An economical fluorescent method for microplastic detection in soil samples.

Area of Science:

• Environmental Science
• Analytical Chemistry
• Ecotoxicology

Background:

• Microplastic pollution from urban and industrial waste poses a global ecological threat.
• Existing soil microplastic quantification methods are often complex, expensive, and inaccessible for public use.
• There is a need for simplified, low-cost methods for microplastic detection and education.

Purpose of the Study:

• To develop and validate a simplified, low-budget Nile Red fluorescent dye method for quantifying microplastics in soil samples.
• To assess the method's effectiveness and reproducibility across various environmental soil types.
• To enable accessible microplastic detection for educational purposes and public awareness.

Main Methods:

• A simplified Nile Red fluorescent dye staining protocol was developed using low-cost materials.
• The method was validated using commercial sand spiked with known microplastic sizes (1-5 mm).
• Microplastics were visualized under blue light with orange filter glasses and counted by independent blinded assessors.

Main Results:

• The Nile Red method achieved nearly 100% detection of microplastics (1-5 mm) in spiked sand samples.
• Urban lake shore and garden soil exhibited the highest microplastic densities.
• The method demonstrated high reproducibility and consistent ranking of microplastic levels across different soil types, including detection of smaller particles (<1 mm).

Conclusions:

• The developed low-cost Nile Red method is effective for visualizing and quantifying microplastics in various soil types.
• This accessible technique is suitable for environmental education and public engagement, enhancing awareness of microplastic pollution.
• The method's scalability and ease of use facilitate broader participation in monitoring microplastic contamination.