RESUMO
The present work aims at evaluating the respiratory effects among a group of Egyptian coalworkers chronically exposed to coal dust. The present work comprised 228 coal workers employed for durations ranging from 0.2 to 33 years in various sections of a coal mine, located at north Sinai of Egypt. The workers were subjected to a questionnaire comprising full personal, present, past, family and occupational histories, clinical examination, chest X-ray, ventilatory function tests, and assay of immunoglobulins M, G, and E. Total, respirable and non-respirable dust samples were collected and analysed from different workplace air. Personal total, respirable and non-respirable dust samples being collected from different workplace air proved to exceed the TLV, especially at the feeding tunnel and the washing box. The clinical study revealed mild to moderate affection of the ventilatory function parameters, especially for those related to small and medium size airways. Clinically, positive cases were about 40% of the studied workers, and radiologically, abnormal chest X-rays affected about 25% of the surveyed personnel. An increased incidence of obstructive and combined ventilatory defects was noticed with longer duration of employment. The same was noticed with abnormal findings elicited by the chest X-rays, especially mentioning suspected interstitial pulmonary fibrosis [IPF]. Workers at the underground sites had significant higher incidence of chest symptoms, abnormally higher values of IgG and IgE, more cases with broncho-vascular markings and JPF than their colleagues working on the ground. Clinically positive workers had more abnormal chest X ray findings and about 71% of them had COPD, irrespective to the place of work. Positive cases were also correlated well with abnormal IgG and IgE. The study pointed out the presence of definite exposure to coal dust, higher than the recommended TLV, in different sections at Maghara coal mine. The clinical study revealed adverse respiratory effects among coal-workers, which strongly suggest the relation with chronic coal dust exposure. Smoking has significant influence on the development of chest symptoms elicited among the studied workers. Adopting pre-placement and periodic medical examinations, provision of training, and supplying coal-workers with suitable protective equipment. Addition of "Coal dust Exposure and Consequent Effects" to the Egyptian list of occupational diseases. Continuous monitoring of coal dust should be a routine procedure