Diesel exhaust and respiratory dust exposure in miners and chronic obstructive pulmonary disease (COPD) mortality in DEMS II

Andreas M. Neophytou; Jacqueline M. Ferguson; Sadie Costello; Sally Picciotto; John R. Balmes; Stella Koutros; Debra T. Silverman; Ellen A. Eisen

Environment International (Mar 2024)

Diesel exhaust and respiratory dust exposure in miners and chronic obstructive pulmonary disease (COPD) mortality in DEMS II

Andreas M. Neophytou,
Jacqueline M. Ferguson,
Sadie Costello,
Sally Picciotto,
John R. Balmes,
Stella Koutros,
Debra T. Silverman,
Ellen A. Eisen

Affiliations

Andreas M. Neophytou: Department of Environmental and Radiological Health Sciences, Colorado State University, Fort Collins, CO, USA; Corresponding author at: Department of Environmental and Radiological Health Sciences, Colorado State University, 1681 Campus Delivery, Fort Collins, CO 80523, USA.
Jacqueline M. Ferguson: Division of Primary Care and Population Health, Stanford University School of Medicine, Stanford, CA, USA; Division of Environmental Health Sciences, School of Public Health, University of California, Berkeley, CA, USA
Sadie Costello: Division of Environmental Health Sciences, School of Public Health, University of California, Berkeley, CA, USA
Sally Picciotto: Division of Environmental Health Sciences, School of Public Health, University of California, Berkeley, CA, USA
John R. Balmes: Division of Environmental Health Sciences, School of Public Health, University of California, Berkeley, CA, USA; Department of Medicine, University of California, San Francisco, CA, USA
Stella Koutros: Occupational and Environmental Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute (NCI), National Institutes of Health (NIH), Department of Health and Human Services (DHHS), Bethesda, MD, USA
Debra T. Silverman: Occupational and Environmental Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute (NCI), National Institutes of Health (NIH), Department of Health and Human Services (DHHS), Bethesda, MD, USA
Ellen A. Eisen: Division of Environmental Health Sciences, School of Public Health, University of California, Berkeley, CA, USA

Journal volume & issue: Vol. 185
p. 108528

Abstract

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Background: Diesel exhaust and respirable dust exposures in the mining industry have not been studied in depth with respect to non-malignant respiratory disease including chronic obstructive pulmonary disease (COPD), with most available evidence coming from other settings. Objectives: To assess the relationship between occupational diesel exhaust and respirable dust exposures and COPD mortality, while addressing issues of survivor bias in exposed miners. Methods: The study population consisted of 11,817 male workers from the Diesel Exhaust in Miners Study II, followed from 1947 to 2015, with 279 observed COPD deaths. We fit Cox proportional hazards models for the relationship between respirable elemental carbon (REC) and respirable dust (RD) exposure and COPD mortality. To address healthy worker survivor bias, we leveraged the parametric g-formula to assess effects of hypothetical interventions on both exposures. Results: Cox models yielded elevated estimates for the associations between average intensity of REC and RD and COPD mortality, with hazard ratios (HR) corresponding to an interquartile range width increase in exposure of 1.46 (95 % confidence interval (CI): 1.12, 1.91) and 1.20 (95 % CI: 0.96, 1.49), respectively for each exposure. HRs for cumulative exposures were negative for both REC and RD. Based on results from the parametric g-formula, the risk ratio (RR) for COPD mortality comparing risk under an intervention eliminating REC to the observed risk was 0.85 (95 % CI: 0.55, 1.06), equivalent to an attributable risk of 15 %. The corresponding RR comparing risk under an intervention eliminating RD to the observed risk was 0.93 (95 % CI: 0.56, 1.31). Conclusions: Our findings, based on data from a cohort of nonmetal miners, are suggestive of an increased risk of COPD mortality associated with REC and RD, as well as evidence of survivor bias in this population leading to negative associations between cumulative exposures and COPD mortality in traditional regression analysis.

Published in Environment International

ISSN: 0160-4120 (Print)
Publisher: Elsevier
Country of publisher: United Kingdom
LCC subjects: Geography. Anthropology. Recreation: Environmental sciences
Website: https://www.journals.elsevier.com/environment-international

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