Integrated Chemical and Hazard Assessment of Plastic Pellets from the Toconao Spill (Galicia, Spain) Indicates Potential for Environmental Harm

TL;DR

A plastic pellet spill in Spain released harmful chemicals that could damage marine life and ecosystems, highlighting the need for better regulations.

Contribution

This study integrates chemical analysis and toxicity testing to assess the environmental risks of a specific plastic pellet spill.

Findings

Over 50 chemical substances, including additives and nonintentionally added substances, were identified in the pellets.

Toxicity assays showed significant effects on microalgae and copepods, suggesting risks to primary producers and food webs.

Zebrafish embryos showed no developmental effects, while human cells had modest viability reductions.

Abstract

Plastic pellet spills are a major source of microplastic
pollution,
and pellets are found on beaches worldwide. However, the potential
environmental impacts of these spills remain poorly understood. In
December 2023, approximately 25,000 kg of polyethylene pellets containing
high concentrations of the additive Tinuvin UV-622 were spilled during
a shipping accident off the northern coast of Portugal. Pellets collected
from an affected beach located in Galicia, Spain, along with solvent
extracts and aqueous leachates, were subjected to both target and
nontarget chemical analyses and tested in a battery of toxicity assays
including a green microalga (Raphidocelis subcapitata), a marine copepod (Apocyclops royi), a fish model
(Danio rerio), and a human cell line. Chemical screening
identified on the order of 50 chemical substances in addition to Tinuvin
UV-622, including a range of known plastic additives and nonintentionally
added substances (NIAS). Toxicity assays revealed significant growth
inhibition and stress-induced cell aggregation in R. subcapitata and acute toxicity causing immobilization in copepods, which could
have potential implications in the environment via the disruption
of primary producers and food web dynamics. In contrast, zebrafish
embryos showed no significant developmental effects, while human cells
exhibited modest, time-dependent reductions in viability. Our findings
underscore the complex chemical burden associated with pellet spills
and stress the need for policies and regulations to prevent them,
reinforcing the importance of applying the precautionary principle
in managing the environmental risks linked to plastic pellet production,
transport, and accidental release.

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