title: House dust mite allergen in US beds: results from the First National Survey of Lead and Allergens in Housing.
abstract: BACKGROUND
  Although exposure to house dust mite allergen is a major risk factor for allergic sensitization and asthma, nationwide estimates of dust mite allergen levels in US homes have not been reported.
  
  
  OBJECTIVE
  The purpose of this study was to estimate the prevalence of dust mite allergen in beds of US homes and to identify predictors of dust mite allergen concentration.
  
  
  METHODS
  Data were obtained from the first National Survey of Lead and Allergens in Housing, a cross-sectional survey of 831 permanently occupied noninstitutional housing units that permitted resident children. Dust mite allergen concentration (Der f 1 plus Der p 1) was determined from a dust sample collected from a bed. The percentages of homes with concentrations at or greater than detection, 2.0 microg/g bed dust, and 10.0 microg/g bed dust were estimated. Independent predictors of allergen concentration were assessed with multivariable linear regression.
  
  
  RESULTS
  The percentages of US homes with dust mite allergen concentrations at or greater than detection, 2.0 microg/g, and 10.0 microg/g were 84.2% (SE, 1.73), 46.2% (SE, 2.0), and 24.2% (SE, 2.1), respectively. Independent predictors of higher levels were older homes, non-West census regions, single-family homes, no resident children, lower household income, heating sources other than forced air, musty or mildew odor, and higher bedroom humidity.
  
  
  CONCLUSIONS
  Most US homes have detectable levels of dust mite allergen in a bed. Levels previously associated with allergic sensitization and asthma are common in US bedrooms. Predictors can be used to identify conditions under which homes are more likely to have increased dust mite allergen levels.
authors.affiliation: Division of Intramural Research, National Institute of Environmental Health Sciences/NIH, 111 Alexander Drive, Research Triangle Park, NC 27709, USA.
authors.forename: Samuel J
authors.initials: SJ
authors.lastname: Arbes
authors.forename: Richard D
authors.initials: RD
authors.lastname: Cohn
authors.forename: Ming
authors.initials: M
authors.lastname: Yin
authors.forename: Michael L
authors.initials: ML
authors.lastname: Muilenberg
authors.forename: Harriet A
authors.initials: HA
authors.lastname: Burge
authors.forename: Warren
authors.initials: W
authors.lastname: Friedman
authors.forename: Darryl C
authors.initials: DC
authors.lastname: Zeldin
mesh_terms: D000485:Allergens / Q000032:analysis*; D000818:Animals; D039741:Antigens, Dermatophagoides / Q000032:analysis*; D060829:Arthropod Proteins; D001249:Asthma / Q000209:etiology; D001512:Bedding and Linens / Q000009:adverse effects* / Q000469:parasitology; D002648:Child; D003546:Cysteine Endopeptidases; D003625:Data Collection; D006798:Housing; D006801:Humans; D012307:Risk Factors; D014481:United States
chemical_list: D000485:Allergens; D039741:Antigens, Dermatophagoides; D060829:Arthropod Proteins; D003546:Cysteine Endopeptidases; C451159:Dermatophagoides farinae antigen f 1; C451162:Dermatophagoides pteronyssinus antigen p 1