Triple combination exposure to MPs, Pb2+ and As3+ induces ferroptosis at environmentally relevant concentrations in early development of zebrafish

There remains a substantial knowledge gap in understanding the coexistence effects of Microplastics (MPs), lead (Pb) and arsenic (As), which are ubiquitous environmental contaminants. Here, zebrafish (Danio rerio) embryos were used to investigate the impact of triple combined exposure to MPs (50 μg/L), Pb²⁺ (10 μg/L) and As³⁺ (200 μg/L) on the developmental responses. Survival and hatching rates were notably reduced to 32.7 % and 58.8 %, respectively. Meanwhile, the frequency of spontaneous tail contractions increased by 8.1 %, whereas heart rate and body length decreased by 4.4 % and 5.1 %, respectively. These findings demonstrated that the triple exposure markedly disrupted developmental processes and altered behavioral profiles in zebrafish larvae. Furthermore, 16 S rRNA sequencing revealed that the metabolic processes of glutathione and xenobiotics, as well as intracellular iron transport, were significantly impacted, triggering ferroptosis in the larvae exposed to triple combination. Collectively, the co-exposure to MPs, Pb²⁺ and As³⁺ even at low concentrations could significantly disrupt the developmental progress and biological functioning during the early stages of zebrafish. This will help guide future comprehensive studies on the impact of triple combined exposure during early developmental stages.