Inorganic Dust Research Articles

Desiccant Moisture Sorption as Altered by Dust

ABSTRACT THE moisture sorption characteristics of silica gel, activated alumina and a molecular sieve each having 0 percent and 5 percent dust were compared. Inorganic dust particles of 10 to 20 micrometers did not affect the equilibrium moisture content of either silica gel, ac-tivated alumina or molecular sieve. Dynamic moisture sorption rates of all three desiccants were reduced by dust contamination. The molecular sieve adsorbs moisture rapidly until saturation, unlike that described by the common falling rate sorption model. While silica gel and activated alumina may be useful in drying air for agricultural applications, the molecular sieve is least likely to be useful due to its low hygroscopic capacity.

Immunological mechanisms in pulmonary diseases

Although the subject of this symposium, IgE and Mechanisms in Immediate Hypersensitivity, is applicable to most of the common atopic respiratory diseases, there are many other respiratory diseases that are not necessarily IgE mediated. In this talk I shall briefly touch on the immunological mechanisms involved in the pathogenesis of some of these diseases including allergic alveolitis (hypersensitivity pneumonitis), the eosinophilic pneumonias and pulmonary fibrosis associated with certain connective tissue, inorganic dust, and occupational diseases.

Adsorption and catalysis at the solid/sulfur dioxide interface in the atmosphere. An examination of statistical data

From the official analytical data for sulfur dioxide and smoke in air pollution for one winter and one summer month covering residential and industrial areas in Great Britain, regression lines are computed. These reveal a large deficiency which is of very high significance of sulfur dioxide relative to smoke in winter compared with summer; the data show clearly that the deficiency is not due to the increase in domestic smoke in winter. Several reasons for the deficiency are examined semiquantitatively, and it is suggested that adsorption of sulfur dioxide occurs on solid particles followed by its catalytic oxidation by oxygen to sulfur trioxide. The amount of sulfur dioxide to be accounted for is far too high to be explained by simple adsorption on smoke particles. The catalysis may be due to traces of metals. The data also reveal that whatever may be the mechanism by which the sulfur dioxide is removed, it becomes less effective as the amount of smoke present increases, in all situations. It is suggested that a cause of this change might be the progressive covering of the very active surface of natural inorganic dust, possibly including meteoric dust, in the atmosphere by the less catalytically active smoke particles as their concentration rises.

Pulmonary granulomatoses due to inhaled particles: personal experience and some immunological considerations.

SummaryClinical, radiological, functional, laboratory and pathologic studies on 114 patients with bronchopulmonary granulomatoses due to inhaled particles are presented, together with measurements of the levels of IgA, IgG and IgM found in the sera of seventy‐three of the patients compared with those of forty blood donors used as normal controls. No differences were found between organic or inorganic dusts as causes in any of these parameters. There was, however, a significant increase in IgA and IgG compared with the controls. The possibility of a common pathogenic factor for this disease, independent of the nature of the causal agent is discussed.

Environmental Lung Disease

Environmental lung diseases are reviewed with regard to classification, diagnosis, the chest roentgenogram, special diagnostic procedures, pathology, and evaluation of pulmonary impairment. Causes of environmental lung diseases are classified as follows: inorganic dusts containing free silica, silicates, carbon, and inert metals; biological dusts; toxic chemicals; microorganisms; and occupational respiratory carcinogens such as arsenic, cobalt, nickel, asbestos, and uraniund. The prevalence of bronchogenic carcinoma due to radioactive uranium among miners in Czechoslovakia is discussed and it is pointed out that there is an increased prevalence of carcinoma among uranium miners in Utah and Colorado. (HLW)

Absorption of serum proteins by inorganic dusts.

Jones, B. M., Edwards, J. H., and Wagner, J. C. (1972).Brit. J. industr. Med.,29, 287-292. Absorption of serum proteins by inorganic dusts. Four samples of coal dust of different ranks, five types of asbestos, and a sample of silica were each incubated with normal serum and with IgG and the amount of protein absorbed onto the particle surfaces was estimated. The total amount of protein absorbed by the coal samples was not related to the rank of coal, and surface absorption by the dusts did not detectably alter protein to a form capable of reacting with rheumatoid factor, the latter finding being in disagreement with the hypothesis put forward by Payne (1963) to explain the presence of rheumatoid factor in the serum of a large proportion of coal workers with pneumoconiosis. Estimation of immunoglobulin levels after incubation of normal serum with 10 samples of coal suggested that IgG might be selectively absorbed, and RF was absorbed in preference to normal serum proteins by dust samples which had not been coated with normal serum.

The collection and analysis of inorganic dust downwind of source effluents.

Two directionally oriented high-volume samplers are used to pinpoint the collection of specific inorganic dusts from an industrial emission. One of the samplers is placed upwind of the source, and the other downwind. Both samplers are activated by winds blowing from the direction of the source to the downwind sampler. Both are de-activated when the wind shifts from the 30/sup 0/ sampling arc. Thus, the upwind sampler sees background dust, and the downwind sampler sees material originating from the source. Microsorban filters are used to collect the dust materials. The filter is then dissolved in benzene and the residue washed with benzene to remove the filter material and organic substances collected. The residue consists of dry, inorganic dust, which is then subjected to X-ray diffraction and optical microscopy, for analysis. This technique was successfully used to collect and analyze cement dust and mica dust from two separate industrial sources. The technique has promise for the analysis of a wide variety of inorganic materials which can be identified by X-ray diffraction, optical microscopy or other techniques. 6 references, 3 tables.

Determination of tetra-alkyl lead vapour and inorganic lead dust in air.

Methods are described for the determination of particulate lead and of tetra-alkyl lead vapour in air, by passing the atmosphere under test through a glass-fibre filter and then through a hydrochloric acid solution of iodine monochloride. Tetraethyl lead and tetramethyl lead are collected in this solution by means of their reaction with iodine monochloride to give the corresponding dialkyl lead ions. The lead collected on the filter is extracted with a nitric acid-hydrogen peroxide reagent, and the amount present is determined colorimetrically as lead dithizonate. This may be done automatically with the Technicon Auto-Analyzer, or manually with a comparator and a standard disc.Manual and automatic procedures are also given for the determination of the amount of tetra-alkyl lead collected. The manual method involves reaction of the dialkyl lead ions with dithizone at high pH and matching the colour of the dialkyl lead dithizonate with a standard disc. In the automatic procedure, the dialkyl lead is converted to the inorganic state before reaction with dithizone and colorimetric measurement as lead dithizonate.The methods are designed for the measurement of lead-in-air concentrations down to 0·1 mg of lead per 10 cubic metres of air, with sampling periods of at least 8 hours. A modified method based on a sampling period of half an hour, and having a sensitivity of 0·3 mg of lead per 10 cubic metres, is also described.

AIR POLLUTION AND ASTHMA.

The rapid growth of population and industry during the last 25 years has resulted in a marked increase of emissions into the atmosphere of a complex mixture of gaseous and solid materials which react not only with each other but with the atmosphere itself. These substances in the atmosphere breathed by man have become a subject of increasing concern to health authorities. The effects of air contaminants on health are difficult to assess. The concentration of air pollutants varies both chronologically and spatially, depending upon climate and atmospheric conditions. Individuals are exposed to varying levels of various pollutants during the course of a single day. It would appear reasonable to suppose that among those who might be most susceptible to the aspiration of pollutants would be those individuals who suffer from asthma. Until recently, allergists have been concerned with the most frequently recognized causes of allergic asthma, namely airborne molds, spores, pollens and dusts. More recently, in addition to these, the allergists are now giving consideration to industrial and urban air contaminants such as sulfur dioxide, carbon monoxide, hydrocarbons, oxides of nitrogen, ozone, many kinds of particulate matter, and other air pollutants. The sources from which these pollutants emanate are many and varied. A few of the more common ones are automobile traffic fumes, chemicals, vapors of dry-cleaning fluids, naphthalene flakes, paints, and gases from leaky heating, cooking and refrigerating equipment.l That there has been an increase in the variety of such substances discharged into the atmosphere is unquestioned. According to Criep, this increase in air pollution has been contributing indirectly to the severity of bronchial asthma and its complications.2 The effects of air pollution on asthmatics is especially evident in industry. Most cases of asthma found in industry have been attributed directly to inorganic and organic mineral dusts, fumes, and ~apors.~ Much of the information concerning the effects of air pollution upon allergy and asthma has been based on observations made in private clinical practice. More recently, epidemiological studies have been conducted in an effort to relate air pollution, and in some cases specific air-borne agents, to the causation of asthma.

USE OF SINGLE URINE SAMPLES FOR THE ASSESSMENT OF LEAD ABSORPTION.

The variation of urinary lead concentration (μg. Pb/litre) of short-period samples has been studied in a group of men exposed to inorganic lead dust. The urinary specific gravity was used to correct for the variation in urinary volume, but the residual variation was still too great to assess the mean lead concentration. The effect of creatinine correction was studied as an alternative, but there is no statistical difference between either method of correction. It is shown that the variation of lead concentration is related to the time of day. The highest concentration occurs at approximately 4.00 p.m. in day workers. The diurnal rhythm of the lead excretion rate (μg. Pb/minute) is described in day and night shift workers. The rate of excretion rises to a maximum at approximately 5.00 p.m. in the former but decreases in night workers, falling to a minimum at approximately 2.00 a.m. The rhythm is independent of immediate exposure and is thought to be physiological in origin. The plasma lead clearance is estimated at 1·4 ml. plasma per minute. This suggests that only a small proportion of plasma lead may be ultrafiltrable and that little lead is secreted by the tubules.

Lung Disease Caused by Inorganic and Organic Dust

Lung Disease Caused by Inorganic and Organic Dust

Experimental Study on Pneumoconiosis of the Rat : Histological Comparison of the Epithelial Proliferation by the Inhalation of Several Kind Inorganic Dust

Experimental Study on Pneumoconiosis of the Rat : Histological Comparison of the Epithelial Proliferation by the Inhalation of Several Kind Inorganic Dust

Epicuticle of blow-fly larvar.

IT is now clear that in many insects the epicuticle is the waterproofing layer of the cuticle. Although difficult to define morphologically1, it often carries a wax layer, removable by abrasion or adsorption. Rhodnius2 and Tenebrio3 undergo desiccation after removal of the wax layer by inert inorganic dusts; but blow-fly larvae are unaffected4, suggesting a different constitution of the epicuticle. Indeed, the habits of blow-fly larvae in liquefying the food in which they burrow suggests that the prime function of the epicuticle is other than the prevention of evaporation from the surface of the cuticle. Since the food is liquefied by the secretion on it of the digestive enzymes, it is desirable to discover whether or not a function of the epicuticle is to protect the underlying protein-containing endocuticle against digestion. The great chemical stability of the outer layer of the epicuticle is in agreement with such a view, for it is not dissolved by saturated potassium hydroxide solution heated to 160° C., or by cold concentrated hydrochloric or nitric acids. On boiling with concentrated nitric acid to which potassium chlorate has been added, however, it disrupts into oily droplets which stain with Sudan Black B. It therefore appears to be composed of the material termed cuticulin by Wigglesworth1,5.

Some New Properties of Inorganic Dusts

Some New Properties of Inorganic Dusts

The Performance Of Certain Inorganic Insecticide Dusts In The Control Of Cucumber Beetles

Journal Article The Performance Of Certain Inorganic Insecticide Dusts In The Control Of Cucumber Beetles Get access Harry F. Dietz, Harry F. Dietz Search for other works by this author on: Oxford Academic PubMed Google Scholar E. E. Zeisert E. E. Zeisert Search for other works by this author on: Oxford Academic PubMed Google Scholar Journal of Economic Entomology, Volume 28, Issue 2, 1 April 1935, Pages 310–314, https://doi.org/10.1093/jee/28.2.310 Published: 01 April 1935

SILICOSIS AND PRIMARY CARCINOMA OF THE BRONCHUS

Pneumonoconiosis includes all forms of pulmonary fibrosis occurring as a result of the inhalation of organic or inorganic dust. It is definitely an occupational disease and is rare outside of large industrial and mining districts. The group comprises: Anthracosis—inhalation of coal dust. Siderosis—inhalation of iron and steel dust (usually by metal grinders and polishers, nail and file makers, and so on). Chalicosis or silicosis—inhalation of stone dust (usually by stone workers, such as potters, grinders, plasterers, porcelain makers or quarry workers). This report is concerned with chalicosis or silicosis. Under normal conditions the lung is fairly well protected from ordinary amounts of city dust. This protection is effected by the action of the ciliated epithelium, phagocytes, mucous secretions, and the cells of the bronchial tubes. However, in persons who work in atmospheres heavily laden with dust these protective mechanisms are insufficient and depositions of the particles occur.

Pneumonoconiosis

PNEUMONOCONIOSIS is a lung disease due to inhalation of minute particles and characterized pathologically by fibroid induration and pigmentation. Although it has been known for many years (Ramazzini, 1703) that dust inhalation incident to certain occupations and trades is accompanied by varying forms of pulmonary fibrosis, still it is only within the last half-century or over, with its enormous industrial development, that pneumonoconiosis has assumed importance as a disabling disease. The different types of pneumonoconiosis vary in relation to the industry: thus, we meet with anthracosis in coal miners, silicosis in rock drillers, asbestosis in asbestos workers, siderosis in gold miners, byssinosis in cotton mill workers, etc. In each of the industries mentioned, these factors, in the order of increasing importance, tend to cause the development of pulmonary fibrosis (pneumonoconiosis). 1. (1) Shape.—The sharp angular particles exert an irritative action on the lungs and are more dangerous potentially, although this is disputed by some authorities. 2. (2) Size.—Small particles below 10 microns, other things being equal, are more hazardous. 3. (3) Extent of Exposure.—The time element requisite for the development of pneumonoconiosis in the dusty trades varies in different industries, in some as low as two years or even less. 4. (4) Number of Dust Particles per Cubic Foot of Air.—It has been estimated that if the number exceeds ten or fifteen millions, the development of pneumonoconiosis is likely; if twenty millions or over, it is almost certain, unless preventive measures are adopted. 5. (5) Physio-chemical Properties.—(A) organic dusts; (B) inorganic dusts. (A) Some authorities are of the opinion that they play no part in the production of pneumonoconiosis, yet pulmonary fibrosis as a result of cotton-mill-dust inhalation is a recognized form of pneumonoconiosis. It is held by most writers that this is due to the admixture of inorganic particles with the organic dust. (B) These differ in their potency, as, for example, coal and lime (15) are relatively benign, while silica dust is regarded as the most dangerous. Indeed, the view is held that in all dust inhalation the silica content is the main fibrosing agent. Heffernan (7) is of the opinion that when the silica dust is deposited in the alveoli of the lungs, it is acted upon by the alkaline fluids and transformed into colloidal silica, which exerts a deleterious action on the pulmonary tissue. He further believes that the pulmonary fibrosis encountered in asbestos workers is due to a transformation of the silicates in asbestos into colloidal silica. Silicosis according to this hypothesis results from the action of colloidal silica on the pulmonary tissue, and the acuteness or chronicity of the process depends largely upon the silica concentration and the rapidity with which it is transformed into silica sol.

GLYCERIN PLATE FOR DETECTING NONPOLLEN TYPE OF ASTHMA

To the Editor: —The value of the glycerin microscopic slide for the trapping and identification of air-borne pollen has long been known. I have also found this device of value in the handling of difficult chronic, nonpollen types of hayfever and asthma, especially those sensitive to animal hairs. The glycerin traps not only pollen and inorganic dusts, but also hair, fine feather particles, and fibers of wool, silk, cotton and linen, all of which can be easily identified microscopically with a little practice. They will be found unexpectedly at times in excessive quantity under conditions in which their absence seems so certain as to make them an inconsequential factor. If the slides are stained with compound solution of iodin, unsuspected pollen granules also will be found, if present. If the slides are set out in a patient's room or on the window sill for twenty-four hours, the comparative presence or

MINERS' SILICOSIS: ITS PATHOLOGY, SYMPTOMATOLOGY AND PREVENTION

Dust as a causative agent in the production of lung diseases has been known by writers of medicine from early times. Ramazzini, that pioneer observer of diseases of artificers, published in 1700 a treatise on the effect of dust inhalation. Stratton, in 1838, proposed the name of anthracosis to designate the condition found in coal miners as a result of inhaling coal dust, the term silicosis being applied to miners' consumption produced by quartz, flint and other silicon dusts. Probably the application of the term pneumonoconiosis, as proposed by Zenker in 1867, should be the proper nomenclature in occupational medicine for all inorganic and organic dusts that produce lung disease among workers. The experimental work and observations of Haldane 1 and of Mavrogordato 2 particularly revealed a new aspect of the problem as to how pneumonoconiosis is developed, and in view of the recent investigations of the fundamental changes arising

MILK SEDIMENTS OR DIRTY MILK IN RELATION TO DISEASE.

Every consumer of milk has doubtless observed the presence of more or less foreign matter at the bottom of the bottle in which it is kept; indeed, it is a matter of such common occurrence that it hardly excites our attention, and many are disposed to look on it as a matter of course. Professor Soxhlet of Munich was perhaps the first to point out that these deposits are largely made up of the excrementitious matter from the cow, which adhering to the udder of the animal, gained access to the bucket during the act of milking. If these sediments are subjected to microscopical examination we will find that they are composed of epithelial debris, hairs of the cow. organic and inorganic dust particles, excrementitious matter, vegetable fibers, bacteria, fungi and spores of every description: fully 90 per cent. of the germs are fecal bacilli—all of which is not only