title: Development of an occupational airborne chemical exposure matrix.
abstract: BACKGROUND
  Population-based studies of the occupational contribution to chronic obstructive pulmonary disease generally rely on self-reported exposures to vapours, gases, dusts and fumes (VGDF), which are susceptible to misclassification.
  
  
  OBJECTIVE
  To develop an airborne chemical job exposure matrix (ACE JEM) for use with the UK Standard Occupational Classification (SOC 2000) system.
  
  
  METHODS
  We developed the ACE JEM in stages: (i) agreement of definitions, (ii) a binary assignation of exposed/not exposed to VGDF, fibres or mists (VGDFFiM), for each of the individual 353 SOC codes and (iii) assignation of levels of exposure (L; low, medium and high) and (iv) the proportion of workers (P) likely to be exposed in each code. We then expanded the estimated exposures to include biological dusts, mineral dusts, metals, diesel fumes and asthmagens.
  
  
  RESULTS
  We assigned 186 (53%) of all SOC codes as exposed to at least one category of VGDFFiM, with 23% assigned as having medium or high exposure. We assigned over 68% of all codes as not being exposed to fibres, gases or mists. The most common exposure was to dusts (22% of codes with >50% exposed); 12% of codes were assigned exposure to fibres. We assigned higher percentages of the codes as exposed to diesel fumes (14%) compared with metals (8%).
  
  
  CONCLUSIONS
  We developed an expert-derived JEM, using a strict set of a priori defined rules. The ACE JEM could also be applied to studies to assess risks of diseases where the main route of occupational exposure is via inhalation.
authors.affiliation: Institute of Occupational and Environmental Medicine, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK, s.sadhra@bham.ac.uk.
authors.forename: S S
authors.initials: SS
authors.lastname: Sadhra
authors.affiliation: CTSU, Nuffield Department of Population Health, University of Oxford, Oxford OX3 7LF, UK.
authors.forename: O P
authors.initials: OP
authors.lastname: Kurmi
authors.affiliation: Centre for Workplace Health, Health and Safety Laboratory, Harpur Hill, Buxton SK17 9JN, UK.
authors.forename: H
authors.initials: H
authors.lastname: Chambers
authors.affiliation: Institute of Occupational and Environmental Medicine, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK.
authors.forename: K B H
authors.initials: KB
authors.lastname: Lam
authors.affiliation: Centre for Workplace Health, Health and Safety Laboratory, Harpur Hill, Buxton SK17 9JN, UK.
authors.forename: D
authors.initials: D
authors.lastname: Fishwick
mesh_terms: D000395:Air Pollutants, Occupational / Q000032:analysis* / Q000592:standards; D004391:Dust / Q000032:analysis; D006801:Humans; D016273:Occupational Exposure / Q000009:adverse effects / Q000145:classification* / Q000592:standards / Q000706:statistics & numerical data; D009786:Occupational Health Services / Q000379:methods*; D009790:Occupations / Q000145:classification*; D052638:Particulate Matter / Q000009:adverse effects* / Q000032:analysis* / Q000592:standards; D012307:Risk Factors; D001335:Vehicle Emissions / Q000032:analysis
chemical_list: D000395:Air Pollutants, Occupational; D004391:Dust; D052638:Particulate Matter; D001335:Vehicle Emissions
keywords: Airborne workplace pollutants; COPD; job exposure matrix; occupational exposure; population epidemiology.