Multigenerational effects of tire wear particle leachate through trophic transfer from producer to primary consumer

Tire wear particle (TWP) and their leachate have been known toxic for aquatic organism due to additives released from the rubber matrix. However, it is not clear whether the ecotoxicity of TWP leachate could be transferred through algae-zooplankton food chain especially after multi generations. In this work, the effect of different concentrations TWP leachate on growth of microalgae, Chlorella pyrenoidesa, was studied. Subsequently, those algae were fed to zooplankton rotifer, Brachionus calyciflorus, which continuously lasted for ten generations to explore multigenerational accumulation of TWP leachate ecotoxicity through food-chain transfer. The results showed that the TWP leachate displayed growth inhibition for algae with evident concentration effect. For rotifer fed with those contaminated microalgae, though the first two generations showed hormesis, the ecotoxicity exhibited after 2 generations, characterized by reduction of lifespan and offspring number. The ecological effects of TWP leachate were transferred from algae to rotifer. In addition, the ecotoxicity gradually aggravated along with generation passage and exposure concentration of algae. What was even more, population passage of rotifer collapsed totally with no offspring after 5-generations feed by algae exposed to high concentration TWP leachate. Based on those, it is summarized that the ecological effects of TWP leachate indeed can be transferred from low to high trophic level in food chain, and accumulate across generations passage. The indirect non-contact exposure through food chain should be considered at the risk assessment of TWP. Single generation exposure will underestimate their ecological risk from long term.