Microplastics are common in homes across 29 countries. New research shows who's most at risk
- Written by Mark Patrick Taylor, Chief Environmental Scientist, EPA Victoria; Honorary Professor, School of Natural Sciences, Macquarie University
The evidence is clear: microplastics have contaminated every corner of the globe[1]. We can’t escape exposure to these tiny bits of plastic (less than 5mm across) in the environment, which includes the homes where people spend most of their time[2].
Recent research has discovered microplastics in the blood of humans[3]. However, the question of harm to humans remains unresolved[4]. Despite concerns that some substances in microplastics could cause cancer or damage our DNA, we still have a poor grasp of the true risks of harm.
Our study of global microplastics[5] exposure inside homes across 29 countries, published today, shows people living in lower-income countries and young children are at greater risk of exposure. But our analysis of the chemical composition of microplastics in the home shows the specific health risk is surprisingly low. The study covered all the continents, including Australia.
The current challenge in understanding health risks from microplastics is the very limited data on toxic effects of the petrochemicals used in plastics production.
A recurrent theme in the environmental health research literature is that early concerns about suspect chemicals and related compounds, including those found in plastics, were eventually justified[6]. The effects of suspect substances only become clear after extensive toxicological and epidemiological research.
Read more: You're eating microplastics in ways you don't even realise[7]
What did the new study look at?
Our study investigated three main questions relating to exposure to microplastics inside homes:
what are the impacts in different countries across the world?
who is most at risk?
what are the specific health risks?
We reached out to residents across 29 countries to collect their indoor atmospheric dust over a one-month period. At 108 homes sampled across these countries, we also collected information about households and behaviours. This helped us to better understand possible sources and causes of microplastics in dust. These data included:
how often floors were cleaned
flooring type
presence or absence of children
number of people living in each home
percentage of full-time workers.
In each home, atmospheric dust particles were collected in specially cleaned and prepared glass Petri dishes. We measured the levels of microplastics in the collected dust using a suite of microscopic techniques and instruments. We used infrared spectroscopy[8] – which identifies substances by how they interact with light – to determine the chemical composition of these microplastics.
Read more: House dust from 35 countries reveals our global toxic contaminant exposure and health risk[9]
What did the study find?
The household dust contained a wide variety of synthetic polymer[10] fibres. The most common were:
polyester (as polyethylene terephthalate) at 9.1%, which is used in clothing fabrics
polyamide (7.7%), which is mainly used in textiles
polyvinyls (5.8%), which are used in floor varnishes
polyurethane (4.4%), which is used in surface coatings of furniture and in bedding
polyethylene (3.6%), a common polymer used in food containers and reusable bags.
