Michaels - Why Mold is a Problem



	This wasn’t a problem yesterday -- so what changed?? Agriculture -> Industrial Revolution -> Information Age The Hygiene Hypothesis – no more cows in the house Economy dependent on cheap oil (energy is not equal to oil) Transportation, suburban/rural sprawl Petroleum literally drives Western standard of living Energy efficient buildings after 1973 oil embargo Weatherstripping, insulation: build tight! Reduced heat loss means less energy for drying building envelope *Is Homo sapiens* changing? Allergies affect 25-30% of the population nPrevalence of seasonal allergic rhinitis (“hay fever”) up 50%: 6% of children in 1996; 9% in 2002 [National Center for Health Statistics] Asthma in developed nations has more than doubled in the last 20 years In the US, more than 20 million people have asthma [Amer Lung Assoc] nMore immuno-compromised persons return to the workplace Modern building practices – porous synthetic materials, “paper buildings”** An office bldg for $44.95/ft2; an elem school for $53.45/ft2 Per R.S. Means, Square Foot Costs (2003) [M.460 office, M.560 school] New versions of gypsum board: USG “Humitek” interior GWB nLP “DensGlass” exterior sheathing, related line	Stay informed about current technologies and practices. Click here to subscribe to our FREE electronic News Briefs.



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