title: Biological markers of exposure to SO2: S-sulfonates in nasal lavage.
abstract: S-sulfonate levels were measured in the nasal lavage (NAL) fluid of humans exposed to sulfur dioxide as a potential biological marker of exposure. These levels were determined by treating NAL fluid protein with cyanide to cleave the S-S linkage and release the sulfite. The cyanolytically released sulfite was measured by ion chromatography. In two experiments, humans were exposed to air or 1 ppm SO2 for 10 minute, and to air or 7 ppm SO2 for 20 minutes and lavaged immediately after exposure. Releasable sulfite levels in NAL fluid were 1.06 +/- 0.24 and 2.61 +/- 0.55 micrograms SO=3/mg protein, respectively (mean +/- SE, n = 5), for the first experiment, and 1.16 +/- 0.37 and 4.91 +/- 0.76 micrograms SO=3/mg protein, respectively (mean +/- SE, n = 8), for the second. The subjects in the former study were persons with asthma. In both experiments, S-sulfonate levels were statistically elevated in the exposed group compared with the control groups (p < 0.05, paired t-test). The same individuals in the second experiment received five additional 20-minute exposures to 7 ppm SO2 every other day, for a total of six exposures. NAL fluid taken at the conclusion of the final exposure had releasable sulfite levels of 4.99 +/- 1.36 micrograms SO=3/mg protein; these levels were statistically elevated relative to controls but were not elevated relative to the 1-day exposure (mean +/- SE, n = 8). The lack of accumulation of S-sulfonates after 6 days of short-term exposure suggests clearance of these compounds from the nasal passages within 24 hours. The levels of S-sulfonates observed in NAL fluid in this study are almost three orders of magnitude higher than those measured in plasma following similar SO2 exposures. Measurement of S-sulfonates in the nasal passage may be an effective short-term biomarker of exposure to SO2.
authors.affiliation: Inhalation Toxicology Research Institute, Lovelace Biomedical and Environmental Research Institute, Albuquerque, New Mexico.
authors.forename: W E
authors.initials: WE
authors.lastname: Bechtold
authors.forename: J J
authors.initials: JJ
authors.lastname: Waide
authors.forename: T
authors.initials: T
authors.lastname: Sandström
authors.forename: N
authors.initials: N
authors.lastname: Stjernberg
authors.forename: D
authors.initials: D
authors.lastname: McBride
authors.forename: J
authors.initials: J
authors.lastname: Koenig
authors.forename: I Y
authors.initials: IY
authors.lastname: Chang
authors.forename: R F
authors.initials: RF
authors.lastname: Henderson
mesh_terms: D000293:Adolescent; D000328:Adult; D004781:Environmental Exposure; D005260:Female; D006801:Humans; D008297:Male; D017817:Nasal Lavage Fluid / Q000737:chemistry*; D013451:Sulfonic Acids / Q000032:analysis*; D013458:Sulfur Dioxide / Q000493:pharmacokinetics*; D013997:Time Factors
chemical_list: D013451:Sulfonic Acids; D013458:Sulfur Dioxide