Air Allergen & Mold Testing Blog

Part 3
We’ve talked alot about the history and events that led us to the indoor air quality problems that we currently face. Today, we are going to focus on building materials and mold.
In 1979, the use of plaster, for walls and ceilings, was discontinued. Plaster does not support the growth of mold or bacteria. In its place gypsum board was substituted. To this day it is still in use. Gypsum board is really nothing more than thick cellulose paper.
You may have already guessed the connection. Yes – mold exists in nature to DEGRADE cellulose into basic organic matter. Trees, leaves, limbs, all reduced to basic organic molecules by these tiny organisms. Add to this that most of these home building products are left outside for weeks and sometimes months, on site, before they are installed into homes being built in subdivisions. It has been noted that many of these gypsum board pieces already have black mold growing on them as they were being installed. Now we have homes that have very little fresh air exchange AND we have enclosed fungi on material that they naturally reduce in the forest. All we need is to add the magic ingredient – water. It does not have to be a water intrusion, as in a roof leak or bathtub overflow. It can be in the simple form of humidity. Humidity that stays consistently above 50 RH allows fungi to form reservoirs of growth. By the way, Atlanta averages 68%RH during the year.
Lets add a couple more ingredients that assist in making our homes a potentially hazardous environment. In the 1960’s carpeting our homes became big business. Schools followed the trend. In the 1980’s we went from having one parent home to no one home. Family members now work at least one full time job each and in many instances have a part time position, as well. Dust and dirt are being ground into our carpets, surface dust collects on shelves and ceiling fans. Family members are too tired to keep up the cleaning schedule of our grandparents. What is attached to the dirt and dust? Fungi spores. Our research has demonstrated that our carpets, uncleaned and uncared for are major breeding grounds for fungi. And all we had to add was what? Water – relative humidity above 50%. Now we have two hazards working against us – gypsum board and carpeting in homes with high humidity or water intrusion. It doesn’t end there either. We have HVAC systems that run almost constantly in the summer months. The filters that would keep out contamination are, in many cases not the right size or the correct capacity to be very useful. Fungi pass through the filters and land on areas inside the HVAC where bacteria have already colonized. Mycotoxins and endotoxins are produced and passed into the living area. And what else comes in with the microbiological contaminants? Remember the dust and dirt in the carpets and surface dust? Much of that came in through the HVAC and was spread all through the home by air motion. Look in almost any home or business and see fungi growing on the dust that has accumulated on supply and return vents. Here is an area that does not need to be a hazard. With the correct filter type, preferably a MERV 8 rating, contaminants will be kept out of the HVAC system. In addition, if one is to employ a dehumidifier in their home and basement, humidity can be controlled to the 50%RH recommended levels. This is important to keep the fungi from growing, but also to keep dust mites from proliferating. Dust mites are commonly found in carpeting and live on human skin scales that have fallen to the carpet. Dust mites are considered a major trigger for Asthma. Another good reason to use a dehumidifier in the summer months is to save money on electrical costs. Before one degree of temperature is reduced by the HVAC, it must first remove the humidity from the air. Most air conditioning units spend the majority of their time removing the humidity rather than cooling. With the use of a dehumidifier, the water in the air is removed efficiently to allow the air conditioning to do only one thing – cool the air. This will also allow you to keep your temperature at a higher level in the home, as it is the humidity that creates the uncomfortable feeling of warmth.
So we have identified three areas of concern: gypsum board (especially in basements), carpeting and surface dust, HVAC systems. These are not the only concerns – far from it, but these are the areas where we must concern ourselves with the growth of mold.

Part 2 — Mystery in Philadelphia – politics and death
During the 1973 Israeli – Egyptian war in the Golan Heights, England and the US sided with Israel. This provoked a drastic response from the Arab OPEC nations. They placed an embargo on oil bound for England and the US. Oil prices jumped and shortages became the new reality. Here in the US we were advised by our government that we would need to begin conserving energy. Among other things, this meant tightening our windows and doors to fill drafty leaks. We were asked to put an insulating blanket around our water heaters. The president asked us to lower our heat in the winter and raise our thermostats in the summer. Of all of the measures, though, the one that would quickly cost the lives of American citizens was asking everyone to lower their water heaters by 10 °F from the then accepted 170°F. In 1976, the politics of oil was about to kill 29 Americans and sicken 221 more in Philadelphia, Pa.
During an American Legion Convention, in Philadelphia, suddenly, elderly veterans began arriving at local hospitals with a severe pneumonia. Then the deaths began, one followed by another and another and another. The physicians involved had no idea what was accelerating the pneumonia in such a rapid manner. Whatever the agent was, it was extremely virulent and NEW. It was thought to be bacterial or viral, but it was not being isolated or identified. How do you treat something you have never seen before? Worse, the pneumonia accelerated much more rapidly than anything previously seen. The story spread just as rapidly as the pneumonia. Soon the entire country was gripped by a panic. Was this the “killer virus” we had been promised was coming in our time? Parents kept children home from school. People began wearing surgical masks so as not to breathe in a potentially fatal organism. Some just stopped coming out of their homes. The stories could be seen every night on the national news.
Finally, the outbreak subsided. No one knew why it had begun and no one had any idea why it ended. Among the casualties – the hotel that housed the veterans and their families. It went unoccupied and eventually filed for bankruptcy. In the following years, a maintenance worker, at a hospital, several hundred miles away would die from the very same pneumonia. This time, a physician at the hospital decided to track the maintenance worker’s steps before he had become sick. The agent of the pneumonia was isolated. It proved to be a bacterium. It was eventually named Legionella pneumonphila, for the members of the American Legion in Philadelphia, who had died from it. The physician, additionally, was able to determine how the worker had contracted the bacterium. It appears that the Legionella was growing rapidly in a cooling tower on top of the hospital. The tower was leaking warm water and steam was rising from puddles it created. The worker inhaled the bacteria in large quantities from the rising steam. The bacteria then was released into the deep recesses of the worker’s lungs. As the general population had not been exposed to this bacteria previously, it had damaging and fatal effects on its victims.
Why 1976? Why at the American Legion Convention? Why at that hospital?
The answer was in the lowering of the water heaters by 10 degrees F. Currently water heaters are set at 140°F. This is much lower than in the early 1970’s. Bacteria are killed in water heaters at the higher temperatures of the 1970’s. With the lower temperature most of the bacteria are still killed, except for Legionella. The Legionella proliferate and are dispersed into the deep recesses of the lung by the mist produced in bathroom showers. At the American Legion Convention, the victims were killed by merely taking a shower in their bathrooms. The worker at the hospital was killed because he had no protective mask , which would have filtered out the bacteria.
Since the original outbreak, it is now recognized that Legionella is ubiquitous in fresh water. It is probably in every home and workplace’s water supplies. Although, the solution would be to either raise the temperature in water heaters back to 170°F or to treat cooling towers with bactericides, the US government has chosen to take no action, which has led to thousands of deaths since the original outbreak. Legionella is most often contracted in home showers, grocery store misters in the produce area and in hot tubs that have not been treated with bactericides. In every case the bacteria is transmitted through steam or misting. Fortunately, the pneumonia responds very well to erythromycin, if caught early enough.
People most at risk are those with compromised immune systems, smokers, elderly, and males that are overweight and smoke.
Tomorrow part 3 – mold in homes