Microplastics in the disposable face mask leachates act as vectors of antibiotic toxicity: Toxicological insights in Vigna radiata

Disposable face masks (DFMs), predominantly made of polypropylene, have been widely used during and after the COVID-19 pandemic, raising concerns about their environmental toxicity. This study examined the phytotoxic effects of DFMs subjected to ultraviolet (UV) irradiation to simulate solar exposure, with dark conditions serving as controls. Leachates were extracted by immersing the samples in deionized water and tested on Vigna radiata (mung bean) to evaluate physiological and biochemical responses, including root length, vigour index, reactive oxygen species (ROS), and antioxidant enzyme levels. UV-weathered DFM leachates (UV ML) exhibited a time-dependent increase in toxicity, reaching 34 %, while non-weathered leachates (non-UV ML) showed no adverse effects. Subsequent analyses focused on UV ML and their interaction with tetracycline (TET), a persistent antibiotic in agricultural soils. Material characterisation using FT-IR, Raman spectroscopy, and FE-SEM revealed extensive polymer degradation and microfiber fragmentation, and the leachate with microfiber sizes ranging from 10 μm to 3 mm was observed using an optical microscope. LC-MS confirmed a 26 % adsorption of TET onto UV ML and identified diverse phthalate groups, while ICP-MS detected trace metals. Co-exposure to UV ML and TET induced synergistic toxicity, elevating oxidative stress by 32 % and impairing metabolic enzyme activities. The novelty of this study lies in its integrative approach to simulating environmental weathering, characterizing leachate–antibiotic interactions, and evaluating combined phytotoxicity using Vigna radiata as a bioindicator. These findings highlight the compounded environmental risks posed by DFMs as vectors for pharmaceutical pollutants, emphasizing the urgent need for sustainable waste management strategies to mitigate long-term ecological consequences in agroecosystems.