Click to


The New Interest in Mold

I am often asked why mold has suddenly become a major issue in American life. Is the new interest in mold simply driven by scare tactics and profit? If our grand-parents were not overly concerned about mold, why are we?

First, concern over mold is not the new phenomenon that many think it is. People are often surprised when I tell them that the concern over mold is several thousand years old. The book of Leviticus warns the Israelites about the dangers of mold, and instructs them about protecting themselves. In the worst case scenario, Leviticus commands that the building be torn down!

Second, major changes have been made in building construction over the last 100 years. For example, lead was once a popular material for the manufacture of paint. For public health reasons, lead was removed from paint.

Unfortunately, what was good for humans was also good for mold. Metal is a very uncongenial material for mold growth. For this reason, mold rarely grows on lead paint. By contrast, mold has no objections at all of growing on latex paint. Mold is much more likely to grow on painted surfaces than it was 100 hundred years ago.

In order to conserve energy, houses are much better insulated than they were 100 years ago. Older homes were said to “breathe.” Newer homes are described as “tightly built.” This “tight” condition means the newer homes cost less to heat and cool. It also means that less air is exchanged between the outside and the inside.

The EPA has found that outdoor air quality is virtually always better than indoor air quality. Often, the indoor air has 10 times more contaminants than the outdoor air. There are many scientific reasons for this. Biological mechanisms such as beneficial bacteria, the respiration of flora and the complexities of the water system help to purify the outdoor area.

The thing to remember is that the outdoor environment was created by a perfect creator. Our indoor spaces are not.

The “new” concern for mold is not an invention of money hungry contractors. We are grappling with a very old problem that the ancient Israelites took very seriously. Advances in the building arts have complicated this very old problem with some unintended consequences. All the evidence indicates that we should take mold more seriously rather than less.