Dustborne Alternaria alternata antigens in US homes: results from the National Survey of Lead and Allergens in Housing.
BACKGROUND
Alternaria alternata is one of the most common fungi associated with allergic disease. However, Alternaria exposure in indoor environments is not well characterized.


OBJECTIVE
The primary goals of this study were to examine the prevalence of Alternaria exposure and identify independent predictors of Alternaria antigen concentrations in US homes.


METHODS
Data for this cross-sectional study were obtained from the National Survey of Lead and Allergens in Housing. A nationally representative sample of 831 housing units in 75 different locations throughout the United States completed the survey. Information on housing and household characteristics was obtained by questionnaire and environmental assessments. Concentrations of A alternata antigens in dust collected from various indoor sites were assessed with a polyclonal anti-Alternaria antibody assay.


RESULTS
Alternaria antigens were detected in most (95% to 99%) of the dust samples. The geometric mean concentration, reflecting the average Alternaria concentration in homes, was 4.88 microg/g (SEM, 0.13 microg/g). In the multivariable linear regression analysis, the age of the housing unit, geographic region, urbanization, poverty, family race, observed mold and moisture problems, use of de-humidifier, and presence of cats and dogs were independent predictors of Alternaria antigen concentrations. Less frequent cleaning and smoking indoors also contributed to higher Alternaria antigen levels in homes.


CONCLUSIONS
Exposure to A alternata antigens in US homes is common. Antigen levels in homes are influenced not only by regional factors but also by residential characteristics. Preventing mold and moisture problems, avoiding smoking indoors, and regular household cleaning may help reduce exposure to Alternaria antigens indoors.
Salo
Päivi M
PM
National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA.
Yin
Ming
M
Arbes
Samuel J
SJ
Cohn
Richard D
RD
Sever
Michelle
M
Muilenberg
Michael
M
Burge
Harriet A
HA
London
Stephanie J
SJ
Zeldin
Darryl C
DC
D016902:Air Pollution, Indoor; D000528:Alternaria / Q000276:immunology*; D000818:Animals; D000946:Antigens, Fungal / Q000276:immunology*; D003430:Cross-Sectional Studies; D004391:Dust / Q000276:immunology*; D004781:Environmental Exposure; D006798:Housing; D006801:Humans; D006813:Humidity; D015995:Prevalence; D014481:United States
D000946:Antigens, Fungal; D004391:Dust