New research reveals high levels of microplastics in our homes

· Microplastics were identified within all households and 98% of samples, confirming that within indoor settings – microplastics are everywhere · Latest findings build on University of Hull’s research into plastics and the environment

A landmark study of the levels of microplastics in the air – that we are breathing in our homes – suggests levels are high, particularly compared with levels reported for outdoors.

The study – the largest study of microplastics in household homes to date – is the first to find microplastics in all sampled homes, with concentrations exceeding previous worldwide studies and posing potential health risks. Study author, Lauren Jenner, a postgraduate student at Hull York Medical School, said:

“It is alarming that while we think the atmosphere in our own homes, is under our own control, and not subject to contaminants that we associate with outdoors – we are at risk from everyday materials that we have introduced as part of our décor or clothing. Home furnishings and clothing shed small-sized fibres and these are likely responsible for the high levels of microparticles in the air in our homes.”

“Knowledge regarding the presence of suspended microplastics within the air has been lacking, especially indoors, yet the importance of indoor air quality and human health is rising, and is particularly pertinent since we have all been spending more time indoors during the pandemic.”

The significance of indoor air quality is highlighted by the fact that people spend up to 90% of their time indoors and as much as 60% in their homes.

Historically, microplastics have not been considered an atmospheric pollutant, but now they are emerging as a contaminant of concern – especially as little is known about the health consequences after microplastics enter the body. The particles are similar in size to the diameter of a human hair, a piece of fine beach sand or a pollen grain.

The study sampled the air from 20 households, for 6 months, collecting atmospheric fallout at head height within the living rooms, where the occupants spent an average of 7 hours a day.

Microplastics were identified within all households and 98% of samples, confirming that within an indoor setting that MPs are ubiquitous. An average household atmospheric MP concentration rate of 1,400 microparticles per m-2 day-1 was observed. This is significantly higher than reported by all passively sampled studies, and up to 45 times higher than outdoor studies.

In the household daily average of 1,400 microparticles per m2 , the breakdown of microplastics was as follows:

* Smaller (5-250 mm), fibrous, particles were the most abundant (90%), representing types found in carpets, clothing and home soft furnishings. Their smaller size range, which is similar in size to a blood cell or the diameter of a human hair, makes them more likely to enter the human body and cause physiological harm.

* Polyethylene terephthalate (PET) was also present in 90% of samples and accounted for 62% of microparticles. PET is mostly found/associated with food packaging, clothing such as cold weather fleeces, and carpets/soft furnishings.

* Additionally, the polyamide nylon, and polypropylene were commonly detected. These are found in clothing/threads and plus many uses outside the home such as seat belts, air bags and tarpaulins/tents.

It was also evident that the level of microparticles was also subject to seasonal changes with higher levels of PET fibres observed during the winter months compared to the summer.

Lauren said: “These microparticles are potentially more harmful than natural particles – such as cotton or wool fabrics, that we may also be breathing in at times. These microplastics are from materials specifically manufactured to be robust – so they don’t degrade in the same way that natural materials would do, and are likely to remain in our lungs if inhaled.”

“In future, the finding of this study – the size range and types of microparticles observed – will inform laboratory experiments, using human tissue culture approaches. This will allow determination of the wider implications on human health using realistic levels and types of indoor microparticles.”

The study, which is co-authored by Dr Laura Sadofsky and Evangelos Danopoulos of Hull York Medical School, and Professor Jeanette Rotchell of the University of Hull’s Department of Biological and Marine Sciences, has been published in Atmospheric Environment.

Previously, very few studies have focused on the impact microparticles in the air have on human health – though in the 1970s a study of workers in a nylon flocking factory suggested that there was a high incidence of lung-related health concerns.

For the purposes of this most recent study, a total of 20 houses were selected for sampling, all located within the city of Hull and wider East Riding of Yorkshire in the UK. Sampling covered a six-month timescale investigation from July until December 2019. Participants also completed a short questionnaire about their living conditions and routines.

Its publication continues to build on the University of Hull’s reputation for plastics and other environmental research:

· Last year, mussels, oysters and scallops were found to have the highest levels of microplastic contamination among seafood. The study – which was led by researchers at the University of Hull and Hull York Medical School – looked at more than 50 studies between 2014 and 2020 to investigate the levels of microplastic contamination globally in fish and shellfish. The paper ‘Microplastic contamination of seafood intended for human consumption: a systematic review and meta-analysis' was published in Environmental Health Perspectives.

· On world ocean day in 2018, a study of microplastics in mussels reported that 100 per cent of mussels sampled from around the UK coast contained microplastics or other debris. Scientists from the University of Hull and Brunel University, London collected samples from eight locations around the UK’s coastline as well as from eight unnamed supermarkets, representing eight different, unnamed brands. The study was published in the journal Environmental Pollution and attracted widespread coverage in the media.

· The same author team Professor Jeanette Rotchell, Dr Maureen Twiddy, Evangelos Danopoulos and Lauren Jenner recently published a systematic review and meta-analysis of studies of microplastics in drinking water and table salt as well as a study into the variable levels of microplastics in different seafood tissue parts. (This author team is part of the Human Health and Emerging Environmental Contaminants research group which also includes Dr Laura Sadofsky, Dr Andrew Boa, Dr Roger Sturmey, Dr Ireneous Soyiri, Dr Justin Sturge).

· The Human Health and Emerging Environmental Contaminants research group, which brings together researchers from the University of Hull and Hull York Medical School, focuses on understanding the effect of contaminants on the human respiratory and reproductive systems, in addition to the gastrointestinal tract (as above). Respiratory work carried out by Lauren Jenner and led by Dr Laura Sadofsky has so far focussed on microplastics, having determined the level and characteristics of microplastics within the indoor, home environment. With this knowledge they hope to discover whether microplastics can be found within the human lungs and whether these particles have an adverse effect on respiratory health. Studies on reproductive systems, carried out by Vasiliki Papachristofi and led by Dr Roger Sturmey, are investigating the way in which newly emerging and established environmental contaminants affect the tissues of the female reproductive system in ways that change the periconceptual (around the time of conception) environment and the early stages of embryo development.

· Previous research led by Dr Cath Waller at the University of Hull, along with colleagues at the British Antarctic Survey, showed how the levels of microplastic particles accumulating in the Southern Ocean, around Antarctica, are much worse than expected. Dr Waller leads the University’s Plastics in the Environment Research Group focussing on the environmental and social impact of plastics.

· PhD Researcher, Freija Mendrik, recently published her research on the impacts of plastics on corals. The work exposed corals to different types of microplastic and measured photosynthetic yields, gross photosynthesis and net respiration. The work also tested whether impacts increased at higher temperatures that replicate ocean warming under climate change. Negative impacts were observed. However these effects were species-specific and the type of microplastics was found to be important with fibres (from clothes) causing the biggest (40%) drop in photosynthetic yield for the corals, which could reduce growth and survival.

Other environmental research

· The University of Hull is recognised as a leading centre for research into environmental issues of global importance and interest. Researchers specialise in areas such as climate change, globalisation, renewable energy and low-carbon futures. Reducing the demand for single-use plastics and protecting our waters by reducing the impact of chemicals, plastics and synthetics are also key.

· The University of Hull is recognised as a leading centre for research into environmental issues of global importance and interest. Researchers specialise in areas such as climate change, globalisation, renewable energy and low-carbon futures. Reducing the demand for single-use plastics and protecting our waters by reducing the impact of chemicals, plastics and synthetics are also key.

· One of the University’s distinctive features is its strong research culture of collaboration and interdisciplinary working. Researchers across the University collaborate with University institutes such as the Energy and Environment Institute which has established a Plastics Collaboratory to bring together researchers across campus working on the critical issue of plastics in the environment and how to address this through evolving a new circular plastics economy.

· The Energy and Environment Institute at the University of Hull brings together the skills and capabilities of leading researchers to tackle global challenges related to climate change and a low carbon transition, and their consequences for society and livelihoods. Home to over 100 staff and PhD researchers, the Institute is leading research in some of the areas of the world most at-risk from climate change, including flood prone areas such as Vietnam’s Mekong and Red River deltas, the Congo River in Africa, as well as locations much closer to home.

Other University partnerships focused on tackling some of the world’s greatest environmental challenges include: · Aura Innovation Centre, a University-led initiative, that works with SMEs and provides space for businesses to accelerate low-carbon projects, drive green innovation and deliver clean business growth. The Aura Centre for Doctoral Training, led by the Energy and Environment Institute, will appoint more than 70 PhD scholarships in offshore wind energy and the environment over the next 4 years.

· THYME: The University of Hull’s Energy and Environment Institute is collaborating with partners at the University of York and Teesside University on a £5 million project to develop the bioeconomy across Yorkshire, the Humber region and the Tees Valley, building on the existing knowledge and innovation in the region. The University of Hull brings particular expertise in the bioeconomy, particularly on aspects of biofuels, renewable energy and the environment, as well as logistical aspects of the wider circular economy.

· In November 2020, the University of Hull announced an ambitious eight-year plan to become carbon neutral by 2027, pledging a commitment towards a strong, sustainable future.

The University is introducing a range of measures, including a transition to renewable sources of energy to power the campus and reducing energy usage through optimising our estate and campus infrastructure.

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