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  NOTE: May Dooley passed away in March 2024. This site will remain available as a tribute to her.

Common Indoor Air Pollutants

First, let’s mention the quality of outdoor air:

Although this section has to do with indoor air quality, the quality of outdoor air where you live is also significant. See how your community rates at www.breathelife2030.org. You will better appreciate the Clean Air Act if you compare Delhi and many other places to your area. According to that website, one third of deaths are due to poor air quality, and over 90% of the world’s children are breathing unhealthy air.

 Topics on this page:

For more on outdoor air, see also the Pre-Purchase section LINK*****.

Issues having to do with volatile organic gases




Formaldehyde exposure was my introduction to chemical sensitivities maybe 25 years ago. At the time, I was working in a newly renovated office building and was also the weekend manager of a new Ronald McDonald house. For the record, I’d also had previous exposure in science labs at school.

One Friday afternoon, I was sitting at my desk and a headache started. The headache built up for three days, probably close to migraine status, and then slowly dissipated.

After this unsettling experience, the headaches came regularly. I can remember going to put trash out and the next door neighbor must have used Lysol on her garbage pails. Before I was back to my porch, a headache started, and I knew what was coming. Three days knock-out.

I got the not-unexpected responses from doctors: “Everyone gets headaches.” “Try this painkiller.” But I didn’t want any medication. I knew that something in time caused these headaches, and that something could be reversed.

I happened to hear a radio interview with an allergist and asthma specialist from upstate New York, on symptoms linked with mercury toxicity from silver amalgam fillings, which are about 50% mercury. Headaches were one of the symptoms. He said that after fillings were properly removed, he noticed that symptoms gradually let up for his patients over the next five years.

So I got my fillings removed and, in the course of looking for a doctor for chelation during the removal process, I found the name of a nearby environmental doctor in an index in a healthy living book.

When I met with him, he told me that the immediate trigger for the headaches was formaldehyde but that the deeper issue was mercury toxicity from the silver amalgam fillings. He believed that mercury toxicity was at the bottom of much chronic disease in this country.

A hundred years ago in Britain, they knew that mercury toxicity caused neurological damage in hatters, the “mad hatters.” So let’s put it in people’s mouths. That sounds like a good idea…not.

The fillings came out (like, my new car was in my mouth), he detoxed me for mercury, and, though it took two years, the headaches finally left. The last 20 years have been headache-free, and while I avoid Lysol, it would no longer set off a headache. I don’t know where my health would be today had those silver amalgam fillings not come out. So thank you for your work and for that radio interview, Dr. Alfred Zamm, retired now.

I can remember my then-dentist telling me to throw the books I was reading on silver amalgam fillings in the trash, that these fillings are safe and that he put them in his own children’s mouths.


Many building materials, from lumber to insulation to glues and adhesives to paint and on and on, and many contents, contain noxious chemicals that offgas into room air. Most of the offgassing takes place in the earlier years.

Keeping up with least toxic building materials and contents is a job in itself. Healthy home consultants work with individuals planning to renovate or build a new home.

“Green” does not always equate to “least toxic.” Recycled toxic products are still toxic.

Randy Fike (see IAQ Testing Options) told me that Liquid Nails (the adhesive that drywall installers often use to stick up the drywall prior to hammering) shows up in their VOC scan for indoor pollutants.

Renovation/new construction resources: These two individuals are researchers of products and have long experience in working with chemically sensitive individuals:

Much information is available on-line about least toxic products, including at the website of Environmental Working Group, www.ewg.org.

I’ve already pre-ordered Jeff May’s updated book, My House Is Killing Me, due out later in 2020.

To test for VOCs:


When we bring in new furniture, gym mats, cleaning and laundry products, flooring, etc., we run the risk that there will be unhealthy off-gassing from the item.

How do you find least-toxic furniture, bedding, etc.?

As noted above, consulting with Marilee Nelson and Andrew Pace would be a good place to start. As far as interior design with least-toxic materials like mattresses, bedcovers, sheets, pillows, cushions, sofas, etc., there is Rowena Finnegan at Eco Terric, 866-933-1655, in California. Her website has lots to explore, though I have no experience with her service.

Explore websites such as the Environmental Working Group, www.ewg.com and Green Guard, www.greenguard.org. Both are involved with testing all sorts of products, and their websites are highly informative. For example, every year EWG puts out a Dirty Dozen list of those fruits and vegetables that should be bought organic and those where conventional choices may be acceptable. Greenguard offers certifications for least-toxic furniture and other products and links to certified suppliers.

If there is a choice between wood products and solid wood, go for the solid wood (but not where the stain smells). I was in the Ukraine in 1993 when I learned that their furniture was solid wood, but that they anticipated cheaper wood products coming in from a neighboring country. Enter formaldehyde.

Testing options

Issues having to do with particulates


Studies have shown that dust contains all manner of allergens, chemical and other compounds. Money could be spent analyzing what’s in house dust, or steps could instead be taken to greatly reduce levels of dust, such as:

Check your vacuum cleaner. Just upgrading a vacuum cleaner can make a huge difference.


Remove carpeting, which is one of the worst investments in a home.

Pay special attention to the bedrooms. Are there dust collectors, such as carpeting, window treatments, bedspreads that cannot be washed regularly, pillows, stuffed animals that are not washable, pressed wood furniture? Is the home overdue for a de-cluttering?

Check the filter at your heating and AC systems with central ductwork.

Other dust concerns


This subject rarely comes up in an inspection, since clients tend to be more health-conscious. Occasionally there is a renter complaining about smoke or fragrances seeping into their apartment from a neighboring apartment. Unless there are regulations against indoor smoking, sealing up holes between the two units may be the extent of what can be done. Sealing off outlets from the wall cavity is often helpful. Check for energy-saving outlet products at a home supply store. Sometimes there may be a ventilation option as well.

A laser particle counter will easily pick up on smoke.


Many candles give off high levels of particulates, as with chalk. Dust-free versions of both are available.

Sometimes people send me tape samples from dark discolorations up around and on the ceiling, because they are concerned about mold. More likely, these discolorations are smoke particulates, from either a smoker or burning candles.

Ozone is used in fire restoration procedures, but I spoke with the owner of one of these companies. He told me that clean up from a fire or a smoker was never 100%. I had queried him about continuing health issues from a client who had bought a house previously owned by a smoker and had put much money into renovations. She raised the issue with me about whether air from the wall cavities could be making her ill. This smoke damage contractor confirmed the possibility, stating that he would never purchase a home owned by a smoker, because the smoke chemicals remain in the wall cavities.

Short of this client selling or gutting the house, her only other option might be positive pressure, to minimize air being sucked from wall cavities. See the Ventilation page. LINK****

Testing options


A story: When I was a teenager, I lived in a house that was close to a neighboring house, where the owners ultimately exchanged their lives (via cancer) for a pest and weed-free yard. One night, after the owner had sprayed something or other under my bedroom window, I woke in the middle of the night unable to breathe, like my lungs wouldn’t work. I ran down to the front door, threw it open, and took in fresh air. Then (what did I know about anything then?) I went back to bed.

A client told me of an exchange she had with a neighbor who was continually spraying herbicide on her plants and lawn. The client remarked that she, the neighbor, could be killing herself with all those chemicals. The swift retort was, “I don’t care about that. I care about WEEDS.”

Many of my clients over the years have been harmed by pesticides and have had to work with environmental doctors for detoxing as best as possible. Formaldehyde exposures (which I’ve had) are apparently easier to detoxify from than pesticides.

There are hundreds of pesticides, including past pesticides, so testing typically addresses the most common current ones in use. If needing to call in a pest control operator, look for one using organic methods. If an organic company is unavailable in your area, the next best thing would be an IPM (integrated pest management) company, where the use of pesticides is theoretically the last resort.

When I looked at three for-sale houses in my 55+ community, there was a bottle of Raid on one porch. “Thanks for the warning,” I thought to myself and moved on to the next house. Raid smells can last a long time. Years back, I took a course to become a pest control operator and recall the instructor saying that home owners could buy products over the counter that pest control operators had to be licensed to use. The course was taken for enhancement, not that I was planning to become a pest control operator.

Regarding pesticides in food, check out the annual Dirty Dozen list from Environmental Working Group, www.ewg.org, also mentioned above. This list gives you the fruits and vegetables to avoid, with the highest levels of pesticides, and the conventional produce that you could eat with the least risk for pesticide exposure.

A landscaper told me long ago that eating conventional carrots was like eating Malathion. I had a summer job on a lawn crew once, and he kept me away from the Malathion. He is deceased, and I wonder if from cancer.

Check out www.beyondpesticides.org. This group has been around a long time and gives you the resources needed to check out specific pesticides, plus lots and lots of other information.

Testing pesticides?


  1. Asbestos. This 2012 blog post provides the historical background for asbestos in the country: Why Isn't Asbestos Banned in the United States?. The EPA tried to get a total ban on asbestos in 1989, but failed. Under the Clean Air Act, most spray-applied asbestos products were banned.

  2. Review the wealth of information for the homeowner and others at www.epa.gov/asbestos.

  3. Asbestos can be found in various materials in an older house. Rule out the presence of asbestos prior to disturbing original and old building materials. Hire a licensed a certified asbestos inspector, especially before purchase of an older house. Lab testing will be required.

    Such asbestos-containing materials may include: vermiculite insulation, textured walls and ceilings, roofing and siding materials, vinyl floor tiles, lining in some old ductwork, more, as well as automobile clutches and brakes.

  4. Should old asbestos tiles, siding, etc., be removed or covered over? Opinions vary here. On the one hand, it may be less hazardous to cover over old asbestos 12”x12” tiles and siding than to have it removed. If the old tiles are “friable,” i.e., in poor condition and crumbly, asbestos remediation is required.

    On the other hand, if you know that asbestos materials have been covered over, is that a disclosure item when your house is put on the market? That’s a question for your real estate agent and attorney.

  5. Two stories

    • I recall once, when I owned a pre-purchase franchised inspection company previous to my current company, that in one attic, the insulation was labeled, let’s say “fiberglass” because my memory fails on this, but the new homeowners later sent a sample out for analysis just to be safe. Even though asbestos was not listed on the label, the sample came back positive for asbestos, and the franchise insurance company ended up paying for asbestos remediation in the attic.

      There was liability because the inspector wrote “fiberglass insulation in the attic,” essentially guaranteeing that the insulation was fiberglass, even though the report itself excluded asbestos and recommended an asbestos inspection. From this vantage point, I don’t know why the insulation manufacturer also wouldn’t have had liability, because they neglected to mention the asbestos on their label. Well, that was a long time ago.

    • Another story relates to a toilet overflow onto carpeting in a finished basement. The carpeting turned out to be glued to asbestos floor tile, and homeowner insurance paid over $10,000 for an asbestos removal job.

  6. If there is – or was – an old boiler/pipes or oil/wood furnace/ductwork, there would be an elevated risk for asbestos insulation. If so, and the insulation no longer is present, ask what happened to it? Was it properly removed, with post-removal testing done? Did a homeowner rip it out himself, contaminating the house with asbestos? Having an asbestos test done would be in order.

  7. If you want to check for asbestos yourself, search on “home asbestos test.” There are labs and other services offering such tests to homeowners.

  8. You don’t want asbestos fibers stuck in your lungs, so wear a properly fitted P100 or N95 respirator and goggles in the suspect area. Change clothes. Don’t track dust from a contaminated area to a clean area. Don’t sweep dust up.

    This same warning goes for fiberglass insulation. Under a microscope, asbestos looks like tiny glass rods. Again, avoid the risk of inhalation. It may not be out of order to treat fiberglass removal as you would asbestos removal. There used to be an organization called Victims of Fiberglass. When I did a search on that name, nothing came up – but plenty came up relating to dangers of fiberglass exposure.

  9. We’ll be talking about vacuum cleaners in the Particulates section below, but here’s a clue. One of the best vacuum cleaners is the Nilfisk GM80, not only for residential use but also used in lead, asbestos, and mold remediation.

  10. Testing options:

    • Call in a certified asbestos inspector for something with legal consequences.

    • There are several tests listed on-line for homeowners to rule out (or in) asbestos prior to disturbing old building materials. Search “homeowner test asbestos.”


Why is lead paint a concern? Because lead, like mercury, is neurotoxic and can be particularly harmful to young children, affecting the IQ. While the more common lead exposure is hand-to-mouth, inhalation can also lead to lead poisoning.

Children should be checked regularly for lead, especially up to age six. Lead circulates in the blood for about a month before it gets stored in tissue.

Why lead paint? Lead paint is more durable than regular paint. It also cost more so would more likely be found in more upscale old homes on windows, doors, base molding, radiators, bathrooms, kitchens, red floor paint in basements, and outside paint. If outside paint is in deteriorated condition, lead particulates will likely be in the soil around the house. Food plants, especially tomatoes, should not be planted next to the house. The soil may need to be replaced.

Lead paint was ruled against in 1978, but painters were allowed to use up their supplies.

With lead, as with other common pollutants, there is much information to be had on-line. Check in at www.epa.gov/lead. The EPA is the U.S. Environmental Protection Agency.

Lead can show up in unexpected places – such as in the gold rims of old wine glasses.

Old windows/frames

Testing for lead paint

Testing for Lead in water

Combustion Issues


Most of us know that we have to get off fossil fuel, given the fast-approaching specter of irreversible climate change. Check out Hope Jahren’s book, The Story of More, 2020 for an overview of how we got to climate change and where to go from here.

Here we’re looking at natural gas and propane. There are some sensitive folk who can’t do any of these and need to live in an electric house.

Aren’t electric houses expensive to run? Do a Google search for “Nate Adams electrify everything.” There are energy-savings ways to get off fossil fuels. Nate knows how to do this.

There are three potential concerns with gas-fueled houses and appliances:

  1. Carbon monoxide – discussed above;

  2. Gas leaks, natural gas and propane

    • The meter I’ve used for the past 25 years is the TIF 8800, with an updated model sold at grainger.com, for $332 (as of August 2020). That’s a tried and true detector, sensitive, and with on-site calibration by turning a knob.

      • The TIF can be used to look for leaks in vehicle exhaust systems.

      • Since the TIF measures methane and other combustible gases, as well as natural gas and propane, I use it sometimes at drains. The TIF always registers something, due to methane given off by bacteria in the drainpipe, but sometimes the reaction is more significant, pointing to sewer gases.

    • Awhile back, I added a second meter, a digital gas detector: RPI 721 Combustible Gas Leak Detector, also from Grainger. This meter stopped working before a year was up. That’s how I learned that Grainger has a one-year warranty, and they sent me a new meter.

      I would also note that two other RPI meters were replaced. One didn’t work from arrival, and there was no sound on the second. Grainger sent replacements for each one. Maybe that says something about the quality and durability of this meter, but it’s been so useful to me – and I don’t know a lower cost alternative – so I hang in there.

      I didn’t want a meter that had to be sent out for calibration. A representative from a large gas company told me that their gas detectors are sent out monthly for calibration. I doubt there is any such requirement for a small propane company. A client told me that when a representative from a propane company was called in to check for leaks, his detector didn’t work, and he used hers.

      The TIF is more sensitive. It tells me a leak is present, and from the reaction from the TIF, I generally can tell if the leak is small or large. But I don’t know what “large” means, because the detector is not digital.

      • The TIF measures combustion gases, beyond propane or natural gas. I turn up the sensitivity knob to where the ticking just starts to get faster. Since the calibration doesn’t seem to hold when calibrated indoors (rather than outside), I periodically also check the calibration by holding the sensor up to my mouth and exhaling into it. If there’s no response from the TIF, I turn up the sensitivity knob.

      • Outside levels can be compared with indoor levels but more than gas leaks might be measured. Calibration is done outside. At several houses with gas or oil, the meter started ticking faster upon entering the house. Piece of cake. The gas or oil.

        But then I did the same exercise at an all-electric house, and the same thing happened. The ticking speeded up. So what IS the meter measuring upon entering a house? The answer might differ from house to house.

    • The RPI is digital, so the size of the leak can be quantified, i.e., whether it is under or over 500 ppm, 3,000 ppm, or over 10,000 ppm (parts per million). That’s useful information. Every month I find an assortment of gas leaks, with several over 10,000 ppm.

      One woman, 10 years with fibromyalgia, had a vintage stove in her kitchen that was spewing out gas 24/7, over 10,000 ppm. Possible connection with the fibromyalgia, do you think? Other folk have developed MCS (multiple chemical sensitivities), reportedly stemming from exposure to natural gas leaks.

      I’ve said to more than one mold or EMF inspector: “You may be the only environmentalist to cross the threshold of that home. Wouldn’t it be a shame to leave behind a 10,000 ppm gas leak, when it would have taken you 10 minutes to check?”

      I used to own a pre-purchase franchise on Long Island and just shook my head when the man who bought my franchise told me that New York State dropped the requirement for inspectors to use combustion gas detectors or moisture meters in pre-purchase inspections. Whatever were they thinking … but no doubt it has to do with money and liability issues.

    • If a gas leak is found, the gas company or a plumber should be called right away. One would think that a gas detector would be an instrument that a plumber would have, but no, not typically. The plumber uses the soapy water test. That is, spray soapy water on the pipe joint, and see if it bubbles.

      And the gas company typically uses a less sensitive detector that is set more for asphyxiation or explosion than for health issues. The gas company representative may not confirm the leaks the more sensitive TIF finds. A plumber may have to be called in to fix them. Even if he can’t detect them, the homeowner might say, “Humor me. Just treat the joint as if it has a small leak and fix it.”

    • I have had clients who couldn’t tolerate gas stoves or even gas in the home. With any gas stove there should be an exhaust fan that discharges to the exterior. If it is too noisy for a homeowner, find one that is quieter.

  3. Oil spills

    • Homeowners insurance generally does not cover oil spills from tanks, just maybe from a pipe break. If you have an oil tank, look into supplementary insurance. Clean up costs can be huge.

      Within two hours of a leak, representatives of several governmental agencies arrive at the scene. If the oil got into the ground water, the oil has to be siphoned off. This whole operation could cost $100,000 or more, and you will pay, even if through a lien on your home.

      When I lived on Long Island, letters from Nassau County went to all homeowners. The county wanted buried fuel oil tanks shut down properly, i.e., emptied first. They weren’t requiring homeowners to check for oil leaks, because that would have been a disincentive to shutting them down. But Long Island has a single water source, an aquifer under the island. If that water gets contaminated, that’s a big concern.

      My dad wasn’t into reading about healthy lifestyles, but common sense told him that you don’t use poisons above your water supply, so he never used pesticides or herbicides on the property, not when they moved to Pennsylvania, either, and had a well. Pop was an early “organic” gardener.

    • Years ago, I spoke with a homeowner who had had an oil spill on her property. Her message? “Never buy a house with an oil tank.” I also spoke with an associate who was an engineer with the health department and asked if he would buy a house with a buried oil tank. He said that, yes, he would, but he would want the tank pulled before agreeing to the purchase, and he would want to be present while they were taking up the tank, to make sure there were no spills under it. New owners own oil spills.

    • A quick on-line search on “health effects exposure to petrochemicals” brings an avalanche of information, addressing everything from asthma and neurological issues to leukemia.

      I once rented a cottage and only several years into the lease did I learn that there had been an oil spill in the basement. This same engineer from the health department did not think it was a good idea for me to remain in the cottage. Fike Analytical VOC scans were not on my horizon at that time but no doubt the old oil spill would have been detected.


Many houses have attached garages. Years ago, there was an article in the New York Times about a study comparing levels of vehicle exhaust fumes in the garage with levels in the house. As I recall, over 80% of homes with attached garages also had car fumes in the house. When you build your new house, plan on a detached garage or a properly managed attached garage.

That said, there are things you can do to help compensate for having an attached garage with vehicle storage in it:

  • To test for gasoline, car exhaust:


    Carbon monoxide, as you have heard, is a deadly killer. It has no odor and the buildup can be insidious. Take precautions, such as:

    Testing for Carbon Monoxide


    Most folk would be aware that ozone is an air pollutant outside but might be confused about use of an ozone generator inside. Because ozone can harm delicate lung cells, an ozone generator should not be used when anyone, any pet, or any plant, is present in the house. If returning to a house where an ozone generator is running, turn off the generator and open windows to air out the house before staying in the house.

    On-line, you will read both that ozone kills mold and that it doesn’t kill mold. What is correct? Michael Pinto, a mold expert, gives a good overview at: Ozone Generators and Interior Mold Remediation: A Recipe for Disaster (April 2015). Pinto refers to an EPA document on air purifiers. As I recall, there is one italicized line in the entire document: Ozone is harmful to lung tissue.

    Long ago, a mold remediation project manager told me that they stopped using ozone at job locations after they had to replace someone’s upholstered living room furniture, because the ozone had degraded the foam.

    Again a long time ago, Berkeley Analytical, an environmental lab, studied the effects of ozone on tobacco smoke. Tobacco smoke was chosen because it represented various classes of compounds. Results showed that some more toxic compounds that weren’t present before were formed by interaction with the ozone.

    That said, I can think of at least one client who believed that use of an ozone generator, with a fan behind it to send the ozone on its way, was responsible for her being able to remain in her home.

    Ozone can also change moldy smells, maybe buying a person time before either remediation or moving. One chemically sensitive man said that he credited ozone with making his RV tolerable to him so that he could travel. As we learned from Berkeley above, what other worse chemicals may be being produced by the ozone, only there is no associated smell?


    Every cell in the body needs oxygen, but two individuals sleeping in a bedroom with the door closed and no windows opened are using oxygen and giving off carbon dioxide. Do you think they might awake in the morning feeling a bit sluggish?

    Elevations in carbon dioxide are one issue that ventilation should solve. Ventilation is addressed in another tab. But what if these two individuals can’t address mechanical ventilation right away? They could leave the fan on for the heating and air conditioning systems. More oxygen would be brought into the bedroom and carbon dioxide cycled out.

    Another option is to open a window. A colleague was visiting, and we decided to record the rise of carbon dioxide in my small office with the door closed. Levels went up, up, up. Then the window was opened, and down went the levels of carbon dioxide.

    Occasionally I have recommended that the homeowner get a basic carbon dioxide monitor and place it in their offspring’s bedroom. Seeing with her/her own eyes might be the only way to convince someone holed up in a cave.

    Testing for Carbon Dioxide

    - - - - - - - - - -
    Next up, a ventilation discussion, which will include consideration of outside air pollutants. Or, go back to the Indoor Air Quality Topic Index.


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