Population attributable fractions (PAFs) are widely used in cancer prevention, yet few studies have focused on how they could help quantify social determinants of health. Based on the example of occupational cancer, our interdisciplinary approach (epidemiology-sociology) builds on a review of the international literature, qualitative interviews with experts in the field, and the re-analysis of a case-control study conducted in France. The proportion of cancers attributed to occupational exposures varies from less than 2% to more than 8%. While a number of authors acknowledge the concentration of exposures among less qualified occupational groups, this dimension has not yet been integrated into PAF estimates. This blind spot is undoubtedly related to the paucity of data, together with mechanisms involved in the production of ignorance, well described in studies of the sociology of science. Our empirical work illustrates how lifecourse inequalities in occupational exposures could be effectively integrated into population health impact measures. © 2020 John Libbey Eurotext. All rights reserved.