Registry of workers

A recruitment database was created and progressively filled in upstream from and during the whole recruitment campaign. This file gathered relevant information on the company workforce and contact details from managers and/or health and safety specialists. Emphasis was made on the recruitment of workers from companies with known exposure to nanomaterials, while ensuring sample representativeness and between-company comparability of working conditions. This implies a priority focus on the recruitment of companies with the biggest workforce size, i.e. ensuring homogeneity in terms of external exposure nature and extent. Moreover, priority was given to the recruitment of companies concerned with ENM. Companies concerned with incidental and environmental exposure to UFP will be recruited in a second step, and only when the required worker population size cannot be reached otherwise.