RESUMO
In this study, the pulmonary ventilalory changes among workers exposed to cotton dust in textile industry were investigated. The study was conducted in Sharkia Company at Zagazig City in Sharkia Governorate. It included 2 groups. The first one was the group exposed to cotton dust [300 workers, randomly selected from the different cotton departments]. The second group included 100 workers who were randomly selected as a control group from security and management departments. Full clinical examination and measuring the pulmonary ventilatory functions before and after the work shift were carried out for both groups [in control group, the pulmonary functions were measured only once]. Also, dust concentrations were measured in different locations of the cotton mill. Considering the mean values of pulmonary ventilatory measurements it was found that workers in early cotton processings steps had pulmonary ventilatory values which were statistically significantly lower than those among the controls. But, in the late cotton processings steps where less dust was evolved, the workers had the same range of ventilatory values of the controls. Exposure to cotton dust had an acute effect on the pulmonary ventilatory functions with decrease of 10% or more in the post-shift readings compared to the pre-shift and the more the cotton dust concentration, the more was that effect. The longer the duration of exposure to cotton dust. The more the prevalence of post-shift lowering in pulmonary ventilatory functions. The difference between the smokers and non-smokers among workers exposed to cotton dust who had post-shift lowering in the pulmonary ventilatory functions was not statistically significant. But, considering the number of cigarettes smoked per day, the difference between both groups [smoked 20 cigarettes or less/day and smoked > 20 cig. /day] was statistically significant. Regarding dust concentration, the bale-breaking area had the highest concentration of cotton dust, while the spinning area had the lowest cotton dust concentration. There was significant positive correlation between dust concentration and percent of exposed workers with post-shift lowering in pulmonary ventilatory functions [indicating an acute effect]. Proper pre-employment medical examination to exclude workers with chest diseases and proper periodic medical examination at regular intervals [including chest examination and measuring ventilatory functions] were recommended. The duration of exposure to cotton dust must be reduced by periodic transfer of the workers from the dusty departments to less dusty areas. Methods of decreasing dust concentration must be applied with continuous environmental monitoring