title: Serum pneumoproteins: a cross-sectional comparison of firefighters and police.
abstract: BACKGROUND
  Serum pneumoproteins provide a measure of the permeability of the lower respiratory tract, and have shown promise as a biomarker of acute and chronic exposure to respiratory toxicants.
  
  
  METHODS
  To evaluate the effects of chronic occupational smoke exposure, 105 firefighters were compared with 44 police controls in a cross-sectional study using spirometry, diffusing capacity of the lung, serum Clara cell protein (CC16), and serum surfactant-associated protein A (SP-A) measurements.
  
  
  RESULTS
  There were no significant differences in age, gender, height, spirometry (FVC and FEV(1)), and diffusing capacity between the two groups. Serum SP-A was lower in firefighters (260.1 +/- 121.2 microg/L) than police (316.0 +/- 151.4 microg/L, P = 0.019). Serum CC16 was also lower in firefighters (8.39 +/- 3.11 microg/L) than police (10.56 +/- 4.20 microg/L, P < 0.001), although this difference lost statistical significance when adjusted for confounders.
  
  
  CONCLUSIONS
  Firefighters have lower serum concentrations of SP-A than do police. Although the clinical significance of this finding is presently unknown, SP-A deserves further study as a biomarker of toxic exposure to the lower respiratory tract.
authors.affiliation: Environmental and Occupational Health, University of Arizona College of Public Health, 1435 N. Fremont, Box 210468, Tucson, AZ 85719-4197, USA. jburgess@u.arizona.edu
authors.forename: Jefferey L
authors.initials: JL
authors.lastname: Burgess
authors.forename: Mark L
authors.initials: ML
authors.lastname: Witten
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Nanson
authors.forename: Tracy A
authors.initials: TA
authors.lastname: Hysong
authors.forename: Duane L
authors.initials: DL
authors.lastname: Sherrill
authors.forename: Stuart F
authors.initials: SF
authors.lastname: Quan
authors.forename: Richard
authors.initials: R
authors.lastname: Gerkin
authors.forename: Alfred M
authors.initials: AM
authors.lastname: Bernard
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood; D003430:Cross-Sectional Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D016273:Occupational Exposure; D009790:Occupations; D016495:Police; D037662:Pulmonary Surfactant-Associated Protein A / Q000097:blood*; D012044:Regression Analysis; D012129:Respiratory Function Tests; D014598:Uteroglobin / Q000097:blood*
chemical_list: D015415:Biomarkers; D037662:Pulmonary Surfactant-Associated Protein A; C556389:SCGB1A1 protein, human; D014598:Uteroglobin