A study highlights the environmental threat posed by billions of improperly discarded masks, particularly N95s, used during the COVID-19 pandemic.
These masks, made from non-recyclable materials, have significantly contributed to microplastic pollution in terrestrial and aquatic environments.
Authors called for integrated policies to address the issue.
The popular N95 masks and other respiratory masks used during COVID-19 do more harm to the environment than the surgical or other kinds, a study has found. However, all the varieties are damaging the environment as billions of them have been discarded improperly.
The COVID-19 pandemic caused a dramatic rise in the use of disposable face masks (DFM) and these have entered terrestrial and aquatic environments in large numbers, according to the report published in the journal Environment Pollution.
It estimated that the use of single-use face masks increased by nearly 9,000 per cent during the pandemic from March 2020 to October 2020, with World Health Organization (WHO) recording a requirement of about 89 million medial DFMs daily. An additional 129 billion DFMs were used globally per month during the pandemic.
These masks primarily are made from polypropylene, but other polymers such as polyethylene, polyamide / nylon, polystyrene, polyester / polyethylene terephthalate, polycarbonate, polyphenylene oxide and chlorotrifluoroethylene are known types of personal protective equipments (PPE), and serve as a barrier by filtering particles and droplets emitted during coughing, sneezing and speaking.
Studies have proven that respiratory masks are more effective in protecting against airborne pathogens compared to surgical or medical masks. Filtering Face Pieces (FFP) such as N95, N100 masks can prevent inhalation of potential health hazards of dust, smoke, mist, vapour and gases.
The researchers said that these DFMs are currently non-recyclable via conventional routes and witnessed extensive improper disposal, especially during the COVID-19 pandemic.
They identified the careless disposals of masks along street lanes, sidewalks, footpaths, parking areas, street gutter, waterways, parks, beaches, rural areas, among others.
Another study showed that around 3.4 billion DFMs were discarded worldwide each day at the height of the pandemic. It is projected that 4.3 million tonnes of non-recyclable contaminated plastic waste from these items would have been produced between September 2019 and October 2020 across 11 countries, including Australia, Belgium, Canada, France, Germany, the Netherlands, New Zealand, Spain, Sweden, the United Kingdom, and the United States.
Experiments of keeping masks in water revealed that FFPs released 3-4 times more microplastic particles compared to medical masks and DFMs.
“The release of microplastics into water from all tested DFMs without mechanical stress suggests potential microplastic contamination originating from the DFM production process,” the study noted.
The study noted chemicals such as bisphenol B, sulfosuccinate as leachables from medical masks (MM) and surgical masks with varying sizes.
Bisphenol B is known to cause endocrine disruption and behaves like oestrogen when absorbed by bodies of humans and animals.
The main type of microplastics identified in the water leachates of the investigated face masks was polypropylene, accounting for 93-97 per cent for MM and DFMs and 82-83 per cent for FFPs, the study said.
Other polymers such as polyethylene, polycarbonate, polyester / polyethylene terephthalate, polyamide / nylon, polyvinylchloride and ethylene-propylene copolymer were also identified, but in smaller amounts, it added.
These chemicals are known to cause serious impacts on human health and environment, including marine life. They can cause disorders such as birth defects, cancer, negatively impact the nervous system and immune system and compromise kidney functioning.
The researchers also found that FFPs released an extensive variety of and larger share of other polymers (17-18 per cent), compared to MMs and DFMs (3-7 per cent).
“Fragments and fibres were identified in all water-leachate samples, and fragments, particularly debris of polypropylene fibres, were the most common MP morphotype,” the authors wrote in the study.
The researchers emphasised the importance of the findings for developing science-based policy recommendations on the health and environmental impacts of microplastics and associated chemical additives from DFMs, pointing out a significant gap in understanding plastic regulation and management.
It underlined the need for integrated policy carved out between researchers, PPE producers, waste managers, government, policymakers and society.