A study has found that disposable masks, which are used once and discarded, can have serious impacts on soil ecosystems.
A research team led by Professor Gen.Kim Tae-young of the Gwangju Institute of Science and Technology (GIST) has revealed through a joint study conducted with Freie Universität Berlin that disposable mask waste disrupts the reproduction and metabolic systems of soil organisms such as the tiny roundworm (Caenorhabditis elegans), the team said on the 30th.
During the COVID-19 pandemic, hundreds of billions of disposable masks were used worldwide each year. Most masks, made from synthetic fibers such as polypropylene (PP), can release microplastics.
The research team proved for the first time at the molecular level that microplastics released from discarded masks can cause biological toxicity by combining with specific chemicals added during the manufacturing process, not just as simple plastic particles.
The team experimented by mixing three types of disposable masks (KF94, medical, and dust-proof) and polypropylene (PP) raw material into standard soil to test the impact on the reproduction and metabolism of the tiny roundworm. The experimental concentrations (the ratio of microplastics in the soil) were set at 0.1% and 0.3%, and the reproductive capacity of the roundworms in each group (the number of hatched larvae) was quantitatively measured. They then conducted precise analysis of the roundworm's metabolic changes using liquid chromatography-mass spectrometry (LC-MS).
The experimental results confirmed a significant decrease in the reproductive capacity of the roundworms exposed to microplastics from KF94 and dust-proof masks at concentrations of 0.3%, with reductions of 33% and 46%, respectively. In contrast, the medical masks and polypropylene (PP) raw materials showed no significant impact in terms of reproductive toxicity.
Metabolomics analysis also confirmed that changes had occurred in the metabolic pathways of the roundworms. The microplastics from KF94 and dust-proof masks similarly disrupted the polyamine biosynthetic pathway, and since different additives were presumably used, the effects on metabolic substances also showed differences. Polyamines are small molecules that play a crucial role in growth and reproduction within the cells of organisms.
High-resolution mass spectrometry detected chemical additives such as phthalates in the masks. This substance is known to be an endocrine disruptor that causes reproductive toxicity. The research team analyzed that these additives are likely the main cause of metabolic disruption and reduced reproductive capacity.
Professor Gen.Kim Tae-young noted that "this research scientifically clarifies the complex biological toxicity that microplastics emitted from disposable masks and the chemical additives used in mask manufacturing have on soil organisms," and emphasized the urgency of evaluating the long-term environmental impact of mask waste and developing eco-friendly mask materials and disposal methods.
References
Ecotoxicology and Environmental Safety (2025), DOI : https://doi.org/10.1016/j.ecoenv.2025.118451