• House dust;
  • Bacterial endotoxin;
  • Mold β(1[RIGHTWARDS ARROW]3)-glucan;
  • Home characteristics

Abstract Residential microbial exposure has been suggested to be involved in the development of asthma. This paper describes bacterial endotoxin and mold β(1[RIGHTWARDS ARROW]3)-glucan levels in house dust and the relationship to selected home characteristics. Dust was sampled from mattresses and living room and bedroom floors of 25 houses in Germany. Endotoxin and β(1[RIGHTWARDS ARROW]3)-glucan levels ranged from 200-48,600 EU/g dust (100-32,900 EU/m2 sampled surface) and 182-3,507 μg/g (157-3,652 μg/m2), respectively. Bio-contaminant levels were highest on living room floors and lowest in mattresses. Dust, endotoxin and β(1[RIGHTWARDS ARROW]3)-glucan levels were 2–3 times higher on living room floors of centrally heated houses built after 1970 compared to older individually heated houses. This was not found for mattresses and bedroom floors. No associations between biocontaminant levels and other selected home characteristics (temperature, relative humidity, damp spots and insulation of windows) were found. β(1[RIGHTWARDS ARROW]3)-glucan levels were associated with total culturable fungi (per m2) in house dust, as well as with the fungal genus Alternaria (per g dust and per m2). In conclusion endotoxin and β(1[RIGHTWARDS ARROW]3)-glucan were readily detectable in house dust and significantly associated with heating system and/or age of the home.