Pneumoconiosis and Respiratory Symptoms in Miners at Eight Collieries

Respiratory symptoms, chronic bronchitis, and ventilatory function in shipyard welders

“…at risk must be compared to those of a control (unexposed) group, as closely matched as possible for age, sex, smoking habits, social class, residence, genetic background, etc The results reported by 3 studies including a control group are summarized in Table 7 in chronologic order, and will serve as a reference in discussing the present findings Also, for comparison, the results obtained by a field survey using similar methods in a group of coal miners and a control group of nonminers in the Jiu Valley (Preda et al , to be published) are worth mentioning: the difference in prevalence was highly 145 33 significant (P < 0 005) for chronic cough ( 51 % in miners vs. 30 % in controls), chronic bronchitis ( 31 vs 14 %), dyspnea ( 29 vs 14 %), and effect of weather ( 28 vs 10 %); the difference was significant at the 2 5 % level for wheezing ( 24 vs. 14 %), while positive physical signs were found in similar proportion ( 16 and 17 %) in miners and control workers The prevalence of cough and chronic bronchitis in our study was similar to that found by Hunnicutt et al ( 1964) and by Kujawska ( 1968) Fogh et al ( 1969 reported somewhat higher figures in both welders and controls, presumably due to higher tobacco consumption and to climatic conditions Though chronic bronchitis tended to be more frequent among welders with longer exposure the difference was not significant, in agreement with the findings of Sewcik et al ( 1960); the lack of an influence of the X-ray picture on the prevalence of chronic bronchitis confirms the results of Kujawska ( 1968) Also in agreement with previous studies, we found a high prevalence of dyspnea among welders (our figure of 20 % lying between those of Hunnicut et al 60 %l and Kujawska 12 %) with a highly significant difference as compared to controls; the welders-to-controls prevalence ratio was 4/1 in our study and 6/1 in the 2 studies quoted above The tendency of dyspnea to be more frequent with increase in the duration of exposure was not significant, nor was dyspnea more frequently present among welders with X-ray pneumoconiosis picture; the latter result is at variance with that of Kujawska ( 1968) who found 87 % dyspnea among welders with small opacities against 37 % among those with normal radiograph (P < O 001) We found slightly more wheezing and/or asthma attacks among welders as did Hunnicutt et al ( 1964); in our study the difference to controls was significant In contrast to the symptoms listed above the prevalence of positive signs at chest examination was similar in welders and controls, i.e , 14 and 12 %, respectively The same result, with slightly higher figures ( 16-17 %), was obtained in the field survey of miners and nonminers (Preda et al , to be published) indicating a divergence between respiratory symptoms and objective indicators of chest disease in the subjects examined, and supporting the view that industrial populations exposed to respiratory occupational hazards may have an increased awareness of their chest symptoms (Rogan et al , 1961).…”

Ventilatory Capacity and Lung Volumes of US Coal Miners

“…The cause of this increase in residual volume is not certain, but, it has been suggested that it is either a consequence of small airways obstruction or of focal emphysema. 2 ? No matter which mechanism is responsible, such an increase by itself has little if any clinical importance as far as respiratory disability is concerned.…”

A comparison of two respiratory symptoms questionnaires.

“…Because ventilatory function tends to decrease with increasing age (Rogan, Ashford, Chapman, Duffield, Fay, and Rae, 1961) and the disability associated with any particular group of symptoms may also be dependent upon age, due account must be taken of the effect of age in any such comparison. By the same token, physique may also play a similar but probably considerably less significant role; because of the comparatively small numbers of men involved and the absence of significant differences in physique between the various groups which are to be compared, it was not considered worthwhile to make allowance for this factor also.…”

“…(Fay, 1957;Fay and Rae, 1959) a short questionnaire about respiratory symptoms has, since 1958, been included in the standard medical examination (Rogan, Ashford, Chapman, Duffield, Fay, and Rae, 1961). To date the PFR Questionnaire has been asked of some 30,000 working coalminers, comprising about 95 per cent of the labour force employed at the 25 collieries at which this research is undertaken.…”