Leachates of micronized plastic toys provoke embryotoxic effects upon sea urchin Paracentrotus lividus.

Abstract Microplastics are defined as plastic fragments <5 mm, and they are found in the ocean where they can impact on the ecosystem. Once released in seawater, microplastics can be internalized by organisms due to their small size, moreover they can also leach out several additives used in plastic manufacturing, such as plasticizers, flame retardants, etc., resulting toxic for biota. The aim of this study was to test the toxicity of micronized PVC products with three different colors, upon Paracentrotus lividus embryos. In particular, we assessed the effects of micronized plastics and microplastic leachates. Results showed a decrease of larval length in plutei exposed to low concentrations of micronized plastics, and a block of larval development in sea urchin embryos exposed to the highest dose. Virgin PVC polymer did not result toxic on P. lividus embryos, while an evident toxic effect due to leached substances in the medium was observed. In particular, the exposure to leachates induced a development arrest immediately after fertilization or morphological alterations in plutei. Finally, PVC products with different colors showed different toxicity, probably due to a different content and/or combination of heavy metals present in coloring agents. Graphical abstract Image 1 Highlights • Effects of PVC commercial products with different colors were assessed on P. lividus. • Microplastics and their leachates resulted toxic on larval development at high dose. • Microplastics toxicity seems to be mainly due to the leached substances. • Different colors showed different toxicity. • PVC virgin didn't result toxic upon P. lividus embryos. PVC commercial products exerted toxicity upon sea urchin larvae development mainly due to leached substances in seawater. [ABSTRACT FROM AUTHOR]