The risks of problems can range from simple discomfort, to chronic symptoms. One of the ways to protect yourself is to assess the quality of the ambient air and rectify any problems.
The quality of ambient air
How we assess air quality
Ambient air refers to the air around us. In other words, it is the air we breathe. However, current climate change has a negative impact on its quality. We spend a lot of time indoors, and breathing clean air becomes crucial to our health.
What influences
the growth of
mold
The following acceptable limits are for optimum comfort and certain parameters such as relative humidity to prevent mold growth and an acceptable dew point ambient temperature.
What influences mold growth
TEMPERATURE
A suitable temperature should be between 20 and 25°C.
RELATIVE HUMIDITY
Relative humidity should be between 30 and 60% because higher humidity could be favorable for microbial growth and lower humidity could dry out your airways. The relative humidity may be lower than 30% depending on the season, for example drier in winter and wetter in summer.
DEW POINT
If the temperature reaches the dew point, the resulting condensation may promote mold. For example, in a space with an absolute humidity of 15 grams of water per cubic meter, a relative humidity of 100% and a temperature of 18°C, the dew point is 18°C.
Air and surface,
two methods of
analysis
Samples are taken from the various locations requested by the customer. Sampling is done either by mechanical aspiration (quantitative), passive or by direct reading (qualifying). Collection time varies depending on the type of test required.
Air
01 - SAMPLING
The principle of this method is to take a determined volume of air by propelling it on an adhesive surface in order to capture the particles in suspension there. Sampling is done using a pump, by suction, passing the volume of air set at a flow rate of 15L/minute inside a cassette. This cassette contains, at one of its ends, sampling ports of rectangular shapes which are directed towards the collection medium where the particles collide and stick to it.
02 - THE ANALYSIS
In addition to the mycological particles present in the sample to be analyzed, other materials usually suspended in the air can be found there, such as dust and other materials. Density background particles can influence the ability to detect spores. For this reason, an estimate of all the particles present in the sample is made and classified from 1 to 4 (Overcharge) according to the percentage.
A rating of 4 or more background particles should be considered a minimum count of spores per fungal genus and the actual number may be higher than reported.
03 - REPORT
In addition to the mycological particles present in the sample to be analyzed, other materials usually suspended in the air can be found there, such as dust and other materials. Density background particles can influence the ability to detect spores. For this reason, an estimate of all the particles present in the sample is made and classified from 1 to 4 (Overcharge) according to the percentage.
A rating of 4 or more background particles should be considered a minimum count of spores per fungal genus and the actual number may be higher than reported.
RELIABLE RESULTS
To have samples that reflect the quality of ambient air inside and not outside
24 to 48 Hours
before the arrival of the specialist
Close doors and windows
Close any air filtration device equipped with a HEPA filter
Put the exchanger
of air in recirculation mode
Surface
01 - SAMPLING
This second method consists of taking a sample directly from an area or surface where mold growth is suspected. Sampling can be done in two different ways, depending on the surface to be analyze, either from a swab in the case of the smear or from a self-adhesive membrane in the case of the Bio-tape. The swipe collection technique uses a large cotton swab (swab) that is passed over the surface to be analyzed in order to retain the surface particles while the sticky blade sampling technique is an adhesive tape that the stick on the area to be analyzed in order to capture the particles there.
It is also possible to send an object or piece of material directly to the laboratory in order to have it analyzed as long as the object is not too heavy or too bulky to transport. This last way is called the "bulk" method.
02 - THE ANALYSIS
Characterization and quantification of mold spores are done directly (without growth or culture) with an optical microscope. The analysis thus made is a quantification of the viable and non-viable spores found on a surface.
03 - REPORT
The results are evaluated according to the presence (rare, low, medium, high) of each spore and level of growth. The objective of this method is to have the qualitative evaluation of each family of spores present on a given surface.
CARBON DIOXIDE
For carbon dioxide (CO2), if we take the standard established by the Quebec Ministry of Education, it is a maximum of 1000 ppm inside the classrooms, so we can take this value for the interior of a residential building.
CARBON MONOXIDE
Recommendations for carbon monoxide are a little different depending on the organism in question. The standard established for this report is that established by the American agency “Environmental Protection Agency (EPA)” which recommends a maximum concentration of 9 ppm.
VOLATILE ORGANIC COMPOUNDS
For total volatile organic compounds (VOCt), there is no standard in Canada. There is an exposure limit for certain VOCs which will not be listed here so as not to complicate the text. They are listed on the Government of Canada website (see references at the end of the report). For VOCt, we can take as reference the “Leadership in Energy and Environmental Design (LEED)” standard, which is based on the EPA with a maximum concentration of 500 μg/m3.
FINE PARTICLES
There are two categories with a standard set by the US Environmental Protection Agency (EPA). The first contains particles smaller than 2.5 micrometers (PM2.5) with a maximum annual concentration of 15μg/m3. The second category is on particles smaller than 10 micrometers (PM10) with a maximum annual concentration
of 50 μg/m3.
FORMALDEHYDE
Another important parameter for ambient air quality is formaldehyde. Much research demonstrates a relationship with high formaldehyde concentration and adverse health effects, such as an increased risk for cancer. Considering this, a maximum concentration of formaldehyde in Canada has been established at 0.3 ppm indoors.