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Biomedical subjects

G Bonnaud

Publications and source records attributed to G Bonnaud.

At least 37 records · Page 2Linked to original sources
PubMed1980

An attempt to determine a medium-term, low-dose asbestos exposure indicator on the basis of clinical and radiological lung changes.

Three groups of people working in buildings with insufficient protection against sources of asbestos (ceilings, lagging, cupboards, etc.) have been compared by clinical and radiological examinations. The first group, G1 (n = 160), comprised people working in direct contact with sources of asbestos; the second one, G2 (n = 277), comprised people who had worked for at least 10 years in buildings with little protection; and the third one, G3 (n = 157), may be considered a control group, since the only period of exposure was while the buildings were being constructed. The prevalence of lung abnormalities (clinical, functional and radiological) was higher in G1 than in G3; G2 was closer to G1 for some signs, but closer to G3 for most. These differences are no explained by obvious possible confounding factors (such as age, sex or tobacco consumption). They were analysed taking the number of years of presence in the buildings into account.

Asbestos↗
PubMed1979

Levels of asbestos air pollution in some environmental situations.

Asbestos contamination of the outside aid in Paris and suburbs has been monitored in some environmental situations, namely, "typical" urban sites removed from known sources of asbestos emissions, crossroad locations, the vicinity of a freeway, areas with buildings under construction, and areas around asbestos factories. In the same manner, measurements have been performed inside buildings of various types: those sprayed with asbestos-containing materials, those fitted with asbestos products, and control buildings. Air has been sampled by use of 0.45 micrometer pore size Millipore filters. After low-temperature ashing, ultrasonicated ashes were transferred to carbon film on 200-mesh gold grids examined under an analytic transmission electron microscope. Levels of pollution were expressed in terms of gravimetric concentrations. Inside buildings, when the air was in contact with significant amounts of asbestos-containing materials (spray, sheets), the levels were in the range 0.1--1000 10(-9) g m-3. In the vicinities of asbestos plants, the concentrations were higher: 1000--3000 10(-9) g m-3. Under other circumstances, the levels were of the same order of magnitude: 99% of the values were below 7 X 10(-9) g m-3. The Conseil Supérieur d'Hygiène Publique de France proposed a numerical ambient air quality standard of 50 X 10(-9) g m-3 inside buildings sprayed with asbestos.

Air Pollutants↗
PubMed1979

[Mucoepidermoid tumors in the bronchi. About three cases (author's transl)].

The little frequent mucoepidermoid tumors in the bronchi can be distinguished by their histological characteristics associating epidermoid and mucilage-like cells identified through alcian blue and PAS colour agents. Although these tumors are normally considered as "benign", some of them may have a capacity to develop in very malign way. We enclose three new findings which all developped unfavorably in a short period.

Bronchial Neoplasms↗
PubMed1978

[Use of the transmission electron microscope in the analysis of wine contamination by asbestos].

A method for assessing chrysotile asbestos fibers in wines is described. Particles are isolated from wines samples by means of microfiltration through Nuclepore membrane. Retained particles are entrapped in a carbon layer which is observed under a transmission electron microscope fitted with an energy dispersive spectrometer. Chrysotile fibers identification is based on the determination of three characteristics- namely, morphology, elemental composition and crystal structure. Fibers are counted and measured (length and diameter) on an aliquot of the preparation area: numerical concentrations and their statistical significance are calculated. Several factors affect the accuracy and precision of this method. The feasibility for numerous laboratories to use this method is discussed.

Asbestos↗
PubMed1977

[Incidence and evaluation of the risk of coronary disease. Prospective study in Paris].

The Paris prospective study in an epidemiological study of 7,453 middle-aged men born in France, and initially free from ischaemic heart disease. The current mean follow-up time is 4 years. The mean annual incidence is 5.1 per 1000, which is about one half that found in similar american studies. This incidence is related to the cholesterol level, to the blood pressure, to cigarette consumption when the smoke is inhaled, to diabetes mellitus, and to major abnormalities on the electrocardiogram. These five factors are mutually independant in their prediction of the risk of future illness. A formula has been derived by statistical analysis, and takes these five factors into account: the incidence of illness rises exponentially as a function of this formula. New cases of ischaemic heart disease are distributed, but with a very patchy incidence, in this population, of which only a very small number remain disease-free. A table has been drawn up to show the probability of a middle aged male contracting ischeamic heart disease within 4 years, and takes the 5 factors into account: this probability varies between 0.5 per cent and 34 per cent.

Adult↗
PubMed1976

[Prognostic value of ischemic changes of the electriccardiogram during and after exertion in an active male population].

As part of the first examination conducted in the Paris Prospective Study, 6 565 healthy males aged between 42 and 53 years underwent a submaximal exercise test on the bicycle ergometer. Ischaemic changes in the ST segment during or after exercise were noted in 6% of the tests. The predictive value of these changes for the development of ischaemic heart disease after 4 years has been assessed. The risk of sequelae is 3.2 times greater in this group than in the group with no changes. The variations of this risk with the precise timing of the onset of these ischaemic ST segment changes during the course of the test and with the type of heart disease have been studied.

Adult↗
PubMed1975

Topographic distribution of asbestos fibres in human lung in relation to occupational and non-occupational exposure.

A topographic study of asbestos fibre content of lung and pleura of diversely exposed cases has been carried out. For heavily exposed cases with lung fibrosis, this study has stressed the distinctive behaviour of the peripheral lower lobe in the retention of asbestos fibres in the lung. In these areas were found the smallest asbestos concentrations but the largest fibres. For cases without lung fibrosis, the results clearly demonstrated an accumulation of asbestos fibres, especially of chrysotile type, in peripheral areas. These findings are to be related to the incidence of pleural mesothelioma associated with moderate or low exposure. The small variation of fibre concentration in the pleural plaques of diversely exposed subjects is pointed out.

Adult↗