Decrements in spirometry values associated with chlorine gassing events and pulp mill work

In a previous study of older pulp and paper workers in Berlin, New Hampshire, decrements in spirometry results associated with accidental exposures to high levels of irritant gases depended on cumulative levels of pulp mill exposure and cigarette smoking. Many of those subjects were older and retired. A new study was initiated to assess whether gassing events were a problem among current workers. Three hundred white male pulp and paper workers from the mill in Berlin, New Hampshire, were surveyed in 1992. Testing included spirometry and questionnaires. The mean age was 40.4 yr, and the mean tenure with the company was 18.5 yr. A total of 105 of the 300 subjects (35%) reported ever having an episode of high exposure to chlorine gases (i.e., being gassed). The percentage gassed was 51% for pulp mill workers and only 13% for other employees. For subjects with no more than 26 pack-years of cigarette smoking, obstruction (i.e., abnormally low FEV1 and FEV1/FVC) was observed only among those with a history of gassing. Also, the combination of high cigarette smoking (i.e., > 26 pack-years) and gassing had a greater than additive effect on obstruction. These findings suggest that additional controls are needed to minimize the number of gassing events in this and other chemical pulp mills.