A 17-year epidemiological study on changes in lung function in toluene diisocyanate foam workers

Area of Science:

• Occupational Health
• Respiratory Medicine
• Toxicology

Background:

• Workers in polyurethane foam manufacturing are potentially exposed to toluene diisocyanate (TDI).
• Previous studies have suggested potential respiratory health risks associated with TDI exposure.

Purpose of the Study:

• To investigate the relationship between longitudinal declines in ventilatory capacity and respiratory symptoms in polyurethane foam manufacturing workers and their exposure to TDI.
• To assess the long-term effects of TDI exposure on lung function over a 17-year period.

Main Methods:

• A cohort of 251 UK polyurethane foam manufacturing workers was studied over 17 years (1981-1998).
• Lung function measurements (FEV1, FVC) and respiratory questionnaires were administered at the beginning and end of the study.
• Mean TDI exposures for jobs were assessed and correlated with individual occupational histories.

Main Results:

• Annual declines in forced expiratory volume in 1-second (FEV1) and forced vital capacity (FVC) were not significantly related to TDI exposure.
• The cold-foam handling group reported increased breathlessness and a significant decline in FVC.
• Wheezing increased in the exposed group (primarily smokers), while chest illness decreased in the low-exposure group. Smoking and increased body weight were associated with excess FEV1 decline.

Conclusions:

• The study did not find evidence of TDI-related declines in FEV1 or FVC over 17 years in UK flexible polyurethane foam manufacturing workers.
• Factors such as smoking and weight gain appear to be more significant contributors to lung function decline in this cohort than TDI exposure at the studied levels.