title: Exposure to thoracic aerosol in a prospective lung function study of cement production workers.
abstract: BACKGROUND
  An exposure study was conducted as part of a multi-national longitudinal study of lung function in cement production workers.
  
  
  OBJECTIVE
  To examine exposure to thoracic aerosol among cement production workers during a 4-year follow-up period.
  
  
  METHODS
  Personal shift measurements of thoracic aerosol were conducted among the cement production workers within seven job types, 22 plants, and eight European countries (including Turkey) in 2007, 2009, and 2011. The thoracic sub-fraction was chosen as the most relevant aerosol fraction related to obstructive dynamic lung function changes. Production factors, job type, and respirator use were recorded by questionnaire. The exposure data were log-transformed before mixed models analysis and results were presented by geometric mean (GMadj) exposure levels adjusted for plant or job type, worker, and season as random effects.
  
  
  RESULTS
  A total of 6111 thoracic aerosol samples were collected from 2534 workers. Repeated measurements were obtained from 1690 of these workers. The GMadj thoracic aerosol levels varied between job types from 0.20 to 1.2mg m(-3). The highest exposure levels were observed for production, cleaning, and maintenance workers (0.79-1.2mg m(-3)) and could reach levels where the risk of lung function loss may be increased. The lowest levels were found for administrative personnel (0.20mg m(-3)) serving tasks in the production areas. Office work was not monitored. GMadj exposure levels between plants ranged from 0.19 to 2.0mg m(-3). The time of year/season contributed significantly to the total variance, but not year of sampling. Production characteristics explained 63% of the variance explained by plant. Workers in plants with the highest number of employees (212-483 per plant) were exposed at a level more than twice as high as those in plants with fewer employees. Other production factors such as cement production, bag filling, and tidiness were significant, but explained less of the exposure variability. These determinants factors can be useful in qualitative exposure assessment and exposure prevention in the cement production industry. Respirator use was minor at exposure levels <0.5mg m(-3) but more common at higher levels.
  
  
  CONCLUSIONS
  Production, cleaning, and maintenance work were the job types with highest exposure to thoracic aerosol in cement production plants. However, plant had an even larger effect on exposure levels than job type. The number of employees was the most important factor explaining differences between plants. Exposure reached levels where the risk of lung function loss may be increased. No significant differences in exposure between sampling campaigns were observed during the 4-year study period.
authors.affiliation: 1. Department of Chemical and Biological Work Environment, National Institute of Occupational Health, PO Box 8149 Dep., 0033 Oslo, Norway.
authors.forename: Hilde
authors.initials: H
authors.lastname: Notø
authors.affiliation: 2.Department of Occupational Medicine and Epidemiology, National Institute of Occupational Health, PO Box 8149 DEP., 0033 Oslo, Norway.
authors.forename: Karl-Christian
authors.initials: KC
authors.lastname: Nordby
authors.affiliation: 2.Department of Occupational Medicine and Epidemiology, National Institute of Occupational Health, PO Box 8149 DEP., 0033 Oslo, Norway.
authors.forename: Helge
authors.initials: H
authors.lastname: Kjuus
authors.affiliation: 2.Department of Occupational Medicine and Epidemiology, National Institute of Occupational Health, PO Box 8149 DEP., 0033 Oslo, Norway.
authors.forename: Øivind
authors.initials: Ø
authors.lastname: Skare
authors.affiliation: 1. Department of Chemical and Biological Work Environment, National Institute of Occupational Health, PO Box 8149 Dep., 0033 Oslo, Norway.
authors.forename: Yngvar
authors.initials: Y
authors.lastname: Thomassen
authors.affiliation: 1. Department of Chemical and Biological Work Environment, National Institute of Occupational Health, PO Box 8149 Dep., 0033 Oslo, Norway wijnand.eduard@stami.no.
authors.forename: Wijnand
authors.initials: W
authors.lastname: Eduard
mesh_terms: D000336:Aerosols / Q000032:analysis*; D000395:Air Pollutants, Occupational / Q000633:toxicity; D003252:Construction Materials / Q000633:toxicity*; D004391:Dust / Q000032:analysis; D004784:Environmental Monitoring / Q000379:methods; D005060:Europe; D006801:Humans; D019570:Inhalation Exposure / Q000009:adverse effects*; D008168:Lung / Q000187:drug effects* / Q000503:physiopathology; D015233:Models, Statistical; D009784:Occupational Diseases / Q000209:etiology / Q000503:physiopathology; D011446:Prospective Studies; D012134:Respiratory Protective Devices; D011795:Surveys and Questionnaires
chemical_list: D000336:Aerosols; D000395:Air Pollutants, Occupational; D004391:Dust
keywords: cement production plants; exposure determinants; exposure measurements; job types; thoracic dust