Letter: Asthma and metals.
D001249:Asthma / Q000209:etiology*; D002857:Chromium / Q000009:adverse effects; D006801:Humans; D008670:Metals / Q000009:adverse effects*; D009532:Nickel / Q000009:adverse effects
D008670:Metals; D002857:Chromium; D009532:Nickel