Dust exposure, respiratory symptoms, and longitudinal decline of lung function in young coal miners.

Abstract

Objectives-To study the role of dust exposure on incidence of respiratory symptoms and decline of lung function in young coal miners. Methods-The loss of lung function (forced vital capacity (FVC), forced expiratory volume in one second (FEV,), forced expiratory flow (MEF), carbon monoxide transfer factor (TLCO)) with time and the incidence of respiratory symptoms in 909 Sardinian coal miners (followed up between 1983 and 1993 with seven separate surveys) has been compared with the past and current individual exposures to respirable mixed coal dust. Multiple linear and logistic regression models were used simultaneously controlling for age, smoking, past occupational exposures, and other relevant covariates. Results-According to the relatively low dust exposures experienced during the follow up few abnormal chest x ray films were detected. In the cross sectional analysis ofinitial data, significant associations between individual cumulative exposure to dust, decrements in FEV, and MEFs, and increasing prevalence of respiratory symptoms were detected after allowing for the covariates included in the model.The yearly decline of FVC, FEV,, and single breath carbon monoxide transfer factor (TLCOIVA) was still significantly related to the individual exposure to dust experienced during the follow up, even after allowing for age, smoking, initial cumulative exposure to dust, and initial level ofeach functional variable. In logistic models, dust exposure was a significant predictor of the onset of respiratory symptoms besides age and smoking. Conclusions-The results show that even moderate exposures to mixed coal dust, as in our study, significantly affect lung function and incidence of symptoms of underground miners. Although the frequency of chest x ray examination might be fixed at every three or four years, yearly measurements of lung function (spirometry, MEFs, and TLCo) are recommended for evaluation of the respiratory risk from the coal mine environment to assess the need for further preventive interventions.(Occup Environ Med 1996;53:312-319)

A Comparative Study of Morbid Conditions Amongst Opencast and Underground Coal Miners

“…Carta P et al (1996) [11] studied role of dust exposure on incidence of respiratory symptoms and decline of lung function in young coal miners In logistic models, dust exposure was significant predictor of the onset of respiratory symptoms and decline in lung function. Also Jain B.L.…”

Respiratory symptoms and pulmonary function in coal miners: Looking into the effects of simple pneumoconiosis

“…Some early studies concluded that there was little or no abnormality of pulmonary function in the miners without complicated CWP [Higgins and Oldham, 1962;Rogan et al, 1973;Calvert et al, 1991], and simple CWP was not associated with any respiratory symptoms [Morgan, 1982]. However, there has been growing evidence from both cross-sectional and longitudinal studies to suggest that significant impairment of pulmonary function and occurrence of respiratory symptoms may be associated with exposure to coal mine dust, irrespective of the presence of complicated CWP [Marine et al, 1988;Seixas et al, 1993;Carta et al, 1996).…”

Respiratory protection: Associated factors and effectiveness of respirator use among underground coal miners

“…Carta et al [1996] reported that even moderate exposures to mixed coal-mine dust significantly affected lung function and symptom incidence among underground miners. We evaluated symptoms and lung function among the study miners in order to detect evidence of the effectiveness of respirators under current mining conditions, taking into account smoking, and other factors.…”