Cement and concrete - 213 entries found
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El-Shobaki F.A., El Sewefy A.Z.
The effect of exposure to asbestos dust on iron metabolism in Egyptian workers.
Results of observations carried out on a random sample of 42 workers in an Egyptian asbestos cement pipe factory, constantly exposed to asbestos dust and periodically to quartz and cement dust for 10-38 years, and all showing clinical and radiological evidence of asbestosis and/or mixed pneumoconiosis. 10 non-exposed workers were used as controls. Haematological studies showed that haemoglobin level was not affected by exposure to asbestos; on the contrary, mean haemoglobin erythrocyte concentration and mean erythrocyte volume were higher than normal. Fasting serum iron and percentage of transferrin saturation were low. Rate of iron absorption from the gut and serum transferrin level were enhanced in the exposed workers. The authors suggest the existence of a state of polycythaemia due to anoxia. A haemolytic action of asbestos dust on the erythrocytes seems to be evidenced by the relatively high values of serum total bilirubin, mean haemoglobin erythrocyte concentration and mean erythrocyte volume.
Medicina del lavoro, Nov.-Dec. 1973, Vol.64, No.11-12, p.417-422. 20 ref.
Study of cutaneous sensitivity to various cements among dermatitis sufferers.
Etude de la sensibilité cutanée à des ciments différents chez des porteurs de dermite. [in French]
The first part of this MD thesis is devoted to a study of cement (raw materials, manufacture, chemistry, classification), reviewing present-day theories concerning its allergenic effects and stressing the role of chromium as the principal allergen. The next part deals with the chemistry (potassium dichromate), allergenic properties and origin of chromium; the following part refers to the discrepancy between the results of tests with chromium and with cement, demonstrating that the effects of chromium cannot explain all the cases of cement dermatitis and pointing to the existence of other factors (orthoergic, microbial). The last part describes the author's own research methods and results: in an attempt to elucidate the above discrepancy, she tested 64 subjects suffering from cement dermatitis with 9 different cements. She emphasises the necessity for carrying out such tests under rigorous conditions and puts forward the hypothesis that the ageing of cement and its clinker content may have some influence.
Université Paris VII, Faculté de médecine Lariboisière - St. Louis, Paris, France, 1973. 85p. 58 ref.
Weill H., Waggenspack C., Bailey W., Ziskind M., Rossiter C.
Radiographic and physiologic patterns among workers engaged in manufacture of asbestos cement products - A preliminary report.
An investigation of 908 workers in the asbestos-cement industry shows that with exposure to mixed dust containing asbestos and silica, radiographic patterns include small rounded, as well as irregular and linear opacities. Preliminary analysis reveals that higher cumulative exposures are associated with a higher incidence of both types of opacity. Findings are consistent with the hypothesis that the small rounded opacities are primarily due to silica exposure, while irregular opacities indicate a predominant asbestos effect. The study aims also at relating the varying degrees of pulmonary function impairment to the different radiographic patterns.
Journal of Occupational Medicine, Mar. 1973, Vol.15, No.3, p.248-252. Illus.
Fire and explosion hazards of dusts in the handling of aluminium powder during the manufacture of gas concrete
Staubbrand- und Staubexplosionsgefahren bei der Handhabung von Aluminiumpulver zur Gasbetonherstellung [in German]
Report by the Federal Institute for Materials Testing, Berlin, on safety engineering techniques in the handling of aluminium powder used in the manufacture of gas concrete. Research on explosion pressure (up to 9 at), rate of pressure rise, self-ignition temperature of the air-aluminium mixture (570°C), conditions of combustion and burning of aluminium powder stored in bulk, and the effect of controlled atmosphere from the beginning. Recommendations are given for the preparation of preventively neutralised aluminium powder for safety measures for the prevention of dust explosions (explosion venting, remote control).
Die Industrie der Steine und Erden, Apr. 1973, Vol.83, No.4, p.84-88. 8 ref.#fx, Hannover, Germany (Fed.Rep.), Apr. 1973, Vol.83, No.4, p.84-88. 8 ref.
Cases of silicosis diagnosed by the medical officers of APAS-Paris in workers exposed to concrete dusts
Cas de silicose dépistés par les médecins du travail de l'APAS-Paris chez des travailleurs exposés aux poussières de béton. [in French]
The author confirms the silicogenic character of all concrete dusts and reports, in 2 tables, the results of an analysis of 19 dust samples taken at demolition and concrete grinding posts. He quotes 4 detailed studies concerning cases of silicosis diagnosed among persons working with concrete. Systematic radiological supervision is essential for the 2 most exposed occupations: concrete grinders and concrete demolishers.
Revue de médecine du travail, 1972, Vol.1, No.2, p.51-56. Illus.
Contribution to the study of pulmonary silicosis among building workers - Causality of certain kinds of work on concrete
Contribution à l'étude de la silicose pulmonaire chez les ouvriers du bâtiment - Responsabilité de certains travaux sur le béton. [in French]
M.D. thesis. Describes 6 cases of silicosis which could only have been contracted as a result of resurfacing stonework and of grinding work on concrete surfaces, finishing and grinding floors made of marble or substances derived from marble. Average duration of exposure was 7 months to 4 years, i.e. exposure of short duration. Radiological examination showed similar pictures (micronodulation). Ventilatory insufficiency was relatively discrete. 3 other cases relate to workers engaged in repairing wine vats in enclosed atmospheres. Technical and medical preventive methods applicable to any workplace or job involving exposure to silicosis hazard should be strictly observed, and new and less hazardous methods for smoothing concrete surfaces should be used in future.
Université de Paris VI, Faculté de médecine Pitié-Salpêtrière, Paris, France, 1972. 32 p. 37 ref.
Bühne K.W., Düwel L.
Measurement of dust emissions in the cement industry using the Sick RM4 smoke density measuring instrument
Registrierende Staub-Emissionsmessungen in der Zementindustrie mit dem Rauchdichtemessgerät RM4 der Firma Sick [in German]
Description of a rotary cement kiln, the instrumentation used and the test conditions. Measurements, which lasted for a period of 3 months, were carried out using photoelectric smoke-density measuring instruments which work on the extinction principle. The measurement results are discussed with the aid of diagrams. Using comparative gravimetric measurements, the relationship between the recorded extinction and the gramimetric dust content was determined for all situations occurring during the operation of the cement works; there was a definite linear relationship between extinction and dust concentration.
Staub, Aug. 1972, Vol.32, No.8, p.329-334. Illus. 11 ref.
Bott W., Hampel A.
Accident prevention in the manufacture of concrete, steel-reinforced concrete and pre-stressed concrete pipes
Unfallverhütung bei der Herstellung von Rohren aus Beton, Stahlbeton und Spannbeton [in German]
The most commonly used processes, machines and equipment for the manufacture of concrete pipes are critically reviewed from the occupational safety point of view: coreless moulding, vibration process, vibration-moulding process, radial-compression process, roller-head process, centrifugal process and other special processes for pre-stressed concrete pipes; manufacture of steel reinforcement; processing of finished pipes; slinging; testing. Accidents are illustrated by photographs and practical examples, and suitable safety measures are indicated.
Die Industrie der Steine und Erden, Sep. 1972, Vol.82, No.9, p.212-232. Illus. 16 ref.
Fregert S., Gruvberger B.
Chemical properties of cement
The chemical properties of cement were studied to determine whether it is possible to minimise the content of sensitising components. Following a description of cement manufacture and composition and an anlysis of the processes involved in cement hydration, the authors present the methods used in the analysis of 52 Portland cement samples from 9 countries, together with the results obtained. Chromium, cobalt and nickel were determined by atomic absorption spectrometry which can be used in an alkaline medium and allows trivalent and hexavalent chromium to be differentiated. No correlation was found between water-soluble hexavalent chromium to be differentiated. No correlation was found between water-soluble hexavalent chromium content and total chromium. It is concluded that certain, as yet unknown, chemical factors determine the proportion of total chromium that becomes water-soluble.
Berufs-Dermatosen, Oct. 1972, Vol.20, No.5, p.238-248. 53 ref.
Importance of dermatitis flare-ups in workers with "bricklayer's hand" - results of a field study
Importance des poussées de dermite chez les travailleurs atteints de "main du cimentier" - Résultats d'une enquête sur les lieux de travail [in French]
Paper read at the XIIth National Seminar on Occupational Medicine in Building and Civil Engineering, Paris, 20-23 May 1971. Only the most serious cases of bricklayer's itch come to the occupational physician's attention. Minor forms are nevertheless the cause of inconvenience, suffering and absenteeism. To determine the incidence and consequences, the authors carried out a study of over 300 workers exposed to cement and suffering from "bricklayer's hand"; these were followed up for 10 weeks in winter and summer. The effect of various parameters (seasonal in particular) was examined. During the survey, 14 of the subjects underwent acute flare-ups. On a yearly basis, the incidence of the disease would be around 25%. The 6 new cases of dermatitis recorded indicate that the incidence of new cases in previously unaffected workers handling cement is 10%. (For the proceedings of this seminar, see CIS 73-505.)
XIIth National Seminar on Occupational Medicine in Building and Civil Engineering, Paris, France, 1971. Vol.8, No.4 (special), p.600-620. Illus. 5 ref.
The eradication of bricklayers itch - the effect of gloves and a local anticholinergic agent
Vers l'éradication de la gale du ciment - Effet du port des gants et d'un anticholinergique local [in French]
Paper read at the XIIth National Seminar on Occupational Medicine in Building and Civil Engineering, Paris, 20-23 May 1971. Results of a study to determine whether the wearing of 2 super-imposed gloves (one of which, made from jersey, is in contact with the skin and impregnated with an anticholinergic cream), improves the dermatological condition of bricklayers' hands suffering from dermatitis, and reduces acute flare-ups. The study covered 39 subjects (22 of whom did not wear gloves before the test) who had an average of 21.4 years exposure to cement. The group of 22 subjects was itself broken down into 2 sections (12 subjects who wore gloves during the test and 10 who used only the cream). The cream without gloves is dermatologically as effective as impregnated gloves but no more so than a regular washing of the hands. On the other hand, none of the subjects protected by cream, with or without gloves, suffered an acute dermatitis flare-up. (For the complete proceedings of this seminar, see CIS 73-505.)
Bulletin du Groupement national d'étude des médecins du bâtiment et des travaux publics, XIIth National Seminar on Occupational Medicine in Building and Civil Engineering, Paris, France, 1971. Vol.8, No.4 (special), p.788-811. 11 ref.
Sertoli A., Panconesi E., Fabbri P.
Possible measures for the prevention of cement dermatitis
Possibilités de réalisation de la prévention des dermites de ciment [in French]
Paper read at the XIIth National Seminar on Occupational Medicine in Building and Civil Engineering, Paris, France, 20-23 May 1971. the various methods used so far to prevent cement dermatitis have all been aimed at modifying the physical and chemical characteristics of the chromium hapten, either in the cement or on the skin. The authors review these methods and report on their own experiments on barium chloride (BaCl2) and 2-mercaptopropionylglycine. The definite effectiveness of these substances was brought to light. The authors emphasise the need to make allowance for the cost of the preventive measure and for the changes in the technical characteristics of cement to which these substances have been added. (For the complete proceedings of this seminar, see CIS 73-505.)
Bulletin du Groupement national d'étude des médecins du bâtiment et des travaux publics, XIIth National Seminar on Occupational Medicine in Building and Civil Engineering, Paris, France, 1971. Vol.8, No.4 (special), p.765-779. Illus. 6 ref.
Heavy prefabrication and safety [France]
Préfabrication lourde et sécurité [France] [in French]
This brochure, designed for supervisory staff at all levels of the profession, is a collection of accident-prevention advice for heavy prefabrication. It reviews the various hazards and their prevention: panel prefabrication (traffic aisles, mould stripping, miscellaneous problems, provisional storage); storage (stresses involved, various storage techniques, transport); lifting eyes (eyes cast into the panel, removable eyes, lifting without eyes, lifting hooks); transport; installation; falls from a height. The text is supplemented by 144 photographs illustrating hazardous situations and suitable safety measures.
Institut national de recherche et de sécurité, 30 rue Olivier-Noyer, 75680 Paris Cedex 14, France, 2nd quarter 1972. 118p. Illus.
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