silicon and Respiratory-Tract-Diseases

Consideration of the human epidemiology of diseases arising from exposure to naturally occurring and man-made mineral fibers encompasses the several forms of asbestos (chrysotile, crocidolite, amosite, anthophyllite, tremolite-actinolite), other naturally occurring silicates (talc, sepiolite, erionite, attapulgite, vermiculite, and wollastonite), and man-made mineral fibers (glass continuous filament, glass/rock/slag insulation wools, ceramic and other refractory fibers, and glass microfibers). The diseases arising from exposures to some of these fibers include pleural thickening (plaques, diffuse pleural thickening, and calcification), pulmonary fibrosis, lung cancers, mesothelioma of the pleura and peritoneum, and other cancers). Risk factors important in assessing these diseases include assessment of latency, duration of exposure, cumulative exposure, fiber origin and characteristics (length and diameter), other possible confounding occupational or environmental exposures, and smoking. Methodological issues commonly presenting problems in evaluation of these data include assessment of the adequacy of environmental exposures, particularly in regard to fiber identification, distribution, and concentration over the duration of exposure, and the adequacy of study design to detect health effects (disease frequency, latency, and cohort size). Research priorities include further assessment and standardization of pleural thickening relative to fiber exposure, uniform mesothelioma surveillance, further epidemiological assessment of certain silicate and man-made mineral fiber cohorts with emphasis given to assessment of tremolite and small diameter glass and ceramic fibers. Further assessment of possible health risks of the general public should await improved definition of relevant fiber exposure in ambient air.

Topics: Asbestos; Asbestosis; Humans; Lung Neoplasms; Mesothelioma; Minerals; Neoplasms; Pleural Diseases; Respiratory Tract Diseases; Silicon

The article covers data on levels of oxidative and antioxidant processes under influence of low fibrogenous dust in workers at steel mills. Reliable differences were seen between groups of workers with different dust load, dust particles size in blood, acitvity level of lipid peroxidation products occurrence--that worsens inflammatory reaction and dysfunction of lower respiratory tract. Findings are that occupations--preparation of steelpouring mixtures, converter melters, batchers--with highest silicon content of blood, if compared to other occupations and to the reference group (1.6 and 2.9 times respectively), demonstrated more intense change in parameters of oxidation processes activation (increased level of lipid hydroperoxide and malonic dialdehyde) with depressed antioxidant defense (lower level of general antioxidant defense).

Topics: Adult; Antioxidants; Dust; Female; Humans; Male; Metallurgy; Nanoparticles; Occupational Diseases; Particle Size; Respiratory Tract Diseases; Silicon; Steel; Workforce

Topics: Adult; Aluminum Silicates; Calcium Hydroxide; Health Education; Health Promotion; Humans; Magnesium; Magnesium Compounds; Male; Middle Aged; National Institutes of Health (U.S.); Occupational Diseases; Research; Respiratory Tract Diseases; Risk; Silicon; Silicon Compounds; Smoking; United States; Workers' Compensation

Chest x rays, smoking histories, and pulmonary function tests were obtained for 171 men employed in the manufacturing of silicon carbide. A lifetime exposure to respirable particulates (organic and inorganic fractions) and sulphur dioxide was estimated for each worker. Chest x ray abnormalities were related to respirable particulates (round opacities) and to age and smoking (linear opacities). Pulmonary function was affected by respirable particulates (FVC) and by sulphur dioxide and smoking (FEV1). Pleural thickening was related to age. No exposures exceeded the relevant standards; we therefore conclude that the current standards do not provide protection against injurious pulmonary effects, at least in this industry.

Topics: Adult; Air Pollutants, Occupational; Carbon; Carbon Compounds, Inorganic; Chemical Industry; Environmental Exposure; Humans; Lung; Male; Middle Aged; Occupational Diseases; Radiography; Respiratory Function Tests; Respiratory Tract Diseases; Silicon; Silicon Compounds; Smoking; Sulfur Dioxide

Topics: Acute Disease; Air Pollutants, Occupational; Chemical Industry; Environmental Exposure; Humans; Maximum Allowable Concentration; Occupational Diseases; Occupational Medicine; Respiratory Tract Diseases; Silicon; USSR

Topics: Cardiovascular System; Chemical Industry; Environmental Exposure; Humans; Mouth Diseases; Mouth Mucosa; Occupational Diseases; Respiratory Tract Diseases; Silicon