Metals in microplastics: determining which are additive, adsorbed, and bioavailable

Area of Science:

• Environmental Science
• Marine Biology
• Analytical Chemistry

Background:

• Microplastic pollution is a growing global concern, with significant accumulation in oceanic gyres.
• North Atlantic Gyre microplastics have been found on Guadeloupe beaches, necessitating characterization.
• Understanding the chemical composition of microplastics is crucial for assessing ecological risks.

Purpose of the Study:

• To develop and apply a novel method for identifying elemental additives in microplastics.
• To characterize microplastics sampled from Guadeloupe beaches originating from the North Atlantic Gyre.
• To assess the potential bioavailability and ecotoxicity of leached elements from microplastics.

Main Methods:

• Microplastic samples were collected from Guadeloupe beaches.
• A new analytical method combining acidic leaching and acidic digestion was employed.
• Elemental analysis was performed to identify pigments and additives.

Main Results:

• Several elements (Al, Zn, Ba, Cu, Pb, Cd, Mn, Cr) were identified as pigments within the microplastics.
• Non-essential elements, likely from plastic additives, significantly contributed to acidic leaching.
• Leached elements suggest potential bioavailability and adsorption onto microplastic surfaces.

Conclusions:

• Microplastic additives can leach, becoming bioavailable and potentially harmful.
• Cadmium (Cd) is identified as the primary element posing a direct danger to fish ingestion.
• Further investigation is required to understand synergistic effects of multiple leached elements and microplastics on health.