Nanoplastic Particle Emissions from Plastic Smoldering Combustion

Area of Science:

• Environmental Science
• Atmospheric Chemistry
• Materials Science

Background:

• Atmospheric nanoplastic particles (NPPs) are an emerging environmental concern.
• Sources often involve heating plastics, but airborne emission data is scarce.
• Understanding emissions is crucial for assessing human and ecosystem health risks.

Purpose of the Study:

• To systematically characterize particle and volatile organic compound (VOC) emissions from smoldering combustion of common plastics.
• To identify the composition of emitted NPPs and oxidation products.
• To quantify emission factors for airborne particles and VOCs.

Main Methods:

• Smoldering combustion experiments were conducted on five plastic types: LDPE, PP, PS, PET, and PVC.
• Emitted particles and VOCs were analyzed using aerosol mass spectrometry.
• Mass fractions of NPPs were estimated based on characteristic fragment ions.

Main Results:

• A dominant submicron particle mode was observed for all plastic types.
• Distinctive fragment ions identified NPP composition (hydrocarbon, aromatic, phthalate, organochlorine ions).
• Emission factors for submicron particles ranged from 0.5-769 g kg⁻¹, and for VOCs from 46-393 g kg⁻¹.

Conclusions:

• Open plastic combustion is a significant source of atmospheric NPPs, potentially exceeding oceanic microplastic emissions.
• These emissions are comparable to microplastics from tire and brake wear.
• Plastic smoldering combustion plays a central role in the global plastic cycle and atmospheric nanoplastic pollution.