Detection and quantification of microplastics in cerumen.

Area of Science:

• Environmental Science
• Toxicology
• Human Health

Background:

• Microplastics (MPs) are ubiquitous environmental pollutants with increasing concern for human exposure.
• Evidence suggests MPs can systemically distribute within human tissues and fluids.
• The ear canal, due to its environmental exposure, is a potential site for MP accumulation.

Purpose of the Study:

• To investigate the presence of microplastics in human cerumen.
• To assess the ear canal as a potential site for MP accumulation and elimination.
• To evaluate cerumen as a noninvasive bioindicator for MP exposure.

Main Methods:

• Cerumen samples were collected from 12 adult patients (23 samples) and three water controls.
• Microplastics were extracted, filtered (0.22 μm), and identified morphologically via microscopy.
• Descriptive statistics were used for analysis; chemical identification was not performed.

Main Results:

• Microplastics were detected in 83.3% of patient cerumen samples (10 out of 12 patients).
• A total of 31 microplastic particles (16-930 μm) were found in patient samples.
• Water controls had fewer and smaller particles (3-46 μm), indicating genuine human presence.

Conclusions:

• Human cerumen contains microplastics, suggesting a novel elimination route.
• The high detection rate and distinct particle characteristics support genuine accumulation.
• Cerumen shows potential as a noninvasive bioindicator for microplastic exposure assessment.