Evaluation of isocyanate exposure among car painters and its association with occupational asthma symptoms: A case-control study in Kermanshah, Iran

Rahmanizadeh, Reza; Barzegar, Akbar; Ahmadi Jouybari, Touraj; Shaahmadi, Zahra

doi:10.22034/emt.2026.607358.1011

Evaluation of isocyanate exposure among car painters and its association with occupational asthma symptoms: A case-control study in Kermanshah, Iran

Document Type : Original Article

Authors

Reza Rahmanizadeh ¹

Akbar Barzegar ¹

Touraj Ahmadi Jouybari ²

Zahra Shaahmadi ²

¹ Department of Occupational Health Engineering, School of Health, Kermanshah University of Medical Sciences, Kermanshah, Iran

² Clinical Research Development Center, Imam Khomeini and Mohammad Kermanshahi and Farabi Hospitals, Kermanshah University of Medical Sciences, Kermanshah, Iran

10.22034/emt.2026.607358.1011

Abstract

Background and Objectives: Industrial workers are increasingly exposed to complex chemical agents, leading to a rise in acute and chronic occupational diseases worldwide. Isocyanates, widely used in paints and coatings, are one example of such chemicals. Therefore, this study aimed to assess isocyanate exposure and its association with occupational asthma symptoms among car painters in Kermanshah, western Iran.
Methods: Air samples were collected from painting workshops during painting operations according to the NIOSH 5522 method to assess workplace isocyanate exposure. The presence of isocyanate compounds in workplace air was subsequently assessed by gas chromatography–mass spectrometry (GC-MS). Because quantitative airborne concentrations were not measured, the study evaluated the presence of isocyanate compounds rather than dose-specific exposure.
Results: Three isocyanate compounds were identified in workplace air. Serum IgE levels were significantly higher in the case group than in the control group (p < 0.05), and respiratory symptoms compatible with occupational asthma were more frequently reported among car painters.
Conclusion: Occupational exposure to isocyanates was associated with higher serum IgE levels and a greater prevalence of respiratory symptoms in this study. However, because quantitative exposure measurements and objective pulmonary function testing were not performed, the findings should not be interpreted as evidence of a causal relationship or as confirmation of occupational asthma.

Highlights