Environmental Health, Harvard T. H. Chan School of Public Health, Boston, MA, USA; Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA.
³ Epidemiology Program, Division of Public Health Sciences, Fred Hutchinson Cancer Center, Seattle, WA, USA; Department of Epidemiology, University of Washington, Seattle, WA, USA.
⁴ Health Effects Institute, Boston, MA, USA.
⁵ Occupational and Environmental Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, Rockville, MD, USA.
⁶ Department of Environmental Health, Harvard T. H. Chan School of Public Health, Boston, MA, USA; Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA; Department of Epidemiology, Harvard T. H. Chan School of Public Health, Boston, MA, USA.
⁷ Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA.

PMID: 40609469
DOI: 10.1016/j.jhazmat.2025.139115

Abstract

Background: Limited evidence exists from prospective cohorts on residential dioxin exposure and incident non-Hodgkin lymphoma (NHL) and multiple myeloma (MM). We assessed the associations in two US nationwide cohorts - the Nurses' Health Study (NHS, 1986-2012) and NHSII (1989-2019).

Methods: We estimated residential proximity, duration of residence and emissions from industrial dioxin-emitting facilities within 3 km, 5 km, and 10 km radii. Outcomes included overall NHL, major NHL subtypes, and MM. Using time-varying Cox proportional hazards models, we estimated hazard ratios (HRs) with 95 % confidence intervals (CIs) and meta-analyzed cohort-specific results.

Results: We observed 984 NHL and 227 MM cases in NHS (1,921,802 person-years), and 396 NHL and 61 MM cases in NHSII (2,845,710 person-years). We did not observe consistent associations between dioxin exposure and overall NHL or MM incidence. Results were heterogeneous across major NHL subtypes. Increased follicular lymphoma incidence was suggestively associated with residential proximity to dioxin-emitting facilities (HR_{yes vs. no} and 95 % CI: 1.26, 0.95 -1.68) and duration of residence near these facilities (HR_{≤median vs. non-exposed} and 95 % CI: 1.44, 0.98 -2.12) and significantly with dioxin emission levels (HR_{≤median vs. non-exposed} and 95 % CI: 1.52, 1.07 -2.16) within 3 km. These positive associations remained suggestive for up to 10 km.

Conclusion: Dioxin exposure showed no consistent association with overall NHL or MM, but a positive association with follicular lymphoma was suggested.

Keywords: Dioxin; Environmental exposure; Multiple myeloma; Non-Hodgkin lymphoma.