Pulmonary function abnormality and respiratory tract irritation symptoms in epichlorohydrin-exposed workers in Taiwan

Epichlorohydrin (ECH) is a strong irritant of the eyes, respiratory tract, and skin. The aims of this study were to examine the dose-response relationship between observed abnormal pulmonary function tests and respiratory tract irritation symptoms among epichlorohydrin-exposed workers in Taiwan.

A total of 167 workers were randomly selected from a resin synthesis factory. Sixty-six air samples were taken to determine ECH concentration in the workplace. Demographic data, work history, smoking status, and respiratory tract irritation symptoms were gathered by a standard self-administered questionnaire. Pulmonary function tests were also performed.

There were 13 of 41 (31.7%) abnormal mean mid-expiratory flow (MMEF) among the high-ECH-exposed workers, 11 of 38 (29%) among the low-ECH-exposed workers, and 4 of 59 (6.8%) among non-ECH-exposed workers. There was a significant linear trend between ECH exposure and the prevalence of small airway abnormalities (P = 0.007) after adjusting for other factors. There was also a significant dose-response relationship of respiratory tract irritation symptoms (cough, phlegm, chest tightness, and dyspnea) among the ECH-exposed workers.

This study suggests that obstructive lung abnormalities and small airway lung damage are associated with ECH exposure. The study also suggests that exposure to very low concentrations (<0.2 ppm) causes significant higher prevalence of respiratory tract irritation symptoms. Causal inferences from the findings cannot be made from this cross-sectional study and further longitudinal studies are needed to better clarify the nature of the observed associations.