We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Mixture toxicity of 6PPD-quinone and polystyrene nanoplastics in zebrafish
Summary
Researchers studied the combined toxicity of 6PPD-quinone, a toxic chemical from tire rubber, and polystyrene nanoplastics on zebrafish. While nanoplastics alone did not affect fish movement, the tire chemical caused hyperactivity, and the combination made this behavioral effect even worse. The study found that these co-occurring pollutants disrupted genes involved in brain signaling and fat metabolism, suggesting that real-world mixtures of plastic pollutants may be more harmful than individual ones.
Plastic pollution, including micro- and nanoplastics, is a growing concern. Tyre-wear particles (TWPs) are the second largest source of microplastics in the ocean following abrasion of synthetic fibres. In addition to the particles themselves, TWPs contain many harmful chemicals, including 6PPD. This chemical reacts with atmospheric ozone and forms the toxic compound 6PPD-quinone (6PPDq), which poses a danger to aquatic life. There is a knowledge gap in understanding risks associated with the combined toxicity of nanoplastics (NPs) and 6PPDq. The present study aimed to investigate the toxicity of NPs and 6PPDq on adult zebrafish using phenotypic (behaviour, histology) and transcriptomic endpoints. Zebrafish were exposed to four treatments: control (contaminant-free), 50 μg/L 6PPDq, 3 mg/L polystyrene (PS)-NPs, and a combination of 50 μg/L 6PPDq and 3 mg/L PS-NPs. We did not observe locomotory dysregulation in zebrafish exposed to NPs. However, we found significant hyperlocomotion in zebrafish exposed to 6PPDq and this effect was even more substantial after co-exposure with PS-NPs. This study explores the molecular mechanisms behind these effects, identifying genes associated with neurotransmitters and fatty acid metabolism that were dysregulated by the co-exposure. Transcriptomic analysis further showed that both 6PPDq and PS-NPs impacted cellular processes associated with sterol biosynthesis, cholesterol metabolism, and muscle tissue development. The effects on these mechanisms were stronger in co-exposed zebrafish, indicating a heightened risk to cellular integrity and mitochondrial dysfunction. These results highlight the significance of mixture toxicity when studying the effects of NPs and associated chemicals like 6PPDq.
Sign in to start a discussion.
More Papers Like This
Polystyrene microplastics alter the toxicity of 6PPD to zebrafish (Danio rerio) larvae
Researchers investigated the combined toxicity of polystyrene microplastics and the tire-derived chemical 6PPD on zebrafish larvae. Co-exposure produced synergistic toxic effects, significantly increasing oxidative stress markers and altering metabolic profiles beyond what either pollutant caused individually. The study found that microplastics increased the concentration of the toxic transformation product 6PPD-quinone in zebrafish, suggesting they can enhance the chemical hazard of tire-related pollutants in aquatic environments.
Enhanced neurotoxic effect of PCB-153 when co-exposed with polystyrene nanoplastics in zebrafish larvae
Researchers found that when zebrafish larvae were exposed to both polystyrene nanoplastics and the toxic chemical PCB-153 together, the neurological damage was significantly worse than from either pollutant alone. The combined exposure caused hyperactive swimming behavior and suppressed immune, brain, and detoxification pathways at the genetic level. This is concerning because nanoplastics and persistent organic pollutants frequently co-exist in the environment, meaning their real-world health effects on aquatic life and humans may be greater than studies of single pollutants suggest.
Adverse effects of polystyrene nanoplastic and its binary mixtures with nonylphenol on zebrafish nervous system: From oxidative stress to impaired neurotransmitter system
Researchers investigated the individual and combined effects of polystyrene nanoplastics and the industrial chemical nonylphenol on the zebrafish nervous system over 45 days. Both substances induced oxidative stress and disrupted neurotransmitter systems, with combined exposure generally producing more severe effects on glutamate metabolism and brain tissue damage. The study suggests that the interaction between nanoplastics and co-occurring environmental pollutants can amplify neurotoxic effects in fish.
Nanoplastics amplify 6PPD ocular toxicity in zebrafish
Researchers studied the combined effects of polystyrene nanoplastics and the tire-derived chemical 6PPD on zebrafish eye development. They found that co-exposure significantly amplified ocular toxicity compared to either contaminant alone, with nanoplastics acting as vectors that increased tissue accumulation of 6PPD and worsened oxidative stress. The study reveals that nanoplastics and tire chemicals can interact synergistically to damage visual development in aquatic vertebrates.
The Effects of Single and Combined Exposure to Polystyrene Nanoplastics and Copper on the Behavior of Adult Zebrafish
Researchers studied how polystyrene nanoplastics and copper ions affected zebrafish behavior when the fish were exposed to both pollutants simultaneously. The combination was more toxic than either pollutant alone, reducing the concentration needed to kill fish by up to 32%. Since nanoplastics and heavy metals commonly occur together in polluted water, their combined effects on aquatic life could increase the risks associated with consuming contaminated fish.