Airborne mold is a common issue in residential buildings that can pose a significant threat to the health and safety of occupants. Mold growth can occur due to various factors, including water damage, poor ventilation, and high humidity levels. In this article, we will discuss normal mold levels in residential buildings and how water damage can lead to elevated mold contamination.
mold spores and skin cells
Mold is a natural part of our environment and can be found almost everywhere, including indoors. This is considered normal. Water damage is a significant contributor to elevated mold contamination in residential buildings. When water damage occurs, mold spores can quickly multiply and spread, leading to elevated mold levels in the air. This is why in building science, mold is often used as an early indicator of water damage, even if it is not always obvious.
In this article, we want to compare our own results (LCS Laboratory Inc.) on mold distribution with expert opinions published by Air Analysis Inc. and Environmental Analysis Associates. In all three studies, the laboratories used ASTM method 7391, and the total mold count is used as an indicator of excessive mold growth. The conclusions below are sort of “epidemiological” studies where no direct experiments were conducted. The basis for classification was as follows:
- LCS Laboratory Inc.: The entire database of indoor air quality results collected in Canadian houses and offices was sorted in an order of mold concentration. 25% of results with the lowest reading were classified as “low,” and 25% of samples with the highest readings were classified as “elevated” or well above the country median. In our study, the clients were advised to keep windows closed for 24 hours before the test, to minimize the impact of outdoor air.
- The other two sources do not disclose the basis of their interpretation of the findings and are likely based on expert opinions.
The observations derived from three independent sources were surprisingly coherent and are shown in the table below:
This simplified approach for evaluating mold levels in your home or office is very useful when the number of observations is limited, and mold concentration in outdoor air is unknown. The results above are provided as part of our research program and are offered as information for consideration. Our study was conducted in Canada, in residential houses and offices. If you live in a country with a different climate and different construction code, those acceptance criteria may not be applicable to your case.
If you would like to check your home or office for mold contamination, please email us to order your air sampling kit for mold.
at 5:50 pm
Very very silly
1) when there are 70,000sp/m3 in the external environment you will get over 20,000sp/m3 in the internal environment
2) no appreciation for aspergillus/penicillium in your evaluation
3) no appreciation for Stachybotrys/Chaetomium in your evaluation
4) no appreciation for basidiospores/ascospores in your evaluation
5) no appreciation for clusters in your evaluation
at 8:36 am
Hello Joseph, the studies that we publish here are collections of about 20 separate statistical analyses. We already added one more study of the effect of outdoor mold on the indoor level. One day we will publish them all. It will include the topics that you raised. I promise