Combined approaches for detecting polypropylene microplastics in crop plants

Area of Science:

• Environmental Science
• Plant Science
• Materials Science

Background:

• Microplastic (MP) pollution is a growing concern in terrestrial ecosystems.
• Accumulation of MPs in crop plants poses potential risks to human health through consumption.
• Understanding MP uptake and translocation in plants is crucial for risk assessment.

Purpose of the Study:

• To quantify polypropylene (PP) microplastic accumulation in maize and wheat.
• To investigate the distribution of PP MPs within different plant tissues (roots, stems, leaves).
• To evaluate the efficacy of Nile red staining for MP detection in plant matrices.

Main Methods:

• A two-step alkaline and wet peroxide oxidation method was used for PP extraction from plant tissues.
• Nile red staining was employed to detect and visualize PP particles in digested solutions.
• A heating method was used to confirm the presence of PP particles by observing melting behavior.

Main Results:

• Polypropylene MPs were successfully detected in both wheat and maize plants after 75 days of exposure.
• PP MPs predominantly accumulated in wheat roots and maize stems.
• Maize plants showed significantly higher accumulation of both quantity and size of PP MPs compared to wheat.

Conclusions:

• Crop plants can accumulate microplastics from the soil environment.
• Plant species and tissue type influence the extent of microplastic accumulation.
• The Nile red staining method offers a novel approach for microplastic detection in plant samples.