As mold inspectors, we hear this almost daily … “the mold is inside
the wall so it can’t hurt you”. This phrase has been uttered by
countless people, including builders, landlords, property managers,
maintenance personnel, handymen, homeowners, even mold inspectors and
mold remediators themselves!!
So what’s the story on mold inside walls?
People wrongly assume that mold spores are what makes people sick.
There are many more components of mold that can be harmful. Yes, in most
cases, mold spores do not come out of a wall into the occupied space,
however molds produce toxic gases called MVOCs (Microbial Volatile
Organic Compounds). These gases can easily travel out of wall cavities in the same way
sewer gas or carbon monoxide can. They can circulate through electrical
outlets, small cracks and under the baseboard. They CAN and DO affect
occupants, sometimes in a major way.
For
example, an office worker complained of severe headaches, flu- like
symptoms, and brain fog when she was in the office. Symptoms went away on weekends when she was home. Her boss was skeptical that anything
was wrong with the office but a cavity test of the wall behind her desk
revealed Stachybotrys (aka Toxic Black Mold) was present. A roof leak
has caused water to drip into the wall cavity and water was pooling
behind the baseboard causing active growth.
These gases are also responsible for the musty smell that we
associate with mold. If we don’t see mold, sometimes the musty odor is
the only sign that mold is present in a room but sometimes there is no
odor to warn us.
If the mold is no longer active (dormant) then it may not produce a
gas but it could reactivate at any time when the temperature and
humidity are just right.
Mold growth is often accompanied by bacterial growth and mycotoxins
production. Bacteria produce toxic by-products called endotoxins. Some
scientists believe these are even more poisonous than mycotoxins and
mold-literate doctors are now asking patients to test their homes for
both mycotoxins and endotoxins.
So mold inside walls should never be ignored unless the quantity is
minute. It must be removed with proper controls by a professional mold
remediation contractor who will use plastic containment, air scrubbers
with negative air pressure and make sure mold will not be dispersed into
the rest of the home. Once the mold is removed, the surfaces will then
be HEPA-vacuumed, disinfected and dried.
For more information about mold’s health effects visit the US EPA Mold Page
For information about Biological Pollutants in your home, see this
article
https://www.epa.gov/indoor-air-quality-iaq/biological-pollutants-impact-indoor-air-quality#Health_Effects