Fig 1. Gas production from LDPE exposed to ambient solar radiation and identification of plastic collected in the open ocean.

The cumulative amount of hydrocarbon gases normalized to weight and production rates of CH₄, C₂H₄, C₂H₆ and C₃H₆ from (A) & (C) virgin LDPE pellets (0.2 g) and (B) & (D) LDPE plastic pieces (0.2 g) collected from the open ocean. Measurements were taken at approximately two-week intervals during the incubation period. Error bars represent the error propagation of the standard deviation of the mean for each time point. Panel (E) represents the micro-Raman spectra for the aged LDPE collected in the open ocean (red) and the virgin LDPE pellets (blue).