Fate, abundance and ecological risks of microcystins in aquatic environment: The implication of microplastics

Microcystins are highly toxic cyanotoxins and have been produced worldwide with the global expansion of harmful cyanobacterial blooms (HABs), posing serious threats to human health and ecosystem safety. Yet little knowledge is available on the underlying process occurring in the aquatic environment with microcystins. Microplastics as vectors for pollutants has received growing attention and are widely found co-existing with microcystins. On the one hand, microplastics could react with microcystins by adsorption, altering their environmental behavior and ecological risks. On the other hand, particular attention should be given to microplastics due to their implications on the outbreak of HABs and the generation and release of microcystins. However, limited reviews have been undertaken to link the co-existing microcystins and microplastics in natural water. This study aims to provide a comprehensive understanding on the environmental relevance of microcystins and microplastics and their potential interactions, with particular emphasis on the adsorption, transport, sources, ecotoxicity and environmental transformation of microcystins affected by microplastics. In addition, current knowledge gaps and future research directions on the microcystins and microplastics are presented. Overall, this review will provide novel insights into the ecological risk of microcystins associated with microplastics in real water environment and lay foundation for the effective management of HABs and microplastic pollution.