title: Endotoxin in inner-city homes: associations with wheeze and eczema in early childhood.
abstract: BACKGROUND
  An inverse association between domestic exposure to endotoxin and atopy in childhood has been observed. The relevance of this aspect of the hygiene hypothesis to US inner-city communities that have disproportionately high asthma prevalence has not been determined.
  
  
  OBJECTIVE
  To measure endotoxin in the dust from inner-city homes, evaluate associations between endotoxin and housing/lifestyle characteristics, and determine whether endotoxin exposure predicted wheeze, allergic rhinitis, and eczema over the first 3 years of life.
  
  
  METHODS
  As part of an ongoing prospective birth cohort study, children of Dominican and African-American mothers living in New York City underwent repeated questionnaire measures. Dust samples collected from bedroom floors at age 12 or 36 months were assayed for endotoxin.
  
  
  RESULTS
  Among the samples collected from 301 participants' homes, the geometric mean endotoxin concentration (95% CI) was 75.9 EU/mg (66-87), and load was 3892 EU/m2 (3351-4522). Lower endotoxin concentrations were associated with wet mop cleaning and certain neighborhoods. Endotoxin concentration correlated weakly with cockroach (Bla g 2: r = 0.22, P < .001) and mouse (mouse urinary protein: r = 0.28; P < .001) allergens in the dust. Children in homes with higher endotoxin concentration were less likely to have eczema at age 1 year (odds ratio, 0.70 [0.53-0.93]) and more likely to wheeze at age 2 years (odds ratio, 1.34 [1.01-1.78]). These associations were stronger among children with a maternal history of asthma.
  
  
  CONCLUSIONS
  Endotoxin levels in this inner-city community are similar to those in nonfarm homes elsewhere. In this community, domestic endotoxin exposure was inversely associated with eczema at age 1 year, but positively associated with wheeze at age 2 years.
  
  
  CONCLUSIONS
  Endotoxin exposure in the inner-city community may be related to wheeze in the early life; however, given the inverse association seen with eczema, the long-term development of allergic disease is still in question.
authors: Columbia's Center for Children's Environmental Health, Columbia University, New York, NY 10032, USA.
authors: Matthew S
authors: MS
authors: Perzanowski
authors: Rachel L
authors: RL
authors: Miller
authors: Peter S
authors: PS
authors: Thorne
authors: R Graham
authors: RG
authors: Barr
authors: Adnan
authors: A
authors: Divjan
authors: Beverley J
authors: BJ
authors: Sheares
authors: Robin S
authors: RS
authors: Garfinkel
authors: Frederica P
authors: FP
authors: Perera
authors: Inge F
authors: IF
authors: Goldstein
authors: Ginger L
authors: GL
authors: Chew