Estimation of exposure

To estimate the proportion of workers exposed to carcinogens for lung cancer and leukaemia, we use the exposed proportions  of workers in the industrial sectors or occupations who were exposed to the carcinogens (from CAREX, a European survey described below in Section 5.2).  This was  the approach recently used in a global estimate of the disease burden (Ezzati et al., 2002; WHO, 2002; Concha-Barrientos et al., 2004).  However, should exposure data be available for the national or local level, they should be used instead of the CAREX data.  For the CRA project (Concha-Barrientos et al., 2004), routine employment data were used to determine the proportion of people in each industrial sector.  The exposed populations were then divided into high and low exposure groups.  This information was then combined with the CAREX data to estimate the proportion of workers exposed at high or low levels to the carcinogens.

Ideally, the above information should come from data assessed in the country or study area, particularly the first three requirements, but since this is not always possible values based on the global analysis can be used (Concha-Barrientos et al., 2004).