December 3, 2002 – Recently, 1,000 students at a high school in Memphis, Tennessee, demonstrated for a whole day against the presence of mold growing in their schools and threatening their health. Mold makes asthma worse, irritates the eyes, respiratory system and skin.
And it’s not just schools and public buildings that are affected. For example, in the United States, the 1995 census showed that between 10 and 20% of houses had problems with water leaks, promoting the proliferation of mold. In Montreal, the proportion would be the same. According to a study carried out in 1991 by INRS-Urbanization, 15% of housing is poorly maintained or in a sorry state.
Molds are microscopic fungi that thrive when the humidity level is too high (over 60%). Although not all are harmful to health, some produce mycotoxins dangerous to health, which can be absorbed by inhalation. In addition, the cell wall of these molds contains an inflammatory agent, called glucan, which particularly affects the conjunctiva, throat and upper respiratory tract. According to a recent study1, the mushroom Stachybotrys chartarum represents one of the most serious threats to the health of occupants of buildings where water infiltration has been detected.
For some time now, in the Montreal region, the consequences of the presence of mold in buildings have become better known and complaints have exploded. In each case, immediate corrective measures must be taken to prevent the reappearance of mold. Any infiltration and water damage should be corrected quickly, the relative humidity should be kept below 60% and any fungal growth should be cleaned with bleach diluted with water. If, despite everything, the mold resurfaces, then modifications must be made to the building which will permanently solve the problem, which is much more expensive (up to a million dollars and more sometimes for a medium-sized school). Often, it is necessary to improve the drainage and ventilation system or to insulate the basement (in the case of a crawl space). Due to lack of budget, these changes are not always made on time.
According to Norman King, epidemiologist at the Direction de santé publique de Montréal-Center, the problem will grow in importance since the buildings are aging and their maintenance sometimes leaves much to be desired. In addition, buildings are hermetically constructed (windows often do not open) and people are spending more and more time in them. Thus, we would spend up to 90% of our time indoors, workplace and residence included, which increases our exposure.
Stéphane Gagné – PasseportSanté.net
According to La Presse, November 13, 2002; Intelihealth, November 25, 2002 and Le Médecin du Québec, vol. 37, no. 9, September 2002.
1. Jarvis BB. Chemistry and toxicology of molds isolated from water-damaged buildings. Adv Exp Med Biol 2002; 504: 43-52
