The role of respiratory muscles in the impairment of the respiratory system function in the workers of a chemical plant division producing pesticides.

Workers of a chemical plant department producing dust and liquid pesticides (37 males and 17 females) exposed to dust containing free silica, organic solvents and active substances, among others: organophosphate compounds, pyrethroids, triazines, carbamates and dithiocarbamates, 2,4-D, captan, carboxine, carbendazim and dodine were studied. Spirometric investigations, including evaluation of vital capacity (VC), 1 second forced expiratory volume (FEV1) and its percentage index (FEV1%VC), peak expiratory flow and maximal end-expiratory flow (MEF25), were performed directly at the workplace. At the same time mouth inspiratory pressures (MIP) and maximal expiratory pressures (MEP) were evaluated. Chronic bronchitis (according to BMRC questionnaire) was diagnosed in every second worker, and in 11 males and females obstructive impairment of pulmonary function was established; 41% of females and 27% of males were found to have diminished peak expiratory flow. Maximal inspiratory pressures were significantly lower both in the studies males (p < 0.001) and females (p < 0.02) than those in the control groups and amounted to 74.4 +/- 21.5 and 58.1 +/- 24.3 cm H2O, respectively. Maximal expiratory pressures were also significantly lower in the studied males (p < 0.001) and females (p < 0.05) and amounted to 116.6 +/- 28.4 and 74.5 +/- 17.9 cm H2O, respectively. Significant correlation between decreased PEF and the force of expiratory muscles-MEP (In males r = 0.3279, p < 0.05; In females r = 0.7049, p < 0.01) was founded. The investigations performed at the workplace allow the assumption that work at the production of pesticides may result in impairment of pulmonary ventilation, development of chronic bronchitis as well as impaired function of respiratory muscles.