A longitudinal observation of early pulmonary responses to cotton dust

Abstract

Aims: To examine early adverse pulmonary effects of exposure to cotton dust, and to identify potential risk factors, including atopy for pulmonary responses to cotton dust. Methods: Spirometry, methacholine challenge testing, and questionnaire; performed among 101 nonsmoking newly hired textile workers at baseline (prior to starting work), and at 3, 12, and 18 months after starting work. Concentrations of airborne cotton dust in various work areas were measured at each follow up survey using vertical elutriators. Results: The incidence of non-specific respiratory symptoms was 8% at three months, then diminished afterwards. Substantial acute cross shift drops in FEV 1 at each follow up survey, and longitudinal declines in FVC and FEV 1 after 12 months of exposure were observed. Airway responsiveness to methacholine increased with follow up time, and was more pronounced among atopics. Increasing airway responsiveness was strongly correlated with cross shift drops in FEV 1 . In addition, one or more respiratory symptoms at three months was significantly, and pre-existing atopy marginally significantly, associated with cross shift drops in FEV 1 after adjusting for other covariates and confounders. Conclusion: Results suggest that non-specific respiratory symptoms, decreasing lung function, and increasing airway responsiveness are early pulmonary responses to cotton dust. In addition, the occurrence of respiratory symptoms and increasing airway responsiveness, as well as atopy, may be important predictors for acute changes in lung function among cotton textile workers.

Exposure–response relationship between endotoxin exposure and lung function impairment in cotton textile workers

“…These results correspond to findings of other studies reporting associations of cross-shift lung function changes with the level of endotoxin exposure (Kennedy et al 1987;Wang et al 2002Wang et al , 2003Schwartz et al 1995;Zock et al 1998;Christiani et al 2001;Torres et al 2004). In 1998, Zock et al examined 61 employees of a potato-processing factory; highly exposed subjects tended to have lower lung function variables than those with lower endotoxin exposure (FEV 1 95 vs. 102% predicted).…”

“…Apart from the highest exposure group, they showed a decrement of FEV 1 in relation to increased endotoxin exposure. Wang et al (2003) performed a longitudinal observation among 101 never smoking newly hired Chinese textile workers to examine early endotoxin-dependent adverse pulmonary effects. They found acute crossshift drops in FEV 1 at each follow-up survey (after 3, 12 and 18 months).…”

Phthalate exposure and pulmonary function.

“…Urinary phthalate measures have a short biologic half-life but are reproducible from one day to the next (Hoppin et al 2002); long-term reproducibility has not been evaluated. Pulmonary function tests generally represent long-term changes in lung function, although work shift changes in FEV 1 and other pulmonary function tests have been demonstrated (Wang et al 2003). Whether our measure of phthalates was indicative of long-term exposure, and thus long-term change in pulmonary function, or indicative only of recent exposure, and thus short-term changes in pulmonary function, we cannot determine from our cross-sectional analysis.…”

Lung Function before and after a Large Chlorine Gas Release in Graniteville, South Carolina

“…We included at-hire and annual spirometry records; but not spirometry performed because of byssinosis symptoms. We also required a minimum of 240 days between the at-hire and second spirometry assessment (26). Further information regarding sampling strategy can be found in the online supplement (see EXPANDED METHODS).…”