A bit about molds


I am commonly confronted with patients who are concerned about mold exposure, both at home and at work. This can be a tricky issue, since molds can cause problems via allergic and non-allergic mechanisms. Molds also been implicated in a wide variety of problems, though there is a paucity of good science to back up many of these accusations.

First, a word about molds in general. Molds are a natural part of the outdoor environment. One of their major functions is degradation of organic material. In English, this means they are nature’s recyclers. They take dead plant and animal matter and turn it into dirt. The life cycle of molds can be very complex, but at some point they produce a spore which can become airborne. It is these spores which can lead to allergy problems. Damp conditions and an abundance of vegetation equals lots of mold spores.

For molds to become an indoor problem, there must be excessive indoor moisture. Often this follows areas of water damage or leaks. If water beads up on the inside of your windows, then there’s too much moisture. The best simple test for molds is still your eyes and nose. If you can smell it or see it, then its a problem. If that’s not satisfactory, then there are good tests for indoor mold levels. Simply placing a petri dish on your dresser is not a good test! Since molds are a normally present in indoor air, this test will always grow some type of mold. A proper test involves volumetric sampling, where a device that looks like a dust-buster takes in a fixed amount of air from several places inside and outside the home. The amount of mold that grows from each sample is the quantified and if there excessive growth from an indoor sample compared to an outdoor sample then there is a mold problem.

Excessive indoor molds cause respiratory problems via both allergic and non-allergic mechanisms. They can cause nasal and chest allergy symptoms in much the same way that other airborne allergens do. These allergies can be tested for and respond to medications and immunotherapy. Molds can also cause problems via non-allergic mechanisms. They release chemicals called volatile organic compounds (VOC’s) which are respiratory irritants. The symptoms they elicit are similar to allergy symptoms, but there is no test for sensitivity to VOC’s and they do not respond to immunotherapy.

The link between mold exposure and respiratory symptoms is reasonably clear. The myriad other complaints that have been blamed on mold have little evidence to support them. The infamous, inflammatory term, “toxic mold” is a term created by litigators and sensationalist news programs, not by physicians. If you have concerns about mold problems, your local allergist can probably help.

Leave a Reply

Required fields are marked *.