What Is Radon?

“So what exactly is radon?  Is that bad for you?”

I was asked these questions recently and it struck me how little the general public seems to know about this insidious gas.  In my experience, there is a greater understanding of radon today then there was roughly 20 years ago.  However, I believe that there still needs to be a greater understanding of radon and the threats that can be associated with it.

First off, what is radon?  Radon is a colorless, tasteless, and odorless gas which is naturally occurring in the soil and is part of the radioactive decay chain of uranium.  It is naturally occurring and found in the ground at varying concentrations worldwide.  It gets indoors through cracks and openings, found especially in rooms at or below the ground surface.  For single family residences, this includes basements and rooms above crawl spaces and slab foundations.  

Now the bad part.  What does this mean for your health?   Radon is a known human carcinogen; it is the leading cause of lung cancer in non-smokers, and the second leading cause of lung cancer overall.  This has been proven through epidemiological data and laboratory evidence.  According to the Environmental Protection Agency (EPA), “Radon is responsible for roughly 21,000 lung cancer deaths every year.  Roughly 2,900 of these deaths occur among people who have never smoked.”.  (  

The EPA and Illinois Emergency Management Agency (IEMA) Action Level for radon in a property is at or above 4.0 pCi/L (picocuries per liter of air) during a testing period lasting at least 48 hours.  How prevalent are elevated radon levels in the state of Illinois?  The University of Illinois reported that “Professional radon measurers have found over 41% of Illinois homes tested at or above the recommended action level of 4 picocuries per liter of air.” (

What is the best way to know if you have elevated radon levels in your home?  Testing is overwhelming the best way!  A radon professional will be able to provide the most accurate numbers for your home or commercial business.  If you have any concerns regarding radon, feel free to contact Indoor Science at 312-920-9393.  

Is That A Cat Skeleton?

For the past three months, I have spent several days a week crawling on my hands and knees (and occasionally on my stomach), wearing a Tyvek suit, a respirator, gloves and lugging equipment underneath unlit residential buildings. What was the purpose (besides building character)?  To help clients of ours assess mold and water issues in several of their properties’ crawlspaces. Somehow I was designated to be- “crawlspace guy.”

Fungal growth

Besides the physical challenges of navigating through the crawlspace, the inspections themselves became very straight forward.  The majority of any water damage issues and subsequent mold growth were associated with plumbing problems.  Broken pipes, missing pipe caps, and condensation on uninsulated pipes were all very common.  All of these plumbing issues introduced water into the crawlspace causing fungal growth with varying degrees of severity.  In a few properties I even saw large fungus growing on structural components of the building!  Some crawlspaces had minimal mold growth that could easily be wiped away, while other crawlspaces will require the complete replacement of material such as joists or subflooring not to mention major plumbing repairs.

More Fungal Growth

Dead cat?

Although I was hoping to find a pot of gold hidden in one of these crawlspaces, all I found was broken glass, rusty nails, garbage, skeletal remains of different critters, old Old Style beer cans, and rats in various states of existence.  At least I’ll sleep well knowing that we helped improve the air quality for many clients.


Joel Silva

The Basics of Legionella


File:Legionella Plate 01.png

Legionella bacteria can pose a serious health risk in the indoor environment. Legionella is a gram-stain negative bacteria that was discovered in 1976 after an outbreak in Philadelphia. The outbreak occurred at an hotel during a convention for the American Legion, where 34 died and hundreds were hospitalized.  Up to that point in time, the bacteria was not discovered or named.


Legionella can be found naturally in freshwater environments as well as in man made water systems such as cooling towers, water tanks, and decorative fountains.  It typically forms in warm, stagnant water and spreads when that water becomes aerosolized. It can form two different types of infections in humans:the more severe Legionnaires’ disease and the milder Pontiac fever.


Legionnaires’ disease is a type of pneumonia, which is typically more fatal than a common pneumonia. Exposure occurs when Legionella contaminated water is aerosolized and then inhaled by a person. Symptoms of Legionnaires’ disease include cough, high fever, shortness of breath and wide variety of symptoms similar to pneumonia. The infection is typically treated with antibiotics. The people who are most at risk for Legionnaires’ disease are smokers, elderly and the immunocompromised.


Another infection caused by the Legionella bacterium is Pontiac Fever. Pontiac Fever is a condition that resembles influenza, and is a Legionella infection that does not include a form of pneumonia. It was discovered retrospectively after the Legionnaire’s disease outbreak of 1976 when blood samples from a 1968 influenza outbreak in Pontiac, Michigan showed the presence of the Legionella bacterium. Pontiac Fever is treated with antibiotics like Legionnaires’ disease. Both Legionnaires’ Disease and Pontiac Fever are generally not spread from person to person.


If you are concerned that your water systems are contaminated with Legionella, consider hiring a consultant such as Indoor Science to do an assessment of your property.

Pesky Particles

The term particulate matter refers to the combination of liquid or solid particles that are present in the air. The size of particles varies with some types being visible to the unaided eye while others are only visible through microscopy. These particulates can originate from a wide variety of sources, such as combustion, the breaking apart of larger materials,  the wind blowing particles from settled dust, and a myriad of other sources. In recent decades various agencies and officials have linked elevated particles to having a negative impact on indoor air quality and health.


Particulate matter with a 2.5 micrometer aerodynamic diameter or smaller may pose special health risks and are monitored by the EPA. Particles of that size are respirable and are not removed by the lungs’ mucus and cilia. Exposures to elevated fine or ultra-fine particulates can lead to negative health effects such as heart attacks, reduced lung function, asthma, and various pulmonary issues. Elevated particulate matter in outdoor air can cause environmental issues such as reduced visibility, acid-rain, and damage to ecological systems.


Indoor Science recently had a project where construction dust from one condo unit caused an extremely high level of particles in the neighboring unit.  If you are concerned about particulate matter affecting indoor air quality at your property, please contact Indoor Science to assess the situation.


PAACB Certification

Laboratories who analyze samples for mold typically have accreditation from the AIHA (American Industrial Hygiene Association) Laboratory Accreditation Program, LLC. This accreditation is for the lab as a whole covering everything from the facilities, equipment, standard operating procedures (SOP), and even record keeping. What may be surprising to some is that this accreditation does not cover the qualifications and proficiency of the analysts. For that, there is only one certification available: Pan American Aerobiology Certification Board’s (PAACB) Spore Analyst Certification.

The Pan American Aerobiology Association (PAAA) realized the importance of individual competency when it came to fungal analysis, so they coordinated the creation of the Pan American Aerobiology Certification Board, commonly known as PAACB. This group oversees the certification of individual analysts for fungal spore identification. This is the only certification currently available that covers the proficiency of the individual analyst. The certification is made up of two exams which cover everything from basic mycology to fungal spore identification and enumeration.

PAACB is globally recognized certification to demonstrate the proficiency of the individual. PAACB certification is actually recognized by the State of Texas as qualification for receiving a Mold Analysis Laboratory License. There are certified analysts in many different commercial labs and agencies as well as individual persons who have achieved this certification. Indoor Science has a certified analyst on staff who handles many of our mold samples in our in-house lab. We also have the unique ability to take the microscope and analyst on the project site for on-site analysis of mold samples for the fastest possible turnaround time!

Baby, it’s cold outside!!

During this time of year, I love to hear the old song “Baby, it’s cold outside!” play on the radio.  It sums up winter time in the Chicago area.  And with this frigid weather, we retreat to the comfort and warmth of our homes.  

But the warmth that we feel inside our homes can bring hidden dangers that can spell “M-O-L-D”.  Now, how can this be?  We usually associate mold with summertime flooding or a leaking pipe.  How can mold develop in the absence of a major water event?  I can answer that in one word – “Humidity”.  

Mold needs moisture more than anything else in order to survive and grow.  On days when we experience extreme cold outdoors, it is possible to have humid indoor air (humidity is a form of moisture) hit a super cold surface, like a window, and create condensation.  This moisture can roll down a window pane and lead to mold on the window sill, or worse, in the wall below.

What’s the best way to prevent this mold growth?  We recommend that during periods of extreme cold, make sure your indoor humidity level is reduced.  A handy gadget to help you monitor the level of humidity indoors is a hygrometer.  Some professional organizations recommend that your humidity level should be below 60 percent, but I would recommend continuing to reduce the humidity level until you no longer have condensation on the windows. You may need to keep humidity down below 20% to prevent condensation on some inefficient windows. 

If you see condensation on windows, we recommend turning down your humidifier, or turning it all the way off if that is the only way to keep windows dry.  Be sure to always operate your bathroom exhaust fan when showering and kitchen exhaust when cooking (if you have one that exhausts to the outdoors).  Only on rare occasion would you need to operate a dehumidifier during the wintertime; it’s better to catch the moisture at the source.  
“Baby, it’s cold outside”, but you can still be comfortable and mold free inside your home.

Ancient Asbestos


The usage of asbestos has been documented since antiquity. Before its usage in modern building materials, asbestos was used in pottery, clothing, and even ceremonial items throughout the world. Many ancient civilizations used asbestos because of its amazing properties which included fire resistance and ability to be woven and integrated into many objects.

In ancient Finland, many of the clay pots that were used had asbestos embedded in them. This was possibly added to the pots for its fire-resistance and strengthening of the pots. The asbestos found in Finnish pottery contained Anthophyllite asbestos, unlike Chrysotile asbestos which was commonly used in most modern building materials. The Anthophyllite was possibly mined from metamorphic rock deposits in the region.

Asbestos was first used in China during the Zhou dynasty (1046-256 BCE). Chrysotile was intertwined with fabric in order to produce a fireproof materials. Fables of the time stated that the asbestos originated from a salamander-like animal who could walk on fire. Historical traveler Marco Polo, referenced the material in his journals and visited a mine to disprove the legends of its origin. With increasing trade in Asia moving westward, eventually the Persians began using the material which they had imported from India. Many royals in Persia were noted to have used asbestos-laden cloth for clothing, napkins, and other decorative objects.

Asbestos containing materials have had a long history of being used in ceremonial ways. In ancient Egypt, during the embalming process of Pharaohs, a cloth of asbestos was placed on the body in order to preserve it further. In Rome, many ceremonial temples of the gods had used asbestos in sacred fire rituals. The lamps of the roman group of vestal virgins contained an asbestos wick which allowed the lamp to burn without being extinguished.

Throughout history many other cultures would use asbestos for a wide variety of purposes due to its versatility and durability.  This is one of the reasons it was called the “miracle mineral” and its later implementation into modern building materials.

The Dangers of Carbon Monoxide


Every few months a new tragic story about a fatal carbon monoxide (CO) poisoning surfaces.  The stories of people who have lost their lives from a common environmental compound can be sad and unsettling.  CO poisoning is preventable but first it is essential to know some general information about this dangerous gas.

Many individuals are aware that car exhaust emissions contain carbon monoxide but unfortunately the grayish, smoky, irritating smell is not what CO smells or looks like.  In reality CO is a toxic, odorless, colorless gas.  This compound is often confused with carbon dioxide (CO2).  CO2 is a product of respiration meaning that people and other mammals breath it out. CO, on the other hand, comes from incomplete combustion found in exhaust emissions and other gas-powered appliances and pieces of equipment.  While it may seem that the outdoor air is only affected by CO, windows, doors, and leaking chimneys can very easily draw in CO from the outside.  This can be especially pronounced if the home is close to a busy road or has an attached parking garage as is the case for many Chicago residents.  

Indoor sources can contribute to elevated levels of CO as well.  Gas stoves, furnaces, gas space heaters, hot water heaters, and generators can dangerously raise CO levels when not vented correctly.

High concentrations of CO can be fatal which is why many cities, like Chicago, require that carbon monoxide alarms be installed.  Carbon monoxide detectors alert the occupant of deadly concentrations, but lower concentrations may not sound the alarm.  Lower concentrations can have adverse health effects including fatigue in healthy individuals and chest pain in people with heart disease.  A quick synopsis on how CO enters the body may help highlight the danger of this compound.  

First, the body transports oxygen using the air inhaled through the lungs.  The oxygen within the air is transported throughout the body using red blood cells.  Carbon monoxide impedes the body’s ability to transport oxygen by occupying the oxygen binding sites within these red blood cells.  With less bonding sites available, less oxygen can be delivered to cells.  The higher the concentration of CO in the blood, the less oxygen is available for the body and the more dangerous it becomes.  The health effects from being exposed to CO can be detrimental to anyone, not just a single demographic.

Being informed about this common compound is very important, it may even prevent another tragic story.

Featured Mold – Aspergillus and Penicillium

Aspergillus and Penicillium are two of the most common mold genera that we see in air samples.  When dealing with spore trap lab results, you will often see these types listed together in groups such as Aspergillus/Penicillium, Asp/Pen, or Pen/Asp. Visually, spores of these genera are so similar that analysts can not differentiate them, so they are reported together. Occasionally spores from other genera which produce similar small amerospores (spores with no septations and no projections longer than the length of the spore) will be counted in this group also. Because there are over 200 separate species of both Aspergillus and Penicillium, an Asp/Pen designation on a lab report represents a large grouping of different species.

Aspergillus conidia at 400x

Since there are so many different species in this group, we can find Aspergillus and Penicillium in a broad range of habitats. Some species such as Aspergillus penicillioides are xerophilic, which means they grow with only a small amount of moisture. Other species like Aspergillus versicolor are more prevalent in environments with high water activity. In a home without any moisture problems you can often find Aspergillus and Penicillium growing on spoiled fruit.

Like all mold, Aspergillus/Penicillium can cause allergic reactions in people who are sensitive to these types. They can also occasionally cause fungal infections of the ear, eyes, and skin.  In people with underlying health issues and compromised immune systems, Aspergillus can infect the lungs causing pulmonary aspergillosis.

Surprisingly, mold isn’t always the bad guy. There are many important uses for fungi in industry. For example, Aspergillus and Penicillium are used to make all sorts of products from cheese to pharmaceuticals. Without these fungi we would be without many important antibiotics, soy sauce, or soft drinks.

Air Cell Pipe Insulation


Air Cell refers to an asbestos-containing pipe insulation product. It has alternating layers of plain and corrugated asbestos paper.  The term “Air Cell” was used as a product name by Armstrong Contracting and Supply Corporation and others.  However, the term “Air Cell” can also be used in a generic manner for various types of similar asbestos-containing pipe insulation.

How can you tell if pipe insulation contains asbestos?  Some pipes might be insulated with corrugated cardboard paper that contains no asbestos.  Others have cardboard paper, yet contain an inner-layer of asbestos insulation.  Some pipe insulation was adhered using an asbestos-containing mud/adhesive.  All of these may be referred to as “Air Cell”, but the only way of knowing the asbestos content is to perform a test.

The asbestos paper typically had 15%-25% asbestos. While most of the insulations may contain Chrysotile, several varieties may contain amphibole asbestos minerals such as Crocidolite.  Air Cell was typically covered with an outer wrap that does not contain asbestos.  

What is that terrible odor?



There is an old story that I tell that goes like this.  I am sent to a home where the owners have noticed a strange odor that they want us to identify.  As soon as I enter the door, I am immediately asked “Can’t you smell it?  Can’t you smell it?!!”.  After sniffing around for a few moments, I tell the owners “I smell the oregano from last night’s dinner, I smell the dog, I even smell some wet towels.  But I don’t quite know yet what you are smelling.”

And that is the problem with odor detection.  In truth, every home has its own unique smell, but our minds have the ability to block it out.  We can block out certain odors that we deem to be “normal”, but other odors can stand out and drive us crazy.  What exactly is that odor?

Odors can come from a wide variety of sources.  So in dealing with an unusual odor it’s best to ask some questions.  One question involves asking “what does it smell like?”  At first blush, this seems like a very obvious question.  However, during the last year I have investigated at least eight homes where the owners thought they smelled mold in the property.  In reality, what they smelled were odors associated with a natural gas leak.  In another case, a client noticed that his coats and sweaters had an unusual odor.  He thought it was mold, but in reality it was a heavy stain on his hardwood floor.  

So ask yourself these questions: is the odor that I am smelling “musty” (like in an old basement) or does it have a more “chemical” smell.  Musty odors are usually associated with mold, whereas chemical type smells can be associated with volatile organic compounds (VOCs) that are often affiliated with building materials.  A “rotten egg” smell could be hydrogen sulfide from sewer gas.

Another question that you can ask yourself is “when did you first notice this odor?”  Let’s say that you noticed the odor roughly two months ago.  During that time, what changed in the home?  Did you have a flooding event in your basement?  Did you have some remodeling done in a particular area of the house?  Was there a dead animal somewhere in the property?  Did you switch from heating to cooling?  At first we may think that the odor just suddenly appeared, but in truth we can usually connect it to some event.  

We may also ask, “is the odor particularly worse at a certain times of the day or week?”.   Some clients have noticed that there is a cigarette smell that they suspect comes from a neighbor in an apartment building.  Does the neighbor have a tendency to smoke in the morning?  Late in the evening?  There are some clients who live above a commercial property where they run certain machines or use various chemicals at specific times.  In this regard, it may be best to keep an odor log to see if there are any discernable patterns.      

Once we have determined what the odor is, the next logical question is ‘How do I get rid of it!”  Depending on the source… it depends.  If the odor is musty, then it is highly likely that it is coming from mold or bacteria and the best way to eliminate the smell is to fix the underlying moisture problem and clean the area.   If the odor is coming from a VOC, the solutions can be a little more complex.  If removing the source is too expensive or not feasible, outdoor air ventilation is typically best.  Ventilation is a fancy way of saying open up the windows and allow as much fresh air as possible to flush the area of concern.  I often times recommend having box fans in windows to blow good air in and bad air out.  

So the next time you think to yourself “What on earth is that terrible smell?”, think about some of the questions that I mentioned above.  If all else fails, consider having Indoor Science examine your property for a more thorough investigation.

Marvel Comics & Asbestos


In the colorful universe of Marvel Comics, many of its superpowered characters gained their abilities via a science experiment, magic, technology, or other uncanny circumstances. In the late 1940s Marvel (known at the time as Timely Comics) created a character that drew their abilities from a real world material known as asbestos. This character took the form of Asbestos Lady.

Asbestos Lady, also known as Victoria Murdoch, was a bank thief that utilized fire in her crimes so that no one would be able to capture her. To survive the flames she developed a suit formed of woven asbestos with an internal cooling system. In order to get an edge on her primary adversary, Jim Hammond, The Original Human Torch; she kidnapped renowned “Asbestos Scientist”  Fred Raymond to upgrade her arsenal to battle her foe. Her new arsenal included items such as a new suit with better asbestos insulation and asbestos bullets. Ironically enough, Fred Raymond was sick from his experimentations in asbestos research. Eventually, the Asbestos Lady was apprehended and placed in prison.

Two decades later Marvel created another asbestos-laden villain known as the Asbestos Man. Asbestos Man also known as Orson Kasloff was a scientist who believed his works didn’t get the recognition that they deserved. In order to gain the acceptance he desired, Kasloff developed a substance called “Super-Asbestos”. This mixture contained Chrysotile asbestos, iron, and calcium. With this new substance, Kasloff created a suit, shield, and energy net which gave him the ability to be bullet-proof and fire resistant. He subsequently began robbing banks and even at one point challenged the new Human Torch for notoriety. Like Asbestos Lady before him, he was captured and arrested.

During the following decades both characters fell into obscurity until the 21st century, where both characters reappeared separately. Ironically enough, both characters were diagnosed with mesothelioma as a result of their exposure to their asbestos-based arsenals. Asbestos Lady & Asbestos Man eventually succumbed to their illnesses.

Both characters were created before the first asbestos ban in the late 1970s and its official designation as a carcinogen. They were conceived in an era when research showed the negative effects of exposure but large asbestos manufacturing companies used their resources to hide these facts from the general public. By creating these characters, Marvel brought awareness to the dangers of asbestos exposure to a larger audience under the veil of comic strips.

Indoor and Outdoor Pollutants in Chicago


Living less than a half mile away from Lake Michigan in Chicago made the Lakefront Trail (LFT) effortlessly accessible. I could quickly warm up with a short walk or jog and almost instantly have access to the beautiful lake and a path designed specifically for pedestrians and bicyclists. The LFT lines the edges of the lake for 18 miles making it a very scenic and relaxing space for runners. Moving to a landlocked neighborhood on the west side of Chicago changed all of that.


Now, it is difficult to find a route that isn’t dotted with multiple stop lights or heavy traffic. The unveiling of The Bloomingdale Trail, also known as The 606, was the only glimmer of hope for this new west side resident. Unfortunately, the 2.7 mile distance was very underwhelming not to mention that the narrow 606 is often congested. Hanging above buildings, streets, busses, people and occasionally intersected above by an L train is an impressive work of engineering and planning, but it made me nostalgic for lake views, green grass, and cleaner air. Breathing in clouds of exhaust while running outdoors can be a runner’s high buzz kill, but luckily I can quickly escape it by going indoors, right?


Just as there are pollutants in the outdoor air, there are pollutants in the indoor air. Some of the indoor pollutants originate from the outdoors. Outdoor particulate matter, carbon monoxide and ozone can penetrate the outside of buildings and come in. Other pollutants such as volatile organic compounds (VOCs), have their strongest sources indoors. The point is: you don’t escape air pollution once you go inside.


As a runner who IS overly concerned about his respiratory and cardiovascular health, I immediately noticed the increased emissions when changing neighborhoods. Who would have guessed that running in the City of Chicago would bring me so much awareness of pollution: indoors and out? Different neighborhoods can bring varying amenities, but with those changes also come different environmental challenges. It’s good to be aware of the surrounding outdoor air quality and possible indoor air quality contaminants. Perhaps now that the temperature is dropping, it may be time to hit the treadmill indoors. Although I’ll avoid the exhaust fumes and Chicago snow, I will still need to contend with the indoor air!

Health Effects Associated with Asbestos Exposure

What are the health problems associated with asbestos exposure? In this blog post I will discuss the common routes of exposure for asbestos and its health effects related to exposure.

The term asbestos refers to a group of six naturally occurring fibrous silicate minerals which often have a length-width ratio of roughly 1:20. These minerals were widely coveted because of their fire-resistance, tensile strength, and durability. Many dubbed asbestos the “miracle mineral” because of its versatile uses in a wide variety of industries. However, its health effects associated with exposure have been documented since antiquity.

The Roman philosopher, Pliny the Elder, documented in his writings in the 1st century that the workers in the asbestos mines often died faster than the rest of the population from a lung sickness. In the early 1900s, researchers worldwide began correlating workers exposed to asbestos to lung disease related deaths. These discoveries eventually led to the ban of its many uses in 1977 in the United States and the classification of it as a carcinogen.

The most common route for asbestos exposure is from inhalation. Ingestion is another route of exposure that is far less prevalent than inhalation. Skin contact with asbestos has been not know to cause any serious health effects. The most common activity that causes asbestos exposure is disturbing asbestos containing materials during renovation activities. Breaking or disturbing these materials may release asbestos fibrils in the surrounding air. Once inhaled the asbestos fibers enter the lungs undetected because of its microscopic size and are deposited into the lungs over time. The larger the amount and duration of deposition of fibers into the lungs will increase the likelihood of asbestos related diseases to occur.

Asbestos related diseases do not generally occur directly after exposure. In fact many asbestos related diseases have a long latency period, which is generally 10-50 years after exposure. The three most common asbestos exposure related diseases are mesothelioma, asbestosis, and lung cancer. Mesothelioma is an asbestos-related cancer that forms in the lining of the lungs and abdomen and usually but not always attributed to amphibole asbestos minerals (Amosite & Crocidolite).There is no current cure for mesothelioma.

Individuals exposed to asbestos are far more likely to develop lung cancer than those who aren’t. People who smoke and are exposed to asbestos have an even higher likelihood of developing lung cancer because the lungs are more vulnerable to asbestos fibers. This is known as the synergistic effect in which two factors produce a greater effect than the sum of its components. Asbestos is primary cause of mesothelioma, whereas there are many causes of lung cancer.

Asbestosis is a pulmonary fibrosis of the lungs that results from asbestos fibers scarring lung tissue. People with asbestosis have a higher likelihood of developing mesothelioma or lung cancer.

Currently there is no safe threshold for asbestos exposure. OSHA and the EPA have accepted guidelines for exposure limits, however these should not be interpreted as safe levels. All carcinogens should be kept at the lowest possible concentration. If you plan to disturb or remove materials that may contain asbestos, I recommend you hire a licensed asbestos inspector (such as our company, Indoor Science) to inspect and collect the material before starting renovation activities.

D’oh! The Simpsons have Air Quality Problems

With each passing year, the general public becomes more and more aware of indoor air quality (IAQ) issues. I thought it was because of my educational outreach efforts.  Come to find out… people are more aware because of The Simpsons!


I found over 20 indoor air quality related quotes from Simpsons episodes using the new website  You type in a term such as “asbestos”, and it will search the entire catalog of episodes and then show you relevant screen shots.


Don’t worry, I’ve gone through all the trouble of wasting an entire workday to find all the indoor air quality related Simpson quotes.  I should mention it was the most glorious day of my working life.



asbestos 1


Lead Paint 2

ETS copy

moisture 2 copy

radon 1

virus copy

odor copy

fresh air 2

Lead Paint 1

asbestos 3

fresh air

fumes copy


Mildew copy

healthy copy




co copy

radon 2

tar fumes copy


air vent

asbestos 4 (This one I missed, but Michael Pinto alerted me to it!)


Leave a comment below to let me know which was your favorite!  Also… help me out by linking to this post!

Environmental Inspections During Real Estate Transactions

Now that spring is right around the corner, we have been receiving a lot of phone calls about environmental inspections and testing prior to purchasing a new property. Some people have a general idea of things they want checked out per recommendations of their traditional home inspector. Examples include potential mold in an attic or 9”x9” tile in the basement which may contain asbestos. However, more and more we are getting calls from people who want testing beyond what is covered in a traditional home inspection, but don’t know where to start. Here are three common things that we recommend checking out prior to purchasing a new property.

Mold and Moisture
Although traditional home inspectors will find major moisture issues and many structural issues which may cause moisture problems, finding subtle moisture issues may require calling a specialist. Not many home inspectors are trained in mold inspections or testing. We believe scanning the property with an infrared camera and moisture meter is a key step during pre-purchase inspections. Having mold sampling and testing isn’t always needed, however if there is visible growth, moisture issues, or if you are sensitive to mold it should be something to consider. Moisture is not only a key requirement for mold growth indoors, but high moisture levels also pose other risks in a home such as pests like insects or rodents. Moisture problems can be complex and hard to fix completely, so the best time to find out these details is before you own the property!

Radon is a colorless and odorless soil gas which is the second leading cause of lung cancer, behind tobacco smoke. The EPA says 1 in 15 homes in the US have elevated levels of radon, and the only way to know if your home or prospective home has high radon is to test. The EPA has placed each county in the US into “zones” which predict the average radon level indoors. Several Illinois counties are in the highest radon zone. Radon testing is an easy step to have peace of mind. It is best performed during a real estate transaction so the price of any needed mitigation system can be negotiated into the final sale price. If any problems are found, we can connect you to licensed contractors with a proven track record.

Asbestos has been phased out or banned for use in most building materials for years, however with the average age of homes in the US at around 35 years there are still a large amount of homes which could have asbestos containing materials. Asbestos was used in a number of building materials due to its natural fire resistance. Asbestos is a fibrous mineral which can cause various respiratory diseases when it becomes airborne and inhaled by humans. When asbestos containing materials are undamaged and undisturbed there is very little risk of health issues, however when friable materials become damaged, fibers can be released into the air. If you or your home inspector find any suspect materials, especially if they are worn or damaged, you should call a licensed inspector to check it out.

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Humidity In Winter

With winter now upon us, let’s take a minute to think about humidity in your home. Maintaining proper humidity levels during the cold months is more important than just comfort. Low humidity can cause things from annoying static electricity build up to asthma attacks, but also having high humidity can cause a whole other mess of issues in your home.

Cold air has less capacity to contain water vapor than warm air. Heating your home reduces relative humidity. Breathing this dry air can wreak havoc inside your airways; mucous membranes dry out creating irritation and dryness in the nose and throat. Some say this lack of mucous can not only be very uncomfortable, but can reduce your body’s ability to filter out viruses and other things which can make you more susceptible to illness.

On the flip side, keeping your home too humid in the winter can lead to other issues. When the indoor air is too humid it can cause condensation to form. The same way a cool beverage glass “sweats” when outdoors in the summer, condensation forms when warm humid air meets a very cold surface (i.e. a window in winter). This causes the vapor in the air to condense and form liquid water on these cool surfaces. In some cases condensation can also form on the drywall around the windows. It is not uncommon to see mold issues develop in homes with condensation issues. Dampness also can attract insects and other pests into the home.

We recommend that if you have a humidifier in your home to adjust it so that it is operating at the highest level without condensation. If you see liquid water, or sometimes even ice, on the inside of your windows, it is time to turn down the humidistat. To reduce condensation, it is also important to use an exhaust fan while showering or cooking on the stove.


-Dylan McIntosh

How Long for Mattress VOCs to Offgas?

In a previous blog post, I established that foam mattresses from Casper and Tuft & Needle had high VOCs in the packaging and that they should be opened outdoors.  For good measure, I tested yet another manufacturer’s product… Nest Bedding’s Love Bed.  I got the same results as with the other manufacturers:


What do all these videos prove?  They demonstrate that foam mattresses shipped straight to your home should be opened outdoors and allowed to air out.  But that begs the question, “For how long should they air out?”


To test that question, I did a “backyard” experiment after testing the Nest Bedding mattress.  I pressed my VOC measuring device (ppbRAE 3000 photoionization detector) right up against the mattress.  The video below shows what happened over the next 24 hours:

So as you can see in the video above, it’s important to not only open your mattress outdoors, but let it air out also.  The vast majority of VOC emission occurs in the first hour, and drops considerably after a day.   The mattress will continue to off gas at a much lower rate for an unknown amount of time, which is true of all furniture, finishes and building materials.


For a frame of reference, I let my foam mattresses air out for 2 days before bringing them indoors.  Once inside, I kept the windows open in the bedroom for a week as weather allowed.  If you are chemically sensitive, consider letting your foam mattress air out for even longer (or skip foam altogether).

These backyard experiments have lots of limitations. Nevertheless, they demonstrate that independent tests should be carried out in the mattress industry. I hope this message doesn’t fall on deaf ears. Share this blog post and pass on the message!

Chemical Emissions from Mattresses

Mattress salespeople have a reputation somewhat equivalent to the iconic used car salesman. To avoid the high-pressure sales environment altogether, many people are opting to buy their mattresses online… me included.

I recently bought two foam mattresses online and had them shipped to my Chicago home: a queen-size from Casper and a twin-size from Tuft & Needle. Both companies recommend opening up the packaging inside the room where the mattress will be used. I’m sure 99% of people follow along, but as an indoor air quality consultant, I was concerned about all the chemicals that would be released into my bedroom.

Both companies boast of using foam that is certified by CertiPUR. According to CertiPUR guidelines, the emissions of total volatile organic compounds (TVOCs) must be below 500 micrograms per cubic meter (µg/m3).

I got out my fancy equipment to practically see if the emissions from these mattresses were, in fact, less than 500 µg/m3.  Check out these two videos to see what levels I found in the Casper and Tuft & Needle Mattresses, respectively:


Whoah! These levels were WAY higher than 500 µg/m3. Bottom line: DO NOT open these mattresses inside your house!


I have a few pieces of advice:

1. Unbox and open the mattress outside
2. Let it air out (I kept my mattresses outside for 2 days)
3. After moving it to the bedroom, keep windows open
(I kept mine open almost continuously for a week)

These mattresses are great… comfortable, affordable and no PBDE flame-retardants.  Just watch out for the VOCs when unboxing!


Technical Details:

I took measurements using a photoionization detector (PID) with parts per billion (ppb) sensitivity.  The unit is a ppbRAE 3000 made by RAE Systems.  PIDs approximate total volatile organic compound (TVOC) levels and are calibrated to a specific gas (mine is calibrated to isobutylene).  I did not perform laboratory-based testing to identify individual VOCs.  Nor did I test these mattresses following the same method as CertiPUR (they use ISO 16000).  Nevertheless, this method is reliable enough to show the extremely high VOC emissions from these mattresses.