Severe pneumoconiosis

Acute Effects on Animals and Humans Due to the poor solubility of thorium and the low radiotoxicity of natural thorium, no acute effects on humans are reported. Cases of severe pneumoconiosis have been described in photoengravers working with rare earth elements/thorium electrodes. 

In an early report of 66 workers handling soapstone, no cases of pneumoconiosis were found in workers with an average dust exposure of 2.8 mg/nf but exposures ranging from 22 to 50mg/m caused severe cases. ... 

Larger particles (several micrometers in size) are deposited in the ciliated portion and are cleared from the respiratory system by muco-ciliary action into the gastronomical tract, but may produce systemic toxic effects by absorption in body fluids. Finer particles reach the lower non-ciliated portion of the lungs, are cleared very slowly, and are responsible for diseases such as pneumoconiosis and lung cancer. Metallic lead (Pb), tellurium ( ), selenium (Se), and platinum (Pt) are known to cause both systemic and respiratory toxicity in laboratory animals and several cases of acute and chronic poisoning among metal workers have also been documented. 

Weighting of Occupational Histories—If a worker has been employed in several occupations over a period of years, some measure of his total dust exposure becomes necessary. This is particularly true when medical findings must be correlated with the amount of the workers exposure. Pneumoconiosis is the result of prolonged exposure to dust, and... 

Chronic bronchitis, pneumoconiosis, obstructive lung disease, focal emphysema, progressive massive fibrosis (PMF), coal workers pneumoconiosis (CWP), siUcosis Acute bronchospasm, pneumonitis, chronic exposure leads to Itmg fibrosis, progressive massive fibrosis (PMF), coal workers pneumoconiosis (CWP), silicosis Ocular and upper airway irritation, bronchospasm in severe exposure, contact dermatitis... 

Perhaps the most widely known health impact of coal is black lung disease also known as coal workers pneumoconiosis. This was a widespread respiratory problem of coal miners caused by inhalation of dust particles during mining. The mineralogical content of the coal may play a role in the incidence and severity of the disease (Finkelman et al., 2002). 

Trichloroethane was not found to have produced irritation of respiratory mucous membranes. Acute exposure to lower concentrations of 1,1,1-trichloroethane in controlled studies did not affect respiratory rate or volume in humans (Dornette and Jones 1960 Stewart et al. 1975 Torkelson et al. 1958). Chest radiographs from several (unspecified number) of twenty-eight workers exposed to an undetermined concentration of 1,1,1 -trichloroethane for about 10 years showed changes consistent with early pneumoconiosis (fibrosis), but this was consistent with known exposure to asbestos and... 

CHRONIC HEALTH RISKS pneumoconiosis (dust in the lungs) emphysema bronchitis lesions of the respiratory and digestive systems increase in cancer of the lungs, kidney, trachea, bronchus, and prostrate severe dermatitis skin lesions disfiguring pigmentation of the skin conjunctivitis other skin disorders such as folliculitis, furunculosis, erythema, photosensitivity, melanosis, and warts EPA Group A classifiable as a human carcinogen. 

Cases of pneumoconiosis have been observed in workers exposed to mica dust at concentrations greater than 10 mppcf for several years. There have also been high incidences of silicosis. Other symptoms are coughing, respiratory distress, weakness, and weight loss. TLV-TWA 3 mg/m as respiratory dust (ACGIH), 20 mppcf (MSHA). 

B. Inhalation of insoluble inorganic barium salts can cause baritosis, a benign pneumoconiosis. One death resulted from barium peroxide inhalation. Detonation of barium styphnate caused severe poisoning from inhalation and dermal absorption. 

Pneumoconiosis Pneumoconiosis is a disease of the lungs resulting from the inhalation of certain kinds of dusts or other particles. The term simply means dusty lung. The disease has several names depending on the material involved in an exposure. Table 24-1 lists several forms of pneumoconiosis. 

Occupational granuloma, both dermatological or otherwise, is a well-known and well-defined noso-graphic entity. In recent years, occupational respiratory granulomatous disease has been studied and monitored because it is the cause of numerous and severe cases of occupational disability. An emblematic case is that of mineworkers, whose pulmonary picture after inhalation of mineral dusts (pneumoconiosis) is... 

The toxicity of cobalt and cobalt-nickel alloys in experimental hard metal pneumoconiosis is well documented. Metallic cobalt powder instilled in-tratracheally in the lungs of rats had an acute irritant action and lead to severe alterations in capillaries (Harding 1950, Schiller 1958,1961). The solubility of cobalt in plasma is some 500 times greater than in saline, but a fairly large (10 ml) intraperito-neal dose of plasma saturated with cobalt was without evident effects on the rat (Harding 1950). 

Pneumoconiosis is the pathologic response of the lung to particulates. The lesion consists of focal accumulations of macrophages and, in severe cases, fibrosis. 

Fig.6.9a,b. Coal worker s pneumoconiosis computed tomography scan showing with more severe micronodular lung, subpleural and peribronchovascular involvement, a, b Axial views with slice thickness of 1 mm. Multiple micronodules are seen in both lungs. The distribution of the micronodules is diffuse, and, except for the left upper lobe (b), where micronodules can be seen in the interlobular septa (black arrows) and centrilobular, the relationship between the micronodules and the secondary pulmonary lobule is difficult to appreciate. Notice also the peribronchovascular (white arrowheads) and the subpleural micronodules, as well as focal emphysema surrounding some of the micronodules (white arrows)... 

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