• International Agency for Research on Cancer (IARC), Lyon
• Collaborators of 7 countries contributing to the multi-centre nested case-control study

• European Asphalt Pavement Association (EAPA)
• The European Bitumen Association (Eurobitume)
• CONCAWE
• Asphalt Roofing Manufacturers Association (ARMA)
• National Roofing Contractors Association (NRCA)
• National Asphalt Pavement Association (NAPA)

Assessment of historical exposure to known and suspected carcinogens in a nested case control study among workers exposed to bitumen.

• Statistical analyses of an elaborated inhalation exposure measurement database (AWE)
• Updating Road Construction Workers' Exposure Matrix
• Elaboration Bitumen Workers Dermal Exposure Matrix
• Elaboration of a Chemical Confounders Exposure Matrix
• Assignment of exposure to cases and controls
• Sensitivity analysis of exposure-response relations

The objective of the case-control study is to improve the investigation of mortality from lung cancer among members of the multi-centre European Asphalt Workers cohort study. This will be achieved by collecting more detailed information on occupational and non-occupational factors for all cohort members who died from (or were diagnosed with) lung cancer (the cases) and for a sample of cohort members free from lung cancer (the controls).

The overall motivation behind the case-control study is to improve exposure assessment with respect to the work done in the cohort phase of the study. Information gathered in the cohort study (exposure database, exposure models, job histories) will be used as much as possible in order to focus exposure assessment efforts of the case-control study. Thus, exposure assessment in the case-control study is envisioned as an organic continuation of the work already done in the cohort study.

Improvements in the assessment of exposures within the asphalt industry will be achieved by pursuing the following specific objectives:

1. obtaining better information on the exposures of cases and controls in asphalt companies not included in the cohort;
2. enhancing the accuracy of inhalation exposure estimates for bitumen fume and coal tar;
3. deriving dermal exposure estimates for bitumen condensate and coal tar.

The assessment of exposures in other industries will be achieved by pursuing the following specific objectives:

1. obtaining information on the jobs held by cases and controls in non-asphalt companies;
2. deriving individual estimates of exposure to known and suspected lung carcinogens.

The assessment of extra-occupational exposures will be achieved by obtaining information on socio-demographic characteristics and tobacco smoking habits held by cases and controls.

The main hypothesis to be tested in the case-control study will be whether the risk of lung cancer is increased according to estimated exposure (both by inhalation and dermal uptake) to bitumen fume, coal tar, total polycyclic aromatic hydrocarbons (PAH) or other agents occurring in the asphalt industry, while adjusting for the estimated carcinogenic effect of tobacco smoking and exposure to other known and suspected lung carcinogens.