The association between ambient fine particulate matter and incident adenocarcinoma subtype of lung cancer

Lida Gharibvand,Raymond Knutsen,Samuel Soret,Synnove F Knutsen,Mark Ghamsary,W Lawrence Beeson,David Shavlik

doi:10.1186/s12940-017-0268-7

Abstract

BackgroundAdenocarcinoma (AC) is the most common lung cancer among non-smokers, but few studies have assessed the effect of PM2.5 on AC among never smokers. The purpose of this study was to assess the association between ambient PM2.5 and incident lung AC in the Adventist Health and Smog Study-2 (AHSMOG-2), a cohort of 80,044 non-smokers (81% never smokers) followed for 7.5 years (597,177 person-years) (2002–2011).MethodsIncident lung AC was identified through linkage with U.S. state cancer registries. Ambient PM2.5 levels at subjects’ residences were estimated for the years 2000 and 2001, immediately prior to study start.ResultsA total of 164 incident lung AC occurred during follow-up. Each 10 μg/m3 increment in PM2.5 was associated with an increase in the hazard rate of lung AC [HR = 1.31 (95% confidence interval (CI) 0.87–1.97)] in the single-pollutant model. Excluding those with prevalent non-melanoma skin cancer (NMSC) strengthened the association with lung AC (HR = 1.62 (95% CI, 1.11–2.36) for each 10 μg/m3 PM2.5 increment. Also, limiting the analyses to subjects who spent more than 1 h/day outdoors, increased the estimate (HR = 1.55, 95% CI: 1.05, 2.30).ConclusionsIncreased risk of AC was observed for each 10 μg/m3 increment in ambient PM2.5 concentrations. The risk was higher among those without prevalent NMSC and those who spent more than 1 h/day outdoors.

Highlights

Adenocarcinoma (AC) is the most common lung cancer among non-smokers, but few studies have assessed the effect of PM2.5 on AC among never smokers
Subjects were excluded from the current analysis if they were not linked with state cancer registries (Canadians and subjects living in Maine where we were not able to obtain permission to link with the state cancer registry) (n = 5550); had incomplete address information making it impossible to estimate residence specific air pollution concentrations (n = 677); reported prevalent cancers except non-melanoma skin cancer (n = 7412); were current smokers (n = 249) or had missing values on important covariates (n = 2537)
Our finding of a 31% increase in incident lung AC associated with each 10 μg/m3 increment in ambient PM2.5 concentration is in line with findings of the Nurses’ Health Study (NHS) (33% increase) [12] and stronger than that reported by the Netherlands Study (25% increase) [19]

Summary

Introduction

Adenocarcinoma (AC) is the most common lung cancer among non-smokers, but few studies have assessed the effect of PM2.5 on AC among never smokers. In 2013, the International Agency for Research on Cancer (IARC) concluded that exposure to outdoor air pollution causes lung cancer and classified outdoor air pollution in general and particulate matter (PM) in Gharibvand et al Environmental Health (2017) 16:71 particular, as a Group 1 carcinogen to humans [20]. This conclusion was based on findings from several studies, especially the recent results from the European Study of Cohorts for Air Pollution Effects (ESCAPE) [13] as well as a meta-analyses study [21]

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