A study of ‘new plastic formations’ found in the Seto Inland Sea, Japan

Abstract

In the Anthropocene, the occurrence of 'new plastic formations' is being reported at locations around the globe, but there have been few reports from coasts along the Asian side of the Pacific Ocean. In this study, the cases of 'new plastic formations', consisting mainly of 'pyroplastics', which are drifted on the northwestern coast of Japan's Seto Inland Sea, were described. In Japan, the problem of harmful substances caused by 'hamayaki' (burning of drifted coastal debris at the shore) has been studied from an early stage as the problem of coastal marine plastic pollution. In addition, in the Japan Sea and Yellow Sea, drifting marine litter created via combustion has been studied, and potential amounts of 'pyroplastic' were suggested. 'Pyroplastics' has been identified as the source of microplastics due to those vulnerabilities, and easy degradation into smaller particles was verified in the 'pyroplastic' collected. The potential amounts of microplastics from 'pyroplastics' and their toxicity are not yet clarified. In addition, it is possible that the 'new plastic formation' found in estuary, with plastics stuck to a pebble, may be incorporated into the stratum due to river sedimentation.

Divergent Forms of Pyroplastic: Lessons Learned from the M/V X-Press Pearl Ship Fire

“…Thermally altered (orange), partially combusted (gray), and burnt plastic can enter the marine environment not only from a maritime accident like that of the M/V X-Press Pearl but from more frequent open burning of waste and forest fires. Only recently has pyroplastic been reported on beaches likely because of its camouflaged appearance rather than its absence. − Such a material likely arises from the open burning of an estimated 970 million tons of plastic-containing waste each year. , Similarly, natural disasters, especially wildfires, can be another source of pyroplastic entering the environment. − Forms of plastic like those from the X-Press Pearl are likely produced from these actions, and remnants of this material can then make their way into the environment along the same paths as other mismanaged waste . The environmental uncertainties concerning the spilled plastic from the X-Press Pearl accident also apply to divergent forms of pyroplastics globally.…”

“…Only recently has pyroplastic been reported on beaches likely because of its camouflaged appearance rather than its absence. 2 − 5 Such a material likely arises from the open burning of an estimated 970 million tons of plastic-containing waste each year. 110 , 111 Similarly, natural disasters, especially wildfires, can be another source of pyroplastic entering the environment.…”

“…At the extremes of the continuum, the burnt plastic resembled pyroplastic, seemingly burned or melted brittle plastic of neutral color and geogenic appearance, or the plastic appeared untouched by the events of the fire. Pyroplastics have only recently been documented on beaches due largely to their camouflaged appearance and likely not to their rarity in the environment. − …”

Fire and Oil Led to Complex Mixtures of PAHs on Burnt and Unburnt Plastic during the M/V X-Press Pearl Disaster

“…118,120,[128][129][130][131]133 Owing to their camouflaged appearance, only recently have pyroplastics been reported on beaches. [19][20][21]23,27,145 This fact prompted us to review previous reports for PAHs associated with oceanic plastic to determine whether descriptions, images, PAH compositions, and diagnostic ratios for the most highly contaminated samples reflected features of pyroplastics. From our assessment, samples from Mai et al 131 and Chen et al 132 had attributes suggestive of pyroplastics, and their PAHs were characteristic of pyrogenic sources (Section S3); nonetheless, weathering could skew their PAH composition.…”

“…The burnt plastic pieces and combustion remnants resembled pyroplastic, seemingly burnt or melted brittle plastic of neutral color and geogenic appearance. , Pyroplastic is a newly recognized form of plastic in the Anthropocene that, so far, appears to enter the marine environment following large-scale fires (e.g., forest fires) and leakage of openly burned waste. − Since the first description of pyroplastic in 2019, − they, along with other forms of charred plastic, have been documented on beaches and waters across five continents (Africa, Asia, ,, Europe, − North America, ,, and South America) and have been found ingested by fish . Little is known about the fate of pyroplastic in the ocean, making the spill of burnt plastic from the M/V X-Press Pearl disaster a unique opportunity to monitor the weathering of time-stamped, geolocated pyroplastics and other plastic pieces when exposed to real-world conditions.…”