Levels and predictors of endotoxin in mattress dust samples from East and West German homes

East–West differences in prevalence of asthma and allergies were sug-gested to be associated with lifestyle factors. To describe endotoxin levels inmattress dust samples from East and West German homes collected approxi-mately 10 years after reunification. To identify factors that may account for anEast–West difference. Dust was collected from mattresses of 2157 infants and2108 mothers living in Leipzig (former East Germany) and Munich (WestGermany). Endotoxin was measured using a chromogenic kinetic Limulusamoebocyte lysate test. Data on bedding, dwelling, and housing characteristics,and occupantsÕ behavior were collected using a self-administered questionnaire.Endotoxin levels were significantly higher in Leipzig compared with Munich forthe infantsÕ mattresses but not for the mothersÕ mattresses. Apart from this,predictors for the mothersÕ and the infantsÕ mattresses were very similar. Pet-ownership and contact with animals outside the home were most influential.Endotoxin levels in mattress dust were highest in summer and increased with thenumber of persons living in the household. The overall percentage of variabilityin endotoxin levels explained by these factors was low. Endotoxin levels wereassociated with lifestyle factors discussed within the framework of the hygienehypothesis. None of these factors explains the difference in infant’s mattress dustendotoxin between Leipzig and Munich or could be used as a surrogate forendotoxin.