Continental microplastics: Presence, features, and environmental transport pathways

Area of Science:

• Environmental Science
• Ecotoxicology
• Environmental Chemistry

Background:

• Microplastics (MPs) are pervasive environmental pollutants detected across diverse ecosystems.
• Understanding the continental pathways of MPs is crucial due to their increasing environmental concern.

Purpose of the Study:

• To review and integrate current knowledge on the primary pathways of microplastics in continental environments (air, soil, freshwater).
• To analyze how microplastic characteristics influence their transport and deposition.
• To identify knowledge gaps and future research directions for continental microplastic contamination.

Main Methods:

• Literature review synthesizing existing research on microplastic occurrence, sources, and behavior.
• Analysis of factors affecting microplastic transport, including particle properties and environmental variables.
• Identification of key pathways such as wind resuspension, atmospheric fallout, groundwater migration, and surface water flow.

Main Results:

• Identified wind resuspension, atmospheric fallout, groundwater migration, runoff, and riverine/effluent flow as principal microplastic pathways.
• Demonstrated that microplastic characteristics (size, shape, polymer, density) interact with environmental factors (soil properties, climate, water conditions) to govern transport and fate.
• Highlighted the need for refined sampling strategies considering environmental heterogeneity and extreme events.

Conclusions:

• Continental microplastic contamination is driven by complex interactions between particle properties and environmental conditions.
• Further long-term monitoring and laboratory experiments are essential to fully elucidate microplastic behavior in the environment.
• An integrated understanding of continental microplastic pathways is vital for effective environmental management and mitigation strategies.