Quantitative Assessment of Elemental Carbon In The Lungs of Never Smokers, Cigarette Smokers, and Coal Miners

Abstract

Inhalation exposure to particulates such as cigarette smoke and coal dust is known to contribute to the development of chronic lung disease. The purpose of this study was to estimate the amount of elemental carbon (EC) deposits from autopsied lung samples from cigarette smokers, miners, and control subjects and explore the relationship between EC level, exposure history, and the extent of chronic lung disease. The samples comprised three subgroups representing never smokers (8), chronic cigarette smokers (26), and coal miners (6). Following the dissolution of lung tissue, the extracted EC residue was quantified using a thermal-optical transmission (TOT) carbon analyzer. Mean EC levels in the lungs of the control group were 56.68 ± 24.86 (SD) μg/g dry lung weight. Respective mean EC values in lung samples from the smokers and coal miners were 449.56 ± 320.3 μg/g and 6678.2 ± 6162 μg/g. These values were significantly higher than those obtained from the never-smoker group. EC levels in the lung and pack-years of cigarette smoking correlated significantly, as did EC levels and the severity of small airway disease. This study provides one of the first quantitative assessments of EC in human lungs from populations at high relative risk for the development of chronic lung disease.

Acknowledgments

We remember our dear friend and colleague Dr. V. Vallyathan, who passed away in an automobile accident during the preparation of this article. R. K. Saxena was supported through a senior fellowship of the U.S. National Research Council. F. H. Y. Green was supported through a grant from the Alberta Lung Association, Health Canada, and a contract with the U.S. National Institute of Occupational Safety and Health. This article has been reviewed by the National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency, and approved for publication. Approval does not signify that the contents necessarily reflect the views and policies of the agency, nor does the mention of trade names or commercial products constitute endorsement or recommendation for use.