Cadmium, lead and bromine in beached microplastics.

Area of Science:

• Environmental Science
• Marine Biology
• Analytical Chemistry

Background:

• Microplastic pollution is a growing concern in marine ecosystems.
• Understanding the chemical composition of microplastics is crucial for assessing ecological risks.

Purpose of the Study:

• To analyze heavy metal (Cd, Pb) and halogen (Br) content in microplastics from two English beaches.
• To determine the bioaccessible concentrations of Cd and Pb for seabirds.
• To identify potential sources of detected contaminants in microplastics.

Main Methods:

• Field-portable X-ray fluorescence (FP-XRF) spectrometry was used to analyze 924 microplastic samples.
• Microplastics were characterized by type (primary pellets, secondary fragments) and color.
• Bioaccessibility was assessed using a physiological extraction method simulating seabird digestion.

Main Results:

• Primary plastic pellets constituted over 70% of microplastics analyzed.
• Cadmium (Cd) and lead (Pb) were detected in 6.9% and 7.5% of samples, respectively, often in colored plastics.
• Bromine (Br) was found in 10.4% of samples, primarily in neutral pellets, suggesting brominated flame retardants.

Conclusions:

• Microplastics on English beaches contain potentially harmful heavy metals and flame retardants.
• Bioaccessible Cd and Pb concentrations in microplastics significantly exceed estimated seabird dietary intake levels.
• The findings highlight the ecological risk posed by microplastic chemical contaminants to marine birds.