Occhealth Bulletin
25 May 2010
Respiratory health in textile workers after work cessation
Category: Reviews
In industries such as manufacturing and construction employees face respiratory hazards on a daily basis including harmful atmospheres containing dusts, particulate matter, gases, sprays or volatile chemicals. Good workspace design, ventilation and respiratory protection all reduce the risk of respiratory conditions or disease as a result of occupational exposure. Industries have specific hazards related to the work activities that are undertaken and the hazardous chemicals or materials that are used.
For example, a recent study by Jing Shi and co-workers aimed to discover changes in lung function and reversibility of respiratory symptoms after workers stopped cotton textile activities. Workers in the textile industry are potentially exposed to cotton dusts and associated endotoxin. Inhalation of cotton dust can induce respiratory responses such as bysinnosis with symptoms including chest tightness and wheezing. Endotoxin is thought to cause acute and chronic lung function declines. Smoking appears to have an additive effect on respiratory problems in cotton textile workers.
The researchers completed a study on 447 workers exposed to cotton dust and endotoxin and 472 unexposed silk textile workers with 25-year follow-up. Respiratory questionnaires and spirometry tests were carried out over five-year intervals. To discover the impact on lung function over the years following retirement from textile work, changes in the prevalence of respiratory symptoms and longitudinal changes in Forced Expiratory Volume in one second (FEV1) were assessed over the period. FEV1 is the volume of air (measured in liters) that is forcibly expelled in one second after full inspiration (intake of air) and is a measure of lung function.
The researchers showed that textile workers have improved FEV1 and fewer chronic respiratory symptoms after leaving work with greater changes seen in cotton workers than silk workers. The researchers also found that there was a positive correlation between improvements and the amount of time since retirement. They were not clear on why there were improvements in lung function in silk workers following retirement as they were not exposed to cotton dust and endotoxin levels were measured at ambient levels. The authors suggested that perhaps silk workers had “improved in lung function as a result of removal from some unmeasured exposure, this would result in the underestimation of the effect of cotton dust/endotoxin exposure on lung function loss”. The authors of the study also showed that smoking had an additive effect in cotton workers (ie there was greater FEV1 decline when actively exposed) and there appeared to be faster improvement in lung function loss and reduction in respiratory symptoms than non-smokers.
REFERENCE
Shi, J., Hang, J-q., Mehta, AJ., Zhang, H-x., Dai, H-l., Eisen, EA. and Christiani, DC. (2010) Long term effects of work cessation on respiratory health of textile workers: a 25-year follow-up study. American Journal of Respiratory and Critical Care Medicine. Published online ahead of print.