By Doug Hoffman

One of the interesting things we’ve learned through our years of experience in dealing with indoor air quality problems, is that everyone reacts differently to IAQ issues.  Where one person might sneeze, another might get a headache and yet a third might have no reaction at all. There is a tendency to treat everyone the same.  We are inclined to believe that either there is an IAQ problem or not, and if there is, everyone should have the same level of IAQ sensitivity.  This is not true.

My sister-in-law was highly allergic to perfumes, specifically women’s perfume.  When she went to church and a heavily-perfumed elderly woman sat down in front of her, my sister-in-law had to move to avoid getting a headache.  Her husband, on the other hand, never even noticed that the elderly woman sat down.  Similarly, sometimes one employee will complain about “sick building syndrome” — where a certain area of the building causes them to experience various symptoms and feel unwell — yet until several people complain about the same area, the employer often doesn’t acknowledge that it could be a problem.

It’s time to take ALL employee complaints seriously. The first employees to complain about a certain area of your building aren’t making their symptoms up; they likely have a higher level of IAQ sensitivity than others, so they experience the symptoms earlier and more severely.

One reason that government agencies have not set standards for levels of mold contamination in indoor air environments is because everyone responds differently to mold and other IAQ contaminants.  Why is that true?  Here are three reasons:

  1. We have different immune systems. Some of us are very concerned about the water we drink, the food we eat, and the exercise we get. Others of us are not so concerned. Frankly, some of us are healthier than others and if our immune system is suppressed, we will react to IAQ contaminants when a healthier person might not.
  2. We have different levels of sensitivity. Some people simply have a much stronger sense of smell than others or may have more sensitive skin. Some people are highly allergic to many things while others have no allergies at all. All of these differences contribute to varied levels of sensitivity to IAQ issues.
  3. Molds have different levels of toxicity. Mold is ubiquitous, even indoors, so we are seldom in an environment where mold is not present. Why don’t all of us react?  Some molds produce much higher levels of mycotoxins than others, meaning a very small amount may still cause a reaction. Additionally, some people react to specific types of mold, while other types cause no reaction. Some people may tolerate a small amount of mold but will react to a lot of mold. In this discussion, the type of mold, the amount of mold, and the environment in which it is growing are all factors influencing a person’s reaction.

As employers, we should take employee complaints about IAQ and mold problems seriously.  If we are proactive about dealing with environmental issues — including those that we are not personally experiencing — it will validate the concerns of those who may have higher IAQ sensitivity and establish a confidence that we are serious about protecting the health and safety of all employees.

Doug Hoffman is the CEO of NORMI, the National Organization of Remediators and Mold Inspectors. He can be reached via e-mail at