[Passive smoking respiratory risk. A quantitative synthesis of the literature]. / Tabagisme passif et risque respiratoire. Une synthèse quantitative de la littérature.

Fifty nine scientific papers had been published in english or french literature, by 1988, on the matter of respiratory health effects of environmental tobacco smoke exposure (ETS). Fifteen dealt with lung cancer. An original meta-analytical approach was used in order to assess the consistency of these results, where the quality of the papers contributes to the weighing scheme, along with the traditional precision parameters. Lung cancer studies converge towards a point estimate of the relative risk (RR) near 1.5, contrasting non smokers exposed during a long time to ETS (mostly at home) and non exposed non smokers (95% confidence interval = 1.3-1.6). Important methodological difficulties did not allow, to date, to show consistent dose-effect relationship with duration or intensity of exposure. Chronic infections of lower respiratory tract related to ETS have been frequently observed (RR = 1.3; 1.2-1.4) as well among adults as among children. Wheezing and asthma are likewise more frequent among children exposed to ETS at home (RR = 1.2; 1.1-1.4). A modest, although statistically significant decrease of Forced Expiratory Volume at One Second is associated with passive smoking among children (mean effect = -0.5%). Health risk related to passive smoking are much lower than those caused by active smoking. However, this hazard should not be underlooked, since ETS is universally present in everyday life and since anyone may be exposed, including children, the elderly and those who suffer from chronic respiratory diseases. Many research needs are underscored by this meta-analysis. It remains that the current state of knowledge on health risks associated with passive smoking warrants that strong preventive action, educative or statutory, be promoted.

[Diagnostic radiology in mediastinal disorders : technical progress and current strategy (author's transl)]. / Le diagnostic radiologique des affections du médiastin evolution technique et stratégie actuelle.

After a brief reminder of recent progress in radiological methods in the diagnosis of mediastinal disorders, the authors study the contribution of Computerised Axial Tomography (T.D.M.). The advantages of T.D.M. in mediastinal disease rest on two characteristics : the morphological study of the mediastinum is made easier by the display of transverse axial cuts with nothing superimposed; the density measurements can distinguish between opacities which would appear similar on conventional radiology. Three facts have been established by the authors : T.D.M. raises the diagnostic sensitivity of radiology; in distinguishing between fatty, watery, vascular and solid tumours, it increases aetiological specificity; it simplifies the diagnostic approach while increasing the efficiency of radiology and the importance of its role in therapeutic decisions. In a typical case where one has just discovered an abnormal mediastinal opacity (and in whom a gastro-intestinal primary has been excluded), T.D.M. should be the first examination after standard radiography, because its results determine the remaining investigation. T.D.M. is specially indicated in evaluating a myasthenic or when investigating an anomaly in the infero-posterior mediastinum. A few cases do not entirely fit in to this schema, because of a particular clinical or radiological situation such as : mediastinal adenopathy; the assessement of the extent of a bronchogenic carcinoma; anterior cardio-phrenic opacities. The examination of the hila again has its limits when the abnormal opacity is small as there are errors in the technique due to the effects of incomplete volume. Finally, there remains the improved cost-effectiveness of the radiological examination of the mediastinum with the rational use of T.D.M.