Job function as determinant of clinker exposure at workplaces during cement production

Objectives In the cement production industry, exposure to airborne particulate matter is associated with a decline in lung function and increased airway symptoms. Exposure to clinker—the major constituent of cement and supposedly the cause of the observed adverse health effects—was determined recently in 15 cement production plants located in 8 different countries (Estonia, Greece, Italy, Norway, Sweden, Switzerland, Spain, Turkey). It was shown that the median clinker abundance in the thoracic fraction varied between approximately 20% and 70% for individual plants. The present study complements the previous work by investigating the significance of job function as a determinant of clinker exposure. Methods The elemental composition (water and acid-soluble fractions separately) of 1,227 personal thoracic workplace samples was analyzed by positive matrix factorization (PMF) to determine the contribution of different sources to the composition of airborne particulate matter and to quantify the clinker content. Results Median thoracic mass air concentrations varied for individual job functions between 0.094 and 12 mg/m3 (estimated separately for different plants). The PMF 5-factor solution yielded median relative clinker abundances in the personal thoracic samples between 7.6% and 81% for individual job functions. Thoracic clinker air concentrations are highest for cleaning, production, and maintenance work, and lowest...