The fatty acid spectrum of an expired air condensate was studied in the workers of the Kharanor coal stripping and in the dwellers of Chita (a control group). Regularities in the changes of the expired air fatty acid profile were assessed by the degree of exposure to coal dust and by the length of service. The findings indicated the relationship of profile changes with the degree of exposure to occupational noxious agents: the proportion of saturated fatty acids decreases much more significantly in workers who were directly exposed to the dust than in those were indirectly done. It is concluded that the fatty acid composition of an expired air condensate adequately reflects the changes occurring in the respiratory system upon exposure to dust.
The existence of polycyclic aromatic hydrocarbons (PAH) in the particulate phase of diesel engine exhaust has raised concern about a carcinogenic effect in workers exposed to exhaust from diesel engines. Some of the PAH are carcinogenic following inhalation by experimental animals and are associated with excess cancer mortality in some occupational exposures. Studies of occupational exposure to diesel exhaust show concentrations of PAH are above ambient levels but below the very high levels in occupations with demonstrated excess cancer mortality. A critical review of the epidemiologic evidence on the carcinogenicity of workplace exposure to diesel engine exhaust is suggestive of a carcinogenic effect but the existing data are sparse and contradictory. Further epidemiologic studies of this question are needed.
Clinical and functional examination of the miners who suffered from coronary heart disease showed a higher ectopic activity of the myocardium during their work under underground conditions and during the subsequent 4 hours after its termination. It also indicated a significantly higher fatal cases of sudden coronary death in the miners in the aforementioned periods. To prevent the development of complications occurred in miners, the status of the cardiovascular system was proposed to be dynamically controlled.
A review of 15,689 chest radiographs of Quebec chrysotile miners and millers, representing the latest film prior to November 1, 1966, for all such persons ever x-rayed, identified 206 men with pleural calcification. Of these, 198 had worked in the Thetford Mines area, 6 at Asbestos, and 2 at St. Remi de Tingwick; 2.5%, 0.08%, and 1% of the films from these areas, respectively. A series of case-control studies revealed that pleural calcification was concentrated in men employed at a small group of mines in Thetford Mines and occurred more often among miners and maintenance personnel than among millers. Calcification was not related to past history of illness or injury, place of residence, or employment in other industries. The distribution of pleural calcification in this Quebec industry suggests that it is related to some characteristic of airborne dust or mineral closely associated with the chrysotile that is encountered during mining in Thetford Mines but not in other mining areas. Possible minerals include mica, talc, and breunnerite.
Many companies in different industrial sectors are exploring alternative work schedules to deal with diverse problems associated with shiftwork. The use of extended workday schedules (regular shift lengths exceeding 8 h with compressed workweeks) is attracting growing interest in many industries that use continuous operations. To address concerns regarding possible fatigue effects on safety and work performance associated with such schedules, the U.S. Bureau of Mines conducted a two-phase study at an underground metal mine in western Canada. Data were collected before and after a group of workers employed at the mine changed from an 8- to a 12-h schedule. Results indicate nearly unanimous acceptance and improved sleep quality associated with the new schedule. In general, fatigue-sensitive behavioral and physiological performance measures show either no change or improvement with 12-h shifts. We conclude that the extended workday schedule should be retained but periodically reevaluated.
An in-depth study of the prevalence of hypertonic disease among 3075 underground miners of Krivoi Rog iron-ore basin was carried out. The incidence of the disease was 11.3 +/- 0.6 percent. A correlative dependence between incidence of HD, age and length of work underground was found; there were also found differences in the incidence of HD among different occupational groups and occupations. A single-factor disperse analysis indicated that the proportion of seven identified risk factors for HD accounted for 22.0 percent. Under favourable and unfavourable combination of factors the risk of HD, as demonstrated by estimates made with the help of Bayes method, varied from 6.5 to 95.1 percent. Based on the calculated standard intensive indicators the groups of prognosis for HD were determined. Curative and health-promoting activities were conducted in sanatoria facilities among groups of special attention and unfavourable prognosis. The experience was summarized in methodical recommendations.
Combined effects of underground mining (nonuranium mines) and smoking were analyzed in a case-control study of male lung cancer in northern Sweden. Lung cancer cases exposed to underground mining had a considerably lower average cumulative tobacco consumption than other lung cancer cases, indicating that smoking is especially dangerous for underground miners. When relative risks were estimated, a synergistic effect of multiplicative type was found between smoking and underground mining.
