“The Basement Smell”: Why Basement Air Is Unhealthy

Do you or know somebody who lives in a home with the noxious “Basement Smell”?  Based on thousands of assessments we’ve conducted and the resulting tens of thousands of samples processed as Indoor Air Quality Specialists, I can say with certainty that basement air is the most compromised air in every house.  Even an apparently clean, finished basement often carries ten times the pollution levels as upper floors and, because these pollutants are buoyant and therefore rise, often spoil air in rooms above them. But, why does the air in basements smell unhealthy enough that we’ve coined colloquial phrase after it?

Finished basements with carpeting and gypsum-based wallboard may accentuate the “Basement Smell” and degrade the overall air quality because carpeting absorbs moisture through the foundation in a process called capillary action; this capillary action in turn creates excess humidity, putting more moisture into the air and wetting the insulation. While carpeting manufacturers claim the carpeting is resistant to mold, dusts, dirt and skin cells in the fibers are not. Combined with excess moisture, conditions become ripe for smell molds like Penicllium and Aspergillus. To even further complicate matters, standard gypsum wallboard is a common source for the “Black Toxic Mold” such as Stachybotrys, Chaetomium, and Ulocladium. Typically the insulation behind the wet wall will absorb the moisture from exterior cement walls or a moisture intrusion source like a sponge, making the backside—out-of-sight—moldy first. When you are able to see patches of mold on the front of your wallboard, it is the tip of the ice berg. As a note: even a one-time water damage incident can lead to Black Mold, which can continue to grow and release pathogenic spores even after the wall has dried. It may take months for this insulation to dry. Such environmental circumstances lead to the foul odor we refer to as “The Basement Smell.”

Unfinished basements also create conditions optimal for mold growth because they often contain more organic content (dust, dirt, debris), encouraging fungal growth, than finished basements. Because basements are typically designed with the limited cross flow ventilation, their lack of airflow, combined the humidity from the capillary action described above, insight toxic mold, bacteria and virus growth. It’s not just the toxic properties of these pathogens that make for an unpleasant odor but the irritating and harmful microbial volatile organic compounds (mVOCs) present.  So, when you say it “smells like a basement,” you’re really saying “these mVOCs are out of control. I need fresh air!”

Stored utilities further degrade basement air quality by spitting out ultrafine lung damaging debris referred to as particulate matter. These particles ranging from 0.3-10.0 microns are so tiny you can’t see them, but have the ability to infiltrate the lung tissue in your respiratory tract. The smaller the particle, the more likely these toxins are to enter your blood stream. Just because you have a door separating the finished to unfinished section does not block these particles; you can fit hundreds of thousands of these particles on a pinhead. At IndoorDoctor, we use digital meters to quantify these particles so you can make informed decisions about how to properly service and ventilate your basement.

Other environmental concerns contribute to an overall the unhealthy basement environments that produce the “Basement Smell.” Some are listed below:

• Fiberglass: Often ignored, fiberglass insulation is another pollutant that very common in basements; it can be found within walls, on ceilings, stored in crawlspaces, and lining duct work. Unfortunately, despite being a known carcinogen and terribly irritating to breathe, little effort is made to reduce breathing in the tiny jagged glass particles.  It is not uncommon to see exercise equipment below or near exposed insulation even though the vibrations from this equipment can jar thousands of lung-damaging glass particles into the air.
• Crawlspaces: Crawlspaces are often so dank and inaccessible that most homeowners don’t bother trying to make improvements because redoing a foundation, tearing out walls, installing vapor barriers becomes cost prohibitive. These crawlspaces , which are often nesting areas for vermin, account for the majority of odors, With our advanced equipment, IndoorDoctor can help you make sound practical decisions to reduce the harmful toxins generated in crawlspaces.  
• Radon: Radon is the 2^nd leading cause of lung cancer in the United States and New England is a hot spot for for the gas due to the ledge and granite rock formations. Radon, which comes up through the basement foundation, is colorless and odorless, making it almost impossible to detect without the testing that the EPA suggests every two years.  Beware of uncapped sump pits, too, which allow for greater passage of radon gas into your airspace.
• Traditional Volatile Organic Compounds (VOCs): Traditional Volatile Organic Compounds (VOCs), which are found in the paint cans and fertilizer bags we tend to store in our basements because we cannot take them to the dump, can also emit odors and have serious health effects.

So, what can you do about the “Basement Smell” when you can’t get rid of your basement? The first step is to get it tested. An Indoor Air Quality Specialist from IndoorDoctor can help you quantify the molds, pathogens and other environmental factors that are either emitting a foul odor or, sometimes even worse, are dormant below your main living area. The information from these tests will help you develop a cost-effective plan to reverse the conditions and improve your indoor air quality. As I mentioned at the beginning of this article, basement environments account for a large percentage of the Indoor Air Quality Assessments I conduct, and I am confident that proper testing and follow-up will prevent you from having to talk about your “Basement Smell.” Contact IndoorDoctor today to see how we can make your home healthier. 

Microbial Volatile Organic Compounds (MVOCs) and Health Consequences

Clients often tell us that they smell mold and it's causing adverse health symptoms. However, they are confused when an air sample sent to the laboratory shows little to know spore activity in the areas of concern. Does this mean there is no mold and not to worry? No, what they are actually smelling is decay off-gassing from biological growth which includes molds, bacteria and biofilm. These odors contain microbial volatile organic compound (MVOC). People may compare this odor to a dank locker room, old cheese, dirty socks, or wet dog.

Microbial Volatile Organic Compound Overview:
The dank musty odor signifies the presence of microbial volatile organic compounds (MVOCs). Traditional volatile organic compounds (VOCs) are mainly industrial made chemicals with low molecular weights, high vapor pressure and low water solubility. MVOCs are released from metabolic processes of decay agents like fungi, bacteria and biofilm. The off gassing of MVOCs include a wide range of alcohols, ketones, aldehyde, esters, carboxylic acids, lactones, terpenes, aromatic hydrocarbons, sulfur and nitrogen compounds.

MVOCs produced during primary fungal metabolism include: Ethanol, 1-octen-3-ol, 2-octen-1-ol, and benzyl cyanide. MVOCs produced during secondary metabolism include 2-methyl-isoborneol, geosmin (1-10-dimethyl-trans-9-decalol) and terpenes.

Significance:
The perception of MVOC's is an indication that microbial growth is occurring. In the indoor environment, exposure to MVOC's has been blamed for headaches, nasal irritation, dizziness, fatigue, and nausea. Information on MVOCs produced in indoor settings and health effects is limited. The specific toxic properties and concentrations of MVOC's needed to produce symptoms are still unknown.

Recommendations:
Prudent and preventative measures should be taken to eliminate or reduce musty odors and associated MVOCs. These measures include but are not limited to:

• Professional HVAC system and air duct cleaning
• Disengage any built in humidification devices within the HVAC system
• Control humidity below 45% year round 
• Replace carpeting with a more synthetic floor system 
• Remove water damaged building materials 
• Improve airflow in the home or building by encouraging fresh air with windows open or with an air recovery system (HRV/ERV)

Blizzard Will Cause Widespread Mold Damage for Hundreds of Thousands of New Englanders

As New Englanders dig out from last week’s historic blizzard, a silent threat is creeping into their homes: mold. The snow accumulation on roofs and the high drifts against homes will soon start to melt as temperatures increase. While temperatures are expected to rise above the freezing point during the day, however, they are predicted to retreat below 32 degrees during the night, creating ideal conditions for ice damming and moisture penetration. Such conditions are breeding grounds for mold growth. 

Progressed Black Mold Attic Sheathing

IndoorDoctor is bracing for a surge in mold-related claims due to the storm. We recommend that homeowners inspect their attics, basements and other moisture-prone areas for signs of damage and to call one of his specially-trained and accredited mold inspectors to detected hidden deficiencies.  To eliminate any doubt about the safety of your air quality or home environment, IndoorDoctor’s engineers use specialized detection equipment such as digital moisture meters and infrared cameras to identify areas susceptible to mold growth. If mold is present, IndoorDoctor will have additional diagnostic testing equipment on hand to identify and quantify the type of fungal activity. Bradley urges homeowners to hire a properly-equipped, independent environmental engineering company such as IndoorDoctor to detect these hidden deficiencies and storm damage before family members start to get sick or areas of the home cannot be salvaged. He also reminds concerned parties to check their homeowner’s insurance policy regarding storm damage and to specifically inquire about any mold coverage they have. This coverage, Bradley says, may include the proper testing and inspecting along with any remedial actions that have the power to thwart mold-related illnesses.

10 Ways Expecting Parents Can Improve the Air Quality in Their Baby’s Bedroom

1.  Only use Non-VOC and odor-free paints: Before you paint your baby's nursery that perfect shade, make sure the paint you've chosen does not contain volatile organic compounds (VOCs) or harmful odors. Such paints can off-gas for months, or even years, exposing your newborn to unnecessary chemicals that can lead to respiratory distress or other serious medical conditions.

2. Avoid thick pile carpeting: Carpeting harbors many environmental allergens, often increasing the air pollutants in confined spaces. These environmental allergens, such as molds and dust mites are often found in carpeting with thick pile (fiber) and can compromise the air your baby breathes. Avoiding carpeting all-together is the safest air quality option, but parents who insist on having carpeting in their baby’s bedroom should at least use a low pile carpet, as they are easier to clean and maintain. These parents should also schedule regular professional carpet cleaning and always request the extraction based method for most effective allergen removal.

3.  Purchase natural, chemical-free furniture: New furniture may give off cancer-causing gases such as formaldehyde. Baby furniture, especially cribs, is notorious for high levels of this dangerous gas. To avoid this, parents should not purchase furniture that contains pressed woods or heavy lacquers.   

 4. Replace the window air conditioner or regularly change central air filters. If your window air conditioner is more than 3 years old, take a flashlight and peer into the vent and housing. It’s likely you’ll see progressed mold everywhere. Old air conditioners spew out exponential mold spores, which in turn contaminate bedrooms, leading to coughing-based illnesses. If you have central air conditioning or heating, you should also change the air filters and schedule a quality cleaning of the HVAC unit. Replacing old and compromised units can drastically reduce the threat of sickness.

5. Control the humidity. Too much overall humidity, often caused by humidifiers, leads to unwanted bacteria, yeasts, and molds. Mount a hygrometer (purchased at any hardware store) on your nursery wall to measure the humidity; if the relative humidity in the room exceeds 60%,  then reduce the amount of time you use your humidifier. Remember to fully clean and sanitize the humidifier at least every other day.

6. Use a HEPA filter vacuum: In order for a vacuum to have HEPA (high efficiency particulate air) credentials, it must filter and capture 99.7 % of physical matter below the 0.3 micron level. HEPA vacuums, then, remove the harmful, microscopic allergens that often result in respiratory illness. Miele brand vacuums are some of the best  to control allergens and improve the overall air quality. Make sure, however, to change out the bag once it’s more than half way filled. Use the correct floor attachment for optimal cleaning.

7.  Avoid any remodeling prior to or after the birth of your baby: During renovations ultra-fine debris such as fiberglass, mold spores and even asbestos dust is released into the air, where it can stay for several weeks. These ultra-fine particles are much more dangerous than larger particles, as the lungs have difficulty filtering the microscopic airborne debris. Because infants' and children's' lungs are still developing, they are most prone to serious infection and bronchial irritation.

8.  Use a quality air purifier in the nursery: There are an overwhelming number of air purifiers on the market, all claiming to increase the indoor air quality in a given room. We have found the two brands that work most efficiently and reliably are the Austin Air and IQAir products. You can read independent reviews at www.allergybuyersclub.com.

9. Clean the windowsills: Windowsills often absorb excess moisture, leading to fungal growth. The most typical mold found in this area of the bedroom is Cladosporium, which can become airborne easily and often leads to poor air quality in the room. Because babies are particularly sensitive to mold presence, parents should regularly clean nursery windowsills, making sure to remove excess debris to prevent the onset of Cladosporium.

10.  Have your home’s indoor air quality tested: At IndoorDoctor we use state of the art equipment and only the best laboratories in the nation to assess your indoor conditions. You want the safest environment for your new baby and so do we. Contact us to schedule air quality evaluation and ask for the New Baby Air Check.  

Relative Humidity and Why It Matters

You can control a key variable associated with proper air quality in your home by maintaining relative humidity levels.  

Anyone who has watched the Weather ChannelEverybody’s heard the weather report and grasp the concept that excess humidity is muggy and low humidity is dry. New Englander’s know that basements should have a dehumidifier to lower the humidity. Physicians recommend humidifiers to increase humidity in the winter when its’ dry or to relieve coughing and congestion. So what’s the big deal with humidity in the home and what’s the ideal range? For indoor air quality purposes the ideal range is between 35-45% relative humidity.

Let me try to clear the air regarding some of the basic terms which are not interchangeable.

Relative humidity is a ratio of the amount of water in the air compared with the amount of water the air can hold at a given temperature. Air’s capacity to hold water vapor increases with increasing temperature. Warmer air can hold more vapor than colder air. This is why 60% relative humidity at a temperature of 95F feels muggier than 60% humidity at a temperature of 40F.

Dew point is an absolute measure of the amount of water in the air. It is the temperature at which the air, at the current amount of water vapor, will be 100% saturated. Reduce the temperature any further and water will condense out and form dew or fog, hence the dew point. In fact, you'll often see fog forming even before you reach that point.

Mold spores and dust mites will increase exponentially when the relative humidity exceeds 60% for a sustained period of time. A typical basement without a dehumidifier will read between 65-75% relative humidity during summer months and between 45-60% during winter months.

Most people will know when it’s dry or below 20% RH or muggy when above 70%. However while the average person will notice a five degree change in temperature they are not able to notice changes between 20-70% relative humidity. This is why monitoring the relative humidity in your home or basement is so important, yet few people do. 

Relative humidity is measured using a hygrometer. You will want to set your dehumidifier to around 35% or continuous mode to ensure the relative humidity at the opposite end does not exceed 55%. Don’t rely soley on the relative humidity reading on your dehumidifier. These displays are notorious for being inaccurate. We recommend a quality digital hygrometer like the Extech brand sold through Professional Equipment for around $45.