As I was frantically cleaning my apartment last month in preparation for a visit from my parents, I paused for a moment to stare at the dark smudge on the damp cloth I was dusting with. Never in my wildest dreams did I imagine that little dust smudge contains a whole universe of toxic chemicals—chemicals that pollute the globe and build up in wildlife and humans, that can cause cancer, or are linked to birth defects in babies.
Never, that is, until I collaborated on a new study to put together all the data we have on chemicals in U.S. indoor dust with scientists from George Washington University, Silent Spring Institute, Harvard University, and University of California–San Francisco. Dust is the common congregation place for all kinds of chemicals that migrate out of everyday products in our homes—flooring, furniture, personal care products, cleaning products, and myriad others. So our idea was that by looking at dust, as well as the individual chemicals in dust, we could reveal the bigger picture of chemical contamination in the home—just like individual dots in an Impressionist painting create a larger image. And what we found paints a disturbing picture of what’s really inside home sweet home across America.
The dust in U.S. homes is chock-full of hazardous chemicals from our products—phthalates, flame retardants, and other toxic chemicals are unwelcome visitors in each and every one of our homes. Even worse, the chemicals don’t stop there: They can waltz right into our bodies when we breathe contaminated air or dust, touch contaminated dust, and accidentally get dust in our mouths from our hands. These chemicals pose health hazards including cancer, hormone disruption, and toxicity to the reproductive system.
We looked at each chemical in household dust from three different angles: how much is in the dust, how much gets into us, and what the health hazards are. But no matter which way we looked at it, phthalate and flame-retardant chemicals stood out as top offenders. They’re found at higher levels, have higher estimated intakes for kids, and are linked to multiple health hazards.
Phthalates are used in numerous plastic and vinyl materials, as well as personal care products and cleaning products. Flame retardants are chemicals found in furniture, electronics, and building insulation. These products all shed phthalates and flame retardants into dust.
To better understand how risky these chemicals in dust might be, we completed an additional analysis separately from the published study. Unfortunately there are not standards established for chemicals in household dust, so we looked for something else we could compare to. Because exposure to dust is a lot like exposure to soil, we used soil-screening levels established by the U.S. Environmental Protection Agency for sites contaminated with chemicals as a comparison. These soil-screening numbers reflect the levels at which a chemical might pose health risks to people, and thus exceedances require further investigation. The EPA calculates two different numbers, one for cancer health risks and another for non-cancer health risks, such as developmental or reproductive toxicity. Note that many chemicals in our study do not have soil-screening levels established, but we did the comparison for the ones that did.
The graphs show the average dust concentration we calculated in our study by pooling data from individual studies (circle), the highest (maximum) level of the chemical found in each individual study (triangle), and the EPA screening level (black line). Shockingly, the levels of some phthalates and flame retardants in U.S. house dust exceeded the EPA’s screening numbers (shown in red).
For the phthalate DEHP, average levels in dust exceeded EPA screening levels—for both cancer and non-cancer effects. DEHP is also ubiquitous in U.S. homes, as studies that tested for it found it in 100 percent of dust samples. This means that if an EPA site manager tested the dust in a typical living room, they would be concerned about the level of DEHP found there!
For the phthalate BBP and the flame retardants TDCIPP, TCIPP, and TCEP, the average level in dust does not exceed the soil-screening level (though it comes close for TDCIPP cancer risks). But as the “highest concentration in dust” data points show, levels in some homes are much higher than the average, sometimes by an order of magnitude or more.
Exceedance of the EPA screening levels for this portion of the population is a concern. Higher levels of phthalates or flame retardants in indoor dust may be linked to the presence of particular products (like vinyl flooring for phthalates or baby products for flame retardants) and/or particular building characteristics, like ventilation rate.
It’s also important to note that our comparison only considers the amount of chemical in dust in the home, but in reality, people’s exposures are almost certainly higher because we come into contact with these chemicals from many other sources, including the food we eat, products we use, and other places we spend time.
Products with these chemicals don’t belong in our homes; hazardous chemicals linked to adverse health effects should be removed and replaced with safer alternatives. With recent reforms to the federal Toxic Substances Control Act, the EPA finally has the opportunity to start protecting the public from toxic chemicals. We’re working hard to stand up to the chemical industry and ensure strong implementation of the new law.
In the meantime, there are a number of steps you can take to protect your families from toxic dust, including:
- Remove dust from your hands. Wash your hands and your children’s hands frequently, and always before eating. Use plain soap and water, avoiding fragranced and antibacterial soaps.
- Keep household dust to a minimum. Dust with a damp cloth, regularly go over floors with a wet mop, and use a vacuum with a high-efficiency particulate air (HEPA) filter.
- Use the Silent Spring Detox Me app. This free smartphone app walks you through simple, research-based tips on how to reduce your exposure to potentially harmful chemicals where you live and work, and it keeps track of your progress.
And please take action now on phthalates. Urge the U.S. Food & Drug Administration and the Consumer Product Safety Commission to protect kids and families from the dangers of phthalates by banning these hazardous chemicals from food, toys, and other children’s products.
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