Welding Fume Exposure Linked to Distinct CT Lung Changes, Functional Decline: Study
Turkey: A new study published in the Canadian Respiratory Journal has identified distinct quantitative computed tomography (QCT) lung patterns linked to welding fume exposure that differ from the effects caused by cigarette smoking. Researchers also found that long-term exposure to welding fumes was associated with progressive decline in lung function, findings that may help improve the diagnosis of welder’s pneumoconiosis, a condition that is frequently underrecognized.
The study was conducted by Merve Demirci Atik and colleagues from Dokuz Eylul University. The researchers noted that diagnosing welder’s pneumoconiosis is challenging because smoking-related lung changes often resemble those caused by welding fumes, making accurate diagnosis difficult. They emphasized that timely identification is important to prevent continued exposure and support workers’ compensation claims.
To differentiate welding-related lung injury from smoking-related changes, the team evaluated quantitative CT (QCT) histogram patterns while accounting for cigarette exposure and also assessed pulmonary function test findings.
The study included 136 men, including 66 welders and 70 controls, all of whom underwent non-contrast chest CT scans. The average age was 40 years among welders and 42 years among controls. More than half of the welders were current smokers, and the average welding career duration was 21 years.
Researchers estimated welding fume exposure using a semiquantitative exposure index and recorded smoking pack-years. Two blinded radiologists analyzed CT histogram measurements using imaging software and manual review, assessing lung attenuation distribution through skewness and kurtosis measurements. Participants were divided into four groups: unexposed, welding fumes only, cigarette smoke only, and combined exposure.
The study led to the following findings:
- The study identified distinct differences between lung changes caused by welding fumes and those associated with cigarette smoking.
- Welding fume exposure and cigarette smoking altered CT histogram patterns in opposite directions.
- After adjusting for smoking pack-years, welding fume exposure significantly reduced the proportion of low-density lung voxels in the −949 to −850 Hounsfield Units range.
- Welding fume exposure was also associated with an increase in lung voxels above −750 HU, a pattern linked to ground-glass opacities and parenchymal infiltration rather than smoking-related air trapping.
- Significant reductions were observed in forced expiratory flow between 25% and 75% of lung capacity (FEF 25–75), suggesting possible small airway disease.
- The reduction in FEF 25–75 may represent an early functional indicator of welding fume–related lung injury.
- Each increase in welding fume exposure index was associated with a decline in predicted FEV1%.
The authors concluded that both cigarette smoking and welding fume exposure contribute to chronic lung inflammation and impaired lung function, but QCT analysis may help differentiate between the two. They noted that improved recognition of welder’s pneumoconiosis could help prevent disease progression and reduce underdiagnosis, particularly among welders who smoke.
Reference:
Atik, M. D., Taylan, A., Çifci, A., Emecen, A. N., Gezer, N. S., Ergör, A., & Uçan, E. S. (2025). Quantitative CT Patterns and Functional Loss Related to Welding Fume Exposure, While Handling the Confounding Effect of Cigarette Smoking. Canadian Respiratory Journal, 2026(1), 2406824. https://doi.org/10.1155/carj/2406824
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