Epidemiologic study of pulmonary obstruction in workers occupationally exposed to ethyl and methyl cyanoacrylate

The association between pulmonary obstruction (e.g., asthma) and occupation al exposure to methyl cyanoacrylate (MCA) and ethyl cyanoacrylate (ECA) was examined in an occupational cohort of 450 persons at an adhesive productio n facility in Puerto Rico. Employee medical records containing information on physical examinations and pulmonary function tests (PFTs), as well as oc cupational histories, on each employee over a period of about 17 yr and ind ustrial hygiene measurements were evaluated. The cohort analysis was based on a Cox proportional hazards model. Workers exposed to ECA or MCA were com pared to workers unexposed to these chemicals with respect to their risk of becoming an "incident case." An "incident case" was defined as any person whose PFTs were normal at the time of employment, but later demonstrated an obstructive pattern, which was defined as a decline in the ratio of forced expiratory volume exhaled in 1 s to forced vital capacity (FEV1/FVC) below 70%. A separate case-control analysis was also conducted that compared "su spected cases," defined as all those whose PFTs ever demonstrated an obstru ctive pattern (e.g., asthma), to persons whose PFTs remained within normal limits throughout their employment with respect to their past peak and cumu lative exposures to cyanoacrylates. All of these analyses showed no evidenc e that exposure to average short-term concentrations of ECA or MCA of ft ss than 0.5 ppm and occasional daily peak exposures of at least 1.5 ppm (usua lly 10 min or less), with occasional higher concentrations during spills, w ere associated with an increased risk of pulmonary obstruction. However, th e study suggested that persons occupationally exposed to cyanoacrylates wer e more likely to have some reversible eye or upper airway irritation than p ersons who were unexposed.