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Updated: Jul 18, 2026
Air-sampled Filter Analysis for Endotoxins and DNA Content
Published on: March 7, 2016
Endotoxin, (1 --> 3)-beta-D-glucans and fungal extra-cellular polysaccharides in New Zealand homes: a pilot study
Jeroen Douwes1, Rob Siebers, Inge Wouters
1Centre for Public Health Research, Research School of Public Health, Massey University, Wellington, New Zealand, Private Box 756, Wellington, New Zealand. j.douwes@massey.ac.nz
Abstract:
Bacterial endotoxin, fungal (1 --> 3)-beta-D-glucans, and extracellular polysaccharides from Aspergillus and Penicillium (EPS-Asp/Pen) have been suggested to be stable markers of microbial exposure. This paper describes a pilot study in which we measured endotoxin, (1 --> 3)-beta-D-glucans, EPS-Asp/Pen and mite allergen in house dust collected in 32 homes in Wellington, New Zealand. Endotoxin (GM 60,295 EU/g; GSD 2.4) and glucan (GM 2,687 microg/g; GSD 1.5) levels were higher in comparison to previous international studies, whereas EPS-Asp/Pen levels (37,347 Units/g; GSD 1.9) appeared comparable. Concentrations expressed per square meter were highly correlated among the measured components (p < 0.05). When expressed per gram of dust only (1 --> 3)- beta -D-glucans and EPS-Asp/Pen were correlated (r=0.55, p < 0.01; n=32). Endotoxin and glucan levels were higher (borderline statistically significant; p < 0.10) in homes with self-reported water damage. A positive association (p < 0.10) was also found for dust mite and a combination of self-reported mould, dampness and water damage. EPS levels were higher in homes where residents indicated the presence of mould spots on the wall, but this did not reach statistical significance. In conclusion, levels of microbial contaminants in a small random sample of New Zealand homes were high and weakly associated with water damage.
Insights
Microbial contaminants like bacterial endotoxin and fungal glucans were high in New Zealand homes. These indoor air quality markers showed weak associations with water damage and dampness.
Area of Science:
- Environmental Science
- Microbiology
- Public Health
Background:
- Microbial exposure markers such as bacterial endotoxin, fungal (1→3)-β-D-glucans, and extracellular polysaccharides (EPS) from Aspergillus and Penicillium are crucial for assessing indoor environments.
- House dust serves as a reservoir for these microbial contaminants and allergens, impacting indoor air quality and occupant health.
Purpose of the Study:
- To quantify levels of bacterial endotoxin, fungal (1→3)-β-D-glucans, EPS-Asp/Pen, and mite allergen in house dust from Wellington, New Zealand.
- To investigate correlations between these microbial markers and mite allergen.
- To explore associations between microbial contaminant levels and self-reported indicators of water damage, dampness, and mould.
Main Methods:
- A pilot study measured endotoxin, (1→3)-β-D-glucans, EPS-Asp/Pen, and mite allergen in house dust samples from 32 Wellington homes.
- Statistical analyses were performed to assess correlations between measured components and associations with self-reported environmental factors.
Main Results:
- Endotoxin and glucan levels in New Zealand homes were higher than reported in previous international studies.
- Concentrations of microbial components per square meter were highly correlated.
- (1→3)-β-D-glucans and EPS-Asp/Pen showed a significant correlation when expressed per gram of dust.
- Higher endotoxin and glucan levels were observed in homes with self-reported water damage.
- Dust mite and a combination of self-reported mould, dampness, and water damage showed a positive association with microbial markers.
Conclusions:
- Indoor microbial contaminant levels in this New Zealand sample were elevated.
- Water damage was weakly associated with increased endotoxin and glucan levels.
- Further research is warranted to understand the implications of high microbial loads in indoor environments.
