Don’t Get Me Started

Indoor air quality

By John deJong

You can’t see it but you may smell it.

The cloud of smog lurking under the latest inversion isn’t the only pollution cloud on the horizon. Every house, office and classroom has its own personalized toxic cloud.

Last month we explored ultrafine particulate matter from the perspective of outdoor air. This month we’ll look at that indoor cloud and see what you can do about it.

Most indoor air pollution is ultrafine particulate matter, gaseous contaminants in particular, from a wide array of sources. We spend upwards of 90% of our day indoors. Good indoor air quality is even more important than outdoor air quality.

Indoor air may be four to as much as 10 times as bad for our health as outdoor air, depending upon whether you are listening to pessimists or the really pessimistic pessimists. Indoor air is a complex brew of off-gassing building adhesives, aerosol health, beauty and cleaning products, cooking fumes, radon, plus whatever is in the outdoor air we ventilate our houses with. You could think of it as taking bad air and making it worse.

More than 80,000 chemicals have been introduced in the last 50 years. The majority of them have not been studied for their health hazards. That hasn’t stopped manufacturers from incorporating these chemicals into their production processes and products. It seems like the only qualification for using a chemical in consumer products is that it enhance the user experience.

Regulatory protections are weak and generally have been co-opted by the industries which produce these products. Grudging acknowledgement of their poisonous nature emerges gradually in the face of consumer resistance to poisonous products. Many products are as safe as RoundUp, safe if you follow the fine print; and who reads, much less follows, the fine print? Maybe you should.

If you can smell it, it probably isn’t good for you. That said, some things that smell good have enormous psychological benefits.

With obvious exceptions, most of nature’s strong scents are warning signals. It turns out that most of the scents of modern chemistry are also warning signals, too. Isn’t that clever of chemists?

That said, it is possible with psychological conditioning to convince people that a particular smell is good. The “new car” smell, for instance, consists of plasticizers, their chemical cousins and overtones of marketing and sales techniques.

If it’s strong enough to make you wrinkle your nose, it’s probably wrinkling your lungs also, as well as anything that comes in contact with the VOC-infused blood.

Our noses evolved to satisfy three different functions. First, to attract us to food; second, to warn us away from dangerous things; and third, to help us procreate. Which brings us to perfumes, colognes and scented candles and the most ironic aspect of indoor pollution. Again, if you can smell it, it’s probably a gaseous contaminant and therefore a danger (which does not mean if you can’t smell it, it’s okay). Gaseous contaminants, even if they smell good, are molecules that want to react with something. It may be your skin, lungs, blood and anything that your blood comes in contact with.

Prioritizing threats

Continuous sources of indoor air pollution pose the most serious threat to our health. Radon, volatile organic compounds (VOCs), solvents from paint and new carpeting and formaldehyde from new furniture, challenge our health 24/7.

An estimated 22,000 Americans die each year from radon-induced cancers. Radon tests are readily available and mitigation can often be done for a couple thousand dollars.

Cooking-related emissions and aerosol products are intermittent activities. Gas stoves pose a double-barrel threat, releasing CO2 and some oxides of nitrogen and sulfur from combustion as well all those great smells that accompany well-cooked food.

Then there are the pollutants we are only occasionally exposed to, such as hobby glues and spray paints, but where we can very quickly receive a large dose. One study of healthy nonsmokers without allergies showed significantly reduced lung function within 55 minutes of exposure to formaldehyde.

Another way to prioritize your cleanup is by the severity of the threat. Acute threats are a major worry for those with pre-existing conditions. A single exposure to very high levels of pollution for only fractions of an hour can trigger heart attacks, strokes, asthma attacks and inflammation.

The strategies used to lessen these threats depend upon the type of exposure. Continuous threats are best dealt with by making wiser decisions when we shop. Tests for formaldehyde, radon and VOCs should be a necessary precaution when buying your next house. New carpeting is a particular threat because of the large quantity of material involved. Natural flooring is a sensible alternative. Underfoot Floors, among SLC’s first B Corps, carries bamboo, cork, hardwood and marmoleum, as well as natural fabric carpet. Owner Eric Cole has been in the business for 18 years and while he carries some vinyl, he states clearly that it’s usually not a good environmental choice.

Then there are chemical air fresheners (if that’s not an oxymoron), indoor storage of pesticides, household cleaners and all those things you can smell under your sink or in cleaning supply closet.

Periodic threats (daily or hourly) include any indoor combustion. Cooking is a particular issue, particularly for those who stir-fry frequently.

Exhaust fans and proper ventilation help. Every indoor environment would benefit from an exhaust hood the operates whenever the stove is being used. Occasional exposures to the solvents found in paints and glues can be alleviated by using VOC-filtering masks.

The U.S. got rid of CFCs, ozone-depleting propellants in aerosols, in the 1960s. But aerosol products are still probably the worst indoor air threats. The chemicals needed to turn your spray paint or hair spray from a liquid into a rust-proof protective coating for your graffiti, or a hurricane-proof hairdo, are mostly solvents which are designed to evaporate. Anyone breathing these fumes is effectively mainlining solvents. Painters have a name for it, chronic solvent-induced encephalopathy, but they can’t remember it.

The cost of remediation

Another way to look at indoor air pollutants is the cost of remediation. Replacing aerosol personal care products (hairspray, deodorant, sunscreen) will reduce levels of indoor air pollution. Opt for pump-spray or cream.

You can get an air cleaner for a couple hundred dollars. An exhaust system for your kitchen stove can be done for under a thousand dollars. Things that take major modifications of your house, like remediating off-gassing insulation foam or venting radon from your basement and granite counter tops, can cost thousands of dollars.

Common sense may lead you to try to improve your indoor air quality by bringing in outdoor air, but that can be a two-edged sword without timely and location-specific readings on air quality in your neighborhood (see “Citizen Scientists Take to the Air,”page 14).

Eliminating all sources of indoor air pollution is easier said than done. Gaseous pollutants like ozone, radon, cigarette smoke, volatile organic compounds (VOCs), solvents, aerosols and the like are particularly difficult to remove. They can’t be mechanically trapped; they must be chemically captured with some sort of active media. Activated charcoal is the most common example, but the filter media must be changed frequently. Regular vacuuming with a HEPA filter vacuum will remove particulate matter that has settled out of the air.

Not only is source reduction very important with indoor air pollution, it is also much more in your control. Many of the same roadblocks to the reduction of outdoor air pollution hinder the reduction of indoor air pollution. Special interests will lobby, obstruct and cheat to protect their “right” to pollute, while seducing us with the convenience of their products. Whether it’s dad spray-painting his latest project in the attached garage, mom getting her hair just right and keeping it that way, or junior degreasing, cleaning and lubricating his bicycle  in the basement, it will take some convincing to change their aerosol ways. Your indoor air will be cleaner for your efforts.


John deJong is associate publisher of CATALYST, and has a long history with many aerosols from before he got wise.

This article was originally published on February 26, 2020.