title: Sensitization and chronic beryllium disease at a primary manufacturing facility, part 2: validation of         historical exposures.
abstract: OBJECTIVE
  The aim of this study was to evaluate the validity of a job exposure matrix (JEM) constructed for         the period 1994-1999. Historical exposure estimates (HEE) for the JEM were constructed for all job and year         combinations by applying temporal factors reflecting annual change in area air measurements (1994-1998) to the         personal baseline exposure estimates (BEE) collected in 1999. The JEM was generated for an epidemiologic study to         examine quantitative exposure-response relationships with sensitization and chronic beryllium disease.
  
  
  METHODS
  The validity of the BEE and HEE was evaluated by comparing them with a validation dataset of independently collected         personal beryllium exposure measurements from 1999 and 1994-1998, respectively. Agreement between the JEM and         validation data was assessed using relative bias and concordance correlation coefficients (CCC).
  
  
  RESULTS
  The BEE and         HEE overestimated the measured exposures in their respective validation datasets by 8% and 6%, respectively. The CCC         reflecting the deviation of the fitted line from the concordance line, showed good agreement for both BEE (CCC=0.80)         and HEE (CCC=0.72). Proportional difference did not change with exposure levels or by process area and year. Overall,         the agreement between the JEM and validation estimates (from combined HEE and BEE) was high (CCC=0.77).
  
  
  CONCLUSIONS
  This study demonstrated that the reconstructed beryllium exposures at a manufacturing facility were reliable and can be         used in epidemiologic studies.
authors.affiliation: National Institute for Occupational Safety and Health (NIOSH), Division of Respiratory Disease Studies, Morgantown, WV, USA.
authors.forename: Ji Young
authors.initials: JY
authors.lastname: Park
authors.forename: M Abbas
authors.initials: MA
authors.lastname: Virji
authors.forename: Aleksandr B
authors.initials: AB
authors.lastname: Stefaniak
authors.forename: Marcia L
authors.initials: ML
authors.lastname: Stanton
authors.forename: Gregory A
authors.initials: GA
authors.lastname: Day
authors.forename: Michael S
authors.initials: MS
authors.lastname: Kent
authors.forename: Christine R
authors.initials: CR
authors.lastname: Schuler
authors.forename: Kathleen
authors.initials: K
authors.lastname: Kreiss
mesh_terms: D016902:Air Pollution, Indoor / Q000009:adverse effects*; D000704:Analysis of Variance; D001607:Berylliosis / Q000453:epidemiology / Q000209:etiology*; D001608:Beryllium / Q000633:toxicity*; D002908:Chronic Disease; D004784:Environmental Monitoring; D062665:Epidemiological Monitoring; D006304:Health Status; D006801:Humans; D007221:Industry; D019570:Inhalation Exposure / Q000009:adverse effects*; D016273:Occupational Exposure / Q000009:adverse effects*; D016272:Occupational Health; D011159:Population Surveillance; D015203:Reproducibility of Results; D013223:Statistics as Topic; D013997:Time Factors; D014481:United States / Q000453:epidemiology
chemical_list: D001608:Beryllium