Significant regional disparities in riverine microplastics.

Area of Science:

• Environmental Science
• Ecotoxicology
• Water Quality

Background:

• Riverine microplastic pollution is a growing global concern.
• Limited large-scale regional analysis exists due to methodological and spatiotemporal constraints.
• Understanding regional disparities is crucial for effective management.

Purpose of the Study:

• To develop a framework for synthesizing and analyzing riverine microplastic data.
• To investigate large-scale regional variations in microplastic abundance.
• To explore correlations between microplastic pollution and country income levels.

Main Methods:

• Literature data synthesis from 76 rivers across Asia, Europe, and North America.
• Comparative analysis of microplastic abundance in surface water and sediment.
• Statistical analysis to determine regional and income-based variations (p < 0.001).

Main Results:

• Asian rivers showed 3x higher surface water microplastic abundance than Euro-American rivers.
• Euro-American rivers had 5x higher sediment microplastic abundance than Asian rivers.
• Rivers in lower-middle and upper-middle income countries had higher surface water microplastics, but lower sediment microplastics compared to high-income countries.

Conclusions:

• Significant regional and income-based disparities in riverine microplastic pollution exist.
• Preliminary attribution of these differences to varying urbanization levels.
• The developed framework aids in understanding environmental microplastic disparities and informs mitigation strategies.