As I've mentioned before, we can imply some things about pest control, for instance, that might be in there. We can learn if there's likely to be some chemical collision in the indoor environment. In some cases, we can read that into it. If we know that, let's say, we know there's visible mold and you have a real low airborne count, but you know it's being suppressed for some reason. We can tell something from the symptoms that the people say is whether or not there can be.
There’s three things that may really relate to mold and that is if you see it, obviously that's an issue; if you can smell it, the odor that's given off, the musty odor that you smell from homes or in homes are the gases that are given off while mold is metabolizing whatever it's growing on. So if you smell that smell, mold is growing somewhere; and the third thing is any kind of health symptoms particularly that are associated with the respiratory system, whether you're having sinus problems, whether you're having any kind of breathing issues.
But it's not limited to that – mold problems go far greater than that for a variety of reasons. One of the reasons is that 70% of those who have asthma also have allergies. They have allergies to the mold spores and when you have, and a lot of people have allergies, you don't have to have asthma to have these allergies, when those get into your windpipe and your respiratory system, you get this redness and swelling just like you would get on your skin if you have your skin broke out some way. And that impairs the mucus system from working properly and those little areas that are rough like that become places where bacteria and viruses can get into your system and cause other kinds of diseases.
There are some studies that suggest that between 10 - 30% of all diseases associated with particulate are associated with indoor air. The other way that it can harm you is that, in sufficient quantities, these spores that carry these toxins, they get down into the, they're small enough to get into the alveolar where the oxygen is exchanged with your blood and your body will break those up and then those toxins go out into your blood and they can go to other organs in your system as well and cause damage elsewhere.
The other thing that we're finding, some recent studies have shown that there was one study that looked at data from 14 states and concluded that 90% of the dust in those homes that were studied contained chemicals that were considered to be unhealthy chemicals. 90% of them contained 1 of 10 chemicals, including one of the chemicals that was a carcinogen, a known carcinogen.
We found that there's about 25 spore types that were positive for that ratio for what we found in the carpet dust. We've done the same thing for allergies and we've done the same thing for respiratory problems and each of them had something in the mid-20s that different spore types were associated but when you look at all the health symptoms that we have found, and we've taken those ratios for all of the different spore types that we've found, about 62 of the 70 spore types that were found in any quantity were associated with, were found more often in homes where there were one of the health symptoms that we track.
We not only provide the report from the laboratory. And a lot of inspectors will just provide that report, and they enhance it, they call it their expanded report and they'll put some colored graphs in there and that kind of thing. But they honestly in many cases don't fully explain where it might be coming from. And, if they do say where it's coming from, they don't necessarily say what to do about it to take care of it. And, presuming that everyone is operating honestly and professionally and all that kind of thing, in trying to deal with these things, we find a lot of times when we do clearance test these things after work had been done that they have not passed. And almost every single time when that happens we say, “Well, did you take this step that we outlined in there, you know, did you take this step, did you encapsulate it afterwards, did you vacuum it off, and that kind of thing?” And they say, “Well, no. you know, I didn't do that. Here's what I did.' And they don't take the proper steps. We put the proper steps in our report about how to do that, and we put remediation guidelines and safety precautions in there if things are needed, so the people can protect themselves from it.
A common kind of a thing that's not well known or not talked about a lot is someone will have some mold on the wall where there's been a leak, potentially from maybe another unit or something in the bathroom on the other side of the wall or something on that unit. And so they'll take bleach and they'll clean it with it. And then a few days later, they'll have mold growing there and they'll say, “I don't know what to do, I put bleach on it, it killed it all, I cleaned it all up and then a few days later we had more mold.” Well, what's happening is that the bleach will kill the mold, but the spores are very, very difficult to kill. If you use chemicals strong enough to kill spores, you're probably going to harm the people or the few chemicals that are involved. Most of them are harmful to the people. So when you clean a surface like that, bleach is not a good alternative because it'll kill the mold, it doesn't kill the spores. The chlorine, having a lower vapor pressure than the water, will evaporate first. It leaves the water and that's all that the spores need to start to grow again. So it didn't come back because it was the same mold, it came back because you left the conditions there to grow new mold. And whether or not the spores were left there, which is most likely, or whether they landed there from being in the air and found a convenient place to grow, you wind up with mold growing back again. So bleach on porous materials is not a good alternative, but oftentimes when we talk particularly with tenants, the landlords or the maintenance people will say, “Hey, we'll go just put some bleach on it and everything will be wonderful.”
We do have data because we've done thousands and thousands of these samples over the years. We have data that we can say, if the amount of mold spores in the carpet is normal, if they tend to be water damage spores or if they tend to be what we called phylloplane spores, which are much less likely to have some kind of a problem and we can give some guidances in carpet dust, for instance. There's only three things you can do with a carpet – you can vacuum it with a HEPA filter vacuum. If you don't use a HEPA filter vacuum, it's just going to broadcast it out into the air. And even with HEPA filter vacuum, some of that stuff is going to get out into the air. That's the real fine particulate in spores.
Or you can clean the carpet. Or you can replace the carpet. And we put instructions in there, if you're going to replace it, how to treat the floor and beneath it ahead of time. If you're going to clean it, what kind of stuff you should use to clean it and how you should handle that. And the fact that the HEPA filter vacuum and that kind of stuff if you're going to vacuum it.
That's one of the kinds of sampling that we do. We tell them how to handle the carpet, but more importantly we find out what else is going on in the environment from that, that we can tell them about.
Another kind of sampling that can be done in addition to air samples and the carpet dust samples, is a tape sample. We have a slide with has some, adhesive on it and we can take the cover off and place it on a surface. And then take that and examine it. Similar to the way examine a slide that's in the air sample. We can identify to the genus level what's on that surface.
If you're trying to identify a particular kind of mold on the wall, just to the common names that you hear, like Aspergillus or Penicillium. You can take that sample and you can identify it. And what you learn from that is what's on that square inch that you've sampled. It doesn't tell you anything about a foot away or two feet away or something else that might be in the room. But if you're trying to identify what's particular thing and try to tie it together with what else you're finding, that can be a useful sample. To be able to go in and use that sample, though they would say that their house is mold-free or something like that, is not accurate.
The other kind of samples we take – we can take a swab sample. The purpose of the swab sample is if you want to get to the species level of a particular mold type. Things like Aspergillus and Penicillium that we can see in the air, have perhaps 200 different species between the two of them. And different species have different health characteristics as I've mentioned from the headaches and the respiratory and the allergy things that we find in the carpet dust. That's done at the species level. If you go and you take a tape sample, you can identify the species. You can say if it's Aspergillus or Penicillium, but you can't say what species it is.
Eventually, it will get so bad that you could have some visible signs. But in general, going into an environment and trying to see whether there is a problem, on the microscopic level that mold spores are, you cannot see mold spores. You can see mold, but the spores are like the fruit of the mold, and you can't, you just can't see them, they're just too small. It makes no more sense to be able to walk into an environment and think that you can see the minor quantities of things that are in the air than it does to say you can look at a glass of water and tell whether there's any kind of pollutants in the water. They're just beyond the ability to do that.
The best thing is a good filter in the HVAC system. They have ratings on filters that can describe how small of a particulate can capture and including mold spores because mold spores basically a particulate. A filter with the equivalent of MERV 8 rating will capture particulate down as small as 3 microns. Most mold spores are 3 microns or higher. Aspergillus and Penicillium, for instance, are in the 3.3 micron range, stachybotrys is around 5 microns. So if you have at least a MERV 8 filtering furnace, you're going to be reducing the amount of mold spores that are in the air. It's not going to eliminate them but it'll be healthier.
If you're looking for the background particulate to the deterioration of the indoor environment there we recommend at least a MERV 10 filter because that will go down to 1 micron. And that will help filter out some of the background particulate as well. The problem that we see in Atlanta, there are no regulations of what kind of filters that the HVAC system should have. As a result, the vast majority of all of the places that we go into where they're having respiratory problems have this fiber glassy see through filters that are statistically equivalent to no filter at all when it comes to helping the indoor air quality. And it’s particularly true in apartment buildings, where we see that the filters are – they're useless in terms of filtering any of these kind materials out of the air.