First National Survey of Lead and Allergens in Housing: survey design and methods for the allergen and endotoxin components.

Abstract

From July 1998 to August 1999, the U.S. Department of Housing and Urban Development and the National Institute of Environmental Health Sciences conducted the first National Survey of Lead and Allergens in Housing. The purpose of the survey was to assess children's potential household exposure to lead, allergens, and bacterial endotoxins. We surveyed a sample of 831 homes, representing 96 million permanently occupied, noninstitutional housing units that permit resident children. We administered questionnaires to household members, made home observations, and took environmental samples. This article provides general background information on the survey, an overview of the survey design, and a description of the data collection and laboratory methods pertaining to the allergen and endotoxin components. We collected dust samples from a bed, the bedroom floor, a sofa or chair, the living room floor, the kitchen floor, and a basement floor and analyzed them for cockroach allergen Bla g 1, the dust mite allergens Der f 1 and Der p 1, the cat allergen Fel d 1, the dog allergen Can f 1, the rodent allergens Rat n 1 and mouse urinary protein, allergens of the fungus Alternaria alternata, and endotoxin. This article provides the essential context for subsequent reports that will describe the prevalence of allergens and endotoxin in U.S. households, their distribution by various housing characteristics, and their associations with allergic diseases such as asthma and rhinitis.

Exposure to Alternaria alternata in US homes is associated with asthma symptoms

“…The weighted characteristics of the survey sample, including distributions of housing characteristics, socioeconomic, and demographic factors, were very similar to characteristics obtained from other national surveys. 23 The NSLAH is the first population-based study that not only measured antigenic and allergenic components of A alternata but also simultaneously estimated levels of other common indoor allergens and endotoxin in the US housing stock.…”

“…A detailed description of the study design and methodology has been published elsewhere. 23 Briefly, information on demographics, household characteristics, and occupant health status was collected by a questionnaire administered to an adult representative of the household. Environmental data were also acquired by sample collection and inspection of the housing units.…”

Are Building-Level Characteristics Associated with Indoor Allergens in the Household?

“…3,16,21,22,[24][25][26][42][43][44][45][46][47] An emerging literature does suggest that indoor allergens associated with asthma are related to the buildings in which people live. 10,11,[48][49][50][51][52] Considerable literature firmly establishes that the presence of cockroaches and rodents (i.e., pests) is associated with higher levels of asthma morbidity. 5,10,24,51,[53][54][55][56][57] Likewise, recent literature has highlighted the relationship between asthma morbidity and building types such as public housing; 54,58 mixed-use buildings, i.e., property containing both residential and commercial space; [59][60][61] and building size.…”

Endotoxin in inner-city homes: Associations with wheeze and eczema in early childhood

“…For endotoxin analysis, dust was extracted in pyrogen-free water with 0.05% Tween for 1 hour shaking, centrifuged and the supernatant was removed and assayed without freezing. Endotoxin was analyzed by the kinetic chromogenic Limulus Amebocyte Lysate assay, described previously (18,19). Results are reported both as the concentration of endotoxin per milligram of dust (EU/ mg) and as the load of endotoxin collected per square meter (EU/m 2 ).…”