Disposable facemask waste combustion emits neuroactive smoke particulate matter

Area of Science:

• Environmental Science
• Neuroscience
• Materials Science

Background:

• The COVID-19 pandemic resulted in massive disposable medical facemask waste.
• Facemasks remain crucial for preventing airborne infections globally.
• Current waste management practices are insufficient for this growing plastic pollution.

Purpose of the Study:

• To investigate the neurotoxic potential of particulate matter derived from combusted disposable medical facemasks.
• To characterize the physicochemical properties of facemask smoke.
• To assess the impact of this particulate matter on neuronal function and neurotransmitter systems.

Main Methods:

• Collection and characterization of smoke particulate matter from combusted polypropylene facemasks.
• Analysis of particulate size, zeta potential, surface groups, and optical properties.
• Neurochemical studies on isolated rat cortical nerve terminals measuring neurotransmitter uptake, release, and extracellular levels.
• Fluorescent measurements of reactive oxygen species (ROS) generation, membrane potential, mitochondrial potential, and synaptic vesicle acidification.

Main Results:

• Combustion of facemasks generated ultrafine particulate matter.
• Exposure to this particulate matter significantly altered neurotransmitter dynamics (glutamate, GABA) in nerve terminals.
• Observed decreases in neuronal and mitochondrial membrane potentials and synaptic vesicle acidification.
• Reduced ROS generation in response to stimuli.

Conclusions:

• Disposable medical facemask waste combustion releases neuroactive ultrafine particles.
• These particles pose a risk to environmental health and can contribute to neuropathology.
• Highlights the urgent need for improved waste management of medical facemasks to mitigate plastic pollution and neurotoxic risks.