These are all tell-tale signs of household molds – fungi that thrive in a humid environment.

This microscopic fungus is not something you want to be living with. It produces allergens, irritants and, sometimes, mycotoxins (a toxic substance that you can inhale).

When it reproduces, mold releases spores that can trigger hay fever reactions and asthma attacks in the mold-allergic. Even those who aren’t allergic can find themselves rubbing their eyes, nursing a skin rash or suffering from a sore throat.

If mold is growing in your house, it’s time to identify the problem and eliminate it.

Spotting It

To determine whether you’ve got mold, there are clues to look for, says Frank Haverkate, an indoor environmental consultant and president of Haverkate and Associates Inc., a Toronto-based environmental testing and consulting company that does mold inspections.

Mold needs moisture to grow, so any source of water that is not contained – such as condensation on your walls or leaky pipes – combined with a lack of airflow, can create perfect conditions for the fungi.

Haverkate suggests looking for peeling and cracking paint, flaking and powdery plaster, and crystalline white formations on the basement foundation that indicate minerals are passing through the stone.

Mold can be furry, powdery, slimy and come in a variety of colours, from black to green to white. In fact, says Haverkate, despite rumours that black mold is the worst for your health, all molds can cause problems. You can’t judge toxicity by the colour.

Companies such as Haverkate’s specialize in mold inspection. For $1,000 to $1,500, he will come to your house with instruments including moisture meters and thermal imaging cameras to suss out the problem and also do lab analyses of air samples.

The firm is one of the few in Canada to use a mold-sniffing dog to help identify hard-to-see cases. (Mold Dogs Inc. in Alberta and MoldDOG Canada in Port Coquitlam, B.C. employ dogs on the job as well.)

The Cleanup

The Canadian Mortgage and Housing Corp. suggests only small areas (no more than three patches of mold, each smaller than one square metre) should be tackled by an untrained individual.

If that’s your situation, protect yourself by purchasing an N-95 respirator that fits properly so you don’t inhale any spores. Wear gloves that come up your forearm as well as goggles without ventilation holes. Using detergent and water, scrub off the mold.

(Do not use bleach as it can react with surface materials and produce toxic gases.) Dry the area completely and make sure it stays arid.

For more serious mold infestations, you’ll need to call in a specialized mold removal contractor, with credentials from the Institution of Inspection, Cleaning and Restoration Certification (IICRC) and the Indoor Air Quality Association (IAQA).

Such contractors will set up a tent-like structure around the mold, which they pressurize before safely removing the fungi, so that isn’t spread around. Haverkate advises that mold inspectors who also do the removal have an inherent conflict of interest.

How To Avoid

There are simple steps to minimize your exposure to mold. Fix any leaks immediately; keep your eavestroughs clear of leaves, so that they drain properly; turn a fan on in the bathroom for 10 minutes after every shower or bath; make sure appliances, such as dryers, are vented properly; and cover cold surfaces, including cold water pipes, with insulation so that condensation doesn’t accumulate.

If you do have a flood or a leak, clean it up quickly. Chances are that if you remove the moisture within 24 to 48 hours, you will stop mold spores from setting up camp. While Haverkate stresses that a mold-free environment does not exist, an infestation in your home is unhealthy and should be eradicated.

Websites of Interest

CMHC page
Centers for Disease Control and Prevention page

Inside, mold thrives in humid areas like the shower or the basement. Outside, you’ll find it growing in shady areas where there is dampness or where vegetation is decomposing.

Mold reproduces by sending out tiny spores that float through the air, looking for a friendly environment to make a home. These spores are resilient and can survive in even the driest conditions.

When the spores do find dampness, mold is extremely fast-growing, and so plentiful that we don’t even know how many species there are.

Estimates suggest there are between 10,000 and 300,000 different kinds. And not all are bad for humans. We use mold in food production to make cheese and soy sauce. But unless you’re making your own Danish blue, you will want to banish mold from your home.

See Also:

• Find and destroy mold in the home.

As a kid, Michele Chase had severe asthma attacks, which her family put down to the polluted air in Mississauga, a suburb of Toronto. But when, at the age of 10, she moved with her family to Fredericton, New Brunswick, a city with a population of only 50,000, Chase’s bouts of asthma surprisingly did not improve.

Her chest would become tight and she’d wheeze so hard she couldn’t catch a breath, despite a daily course of medication. Her family became acquainted with the local ER department.

But there was a difference in Fredericton: many of her asthma flareups started within the family home. For years, she couldn’t figure out the exact trigger. But Chase, now 28, today is certain she knows the spark for her childhood agony.

Asthma attacks triggered by home’s poor indoor air

Three years ago she helped her mother renovate the family home. As they were replacing the gyprock and paneling in the basement, they made an unsettling discovery. Thick, oozing black fungus had completely covered the back side of the gyprock and had permeated the insulation.

While they knew the basement was always damp, they had been completely unaware of the health hazard hidden behind the walls. Chase is thankful her bedroom was not in the basement, but notes, “if it’s in the home, it’s still in what you breathe.”

In Ottawa, Susan Clemens can relate. She watched with increasing distress as Angela,* her young daughter, suffered frightening asthma attacks between the years 2002 and 2004. The family was living in a “maisonette” with 12 apartments connected to a central hallway.

The building’s owners were busily renovating units, and every time a tenant moved out, they would resurface the floor in the vacated unit. Chemical fumes permeated the building, and the Clemens’ immediate neighbour was a smoker, so the family was also breathing in second-hand smoke.

Angela was not a wheezer, but during attacks the skin between the toddler’s ribs and collarbone would suck in as she struggled to breathe. Her lips would turn blue, and she’d break into a sweat. Angela was diagnosed with asthma at 12 months, but didn’t see a respirologist until she was 3.

He questioned Clemens and her husband about their lifestyle. When they explained about the apartment renovations, he immediately connected that to their daughter’s health. “That’s one of your big problems,” she recalls him saying. And then the life-changing words: “You have to move.”

How a home’s indoor air can cause allergies and asthma

Such instances are far from unique. While most North Americans still think of smog as the most serious form of air pollution, a more toxic chemical stew is often found in the air we breathe inside our homes. The U.S. Environmental Protection Agency labels indoor air one of the Top Five environmental health risks, up there with polluted drinking water.

The bad environment in our households starts with polluted air from the outdoors, which is often not cycled effectively in and out of tightly sealed and energy-efficient homes. Trapped, “the pollutant levels may be two to five times higher inside than outside, and in some cases, 100 times higher,” says Tom Kelly, director of the EPA’s Indoor Environments Division.

Then the homeowners mix in other chemicals: pesticides, perhaps cigarette smoke, air fresheners, hairspray, perfume and cleaning supplies. Thrown into the invisible concoction are the gases given off by furnishings or paint. Add animal dander, dust mites and mold – those ubiquitous biological allergy triggers – and suddenly there’s new meaning to the term “the fresh outdoors.”

Who is harmed by indoor air pollution?

Polluted indoor air “can be a very high risk for children, for elderly people, and for folks with diseases such as asthma,” says Kelly. In Canada, asthma is responsible for 10 per cent of all hospital admissions for children under the age of 4. The thought that our homes, our safe havens, can at times be to blame, is sobering.

To get a reading on just how bad household air is becoming a company that designs indoor air monitors, AirAdvice, worked with a network of heating, air conditioning, and air quality professionals to collect and analyze about 1.3 billion air samples from nearly 50,000 homes in the U.S. and Canada between 2004 and 2006.

Its survey showed 96.7 per cent of the homes generating an “alert”, that is, a level outside the recommended range for one of: particle allergens (dust, dander and pollen); chemical pollutants; carbon dioxide; temperature; humidity; and carbon monoxide. Eighty-three per cent of the homes had two or more alerts.