Australians have been urged to reconsider carpeting their homes after a study found the floor covering may double microplastic pollution in household dust.
Scientists from Macquarie University gathered and analysed dust samples from 108 households across 29 countries, including about 30 homes in Australia.
Overall, dust from carpeted homes had roughly twice the microplastics load than dust from homes with other types of flooring.
Dr Neda Sharifi-Soltani led the research and said the scientific community was still trying to understand how microplastics might impact human health.
Separate studies have detected microplastics in human faeces, urine, blood and in people's lungs, with research ramping up globally into potential effects.
The dust study found that even though some of the microplastics polymers detected were toxic, the exposure dose was low.
But Dr Sharifi-Soltani also warned: "This is an underestimation because of all the knowledge gaps and analytical instrument limitations that we encountered.
"Doing the health risk assessment for microplastics in household dust is in its early stages."
In her mind the findings so far are enough to warrant a warning for people to reconsider installing carpets in their homes.
The study was based on indoor atmospheric dust samples gathered over a one-month period from 108 homes in 29 high, medium and low-income countries.
The 16 high-income countries included Australia, the United States, Canada, France, Germany, New Zealand, Singapore and Switzerland.
"Australia had the second-highest amount of microplastics in household dust among higher-income countries," Dr Sharifi-Soltani said.
The dust analysis was informed by a range of other information gathered from study participants, including flooring type, how often floors were cleaned, and how many people lived in each home.
In all countries, greater vacuuming frequency was associated with lower microplastics loads.
Lower-income countries had higher loads of microplastics, which were deposited at an average daily rate of 3,518 fibres per square metre, per day.
The rates for medium-income and high-income countries were 1,268 and 1,257 respectively.
"No matter what country we collected the dust from, the single biggest influence on the amount of microplastics in household dust was ... how often the floors were vacuumed," she said.
The study also showed most of the microplastics found in household dust came from sources inside the home, not outside.
The research has been published in the journal Environmental Pollution.
