Estimates of the proportion of bladder cancers attributable to occupation

In order to estimate the proportion of bladder cancers attributable to occupation in different countries, three criteria were defined, each with a different degree of strictness, for the inclusion of job titles or industrial activities in the estimates. Such criteria were applied to the available case-referent studies, the range for the less severe criterion estimates being 0-19% and that of the strictest being 1-19%. The variability was greater among the studies than among the criteria of inclusion of occupations; therefore the study design and time- and place-specificity of exposures play an important role in the magnitude of such estimates.