Interactions between inhalable aged microplastics and lung surfactant: Potential pulmonary health risks

Area of Science:

• Environmental Health
• Materials Science
• Toxicology

Background:

• Inhalation is a primary route for atmospheric microplastic (MP) exposure.
• Previous studies on MPs and respiratory health used virgin plastics, not accounting for aging effects.
• The health impacts of aged MPs on the respiratory system are largely unknown.

Purpose of the Study:

• To investigate the interaction between inhalable aged MPs and lung surfactant (LS).
• To explore the oxidative damage induced by aged MPs in simulated lung fluid (SLF).
• To elucidate the mechanisms underlying aged MP toxicity in the respiratory system.

Main Methods:

• In vitro experiments analyzing aged MPs' interfacial chemistry with porcine LS.
• Assessment of oxidative damage in SLF exposed to aged MPs.
• Characterization of MP aggregation and hydrodynamic diameter changes.

Main Results:

• Aged MPs significantly increased LS surface tension and reduced its foaming ability.
• Aged MPs showed stronger adsorption to LS phospholipids and proteins, leading to aggregation.
• Persistent free radicals on aged MPs induced reactive oxygen species, causing LS lipid peroxidation and protein damage.

Conclusions:

• Aged MPs can alter lung surfactant function, potentially impairing lung mechanics.
• Oxidative stress induced by aged MPs poses a significant risk to respiratory health.
• This study is the first to reveal the toxic effects of aged MPs on the human respiratory system.