Reduction in cotton dust concentration does not totally eliminate respiratory health hazards: the Greek study

A number of epidemiological studies have shown that byssinosis is associated with exposure to high levels of cotton dust. In this first survey, the prevalence of respiratory symptoms in cotton workers under low concentration of cotton dust was investigated. A respiratory questionnaire consisting of 47 questions was given to 443 cotton workers. Their lung function was measured with spirometry. Breathing zone cotton dust concentration was measured by personal samplers and static sampling was used to define the level of the work area concentration. Workers with abnormalities in the pulmonary function parameters, including forced expiratory volume in 1 second (FEV₁), forced vital capacity (FVC) and peak expiratory flow rate (PEFR), were 5.9%. In this group of operatives 7.7% had symptoms compatible with byssinosis, 65.4% of them were smokers, 69.2% of them had symptoms of allergic rhinitis, while 72.2% of them were smokers. Asthma, which appeared after the age of 30, was reported by 57.7%, while 60% of them were smokers. Mean breathing zone cotton dust concentration was 0.16 mg/m³ and the mean work area cotton dust concentration 0.14 mg/m³. Despite the reduction in cotton dust concentration, byssinosis symptoms, allergic rhinitis, asthma and impaired pulmonary function are the most common findings in our cotton workers depending on the duration of exposure, whether they are smokers or not and the nature of the cotton dust.