Disposable masks leak microplastics and other pollutants in water

The Swansea University College of Engineering researchers identified high levels of pollutants – including lead, antimony and copper – within the fibres of ordinary disposable face masks of the sort widely used by essential workers during the coronavirus pandemic.

“All of us need to keep wearing masks, as they are essential in ending the pandemic,” emphasised Dr Sarper Sarp, who led the study. “But we also urgently need more research and regulation on mask production, so we can reduce any risks to the environment and human health.”

The rise in single-use masks and associated waste during the pandemic has been identified as a new cause of pollution. Last year, the UCL Plastic Waste Innovation Hub estimated that switching single-use for reusable masks could avoid 66,000 tonnes of contaminated plastic waste being generated in a single year.

The Swansea University study explored the characteristics of this waste and identified the level of toxic substances present. They looked not just at single-use face masks, but also novelty and festive masks for children, comparing disposable masks from seven brands.

The researchers submerged the masks in water to simulate the masks being left in the environment as litter and found significant levels of pollutants in all the masks tested. Microplastics, nanoplastics and heavy metals were released into the water during all tests. Their analysis identified the presence of lead, cadmium, antimony and various organic species in the leachate.

They concluded that this could have a substantial environmental impact and raised the question of potential public health damage, warning that these pollutants – with repeated exposure – could be as hazardous as the substances with known links to cell death, genotoxicity and cancer formation.

The researchers advised further investigation and subsequent regulations be put in place regarding the manufacturing and testing of these items.

“The production of disposable plastic face masks in China alone has reached approximately 200 million a day, in a global effort to tackle the spread of the news SARS-CoV-2 virus,” said Dr Sarp. “However, improper and unregulated disposal of these [masks] is a plastic pollution problem we are already facing and will only continue to intensify.

“There is a concerning amount of evidence that suggests that [disposable face masks] can potentially have a substantial environmental impact by releasing pollutants simply by exposing them to water. Many of the toxic pollutants found in our research have bio-accumulative properties when released into the environment and our findings show that they could be one of the main sources of these environmental contaminants during and after the Covid-19 pandemic.

“It is, therefore, imperative that stricter regulations need to be enforced during manufacturing and disposal/recycling of [disposable face masks] to minimise the environmental impact.”

Dr Sarp added that there is a particular need to understand the impact of silicon and plastic microfibre particles on public health, particularly given that they can become easily detached from the masks and leached into water with no agitation, implying that they are mechanically unstable.

“A full investigation is necessary to determine the quantities and potential impacts of these particles leaching into the environment and the levels being inhaled by users during normal breathing. This is a significant concern, especially for healthcare professionals, key workers and children who are required to wear masks for large proportions of the working or school day,” he said.