We have performed a follow-up study of thoracic dust by personal measurements of about 3000 production workers in 24 cement plants in eight countries during the years 2007-2012. The thoracic fraction was chosen as the most relevant for the bronchial effects that are under study, since this fraction depicts the inhalation of dust into the deeper airways.

In 2007 a cohort of approximately 5000 employees in the same plants was established. The cohort was followed for of a maximum of 4.6 years with 1-2 additional spirometric investigations in addition to the measurements at inclusion. The cross-sectional analysis of the cohort at inclusion has been published.

In 2009 a more detailed study of different health-related aerosol fractions was performed. Personal measurements of respirable, thoracic, inhalable, and “total” dust were performed. Each person was carrying the aerosol samplers in a parallel set-up during each day of this sampling campaign. The purpose of this study was to establish conversion factors between our thoracic results and results found in other studies and former results from the plants.

The data will be analysed in order to estimate associations of exposure to thoracic dust and longitudinal decline in dynamic lung function and symptoms, in order to specify exposure levels where such associations may be detected.
The longitudinal study is in the phase of publication.