The aim of the study is to present the principles of assessing asbesto
s exposure ill two different contexts: that of a patient suffering fro
m pleuropulmonary pathology that could be attributed to asbestos and t
hat of a group possibly exposed to asbestos. In the first case this ev
aluation concerns past exposure and depends typically on information o
btained during rite course of an interview with the patient. in the se
cond case, the exposure is assessed by atomospheric analysis. Jobs in
which occupational exposure to asbestos occurs should be examined, the
tasks which entail this exposure and objects containing asbestos are
discussed in the first part of the article. The accent is placed on th
e source of exposure, and the use of materials containing asbestos out
side the asbestos industry. Some guidelines enabling the appreciation
of the intensity of asbestos exposure as a function of the jobs involv
ed and the objects handled are suggested. Regulations and the principl
e of quantifying asbestos in the atmosphere during direct exposure in
the working environment oil the one hand and during the course of pass
ive exposure in the environment on the other are discussed in the seco
nd parr of rite article.