Explorations in the dark continent: Did microplastics and microfibres get here before us?

Area of Science:

• Environmental Science
• Geology
• Ecology

Background:

• Karst areas are understudied regarding microplastic and microfibre pollution.
• Anthropogenic microparticles pose hazards and can reach remote subterranean environments.
• Hypogeal environments are sensitive to surface pollution, hydrodynamics, and geology.

Purpose of the Study:

• To investigate microplastic and microfibre presence in unexplored karst caves for the first time.
• To understand how human activities impact even remote 'dark continent' environments.
• To characterize microparticles found in cave sediments.

Main Methods:

• Sediment samples collected from unexplored caves in Abruzzo, Italy, with speleologists.
• Microparticles counted and characterized using microscopy and spectroscopy (composition, size, shape, fluorescence, color).

Main Results:

• Low or absent microplastic concentrations; higher natural and regenerated microfibre presence.
• Fibre-shape was the most common microparticle type.
• Most microparticles were clear and fluorescent under UV light, with pollution sources including atmospheric deposition and nearby human activities.

Conclusions:

• Anthropogenic microparticle pollution exists in unexplored karst caves, potentially impacting subterranean ecosystems and water resources.
• The connection between surface and karst environments necessitates increased monitoring and protection.
• Speleologists can contribute to understanding karst systems and conservation needs by collecting samples.