ASPO Abstracts
Residential proximity to dioxin-emitting facilities and risk of non-Hodgkin lymphoma in the NIH-AARP Diet and Health Study
Category: Culture and Cancer
Conference Year: 2021
Abstract Body:
Purpose: Few studies have investigated the relationship between risk of non-Hodgkin lymphoma
(NHL) and residential proximity to polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F)
emitted from industrial combustion and manufacturing sources.
Methods: We evaluated this relationship among participants of the NIH-AARP Diet and Health
Study, a prospective cohort (N=548,845) in 6 states and 2 cities in the U.S. We linked geocoded
enrollment addresses (1995-1996) with a U.S. Environmental Protection Agency database of
4,478 historical PCDD/F sources, which contained toxic equivalency quotient (TEQ) emissions
estimates from 1995. Exposure metrics indicated presence/absence of any facility within 3 and
5km of participant homes, overall and by type of facility (e.g., coal-fired power plants, waste
incinerators), which vary in emissions levels and constituency. We also calculated exposure as a
distance- and toxicity-weighted average emissions index (AEI [g TEQ]). We used Cox regression
to estimate associations (hazard ratios; HR and 95% confidence intervals; CI) with NHL and major
subtypes, adjusting for and by strata of sociodemographic and lifestyle characteristics.
Results: With 6,747 incident cases through 2011, we found no association between living near any
or specific types of PCDD/F-emitting facilities and NHL risk. However, participants with an AEI
>95th percentile within 5km had increased risk of NHL compared to unexposed
(HR=1.28;CI=1.05-1.55;p-trend=0.01). Specifically, we observed increased risk for
lymphoplasmacytic lymphoma (HR=2.98,CI=1.16-7.63;p-trend=0.03) and diffuse large B-cell
lymphoma (HR=1.65,CI=1.11-2.46;p-trend=0.01). Non-Hispanic blacks were nearly three times as
likely as whites to live <5km of a facility, although we had limited power to evaluate heterogeneity
in associations by race/ethnicity. Associations did not vary by age, smoking status, body mass
index, or urbanicity of residence.
Conclusions: Using an exposure metric accounting for distance and the toxicity of emissions, we
found significant positive associations between residential exposure to high PCDD/F emissions
and risk of NHL and two subtypes. Our results underscore the hazard for populations living near
sources of these persistent organic pollutants.
Keywords: dioxin, Non-Hodgkin lymphoma, residential proximity, GIS