Pulmonary function changing of workers exposed to metalworking fluids pre-and post-shift

  Objective   The pulmonary function changing of workers to metalworking fluids pre -and post -shift and their respiratory symptoms in an automobile manufacturing company were investigated to explore the effects of metalworking fluids exposure on the respiratory system.

  Methods   Totally 158 workers exposed to metalworking fluids (MWF) and 116 assembly workers (as control group) were examined for occupational health and their pulmonary function were measured pre - and post-shift.

  Results   Low concentrations of diethylamine and triethanolamine were detected in the MWF exposed workers'workplaces. Cough, chest tightness and asthma were common respiratory symptoms in MWF exposed workers. Totally 70 MWF exposed workers (44.30%) had one respiratory symptom at least, which was higher than that in the control group(27 cases, 23.28%)(P < 0.01). The abnormality of PEF of MWF exposed workers post-shift was higher than pre -shift, and the difference was statistically significant (P < 0.05). Compared with the pre -shift, FEV₁, FEV₁/ FVC and PEF of the MWF exposed workers decreased post -shift (P < 0.05), in which FEV₁, FEV₁/FVC and PEF decreased by 7.72%, 4.43% and 6.75%, respectively. FEV₁/FVC and PEF of exposed workers were lower than those of workers in the control group (P < 0.05). The incidence of lung function injury of exposed workers after shift was higher than before shift (P < 0.05), and the abnormal rate after shift was higher than that of control workers (P < 0.05). The main manifestation was obstructive ventilation dysfunction characterized by decreased FEV₁ and FEV₁/FVC. FEV₁, FEV₁/ FVC and PEF of exposed workers with longer working time were lower than those of workers with shorter working time(P < 0.05). 3.16%, 1.90% and 6.33% of exposed workers' FEV₁, FEV₁/FVC and PEF decreased by more than 15% after shift, respectively, and 3.16% could be diagnosed as asthma.

  Conclusions   Exposure to metalworking fluids can cause respiratory health hazards, including increased prevalence of respiratory system and decreased pulmonary function. Therefore, respiratory protection of workers exposed to metalworking fluids should be strengthened.