title: Isocyanate exposure and asthma in the UK vehicle repair industry.
abstract: BACKGROUND
  Organic diisocyanates are a common cause of occupational asthma, particularly in motor vehicle repair (MVR) workers. The UK Health & Safety Laboratory provides screening for urinary hexamethylenediamine (UHDA), a biomarker of exposure to 1,6-hexamethylene diisocyanate (HDI). The UK Surveillance of Work-related and Occupational Respiratory Disease scheme (SWORD) has collected reports of occupational asthma since 1996.
  
  
  OBJECTIVE
  To compare trends in HDI exposure with trends in the incidence of work-related asthma attributed to isocyanates or paint spraying in MVR workers reported to SWORD.
  
  
  METHODS
  Two-level regression models were used to estimate trends in UHDA levels and work-related asthma in MVR workers reported to SWORD. The direction and magnitude of the trends were compared descriptively.
  
  
  RESULTS
  From 2006 to 2014, there was a significant decline in the number of urine samples with detectable levels of UHDA (odds ratio = 0.96; 95% confidence intervals 0.94-0.98) and minimal change in those over the guidance value (1.03; 1.00-1.06). Over the same period, there was a significant decline in all asthma cases attributed to isocyanates or paint spraying reported to SWORD (0.90; 0.86-0.94) and a non-significant decline among MVR workers (0.94; 0.86-1.02).
  
  
  CONCLUSIONS
  The simultaneous decrease in HDI exposure and incident cases of asthma reported to SWORD is temporally consistent with a reduction in exposure to airborne isocyanate leading to a reduction in asthma. Although this is not direct evidence of a causal relationship between the two trends, it is suggestive.
authors.affiliation: NIHR Greater Manchester Primary Care Patient Safety Translational Research Centre, Centre for Primary Care, Institute of Population Health, University of Manchester, Manchester M13 9PL, UK, jill.stocks@manchester.ac.uk.
authors.forename: S J
authors.initials: SJ
authors.lastname: Stocks
authors.affiliation: Health & Safety Laboratory, Buxton, Derbyshire SK17 9JN, UK.
authors.forename: K
authors.initials: K
authors.lastname: Jones
authors.affiliation: Health & Safety Executive, Bootle, Merseyside L20 7HS, UK.
authors.forename: M
authors.initials: M
authors.lastname: Piney
authors.affiliation: Centre for Occupational and Environmental Health, Centre for Epidemiology, Institute of Population Health, University of Manchester, Manchester M13 9PL, UK.
authors.forename: R M
authors.initials: RM
authors.lastname: Agius
mesh_terms: D000395:Air Pollutants, Occupational / Q000009:adverse effects*; D059366:Asthma, Occupational / Q000139:chemically induced* / Q000453:epidemiology / Q000503:physiopathology; D004784:Environmental Monitoring; D006801:Humans; D007221:Industry; D019570:Inhalation Exposure / Q000009:adverse effects* / Q000517:prevention & control / Q000706:statistics & numerical data; D017953:Isocyanates / Q000009:adverse effects*; D018986:Motor Vehicles; D009784:Occupational Diseases / Q000139:chemically induced* / Q000453:epidemiology / Q000503:physiopathology; D016273:Occupational Exposure / Q000009:adverse effects* / Q000706:statistics & numerical data; D010150:Paint / Q000009:adverse effects*; D062486:Public Health Surveillance; D006113:United Kingdom / Q000453:epidemiology
chemical_list: D000395:Air Pollutants, Occupational; D017953:Isocyanates
keywords: Biological monitoring; HDI; hexamethylene diisocyanate; isocyanate exposure; motor vehicle repair; occupational asthma; trends; two-pack spray paints; work-related asthma.