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

Bryan D James; Asha de Vos; Lihini I Aluwihare; Sarah Youngs; Collin P Ward; Robert K Nelson; Anna P M Michel; Mark E Hahn; Christopher M Reddy

doi:10.1021/acsenvironau.2c00020

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

ACS Environ Au. 2022 Jul 29;2(5):467-479. doi: 10.1021/acsenvironau.2c00020. eCollection 2022 Sep 21.

Authors

Bryan D James^{1

2}, Asha de Vos^{3

4}, Lihini I Aluwihare⁵, Sarah Youngs⁶, Collin P Ward¹, Robert K Nelson¹, Anna P M Michel⁶, Mark E Hahn², Christopher M Reddy¹

Affiliations

¹ Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543, United States.
² Department of Biology, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543, United States.
³ Oceanswell, 9 Park Gardens, Colombo 5 00500, Sri Lanka.
⁴ The Oceans Institute, University of Western Australia, 35 Stirling Highway, Perth, WA 6009, Australia.
⁵ Scripps Institution of Oceanography, University of California San Diego, La Jolla, California 92093, United States.
⁶ Department of Applied Ocean Physics and Engineering, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543, United States.

Abstract

In late May 2021, the M/V X-Press Pearl container ship caught fire while anchored 18 km off the coast of Colombo, Sri Lanka and spilled upward of 70 billion pieces of plastic or "nurdles" (∼1680 tons), littering the country's coastline. Exposure to combustion, heat, chemicals, and petroleum products led to an apparent continuum of changes from no obvious effects to pieces consistent with previous reports of melted and burned plastic (pyroplastic) found on beaches. At the middle of this continuum, nurdles were discolored but appeared to retain their prefire morphology, resembling nurdles that had been weathered in the environment. We performed a detailed investigation of the physical and surface properties of discolored nurdles collected on a beach 5 days after the ship caught fire and within 24 h of their arrival onshore. The color was the most striking trait of the plastic: white for nurdles with minimal alteration from the accident, orange for nurdles containing antioxidant degradation products formed by exposure to heat, and gray for partially combusted nurdles. Our color analyses indicate that this fraction of the plastic released from the ship was not a continuum but instead diverged into distinct groups. Fire left the gray nurdles scorched, with entrained particles and pools of melted plastic, and covered in soot, representing partial pyroplastics, a new subtype of pyroplastic. Cross sections showed that the heat- and fire-induced changes were superficial, leaving the surfaces more hydrophilic but the interior relatively untouched. These results provide timely and actionable information to responders to reevaluate cleanup end points, monitor the recurrence of these spilled nurdles, gauge short- and long-term effects of the spilled nurdles to the local ecosystem, and manage the recovery of the spill. These findings underscore partially combusted plastic (pyroplastic) as a type of plastic pollution that has yet to be fully explored despite the frequency at which plastic is burned globally.