Study on genotoxicity, oxidative stress biomarkers and clinical symptoms in workers of an asbestos-cement factory

Our plain-English summary of Study on genotoxicity, oxidative stress biomarkers and clinical symptoms in workers of an asbestos-cement factory, by A. Afaghi, S. Oryan, K. Rahzani, et al (EXCLI Journal, 2015).

The study

• Authors: A. Afaghi, S. Oryan, K. Rahzani, M. Abdollahi
• Journal: EXCLI Journal
• Published: 2015;14:1067-77
• Cited by: 5 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

The purpose of the present study was to investigate whether the markers of oxidative stress could be altered in workers exposed to asbestos. A comparative cross-sectional research was conducted in a group of 50 subjects exposed to asbestos and another group of 50 with the same age and sex unexposed to asbestos. Malondialdehyde (MDA), total thiol molecule (TTM), total antioxidant capacity (TAC), and DNA damage, were measured in the blood samples of workers and controls. Compared to the control group, the workers showed higher blood levels of DNA damage (P=0.0001) and MDA (P=0.0001). The workers showed lower TTM (P=0.02) as compared with the control group. There was no considerable difference on the level of TAC (P=0.1) between the groups. The workers indicated clinical symptoms such as breathlessness, phlegm, coughing and wheezing. There was a positive correlation between levels of 8-OHdG and MDA of asbestos workers and the smoking status suggesting the negative role of smoking.

In plain English

This cross-sectional study compared 50 male workers at an asbestos-cement factory, each with at least 5 years of asbestos exposure, with 50 men of similar age, sex and education who had no work history of asbestos exposure. The authors measured blood markers of oxidative stress (chemical damage to the body's cells) and of DNA damage, and recorded breathing symptoms. On average, workers had higher levels of 8-OH-dG, a marker of DNA damage (26.54 versus 20.17 ng/ml), and of malondialdehyde (MDA), a marker of damage to fats (54 versus 31.83 mM). Workers had lower total thiol molecules (0.033 versus 0.037 mM). Total antioxidant capacity did not differ significantly (p=0.1). Cough, phlegm, wheezing and breathlessness were more common in workers. For example, 19 of 50 workers (38%) had cough, compared with 5 of 50 controls (10%). Among workers only, 8-OH-dG and MDA levels rose with the number of cigarettes smoked per day. The article does not say which asbestos fiber types were used at this factory, and it does not report airborne asbestos measurements there. The authors concluded that these marker changes could be used to predict asbestos-related diseases.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Comparative cross-sectional study comparing exposed workers with unexposed controls
• Who was studied: 50 male asbestos-cement factory workers (mean age 36.34 years) and 50 male controls (mean age 36.10 years) matched for age, sex and education, with no occupational asbestos exposure. Smokers: 21 of 50 workers and 28 of 50 controls (difference not significant, P=0.16). The factory location and study dates are not stated.
• Exposure: Work at an asbestos-cement factory for a minimum of 5 years. The article does not report the fiber types used or the airborne asbestos levels at this factory. Its background mentions chrysotile in asbestos-cement products in general, citing another study.
• Main results:
  • Plasma 8-OH-dG (DNA damage marker) was significantly higher in workers than in controls: 26.54 ± 4.99 versus 20.17 ± 2.06 ng/ml (p=0.0001).
  • Malondialdehyde (MDA) was significantly higher in workers than in controls: 54 ± 8.31 versus 31.83 ± 7.39 mM (p=0.0001).
  • Total thiol molecule was significantly lower in workers than in controls: 0.033 ± 0.009 versus 0.037 ± 0.007 mM (p=0.02).
  • Total antioxidant capacity did not differ significantly between workers (19 ± 3.32 mM) and controls (17.83 ± 3.12 mM) (p=0.1).
  • Symptoms were more frequent in workers than in controls (Table 3): cough 19 (38%) versus 5 (10%), p=0.001; phlegm 18 (36%) versus 8 (16%), p=0.02; wheezing 10 (20%) versus 3 (6%), p=0.03; breathlessness 9 (18%) versus 2 (4%), p=0.02.
  • 8-OH-dG and MDA levels were significantly higher (p=0.0001) in both smokers and non-smokers among workers than in the matching subgroups of controls.
  • In workers, 8-OH-dG was positively correlated with cigarettes per day (r=0.596, p=0.0001), and so was MDA (r=0.403, p=0.005). In controls, neither marker was correlated with cigarettes per day (r=0.252, p=0.07 and r=0.006, p=0.96).
• The authors' conclusion: The authors concluded that workers had higher 8-OH-dG and MDA, lower total thiol molecule, and similar total antioxidant capacity compared with controls. They concluded that these changes in oxidative stress markers can be used as predictive markers for asbestos-related diseases such as asbestosis, lung cancer, mesothelioma and pleural plaques.

Topics

Medical terms in this study, explained in our Lexicon: Genotoxicity, Oxidative Stress, Biomarker, Asbestos-Cement, 8-OHdG.

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