It used to be that dust was just dirt. Not anymore. Today your household dust also contains a mix of toxic chemicals. A look at household dust samples around the country found that the dust in our homes contains a range of carcinogens and endocrine disruptors.

Researchers reported 45 worrisome chemicals overall, with 10 of them present in over 90% of the dust samples, including DEHP and TDCIPP, both carcinogens.

The toxins in dust are a particular health concern for children, especially babies. Not only do they spend much of their life crawling on the floor, they often put their hands in their mouths; and their size makes them more sensitive to small amounts of toxins.

The hazardous chemicals in household dust may also pose a growing global health concern, as people in developed countries spend more and more of their time indoors.

Where the Chemicals Come From

The study, an analysis of results from 26 published papers and one unpublished data set by public health researchers around the country, specifically looked at toxic chemicals that are commonly found in consumer products, including personal care items, cleaners and furniture.

Researchers reported 45 worrisome chemicals overall, with 10 of them present in over 90% of the dust samples, including DEHP and TDCIPP, both carcinogens.

The chemicals fell into five major classes, listed below in order from those with the highest concentrations to the lowest.

  • Phthalates
    Phthalates are commonly found in plastics and have been linked to a host of health problems in humans, including miscarriage. Eight different phthalates were the chemicals detected in the highest amounts in dust samples, led by DEHP. DEHP is a probable human carcinogen.

    • Phenols
    Used as preservatives in personal care products and even detected in small amounts in some mouthwashes, phenols are poisonous and a powerful irritant of eyes, skin and mucous membranes.

    Flame retardants
    Often found in baby products, some are suspected carcinogens. While phthalates had the highest concentration in dust samples, one flame retardant, TCEP, had the highest estimated intake by people when inhalation and absorption through the skin from the air were added in. TCEP has been on California’s list of carcinogens since 1992 and New York has recently banned its use in products intended for children under three years of age because of evidence of adverse health effects.

    Another flame retardant, TDCIPP, sometimes called TDCPP or chlorinated tris, is also classed as a carcinogen by the state of California.

    Synthetic fragrances
    As a class, these are the least studied of the chemicals but worries abound. Fragrances generally aren't listed on labels and can consist of a mixture of dozens of chemicals, making toxicity testing of individual fragrances quite difficult.

    Highly fluorinated chemicals such as PFOA and PFOS
    These chemicals are in cell phones, pizza boxes and many non-stick, waterproof and stain-resistant items. While their presence was the lowest amount overall, they are troubling because they have caused a wide variety of health problems in animal studies. The International Agency for Research on Cancer (IARC) classes PFOA as a possible human carcinogen. The EPA is concerned enough that they lowered the suggested level of both PFOA and PFOC in drinking water more than five-fold in May 2016, from 400 parts per trillion down to 70.

    A Dangerous Synergy

    The amounts of most of these toxins are small, but they can add up. Through a process known as synergy, two toxic chemicals together can cause more harm than each would individually, the researchers — from George Washington University, Harvard, the NRDC, Silent Spring Institute and the Universityof California, San Francisco — warn.

    Are you reaching for the vacuum cleaner? Those that have HEPA filters pick up more particles and leave the air cleaner. But it's better to do what you can to avoid these chemicals in the first place, by reading labels and making sure not to buy personal care products, furniture and other household items that contain them. Because they're also found in cables, wires and electronics, avoiding these toxins totally may be impossible.

    The study appears in Environmental Science & Technology and is freely available.