Styrene associated respiratory outcomes among reinforced plastic industry workers

Abstract

The study aim was to determine whether styrene exposure was associated with respiratory outcomes in a dose-response manner in the fibreglass reinforcement industry. Workers (n=254) from a fibreglass reinforcement factory were subjected to a standardised interview, spirometry and styrene monitoring. Cumulative exposure was calculated across different jobs and levels of exposure. Logistic regression modelling estimated risk for symptoms, respiratory diseases and lung function change across exposure tertiles. The geometric means of styrene in the General Laminating and Fitting Departments were 48.2 mg/m³ (95% CI 36.3–64.1 mg/m³) and 20.7 mg/m³ (95% CI: 15.6–27.5 mg/m³), respectively. The cumulative exposure odds ratios for chronic cough, phlegm, wheezing and breathlessness for high exposure was 3.1 (95% CI 1.1–8.6), 5.3 (95% CI 1.7–16.6), 3.3 (95% CI 1.2–9.1) and 5.5 (95% CI 1.15–26.4), respectively. The cumulative exposure associated reduction in FEV₁/FVC ratio, percent predicted FEV₁ and FVC was 0.01, 0.04% and 0.05%, respectively. Styrene exposure increases the risk of respiratory symptoms and is associated with reduced lung function.

Keywords:

• Styrene
• fiberglass
• reinforced plastic
• lung function
• cumulative exposure

Authors’ contributions

Author: Zanele Zulu contributions: conceived and implemented the study design; collected and analyzed data; wrote manuscript drafts.

Coauthor: Rajen N. Naidoo contributions: assisted in conceiving and implementing the study design; provided feedback on statistical analyses; co-drafted the manuscript.

Acknowledgments

• Sean Chester and APEX for the occupational hygiene exposure assessment.

• Mangosuthu University of Technology for the support given during this research project.

• Management of the research site and its employees for willingly participating in this research.

Conflict of interest and disclosure

The authors declare no conflict of interest.

Institution and ethics approval and informed consent

In compliance with ethical standards, the study was approved by the Biomedical Research Ethics Committee (BREC) of the University of KwaZulu-Natal, South Africa (Reference number BE316/16).

Additional information

Funding

The study was funded by University of KwaZulu-Natal and Mangosuthu University of Technology.