Air Quality Testing How is your air quality in your home Toronto

Interpretation of Mold Spores from Air Test Results

What is the Acceptable Level for Indoor Mold Spores Testing Result - Guide for mold count levels: acceptable and unacceptable?

One of the highest accepted methods of assessing indoor air quality testing and its effects on all building's occupants iare usually the analysis of indoor air quality testing samples. Often these types of air samples are acquired using portable vacuum pumps that are calibrated to pull airflow through a tube at a specific volume of air per minute. The airflow that is pulled into the pump is trapped in a specially made cassette that contains an adhesive slide. Fungal, bacterial spores, airborne particulate that matters are deposited into the adhesive slide, which is then are analyzed under a microscope.

The analysis of these mold spore tape slides can provide results relatively accurately quickly because the samples don't require culturing or growing fungal spores. However, produce spores that are very similar as to not be distinguishable by visual from analysis alone and are grouped together, e.g., Aspergillus/Penicillium. And still, other mold spore types lack identifiable characteristics and do get counted as the part of the larger group, such as Ascospores and Basidiospores.

Typically, all fungus spores assessment of indoor air quality takes into account not only the analysis result of the indoor air samples but also the comparison of these bacterial spore results to all levels of fungi and other airborne in an outdoor air sample. Bacterial spore count levels in indoor air samples most generally should be lower than levels in outdoor air quality samples. Indoor bacteria spore counts that usually are lower than outdoor spore counts; however, we do not automatically indicate that usually the indoor air quality testing is acceptable. High-level counts of individual types of spores count of the total spores in indoor air quality samples may indicate fungus mold growth inside buildings. The conclusions are that indoor mold growth is occurring might be strengthened further if mold spore flowering bodies – called hyphae – they also are identified in the indoor air sample.

There are many other types of considerations to keep in mind when comparing outdoor comparison spore counts to indoor spore counts. The outside aerobiology is not always constrained because of the variable from the change of outside weather. For example, in the winter seasons, the spore count is always low outside samples. Similarly is in rainy weather causes spores to get washed away or tamped down from outside surfaces, resulting in a lower spore count in air samples. Also, in a warmer weather, the evaporation process can as well cause mold spores to rise in the air. Outside air quality has less influence on indoor air quality, on more energy-efficient buildings as well as people's tendency do sometimes leave windows closed and rely use on indoor air conditioning. As a result, when particular species of mold spores – Stachybotrys / Chaetomium, for example – are found in indoor samples cassettes, even in a low count, their presence indicates a seriously high level of indoor mold issue because these mold spore types are not found in outdoor samples.


Raw Spores Count – the number of mold spores actually identified and counted on the adhesive air sample slideSpores per Cubic Meter (Count/m3) – calculated by raw spore count x (1000/(rate of air test sampling) x (sampling test time)The Total Background – Amount of particulate matter fragments present on the slide; graded from 1-5 to 1 being very little, while other debris ratings of 5 are unreadable. The higher the rating the most likely spores may be underestimated and overlap with background particulates.


Fibrous Particulate – Fibrous particulates can mostly come from many different sources, including clothing, floor textiles, building materials, and other paper products. They often are introduced into the air due to turbulence forces and do friction applied into these materials. Improperly cleaned or maintained airflow ventilation sometimes increases the distribution of fibrous particulates.

Skin particulates – the dead skin cells either from humans or pets. Dead skins are continually shed by all the inhabitants of a home. Thousands type of cells per day slough off from each person and into the living environment. Of course, also pets shed lots of dead skin cells. Skin cells gradually do push their way into the top layer. When they do reach the top, they die and are "weathered" by the environment from people's daily activities.

Particulate matter (PM) – and skin particulates can sometimes be inhaled into the lungs where they are absorbed into the bloodstream. They are a respiratory irritant and this can cause many pulmonary effects such as coughing, respiratory illnesses, bronchitis, lung disease, these symptoms increase airway reactivity and exacerbation of asthma. Particulate matter also are thought to have direct effects to the heart (EPA 2008c). Recent mortality studies have shown many times a statistically significant direct association between mortality and daily concentrations from particulate matter in the air space. Numerous of many studies link PM to many varieties of health effects, which include aggravated asthma, increases respiratory symptoms (irritation of the difficulty breathing, airways, coughing,), and decreases lung function in young children.

Hyphal fragments – Hyphae are small fragments from the mycelium of a mold. Mycelium is a mass of hyphae, this are vegetative of the body portion of the mold. It is very common to find numbers of hypha fragments in outdoor air quality testing and possibly in indoor dust. Their presence in the indoor air quality samples are in a high quantity or as large segments do indicate active mold growth in the building. If the conditions are suitable, the hypha fragments begins to grow and eventually lead to mold spore production.

Indoor air mold standard – There is no state or federal statutes or regulations yet regarding molds and disturbed indoor air quality. Acceptable levels for the individual from mold species since bacteria species toxicity varies highly as do the spore sizes, the weight, and other features that can affect the risk to building occupants. However, many public agencies make various publications regarding mold contamination on indoor air quality available for the public. Aspergillus / Penicillium in a "clean" residential building studies ware at a mean of 230/m3; Aspergillus / Penicillium in buildings are known to have moisture and or flooding problem was at 2235/m3; Aspergillus / Penicillium in mold-contaminated buildings was at 36,037/m3.

The publication, From American Conference of Governmental Industrial Hygienists (Air Quality Testing Sampling Instruments for Evaluation of Atmospheric Contaminants 1995), they recommended from the following guidelines:

100 cfu or less for cubic meter of air quality disturbed usually indicates low risk.100 cfu to 1000 cfu for cubic meter of air quality disturbed usually indicates intermediate risk.1000 or more cfu for cubic meter of air quality disturbed usually indicates a high risk.

Many people still believe that spore count of 40 Stachybotrys or Chaetomium spores/m3. The air quality testing disturbed would be unusually high as this mold contamination is usually not normally airborne. Conversely, a count of 199 Aspergillus sp. spores/m3. The air quality in the same circumstances might be considered very clean.

After the study and reviewing the literature standards of indoor the mold spores, Enzcycle Lab, LLC They propose the following actions:

spores/m3 of air


> 500


No Action is Required


500 – 999


Remediation is required



Contact Canada Flooding