Antiozonants and antioxidants are additives commonly used in the rubber industry to enhance the durability and performance of rubber products. Ozone, present in the atmosphere, can cause rubber to degrade over time th...Antiozonants and antioxidants are additives commonly used in the rubber industry to enhance the durability and performance of rubber products. Ozone, present in the atmosphere, can cause rubber to degrade over time through a process known as ozone cracking. These rubber additives are added to rubber compounds to protect against this degradation. They work by reacting with ozone, preventing it from attacking and breaking the molecular chains in the rubber, helping to maintain the structural integrity of the rubber product. It is now well known that 6PPD contributes to the extension of the service life of rubber products. However, recent studies have shown that 6PPD can be harmful to the environment, especially when end-of-life tyres (ELTs) are contaminated with the water. With the effect of ozone, 6PPD is converted to 6PPD quinone, which is toxic enough to kill some sensitive fish species such as Coho Salmon (Oncorhynchus kisutch). This study drew attention to new chemical compounds and natural products that can be used as antiozonants and antioxidants in the rubber industry instead of 6PPD. Although the scientific studies are promising, the fact that 6PPD is still used in production shows that more scientific studies and social awareness need to be developed in this area.展开更多
N-(1,3-Dimethylbutyl)-N0-phenyl-p-phenylenediamine(6PPD)and its oxidation derivative,6PPDquinone(6PPDQ),have been extensively detected in environmental and biological samples,raising significant concerns regarding the...N-(1,3-Dimethylbutyl)-N0-phenyl-p-phenylenediamine(6PPD)and its oxidation derivative,6PPDquinone(6PPDQ),have been extensively detected in environmental and biological samples,raising significant concerns regarding their chronic aquatic toxicity at environmentally relevant concentrations.However,the underlying mechanisms driving this chronic toxicity remain largely unexplored.Here we show that zebrafish exposed to 6PPD and 6PPDQ exhibit distinct toxicokinetic profiles,with 6PPD preferentially accumulating in the liver and 6PPDQ predominantly targeting the brain.Exposure to both compounds impaired zebrafish growth,induced hepatic damage,and disrupted locomotor behavior.Transcriptomic analysis of liver tissue revealed disturbances in lipid and carbohydrate metabolic pathways in both treatment groups,with distinct differences in gene expression patterns and biochemical responses between 6PPD and 6PPDQ.Specifically,both compounds downregulated peroxisome proliferator-activated receptor gamma(PPARγ)and elevated the expression of pro-inflammatory cytokines(TNF-α and IL-6).Molecular dynamics simulations and surface plasmon resonance experiments further demonstrated that hepatotoxicity was associated with direct binding of these compounds to PPARγ,a critical regulator of lipid metabolism and inflammation.Our findings highlight the hepatotoxic risks of 6PPD and 6PPDQ to aquatic life.Importantly,6PPDQ exhibited greater toxicity compared to 6PPD,emphasizing an urgent need for targeted environmental controls and regulatory actions to mitigate ecological harm and potential public health consequences.展开更多
Tire wear particles (TWPs) and associated contaminants, including microplastics, benzothiazoles, polycyclic aromatic hydrocarbons (PAHs), N-(1,3-dimethylbutyl)-N′-phenyl-p-phenylenediamine (6PPD), its byproduct 6PPD-...Tire wear particles (TWPs) and associated contaminants, including microplastics, benzothiazoles, polycyclic aromatic hydrocarbons (PAHs), N-(1,3-dimethylbutyl)-N′-phenyl-p-phenylenediamine (6PPD), its byproduct 6PPD-Quinone (6PPDQ), and heavy metals, are emerging pollutants in aquatic ecosystems. 6PPD, a commonly used tire antioxidant, reacts with ozone to form 6PPDQ, a toxic compound linked to acute mortality in aquatic species, such as Coho salmon. Despite its known impact, data on 6PPDQ in northeastern U.S. freshwater systems, including the Schuylkill River, remain limited. This study examined the spatiotemporal distribution of 6PPDQ in the Schuylkill River and assessed its environmental risks. It also identified key contamination sources and seasonal trends. We analyzed 6PPDQ concentrations at 16 locations across different seasons using the EPA 1634 Draft Method. Their relationship with traffic volume, population density, and tire-related industrial proximity was evaluated. Concentrations ranged from non-detectable to 17.95ng/L, with urban regions exhibiting higher levels. A moderate positive correlation (r=0.416) between 6PPDQ concentrations and Average Annual Daily Traffic (AADT) suggests traffic as a significant source. Population density and industrial proximity also contributed to contamination. Based on the EPA freshwater screening value (11ng/L), two sites posed high risks, while 88% were at medium risk. Risk levels peaked in October, when increased precipitation and reduced flow exacerbated contamination. These findings highlight the seasonal intensification of 6PPDQ pollution, emphasizing the need for stormwater management and long-term monitoring to mitigate risks and assess seasonal dynamics in freshwater systems.展开更多
N-(1,3-dimethylbutyl)-N′-phenyl-p-phenylenediamine(6PPD)is a widely used antioxidant and anti-ozonant in vehicle tires,commonly used to enhance rubber durability and performance.However,its environmental transformati...N-(1,3-dimethylbutyl)-N′-phenyl-p-phenylenediamine(6PPD)is a widely used antioxidant and anti-ozonant in vehicle tires,commonly used to enhance rubber durability and performance.However,its environmental transformation,particularly into 6PPD-Quinone(6PPDQ)through oxidative processes like ozonation,has emerged as a serious concern due to the acute toxicity in aquatic systems.6PPDQ has been linked to significant mortality in sensitive fish species,including coho salmon,at 41 ng/L con-centrations.This review synthesizes recent advances in the understanding of 6PPD degradation path-ways,including ozonation,photodegradation,hydrolysis,microbial metabolism,and atmospheric reactions.This paper systematically examines the formation and characterization of various TPs and outlines the methods used for their detection across water,air,soil,sediments,and biota.It also eval-uates the efficiency of treatment approaches such as advanced oxidation processes(AOPs),microbial degradation,adsorption,and membrane technologies for the removal of 6PPDQ from contaminated media.Additionally,emerging research on bio-based,synthetic,and engineered antioxidant alternatives to 6PPD is reviewed,with attention to their environmental compatibility and industrial feasibility.The paper concludes with a comprehensive outline of future research priorities focused on improving analytical detection,understanding long-term environmental fate and toxicity,optimizing treatment technologies,and guiding the development of safer alternatives.Collectively,this review provides a foundation for environmental risk assessment,regulatory policy development,and sustainable inno-vation in rubber manufacturing.展开更多
文摘Antiozonants and antioxidants are additives commonly used in the rubber industry to enhance the durability and performance of rubber products. Ozone, present in the atmosphere, can cause rubber to degrade over time through a process known as ozone cracking. These rubber additives are added to rubber compounds to protect against this degradation. They work by reacting with ozone, preventing it from attacking and breaking the molecular chains in the rubber, helping to maintain the structural integrity of the rubber product. It is now well known that 6PPD contributes to the extension of the service life of rubber products. However, recent studies have shown that 6PPD can be harmful to the environment, especially when end-of-life tyres (ELTs) are contaminated with the water. With the effect of ozone, 6PPD is converted to 6PPD quinone, which is toxic enough to kill some sensitive fish species such as Coho Salmon (Oncorhynchus kisutch). This study drew attention to new chemical compounds and natural products that can be used as antiozonants and antioxidants in the rubber industry instead of 6PPD. Although the scientific studies are promising, the fact that 6PPD is still used in production shows that more scientific studies and social awareness need to be developed in this area.
基金supported by the China Postdoctoral Science Foundation(No.2023M741216)Guangdong Basic and Applied Basic Research Foundation(No.2023A1515110978+3 种基金2024A1515012900)the National Natural Science Foundation of China(No.32401410)Research Fund Program of Guangdong-Hong Kong Joint Laboratory for Water Security(No.GHJLWS-07)Xiamen Key Laboratory of Intelligent Fishery(No.XMKLIF-OP202304).
文摘N-(1,3-Dimethylbutyl)-N0-phenyl-p-phenylenediamine(6PPD)and its oxidation derivative,6PPDquinone(6PPDQ),have been extensively detected in environmental and biological samples,raising significant concerns regarding their chronic aquatic toxicity at environmentally relevant concentrations.However,the underlying mechanisms driving this chronic toxicity remain largely unexplored.Here we show that zebrafish exposed to 6PPD and 6PPDQ exhibit distinct toxicokinetic profiles,with 6PPD preferentially accumulating in the liver and 6PPDQ predominantly targeting the brain.Exposure to both compounds impaired zebrafish growth,induced hepatic damage,and disrupted locomotor behavior.Transcriptomic analysis of liver tissue revealed disturbances in lipid and carbohydrate metabolic pathways in both treatment groups,with distinct differences in gene expression patterns and biochemical responses between 6PPD and 6PPDQ.Specifically,both compounds downregulated peroxisome proliferator-activated receptor gamma(PPARγ)and elevated the expression of pro-inflammatory cytokines(TNF-α and IL-6).Molecular dynamics simulations and surface plasmon resonance experiments further demonstrated that hepatotoxicity was associated with direct binding of these compounds to PPARγ,a critical regulator of lipid metabolism and inflammation.Our findings highlight the hepatotoxic risks of 6PPD and 6PPDQ to aquatic life.Importantly,6PPDQ exhibited greater toxicity compared to 6PPD,emphasizing an urgent need for targeted environmental controls and regulatory actions to mitigate ecological harm and potential public health consequences.
文摘Tire wear particles (TWPs) and associated contaminants, including microplastics, benzothiazoles, polycyclic aromatic hydrocarbons (PAHs), N-(1,3-dimethylbutyl)-N′-phenyl-p-phenylenediamine (6PPD), its byproduct 6PPD-Quinone (6PPDQ), and heavy metals, are emerging pollutants in aquatic ecosystems. 6PPD, a commonly used tire antioxidant, reacts with ozone to form 6PPDQ, a toxic compound linked to acute mortality in aquatic species, such as Coho salmon. Despite its known impact, data on 6PPDQ in northeastern U.S. freshwater systems, including the Schuylkill River, remain limited. This study examined the spatiotemporal distribution of 6PPDQ in the Schuylkill River and assessed its environmental risks. It also identified key contamination sources and seasonal trends. We analyzed 6PPDQ concentrations at 16 locations across different seasons using the EPA 1634 Draft Method. Their relationship with traffic volume, population density, and tire-related industrial proximity was evaluated. Concentrations ranged from non-detectable to 17.95ng/L, with urban regions exhibiting higher levels. A moderate positive correlation (r=0.416) between 6PPDQ concentrations and Average Annual Daily Traffic (AADT) suggests traffic as a significant source. Population density and industrial proximity also contributed to contamination. Based on the EPA freshwater screening value (11ng/L), two sites posed high risks, while 88% were at medium risk. Risk levels peaked in October, when increased precipitation and reduced flow exacerbated contamination. These findings highlight the seasonal intensification of 6PPDQ pollution, emphasizing the need for stormwater management and long-term monitoring to mitigate risks and assess seasonal dynamics in freshwater systems.
文摘N-(1,3-dimethylbutyl)-N′-phenyl-p-phenylenediamine(6PPD)is a widely used antioxidant and anti-ozonant in vehicle tires,commonly used to enhance rubber durability and performance.However,its environmental transformation,particularly into 6PPD-Quinone(6PPDQ)through oxidative processes like ozonation,has emerged as a serious concern due to the acute toxicity in aquatic systems.6PPDQ has been linked to significant mortality in sensitive fish species,including coho salmon,at 41 ng/L con-centrations.This review synthesizes recent advances in the understanding of 6PPD degradation path-ways,including ozonation,photodegradation,hydrolysis,microbial metabolism,and atmospheric reactions.This paper systematically examines the formation and characterization of various TPs and outlines the methods used for their detection across water,air,soil,sediments,and biota.It also eval-uates the efficiency of treatment approaches such as advanced oxidation processes(AOPs),microbial degradation,adsorption,and membrane technologies for the removal of 6PPDQ from contaminated media.Additionally,emerging research on bio-based,synthetic,and engineered antioxidant alternatives to 6PPD is reviewed,with attention to their environmental compatibility and industrial feasibility.The paper concludes with a comprehensive outline of future research priorities focused on improving analytical detection,understanding long-term environmental fate and toxicity,optimizing treatment technologies,and guiding the development of safer alternatives.Collectively,this review provides a foundation for environmental risk assessment,regulatory policy development,and sustainable inno-vation in rubber manufacturing.
