title: Radiographic abnormalities among construction workers exposed to quartz containing dust.
abstract: BACKGROUND
  Construction workers are exposed to quartz containing respirable dust, at levels that may cause fibrosis in the lungs. Studies so far have not established a dose-response relation for radiographic abnormalities for this occupational group.
  
  
  OBJECTIVE
  To measure the extent of radiographic abnormalities among construction workers primarily exposed to quartz containing respirable dust.
  
  
  METHODS
  A cross sectional study on radiographic abnormalities indicative of pneumoconiosis was conducted among 1339 construction workers mainly involved in grinding, (jack)-hammering, drilling, cutting, sawing, and polishing. Radiological abnormalities were determined by median results of the 1980 International Labour Organisation system of three certified "B" readers. Questionnaires were used for assessment of occupational history, presence of respiratory diseases, and symptoms and smoking habits.
  
  
  RESULTS
  An abnormality of ILO profusion category 1/0 and greater was observed on 10.2% of the chest radiographs, and profusion category of 1/1 or greater on 2.9% of the radiographs. The average duration of exposure of this group was 19 years and the average age was 42. The predominant type of small opacities (irregularly shaped) is presumably indicative of mixed dust pneumoconiosis. The prevalence of early signs of nodular silicosis (small rounded opacities of category 1/0 or greater) was low (0.8%).
  
  
  CONCLUSIONS
  The study suggests an elevated risk of radiographic abnormalities among these workers with expected high exposure. An association between radiographic abnormalities and cumulative exposure to quartz containing dust from construction sites was observed, after correction for potentially confounding variables.
authors.affiliation: Utrecht University, Division of Environmental and Occupational Health, Institute for Risk Assessment Sciences, Netherlands. E.TjoelNij@iras.uu.nl
authors.forename: E
authors.initials: E
authors.lastname: Tjoe Nij
authors.forename: A
authors.initials: A
authors.lastname: Burdorf
authors.forename: J
authors.initials: J
authors.lastname: Parker
authors.forename: M
authors.initials: M
authors.lastname: Attfield
authors.forename: C
authors.initials: C
authors.lastname: van Duivenbooden
authors.forename: D
authors.initials: D
authors.lastname: Heederik
mesh_terms: D000328:Adult; D000368:Aged; D003252:Construction Materials; D003430:Cross-Sectional Studies; D004391:Dust; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016273:Occupational Exposure / Q000009:adverse effects*; D011009:Pneumoconiosis / Q000000981:diagnostic imaging*; D011791:Quartz / Q000009:adverse effects*; D011859:Radiography; D012044:Regression Analysis; D012307:Risk Factors; D012907:Smoking / Q000473:pathology
chemical_list: D004391:Dust; D011791:Quartz