Inflammation Progresses to Normal Tissue in Patients with Anthracosis after Discontinuation of Exposure to Fossil Fuel

Mohammad Samet1, *, Fariba Binesh2, Sanaz Zand3, Mohammad Rezaeisadrabadi4, Ryan Nazemian5
1 Department of Internal Medicine, Shahid Sadoughi Hospital, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
2 Department of Pathology, Shahid Sadoughi Hospital, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
3 School of Medicine, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
4 Department of Internal Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
5 Institute for Transformative Molecular Medicine, Case Western Reserve University, 10900 Euclid Ave, Cleveland, OH 44106, United States

Article Metrics

CrossRef Citations:
Total Statistics:

Full-Text HTML Views: 470
Abstract HTML Views: 250
PDF Downloads: 140
ePub Downloads: 83
Total Views/Downloads: 943
Unique Statistics:

Full-Text HTML Views: 273
Abstract HTML Views: 156
PDF Downloads: 96
ePub Downloads: 50
Total Views/Downloads: 575

Creative Commons License
© 2022 Samet et al.

open-access license: This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International Public License (CC-BY 4.0), a copy of which is available at: This license permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

* Address correspondence to this author at the Department of Internal Medicine, Division of Pulmonology, Shahid Sadoughi Hospital, Yazd, Iran;
Tel: +98(35)3822 4200-9, Fax: +98(35)3822 4100, E-mails:;



Exposure to toxic materials predisposes the lungs to infectious agents and inflammatory responses. The present study was performed on patients with anthracosis caused by exposure to fossil fuels in previous years, and histopathological features of airways’ normal-appearing tissue were compared with histopathological features of anthracotic plaques in these patients.


Bronchoscopic evaluations were performed on bakery workers who were directly in contact with fossil fuels. Samples were taken from anthracotic plaques (Group A) or seemingly intact tissues at their periphery (Group B). Pathological evaluations were done after hematoxylin and eosin staining. Then, microbiological cultures were performed for the diagnosis of Mycobacterium tuberculosis. Data obtained from bronchoscopy, pathology, and cultures were compared between anthracotic and normal-appearing peripheral tissues using chi-square and analysis of variances (ANOVA) at a 95% confidence level.


Sixty-eight patients were diagnosed with anthracotic plaques. The mean ± SD of the patients’ age was 72.12 ± 13.74 years. Females comprised 58.8% of the sample, and 85.3% of the patients were Iranian. The frequency rates of disseminated plaques and obstructive types were 86.8% and 48.5%, respectively. Ten patients (14.70%) were diagnosed with tuberculosis, and 4.41% (3 of 68) had granuloma, which was detectable only in samples gathered from Group A. Fibrosis was more common in Group A (10.3%, p = 0.03), and most of the evaluated samples in both groups exhibited inflammatory features.


Inflammatory changes and tissue damage can be seen in anthracotic plaques and the surrounding normal-appearing tissue, even after removing the triggering factors. So, it is suggested to take a biopsy from seemingly intact tissue at the periphery of the anthracotic plaque when a biopsy is needed in a patient with anthracosis to reduce the risk of bleeding. Besides, medical treatment should be done to control inflammation.

Keywords: Anthracosis, Bronchoscopy, Fossil fuel, Inflammation, Tuberculosis, Fibrosis.