title: An outbreak of occupational asthma due to chromium and cobalt.
abstract: BACKGROUND
  Five metal turners employed by an aerospace manufacturer presented to the Birmingham Chest Clinic occupational lung disease unit. Four cases of occupational asthma (OA) due to chromium salt (3) and cobalt (1) were diagnosed by serial peak-expiratory flow measurements and specific inhalation challenge testing.
  
  
  OBJECTIVE
  To measure the extent of the outbreak and to provide epidemiological data to ascertain the aetiology.
  
  
  METHODS
  Participants answered a detailed, self-administered questionnaire, designed to detect occupational lung disease. Urine chromium and cobalt excretion, spirometry and exhaled nitric oxide measurements were taken. Those with possible, probable or definite non-OA or OA, after questionnaire, were invited to undertake two-hourly peak flow measurements and received specialist follow-up.
  
  
  RESULTS
  A total of 62 workers (95% of workforce) participated. Sixty-one per cent of employees were working in higher metalworking fluid (MWF) exposure areas. Ninety per cent of workers had urinary chromium excretion indicating occupational exposure. Sixty-six per cent of workers reported active respiratory symptoms, although there were no significant differences between exposure groups. Two further workers with probable OA were identified and had significantly higher urinary chromium and cobalt concentration than asymptomatic controls. Eighteen cases of occupational rhinitis (OR) were identified, with significantly raised urinary chromium concentration compared with asymptomatic controls.
  
  
  CONCLUSIONS
  Chromium salt and cobalt can be responsible for OA and OR in workers exposed to MWF aerosols. Onset of symptoms in those with positive specific challenges followed change in MWF brand. Workers with OA had increased urinary concentrations of chromium and cobalt, and those with OR had increased urinary concentrations of chromium.
authors: Occupational Lung Disease Unit, Birmingham Heartlands Hospital Bordesley Green East, Birmingham B9 5SS, UK. gaxwalters@hotmail.com
authors: G I
authors: GI
authors: Walters
authors: V C
authors: VC
authors: Moore
authors: A S
authors: AS
authors: Robertson
authors: C B S G
authors: CB
authors: Burge
authors: A-D
authors: AD
authors: Vellore
authors: P S
authors: PS
authors: Burge
mesh_terms: D000328:Adult; D000395:Air Pollutants, Occupational / Q000009:adverse effects*; D059366:Asthma, Occupational / Q000453:epidemiology* / Q000503:physiopathology / Q000652:urine; D002857:Chromium / Q000009:adverse effects* / Q000652:urine; D003035:Cobalt / Q000009:adverse effects* / Q000652:urine; D003430:Cross-Sectional Studies; D004196:Disease Outbreaks; D006801:Humans; D019570:Inhalation Exposure; D008168:Lung / Q000503:physiopathology; D008297:Male; D008670:Metals / Q000009:adverse effects; D008875:Middle Aged; D006113:United Kingdom / Q000453:epidemiology; D014896:Welding
chemical_list: D000395:Air Pollutants, Occupational; D008670:Metals; D002857:Chromium; D003035:Cobalt