[Prevention of occupational tumors: an update].

A review is made of studies on occupational cancer conducted in different countries in order to compare estimates of the attributable risks (i.e., the proportion of cancers occurring in the general population due to occupational exposure), and to identify the sources of variation. Estimates vary according to several factors, including different study designs and chiefly, different proportions of exposed workers in the geographical areas that have been investigated. For lung cancer, estimates ranged between 1 and 35%, with values of 10-15% occurring frequently; for bladder cancer, the range was between 1 and 19%. The implications of this variability in prevention programmes are discussed and the problems encountered in the identification and compensation of occupational cancer are examined.