Microplastic contaminants potentially distort our understanding of the ocean's carbon cycle.

ABSTRACT: Direct observations confirm that admixtures of sedimentary organic matter (SOM) and microplastics (MPs) are fully oxidized during Elemental analysis (EA), with measured carbon yields, % carbon [%C], C:N ratios, stable- (δ13C) and radiocarbon (Δ14C) abundances consistent with predictions for SOM samples intentionally contaminated with plastic. As an example, MPs would comprise ~40% of all carbon atoms measured via EA in a 100 μg SOM sample (1% OC by mass) that has been contaminated with only 1 μg of polyethylene (PE = 77% C by mass). This MP contamination, amounting to just 1% of the total sample mass, would lower the sample's Δ14C by 258‰ to -622 ‰, lower the sample's δ13C by -3.65‰ to -25.22‰, and overestimate its conventional 14C age by ~4000 years. Moreover, this 1% MP contamination wou

SUBMITTER: Medina Faull LE 

PROVIDER: S-EPMC12517520 | biostudies-literature | 2025

REPOSITORIES: biostudies-literature