Household dust harbours a cocktail of toxic chemicals that have been linked to an increased risk of a range of health hazards, from cancer to problems with fertility, researchers in the US have found.
The chemicals are shed from a host of common products, from flooring to electrical goods as well as beauty and cleaning products.
“We think our homes are a safe haven but unfortunately they are being polluted by toxic chemicals from all our products,” said Veena Singla, co-author of the study from the Natural Resources Defense Council in California.
The scientists cautioned that children were particularly vulnerable to the health effects of contaminated dust as they often play or crawl on the floor and frequently touch their mouths. “They end up having a lot more exposure to chemicals in dust and they are more vulnerable to toxic effects because their brains and bodies are still developing,” said Singla.
Writing in the Environmental Science and Technology journal, Singla and colleagues described how they analysed 26 peer-reviewed papers, as well as one unpublished dataset, from 1999 onwards to examine the chemical make-up of indoor dust. The studies covered a wide range of indoor environments, from homes to schools and gymnasiums across 14 states.
“What emerged was a rather disturbing picture of many different toxic chemicals from our products that are present in dust in the home and [are] contaminating the home,” said Singla.
While, perhaps confusingly, homes that are too clean have been linked to an increase in allergies and asthma in children, potentially due to a lack of exposure to various microbes, the presence of toxic chemicals in dust raises separate concerns.
The researchers highlighted 45 toxic chemicals in indoor dust, 10 of which were present in 90% or more of the dust samples – these included flame retardants, fragrances and phenols.
Among them is the flame retardant TDCIPP that is known to be cancer-causing and is frequently found in furniture foam, baby products and carpet padding, as is TPHP, another flame retardant in the top 10 list that can affect the reproductive and nervous systems.
“They are just a bunch of letters – a lot of people might not recognise what those chemicals are, or what they mean, but they are really a number of bad actor chemicals,” said Singla.
Other toxic substances found in almost all of the dust samples include chemicals known as phthalates that are often found in vinyl flooring, food packaging, personal care products and have been linked to developmental problems in babies, hormone disruption, and are also thought to affect the reproductive system.
Children are particularly vulnerable to health problems associated with contaminated dust as they often play on the floor. Photograph: Hero/Getty
While some chemicals on the list have been banned from use in childcare products, or are being more widely phased out, Singla says many remain widespread in the home. “Especially for building materials there is not as much turnover of a lot of those products, like flooring,” she said, adding: “Unfortunately even though some of these phthalates have been banned from kids products, they are not banned from other kinds of products.”
In a separate, unpublished, analysis, Singla compared the levels of chemicals found in household dust with soil screening levels used by the Environmental Protection Agency in the US. “What we found – and we were shocked by it actually – is that the dust levels exceed those EPA screening levels for a number of the chemicals and again it is the phthalates and flame retardant chemicals that are standing out as the bad offenders here,” said Singla.
But, she adds, there are steps that can be taken to reduce exposure to contaminated dust. As well as vacuuming floors, hands should be washed with plain soap and water before eating, while cleaning with a wet mop and dusting with a damp cloth can help to reduce household dust levels.
While a wider policy change on the use of toxic chemicals is needed, Singla added, consumers could also take action by making careful choices about the products they buy. “It is really important for companies and regulators to get the message that people care about this and want and need safer products for their families.”
Stuart Harrad, professor of environmental chemistry at the University of Birmingham, said the research backed up previous work on the hazards of indoor pollutants.
“This review of evidence for the presence of consumer chemicals in indoor dust from the US confirms the substantial evidence for the presence of the same chemicals in dust from UK cars, homes, and offices, as well as school and nursery classrooms,” he said. “This is pertinent as we and others believe the presence of these chemicals in consumer articles and dust leads to their presence in human milk and blood.”
Stephen Holgate, clinical professor of immunopharmacology at Southampton general hospital, described the research as important. He said though the study was US-based, the findings were also relevant in the UK.
The review, he added, showed “what we all have suspected – namely indoor exposure to household chemical and personal products accumulate in house dust, which serves as a Trojan horse when inhaled carrying these chemicals into the body”.
Holgate raised concerns over the findings that high levels of phthalates and replacement flame retardants appear to be ubiquitous, given their health impacts. Together with evidence from other studies, “there is an urgent need to consider the indoor environment as a crucial source of chemical pollutant exposure”, he said.