The vehicle exhaust exposure has been assessed for 38 job categories in Stockholm county. The assessment is semiquantitatively done is seven exposure levels retrospectively since 1940 by five independent industrial hygienists. General exhausts as well as diesel exhausts were assessed. A consensus estimation was performed to compose the base for individual calculation of exhaust exposure for cases and controls in the SHEEP study. The aim of this study is to validate independent exhaust assessment. The study will be reported in 1997.