In many parts of North America, it is now legal to buy medical marijuana from licensed producers -- and even to grow your own in limited quantities. Marijuana is often used to treat ailments such as anxiety, nausea, fibromyalgia, epilepsy, eating disorders, HIV, arthritis, chronic pain, and depression.
As of early 2017, it is legal to grow marijuana in California, Colorado, Washington, Oregon, New Mexico, Nevada, Alaska, Arizona, Massachusetts, Michigan, Maine, the District of Columbia (D.C.) and Hawaii.
In Canada, laws may also change: According to CBC News, the Canadian government is expected to announce the legalization of recreational marijuana by July 2018.
However, in most states where you can legally grow marijuana plants, you’re limited to 4-6 plants total.
While some people complain that it is not enough, experts warn about the possible repercussions of growing marijuana in your home: Poor indoor air quality.
That’s because marijuana plants need large amounts of humidity and moisture in order to grow. If the humidity is not adequately controlled, it can lead to mold growth in the home, making it an IAQ nightmare for current and future residents.
The smell from marijuana grow-ops can become a cause of complaints from neighbours and deteriorating relationships with those living closeby. If marijuana is not dried and stored properly (and it’s difficult to do - even perfectly dried marijuana plants still contain 10-15% water), there is also a concern of aspergillus mold to develop, which can affect a person once the mold spores enter the human body through ears and nose. Health effects include stuffiness, a feeling of being unwell, coughing, wheezing and lung damage.
These concerns may be more widespread than most people realize. In 2015, there were more than 1,500 licensed grow-ops in the British Columbia city of Surrey alone.
Illegal grow-ops an even bigger IAQ concern
Prospective homebuyers should be extra vigilant if they suspect a property to have been an illegal grow-op.
According to the National Collaborating Centre for Environmental Health, illegal marijuana grow-ops could lead to structural hazards if there were physical changes done to the building, electrical hazards, biological hazards such as mold and chemical hazards from the use of pesticides, fertilizers, and solvents used for the extraction of tetrahydracannibol (THC). Some of these apply to legal grow-ops and other homeowners as well.
The Canadian Real Estate Association warns prospective buyers to inspect the ductwork, floor joists, roof trusses, outside brickwork and soffits, which are often modified to make room for vents. A hot and humid grow-op may also lead to warped wood and drywall in certain areas.
If there are signs of water damage and mold, the affected materials should be cleaned thoroughly and possibly replaced. If there are still sources of humidity and moisture, these should be fixed as quickly as possible, otherwise the mold will come back.
Grow-op carpets and textiles should be tested for chemical hazards. This is where pesticide residues like to accumulate. Remove carpets and existing textiles, if possible.
During the inspection, direct special attention to bathrooms and kitchens, where chemicals may have been mixed and spills could have easily occurred. Possible chemicals hazards include pesticides such as Cypermethrin and Permethrin, fertilizers and solvents such as isopropyl alcohol, methyl hydrate, naphtha, or ethanol.
If there are any leftover chemicals or pesticides, these need to be disposed of in accordance with local and provincial regulation. All interior surfaces should be cleaned with detergent and water, and dried well.
Electrocorp and its parent company AllerAir have worked with contractors, consultants, homeowners, law enforcement, real estate agencies and others affected by poor IAQ due to marijuana grow-ops. Real solutions include the right kind of air filters: Carbon, HEPA and UV. Contact Electrocorp for more information.