Ten chemicals suspected or known to harm human health are present in more than 90% of U.S. household dust samples, according to a new study. The research adds to a growing body of evidence showing the dangers posed by exposure to chemicals we are exposed to on a daily basis. The chemicals come from a variety of household goods, including toys, cosmetics, personal care products, furniture, electronics, nonstick cookware, food packaging, floor coverings, some clothing (e.g., stain resistant), building materials, and cleaning products. How do the chemicals get into the dust? The chemicals can leach, migrate, abrade, or off-gas from the products, which winds up in the dust and results in human exposure. (That's right: vacuum a lot and wash your hands a lot, and try to avoid or cut back use of products with these chemicals,)
What was found in the dust? The main chemicals were: phthalates — a group of chemicals that includes DEP, DEHP, DNBP and DIBP (these were present in the highest concentrations), highly fluorinated chemicals (HFCs), flame retardants (both old and newer replacement ones), synthetic fragrances, and phenols. These chemicals are known to have various adverse health effects, including endocrine disruption, cancer, neurological, immune, and developmental effects. (See posts on endocrine disruptors and flame retardants) Studies typically study one chemical at a time, but household dust contains MIXTURES of these chemicals with effects unknown. How does it get into us? Inhalation, ingestion, and through skin contact. And while the levels we are exposed to may be low, research is showing that even low level exposure can have adverse health effects. From Medical Xpress:
Household dust exposes people to a wide range of toxic chemicals from everyday products, according to a study led by researchers at Milken Institute School of Public Health at the George Washington University. The multi-institutional team conducted a first-of-a-kind meta-analysis, compiling data from dust samples collected throughout the United States to identify the top ten toxic chemicals commonly found in dust. They found that DEHP, a chemical belonging to a hazardous class called phthalates, was number one on that list. In addition, the researchers found that phthalates overall were found at the highest levels in dust followed by phenols and flame retardant chemicals....."The findings suggest that people, and especially children, are exposed on a daily basis to multiple chemicals in dust that are linked to serious health problems."
Chemicals from consumer products are released into the air and get into dust, which can settle on household items or on the floor. People can inhale or ingest small particles of dust or even absorb them through the skin. Infants and young children are particularly at risk for exposure to the chemicals found in dust because they crawl, play on dusty floors, and put their hands in their mouths, the authors say.
Zota and colleagues pooled data from 26 peer-reviewed papers and one unpublished dataset that analyzed dust samples taken from homes in 14 states. They found 45 potentially toxic chemicals that are used in many consumer and household products such as vinyl flooring, personal care and cleaning products, building materials and home furnishings. The meta-analysis combines information from smaller dust studies and thus offers solid conclusions with greater statistical power, the authors say. The team found that:
- Ten harmful chemicals are found in ninety percent of the dust samples across multiple studies, including a known cancer-causing agent called TDCIPP. This flame retardant is frequently found in furniture, baby products and other household items.
- Indoor dust consistently contains four classes of harmful chemicals in high amounts. Phthalates, substances that are used to make cosmetics, toys, vinyl flooring, and other products, were found in the highest concentration with a mean of 7,682 nanograms per gram of dust-an amount that was several orders of magnitude above the others. Phenols, chemicals used in cleaning products and other household items, were the number two highest chemical class followed by flame retardants and highly fluorinated chemicals used to make non-stick cookware.
- Chemicals from dust are likely to get into young children's bodies. A flame retardant added to couches, baby products, electronics and other products, TCEP, had the highest estimated intake followed by four phthalates—DEP, DEHP, BBzP and DnBP. The intake numbers in this study probably underestimate the true exposure to such chemicals, which are also found in products on the drug store shelf and even in fast food the authors say.
- Phthalates such as DEP, DEHP, DNBP, and DIBP, are not only found at the highest concentrations in dust but are associated with many serious health hazards. Phthalates are thought to interfere with hormones in the body and are linked to a wide range of health issues including declines in IQ and respiratory problems in children.
- Highly fluorinated chemicals such as PFOA and PFOS are also high on the potential harm scale. These types of chemicals, which are found in cell phones, pizza boxes, and many non-stick, waterproof and stain-resistant products have been linked to numerous health problems of the immune, digestive, developmental and endocrine systems.
- Small amounts can add up. Many of the chemicals in dust are linked to the same health hazards, such as cancer or developmental and reproductive toxicity, and may be acting together. Exposure to even small amounts of chemicals in combination can lead to an amplified health risk, especially for developing infants or young children, the authors say.
In the meantime, consumers who want to reduce their exposure to chemicals in household dust and the environment around them can take a few simple steps such as keeping dust levels low by using a strong vacuum with a HEPA filter; washing hands frequently; and avoiding personal care and household products that contain potentially dangerous chemicals.
From the original study in Environmental Science and Technology: Consumer Product Chemicals in Indoor Dust: A Quantitative Meta-analysis of U.S. Studies
Indoor dust is a reservoir for commercial consumer product chemicals, including many compounds with known or suspected health effects. However, most dust exposure studies measure few chemicals in small samples. We systematically searched the U.S. indoor dust literature on phthalates, replacement flame retardants (RFRs), perfluoroalkyl substances (PFASs), synthetic fragrances, and environmental phenols and estimated pooled geometric means (GMs) and 95% confidence intervals for 45 chemicals measured in ≥3 data sets. In order to rank and contextualize these results, we used the pooled GMs to calculate residential intake from dust ingestion, inhalation, and dermal uptake from air, and then identified hazard traits from the Safer Consumer Products Candidate Chemical List. Our results indicate that U.S. indoor dust consistently contains chemicals from multiple classes. Phthalates occurred in the highest concentrations, followed by phenols, RFRs, fragrance, and PFASs. Several phthalates and RFRs had the highest residential intakes. We also found that many chemicals in dust share hazard traits such as reproductive and endocrine toxicity.
People in developed countries spend more than 90% of their time in indoor environments, creating an important link between indoor environmental quality and public health. Consumer products and building materials including furniture, electronics, personal care and cleaning products, and floor and wall coverings contain chemicals that can leach, migrate, abrade, or off-gas from products resulting in human exposure. Consequently, chemicals such as phthalates, phenols, flame retardants, and polyfluorinated alkyl substances (PFASs) are widely detected in the U.S. general population, including vulnerable populations such as pregnant women and children. Exposure to one or more of these chemical classes has been associated with adverse health effects including reproductive toxicity, endocrine disruption, cognitive and behavioral impairment in children, cancer, asthma, immune dysfunction, and chronic disease.