The effects of kaolin on the lung.

We studied the prevalence of ventilatory impairment, chest symptoms, and radiographic abnormality in a selected sample of more than 2,000 kaolin workers from east central Georgia. The presence of ventilatory impairment was related to the presence of complicated pneumoconiosis, employment in clay calcining, and cigarette smoking. In those working with calcined clay, there was an increased prevalence of abnormality of the FEV1, but not the FVC, when compared to both wet and dry processors and which could not be explained by either cigarette smoking or the presence of pneumoconiosis. The magnitude of abnormality in the calcined clay workers was, however, unlikely to lead to disabling impairment. In workers with more than 3-yr tenure, there were 90 subjects with simple pneumoconiosis and 18 with complicated pneumoconiosis, yielding an adjusted prevalence of 3.2% and 0.63%, respectively, in the sample examined. Dry processing was associated with a greater risk of developing pneumoconiosis than wet processing.

Pathology of silicon carbide pneumoconiosis.

Silicon carbide is a widely used synthetic abrasive manufactured by heating silica and coke in electric furnaces at 2400 degrees C. Until recently it had been considered a relatively inert dust in humans and animals. However, several roentgenologic surveys had revealed lesions similar to low-grade silicosis. A recent epidemiological study has revealed a 35% incidence of pulmonary problems. Tissues from three such workers were available for light microscopy. A mixed pneumoconiosis was found, and lesions can be summarized as follows: (a) abundance of intraalveolar macrophages associated with a mixture of inhaled particles including carbon, silicon, pleomorphic crystals, silicon carbide, and ferruginous bodies showing a thin black central core; (b) nodular fibrosis, generally profuse, containing silica and ferruginous bodies and associated with large amount of carbon pigment; (c) interstitial fibrosis, less prominent than the nodular form; (d) carcinoma in two cases. We believe this pneumoconiosis is sufficiently characteristic to be recognized as a distinct entity. The Stanton hypothesis on fiber properties and carcinogenesis could be applied to silicon carbide dust. At present, it appears that the occupational hazard is limited to the manufacturing process and powdered product used in some industries.

Clinical report on 62 cases of acute dimethyl sulfate intoxication.

Sixty-two cases of accidental acute intoxication from the inhalation of dimethyl sulfate (DMS) are reported. To facilitate clinical evaluation and treatment, as well as identification of capacity for physical labor, a grading system was established according to the history of exposure to DMS, symptoms and signs of respiratory mucosal irritation, findings on chest radiographs, and abnormalities of leukocyte count. Emergency treatment included prophylactic use of glucocorticoids, supplemental oxygen, sedatives, and antibiotics for prevention and treatment of laryngeal and pulmonary edema, pulmonary infections, and other complications. Follow-up studies for 2-12 years have found only mild to moderate impairment in ventilatory capacity in eight cases, with no abnormal findings in ECG, chest films, and routine blood tests. Nearly all patients have resumed their usual work.

A survey of the respiratory health of silica-exposed gemstone workers in Hong Kong.

Respiratory symptoms and radiographic and lung function alterations were studied in a cross-sectional survey of gemstone workers in Hong Kong. The study population included a group of grinders, polishers, and buffers who were heavily exposed to dust (principally free silica) and a less exposed group of cutters and carvers. Among all 218 male workers who answered the respiratory questionnaire, heavily exposed workers reported significantly higher prevalence of respiratory symptoms suggestive of mucus hypersecretion. Radiological pneumoconiosis defined as opacities with profusion of 1/0 and above was found in 27% of 157 workers who accepted radiographic and lung function examination. Radiological opacities were significantly related to increasing years of employment in both groups of workers after taking into account age and smoking habits. Decline in forced vital capacity (FVC) was significantly related to increasing years of employment in both groups after allowing for the effects of age, height, and smoking. A modest decline in forced expiratory volume in one second (FEV1) was related to dust exposure which was of borderline statistical significance in polishers and buffers who smoked. Radiological pneumoconiosis did not have an independent effect on lung function when allowance was made for dust exposure.

[The significance of dust in the evaluation of the potential health risk in chemical industry plants]. / Die Bedeutung der Stäube bei der Beurteilung von potentiellen Gesundheitsrisiken in Betrieben der chemischen Industrie.

According to statistics, occupational diseases (and respiratory disorders in particular) are rare. Occupational disease accounted for only 1.5% of all job-related disabilities registered with the Swiss Accident Insurance Institute (SUVA) in 1984. Skin disorders (37.1%) are the leading form of occupational disease, followed by disturbances of the locomotor apparatus (36%) arising from physical causes. Pneumoconiosis (quartz, asbestos) accounts for 2.8% of cases. Chronic disorders of the respiratory tract brought about by irritant or toxic gases are buried away under the heading of 'chronic poisoning' (7.8%). Bronchitis caused by organic dust (0.3%) is listed under 'other disorders' (13.9%). It is shown that, depending on the type of chemical manufacturing involved, major significance is attached to the role of dust as a potentially dangerous substance and thus to monitoring and prevention at source. Attention is particularly drawn to the hazard posed by lipophilic dust (aromatic amines, organic phosphates, etc.) which can easily pass through intact skin and penetrate into the body unnoticed. Uptake of toxic agents through the skin is not registered by the devices used to test air quality, but can only be ascertained by detection of toxic substances or metabolites in the urine or the blood (biological monitoring). Finally, it is pointed out that--in general--MAC or BEI limits have not been stipulated for biologically active dust, with the exception of a few values for insecticides. The 'general upper limit' of 6 mg/m3 for inert dust is of no use in the monitoring of dust from biologically active products.(ABSTRACT TRUNCATED AT 250 WORDS)

The natural history of asbestosis in former crocidolite workers of Wittenoom Gorge.

The course of pulmonary asbestosis and its determinants have been examined in 280 applicants for compensation among former workers of the crocidolite mine and mill at Wittenoom Gorge, Western Australia. Serial chest radiographs accrued over more than 3 decades were graded for parenchymal disease separately by two observers according to the 1980 ILO Classification of Radiographs for Pneumoconioses and without knowledge of exposure histories or compensation details. In 136 subjects whose median duration of exposure was 37 months, radiographic asbestosis appeared between 1 and 34 yr after initial exposure and then progressed continuously. Total exposure to asbestos and time from first exposure to the appearance of definite radiographic asbestosis were significant determinants of the rate of progression of profusion of radiographic abnormality. Asbestosis should be considered to be an active disease even 3 decades after exposure has ended.

Respiratory symptoms among glass bottle makers exposed to stannic chloride solution and other potentially hazardous substances.

Concern about upper respiratory tract irritation and other symptoms among workers at a glass bottle manufacturing plant led to an epidemiologic and an industrial hygiene survey. Questionnaire responses from 35 hot end and 53 cold end workers indicated that the incidence of wheezing, chest pain, dyspnea on exertion, and cough was significantly elevated among hot end workers. Among both smokers and nonsmokers, hot end workers reported higher, but not significantly higher, rates of wheezing and chest pain. Among smokers, hot end workers reported significantly higher rates of dyspnea on exertion and cough than did cold end workers. Data suggest that reported exposure to stannic chloride solution likely caused these symptoms. The industrial hygiene survey, conducted when stannic chloride use had been reduced, cleaning had been done, and ventilation improved, focused on measuring air contaminants that might possibly cause symptoms. Levels of hydrogen chloride, which apparently was formed by the combination of stannic chloride and water in the presence of heat, were elevated. The finding of increased prevalence of respiratory symptoms among hot end workers was consistent with this exposure. Recommendations were made to reduce hazardous exposures at this plant. Individuals responsible for occupational health should be aware that relatively benign substances, such as stannic chloride and water, can combine spontaneously to form hazardous substances.

Occupational lung disease following long-term inhalation of pancreatic extracts.

Fourteen employees of a pharmaceutical company, who had been exposed to porcine pancreatic and other organic dusts for 1-18 years were examined because of exercise dyspnea and asthmatic attacks. Airway obstruction or bronchial hyperreactivity and disturbance of oxygen diffusion were present in all cases. Two patients showed evidence of acute alveolitis and 3 had radiological signs of mild fibrosis, whilst emphysema dominated in 7 others. Skin tests and bronchial provocation revealed hyperreactivity to pancreatic extracts. Pancreatic alpha-amylase was determined as a causative allergen for Type I allergy symptoms by means of RAST. Three pathomechanisms of the lung diseases are discussed: 1) Type I allergy of the airways to pancreatic enzymes, 2) broncho-alveolar Type III reaction to porcine proteins; and 3) proteolytic damage of the lung tissue and an increase of non-specific bronchial reactivity.

Pneumoconiotic effects of welding-fume particles from mild and stainless steel deposited in the lung of the rat.

Rats were exposed to single periods of inhalation of fumes generated by arc welding. Two processes were compared: either manual metal arc (MMA) using flux-coated mild steel (MS) electrodes or metal inert-gas (MIG) welding with stainless steel (SS). Widespread but small deposits of fume particles were cleared effectively from alveoli and airways. Peribronchial and subpleural aggregates of particle-laden macrophages remained. More massive and persistent lung-burdens were established by intratracheal administration of suspensions of fume-particles (10 mg and 50 mg, single doses). Initial pneumonitis was attributed to irritant gases or soluble toxic components of particles. MIG-SS particle deposits were more persistent and lesions more severe, inhibition of phagocytosis or clearance and damage to epithelial cells being associated with possible toxic effects in macrophages. Both types of particle caused alveolar epithelial thickening, with proliferation of granular pneumocytes and exudation of lamellar material. Foam cells appeared in alveoli. Long-term effects (80-300 days) involved formation of nodular aggregates of particle-laden macrophages. Giant cells were formed. Nodules containing MIG-SS material were irregular and surrounded by collapsed and thickened epithelium. Soluble chromium or nickel constituents are cited as probable active agents producing effects resembling those of cytotoxic non-fibrogenic dusts, e.g., soluble silicas . MMA-MS particles produced low-grade fibrotic ( collagenised ) changes.

Antimoniosis: a particular form of pneumoconiosis. II. Experimental investigation.

In a pilot experiment 0.5 ml of antimony oxide (Sb2O3 and Sb2O5) dust was injected intraperitoneally and endotracheally in two groups of "Wistar" type female albino rats. After two months, the rats were sacrificed and microtome slices were stained with hematoxylin-eosin and PAS. Morphology investigation revealed changes of pneumoconiosis of a noncollagenous nature.

[Pneumological findings in workers of chemistry and steel industry (author's transl)]. / Pneumologische Befunde bei Arbeitern der Chemie- und Stahlindustrie.

The pneumological examination of workers of the chemistry and steel industry revealed evident bronchopulmonary findings. The clinical and also the bronchoscopic findings are uncharacteristic. Chest X-ray shows interstitial and alveolar involvement, but in some cases it is normal. Lung function tests are valuable for early diagnosis, especially if both targets of the inhalative irritants, bronchus and alveolus, are respected. The essential loss of function concerns the gaseous interchange caused by bioptically demonstrated persisting, pneumoconiotic fibrosis. As a consequence of this findings in respect to diagnosis there has to be a more critical interpretation of chest X-ray, lung function tests including gaseous interchange analysis, perhaps also biopsy for correct interpretation of uncharacteristic complaints in the case of exposition, and finally also widening of the examinations in cooperation with the industry.

[A comparative morphological and enzyme-histochemical study of experimental pneumoconiosis and experimental allergic-hyperergic pulmonary granuloma (author's transl)]. / Vergleichende morphologische und enzymhistochemische Untersuchungen experimenteller Pneumokoniosen und des experimentellen allergisch-hyperergischen Granuloms in der Lungs.

Six endotracheal applications of 15 milligrams of cadmium sulfide (CdS) given to rats at weekly intervals induce pneumoconiosis with massive adhesions. The same quantities of lead sulfide (PbS) given under the same conditions have much less effect, causing only the formation of fairly small fibrous nodules. The tissue reactions to CdS and PbS were studied morphologically (light and electron microscope) and enzyme-histochemically. The results were compared with those observed in experimental anthracosilicosis in rats and with those seen in allergic-hyperergic reactions of the lung in guinea pigs (induced by several applications of the complete Freund adjuvans). A considerable increase in macrophages in the alveoli and interstices of the lungs with increased activity of acid phosphatase and oxydoreductases had occurred in every animal. None showed primary damage to type 2 pneumocytes. The results indicate that the two toxic agents differ in their capacity to induce fibrosis not because they interfere to a different degree with the clearing function of the lung or surfactant production, but because they differ in their capacity to stimulate fibroblast formation.