This mould house

A hazard to health and home, mould requires greater vigilance from construction industry

Roland Walsh can still recall the indifferent attitude towards mould when he first started out in construction. It was over 30 years ago, and he had a job doing renovations while going to school.

"We saw mould, we'd just cut it out and throw it out," he says. "Then you wake up the next morning, you're hacking and coughing, you've got a headache, but you don't really put any thought into it."

Since those early student days, Walsh has gone on to put a great deal of thought into mould. He now owns Canadian Envirotec Inc., an environmental service company based out of Sherwood Park, Alta. Mould inspection and remediation are included among its many services.

Mould is a problem in buildings both old and new, on construction sites exposed to the elements and renovation projects sheltering hidden fungal growths. All it needs to thrive are three things: the right temperature, a bit of moisture and food. Wood, drywall and carpet all provide excellent nourishment for mould-with the application of just a little water, that is.

"In 48 hours of first contact-48 hours from getting wet-mould can go crazy," Walsh says.

Mould spreads quickly, and with it comes a host of health concerns. In its mould guidelines, the Canadian Construction Association reels off a lengthy list of signs that workers have been exposed: eye irritation, skin rashes, congestion, cough, headaches, fatigue and other flu-like symptoms. People with asthma or weakened immune systems are especially vulnerable to the microscopic mould spores, which can even lead to fungal infections.

However, not everyone responds equally to mould exposure, and not all moulds are the same. But there are three strains of mould in particular that demand the attention of the construction industry, according to Dr. Jackson Kung'u, principal microbiologist with Mold and Bacteria Consulting Laboratories Inc., an organization dedicated to testing and identifying different moulds.

"All moulds are potentially health hazards, but in a building, probably Aspergillus, Penicillium and Stachybotrys-the one they call the black mould-would be considered worse than other moulds," he says.

The reason is that these three all produce microtoxins. People encountering such moulds are "not just going to be affected by the spores, but also the toxins that are contained in the spores," Kung'u says, while also noting more research needs to be done into the effects of these toxins when inhaled.

More than a health hazard for building occupants, mould is also a danger to the health of the building itself. It can be an indicator-and sometimes even a cause-of structural problems.

The presence of mould can point to a leak within the building, or some structural flaw that is allowing moisture to gather and play host to fungal or bacterial growths. But mould itself, when left unchecked, can seriously damage the building.

"Mould's number one purpose is to return natural substances back to their natural state," Walsh says. "It will take gypsum and make it so brittle it just falls apart. It will take a piece of wood and just disintegrate it."

With such severe problems, it is little wonder that the presence of mould can prompt fear and strong reactions from building owners. Perhaps most famous in this regard are Steve and Karen Porath, a California couple who, in 2001, had local firefighters torch their home because of the prohibitive cost of clearing out a major black mould problem.

But such drastic measures are not usually necessary, and Kung'u cautions against overreacting to the problem.

"You find sometimes people really panic and they end up spending a lot of money on something they really should not have," he warns. "I hear sometimes people even want to destroy their own clothing because they think that if there was mould in the building, maybe their clothing has got mould."

Cleaning up after a mould contamination can be as simple as washing clothes that have been exposed to spores or as complicated as hiring a remediation company to go through a building room by room. But there are a few basic safety precautions construction workers can take whenever they suspect a job site may contain mould growth.

Protective eyewear, gloves and respirators are all considered essential protection. Disposable coveralls and boots may even be necessary when dealing with severe outbreaks where there is a risk of spreading the spores around the building.

Walsh also has a bit of advice to help workers avoid waking up with the same hacking cough that confounded him in his younger days.

"You've got to put an N95 mask in your toolbox, and if there's any indication [of mould], just put the mask on," he says. "They're just as important as a steel-toed boot."

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