title: Evaluation of personal exposure to monoaromatic hydrocarbons.
abstract: OBJECTIVE
  To evaluate the personal exposure of members of the general public to atmospheric benzene, toluene, and the xylenes, excluding exposure from active smoking.
  
  
  METHODS
  50 volunteers were equipped with active air samplers for direct measurement of personal exposure to monoaromatic hydrocarbons (MAH) and an activity diary was completed during each sampling period. Exposures were also estimated indirectly by combining activity data with independent measurements of hydrocarbon concentrations in several microenvironments.
  
  
  RESULTS
  Personal exposure were generally well in excess of those which would be inferred from outdoor measurements from an urban background monitoring station. A wide range of sources contribute to exposure, with indoor and in car concentrations generally exceeding those measured at background outdoor locations. Environments contaminated with tobacco smoke were among those exhibiting the highest concentrations. Personal exposures determined indirectly from activity diaries/microenvironment measurements were well correlated with those determined directly with personal samplers. Personal 12 hour daytime exposures to benzene ranged from 0.23-88.6 ppb (mean 3.81 ppb), with 12 hour night time exposures of 0.61-5.67 ppb (mean 1.94 ppb) compared with an annual average concentration of 1.18 ppb at the nearest suburban fixed site monitoring station. The excess of personal exposure over fixed site concentrations was greater for benzene and toluene than for the xylenes.
  
  
  CONCLUSIONS
  A wide range of sources contribute to personal exposures to monoaromatic hydrocarbons with exposure duration being as important a determinant of total exposure as concentrations. Exposures generally exceed those estimated from concentrations measured by background fixed point monitors. Microenvironment sampling combined with activity diary information can provide satisfactory estimates of personal exposure to these compounds.
authors.affiliation: Institute of Public and Environmental Health, School of Chemistry, University of Birmingham, UK.
authors.forename: P L
authors.initials: PL
authors.lastname: Leung
authors.forename: R M
authors.initials: RM
authors.lastname: Harrison
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001554:Benzene / Q000009:adverse effects / Q000032:analysis*; D002849:Chromatography, Gas; D002940:Circadian Rhythm; D004739:England / Q000453:epidemiology; D004781:Environmental Exposure / Q000009:adverse effects / Q000032:analysis*; D004784:Environmental Monitoring / Q000379:methods*; D062665:Epidemiological Monitoring; D005260:Female; D006801:Humans; D006841:Hydrocarbons, Aromatic / Q000009:adverse effects / Q000032:analysis*; D019570:Inhalation Exposure; D008297:Male; D008875:Middle Aged; D011159:Population Surveillance; D012424:Rural Population; D014028:Tobacco Smoke Pollution / Q000009:adverse effects; D014050:Toluene / Q000009:adverse effects / Q000032:analysis*; D014505:Urban Population; D014992:Xylenes / Q000009:adverse effects / Q000032:analysis*
chemical_list: D006841:Hydrocarbons, Aromatic; D014028:Tobacco Smoke Pollution; D014992:Xylenes; D014050:Toluene; D001554:Benzene