Chiral perspective evaluations: Enantioselective hydrolysis of 6PPD and 6PPD-quinone in water and enantioselective toxicity to Gobiocypris rarus and Oncorhynchus mykiss

Environment International, Год журнала: 2022, Номер 166, С. 107374 - 107374

Опубликована: Июнь 27, 2022

As a ubiquitous tire antidegradant, N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine (6PPD) is persistently released into the environment. It highly toxic to aquatic organisms, and its transformation product 6PPD-quinone (6PPD-Q), "very toxic" Oncorhynchus kisutch at median lethal concentration (LC50) of < 0.1 ng/mL. Notably, 6PPD 6PPD-Q are chiral compounds. Here, enantioselective evaluations, including hydrolysis acute toxicity were conducted after preparing enantiomer, confirming enantiomer absolute configuration establishing enantioseparation methods. In experiments, products 6PPD-Q, phenol, 4-[(1,3-dimethylbutyl)amino]- (4-DBAP) 4-hydroxydiphenylamine (4-HDPA) detected. different water solutions, 4-DBAP 4-HDPA was very fast (0.87-107 h), while half-lives (12.8-16.3 d) significantly longer than (4.83-64.1 h). At enantiomeric level, no conversion occurred. R-6PPD generated R-6PPD-Q, S-6PPD S-6PPD-Q, formation rate S-6PPD-Q 1.77 times faster R-6PPD-Q. terms toxicity, China-specific Gobiocypris rarus (LC50, 162-201 ng/mL), it had difference. 1.66-4.31 ng/mL) mykiss, which commercial importance, toxicities rac-6PPD-Q 1.9 2.6 higher Furthermore, concentrations R-6PPD-Q in solutions LC50 values O. species-specific, should raise concern. These results provide important information for environmental risk assessments especially from perspective enantiomers.

Язык: Английский

---

Tire-rubber related pollutant 6-PPD quinone: A review of its transformation, environmental distribution, bioavailability, and toxicity

Journal of Hazardous Materials, Год журнала: 2023, Номер 459, С. 132265 - 132265

Опубликована: Авг. 15, 2023

Язык: Английский

---

Exposure to the Tire Rubber-Derived Contaminant 6PPD-Quinone Causes Mitochondrial Dysfunction In Vitro

Environmental Science & Technology Letters, Год журнала: 2022, Номер 9(9), С. 765 - 771

Опубликована: Авг. 4, 2022

N-(1,3-Dimethylbutyl)-N′-phenyl-p-phenylenediamine-quinone (6PPD-quinone), a rubber tire oxidation product found in road runoff, is highly and acutely toxic to selected salmonids including coho salmon, brook trout, rainbow trout but not other fish species invertebrates studied date. Sensitive displayed increased ventilation gasping, suggesting possible impact on respiration. Here, adherent cell lines RTL-W1 RTgill-W1 were exposed 5–80 μg/L 6PPD-quinone, cytotoxicity, oxygen consumption rate (OCR), biotransformation of 6PPD-quinone measured assess the ability uncouple mitochondrial respiration vitro. cells sensitive exposure did result significant impacts cytotoxicity or OCR. In contrast, demonstrated decreased viability at 80 2-fold increase OCR 20 μg/L. Effects appear be partly driven by toxicokinetic differences where incubation with led almost quantitative conversion into suspected hydroxy-metabolite, which was observed cells. Exposure studies primary cultures gill indicated that uncoupling electron transport chain. Together, these findings suggest toxicity might tissue-specific disruption

Язык: Английский

---

Transformation Products of Tire Rubber Antioxidant 6PPD in Heterogeneous Gas-Phase Ozonation: Identification and Environmental Occurrence

Environmental Science & Technology, Год журнала: 2023, Номер 57(14), С. 5621 - 5632

Опубликована: Март 30, 2023

6PPD, a tire rubber antioxidant, poses substantial ecological risks because it can form highly toxic quinone transformation product (TP), 6PPD-quinone (6PPDQ), during exposure to gas-phase ozone. Important data gaps exist regarding the structures, reaction mechanisms, and environmental occurrence of TPs from 6PPD ozonation. To address these gaps, ozonation was conducted over 24–168 h were characterized using high-resolution mass spectrometry. The probable structures proposed for 23 with 5 subsequently standard-verified. Consistent prior findings, 6PPDQ (C18H22N2O2) one major in (∼1 19% yield). Notably, not observed 6QDI (N-(1,3-dimethylbutyl)-N′-phenyl-p-quinonediimine), indicating that formation does proceed through or associated TPs. Other included multiple C18H22N2O C18H22N2O2 isomers, presumptive N-oxide, N,N′-dioxide, orthoquinone structures. Standard-verified quantified roadway-impacted samples, total concentrations 130 ± 3.2 μg/g methanol extracts tread wear particles (TWPs), 34 4 μg/g-TWP aqueous TWP leachates, 2700 1500 ng/L roadway runoff, 1900 1200 creeks. These demonstrate are likely an important ubiquitous class contaminants environments.

Язык: Английский

---

Exposure to 6-PPD Quinone at Environmentally Relevant Concentrations Causes Abnormal Locomotion Behaviors and Neurodegeneration in Caenorhabditis elegans

Environmental Science & Technology, Год журнала: 2023, Номер 57(12), С. 4940 - 4950

Опубликована: Март 13, 2023

6-PPD quinone (6-PPDQ) can be transformed from through ozonation. Nevertheless, the potential neurotoxicity of 6-PPDQ after long-term exposure and underlying mechanism are largely unclear. In Caenorhabditis elegans, we here observed that 0.1–10 μg/L caused several forms abnormal locomotion behaviors. Meanwhile, neurodegeneration D-type motor neurons was in 10 6-PPDQ-exposed nematodes. The associated with activation Ca2+ channel DEG-3-mediated signaling cascade. this cascade, expressions deg-3, unc-68, itr-1, crt-1, clp-1, tra-3 were increased by 6-PPDQ. Moreover, among genes encoding neuronal signals required for control stress response, jnk-1 dbl-1 decreased 6-PPDQ, daf-7 glb-10 RNAi jnk-1, dbl-1, daf-7, resulted susceptibility to toxicity decreasing locomotory ability inducing neurodegeneration, suggesting JNK-1, DBL-1, DAF-7, GLB-10 also induction neurotoxicity. Molecular docking analysis further demonstrated binding DEG-3, GLB-10. Together, our data suggested risk at environmentally relevant concentrations causing organisms.

Язык: Английский

---

Screening p-Phenylenediamine Antioxidants, Their Transformation Products, and Industrial Chemical Additives in Crumb Rubber and Elastomeric Consumer Products

Environmental Science & Technology, Год журнала: 2023, Номер 57(7), С. 2779 - 2791

Опубликована: Фев. 9, 2023

Recently, roadway releases of

Язык: Английский

---

Environmental Occurrence and Toxicity of 6PPD Quinone, an Emerging Tire Rubber-Derived Chemical: A Review

Environmental Science & Technology Letters, Год журнала: 2023, Номер 10(10), С. 815 - 823

Опубликована: Сен. 1, 2023

N-(1,3-Dimethylbutyl)-N′-phenyl-p-phenylenediamine (6PPD) is a chemical added to tires prevent their oxidative degradation. 6PPD highly reactive with ozone and oxygen, leading the formation of transformation products such as quinone (6PPDQ) on tire surfaces and, subsequently, in road wear particles. 6PPDQ toxicant that has been found roadway runoff receiving water systems. Its presence municipal stormwater led acute mortality coho salmon during migration urban creeks reproduce, generating global interest studying its occurrence toxicity environment. This review aims provide critical overview current state knowledge 6PPDQ, assisting researchers policymakers understanding potential impacts this emerging environment human health. As there are many unanswered questions surrounding further research needed. highlights importance including regulations for 6PPD, well all synthetic chemicals concern.

Язык: Английский

---

Acute Toxicity of 6PPD‐Quinone to Early Life Stage Juvenile Chinook (Oncorhynchus tshawytscha) and Coho (Oncorhynchus kisutch) Salmon

Environmental Toxicology and Chemistry, Год журнала: 2023, Номер 42(4), С. 815 - 822

Опубликована: Янв. 24, 2023

Abstract The breakdown product of the rubber tire antioxidant N ‐(1,3‐dimethylbutyl)‐ N' ‐phenyl‐ p ‐phenylenediamine‐quinone (6PPD)‐6‐PPD‐quinone has been strongly implicated in toxic injury and death coho salmon ( Oncorhynchus kisutch ) urban waterways. Whereas recent studies have reported a wide range sensitivity to 6PPD‐quinone several fish species, little is known about risks Chinook tshawytscha ), primary prey endangered Southern Resident killer whales Orcinus orca subject much concern. face numerous conservation threats Canada United States, with many populations assessed as either or threatened. We evaluated acute toxicity newly feeding (~3 weeks post swim‐up) juvenile coho. Juvenile were exposed for 24 h under static conditions five concentrations 6PPD‐quinone. 3 orders magnitude more sensitive compared Chinook, 24‐h median lethal concentration (LC50) estimates 41.0 than 67 307 ng/L, respectively. LC50 was 2.3‐fold lower what previously 1+‐year‐old (95 ng/L), highlighting value evaluating age‐related differences this tire‐related chemical. Both species exhibited typical symptomology (gasping, increased ventilation, loss equilibrium, erratic swimming), that symptomatic generally exhibiting mortality. values derived from our study are below measured salmon‐bearing waterways, suggesting potential population‐level consequences waters. higher relative merits further investigation, including population‐relevant sublethal effects. Environ Toxicol Chem 2023;42:815–822. © 2023 His Majesty King Right Authors. Environmental Toxicology Chemistry published by Wiley Periodicals LLC on behalf SETAC. Reproduced permission Minister Fisheries Oceans Canada.

Язык: Английский

---

Where the rubber meets the road: Emerging environmental impacts of tire wear particles and their chemical cocktails

The Science of The Total Environment, Год журнала: 2024, Номер 927, С. 171153 - 171153

Опубликована: Март 7, 2024

About 3 billion new tires are produced each year and about 800 million become waste annually. Global dependence upon from natural rubber petroleum-based compounds represents a persistent complex environmental problem with only partial often-times, ineffective solutions. Tire emissions may be in the form of whole tires, tire particles, chemical compounds, which is transported through various atmospheric, terrestrial, aquatic routes built environments. Production use generates multiple heavy metals, plastics, PAH's, other that can toxic alone or as cocktails. Used require storage space, energy intensive to recycle, generally have few post-wear uses not also potential sources pollutants (e.g., crumb rubber, pavements, burning). particles emitted during major component microplastics urban runoff source unique highly potent substances. Thus, represent ubiquitous pollutant requires comprehensive examination develop effective management remediation. We approach issue pollution holistically by examining life cycle across production, emissions, recycling, disposal. In this paper, we synthesize recent research data human health risks associated use, disposal discuss gaps our knowledge fate transport, well toxicology leachates. examine remediation approaches for addressing exposure tires. consider three levels: their state, particulates, mixture Finally, information understanding outline key questions improve ability manage remediate pollution.

Язык: Английский

---

Urine Excretion, Organ Distribution, and Placental Transfer of 6PPD and 6PPD-Quinone in Mice and Potential Developmental Toxicity through Nuclear Receptor Pathways

Environmental Science & Technology, Год журнала: 2023, Номер 57(36), С. 13429 - 13438

Опубликована: Авг. 29, 2023

The rubber antioxidant 6PPD has gained significant attention due to its highly toxic transformation product, 6PPD-quinone (6PPDQ). Despite their detection in urines of pregnant women, the placental transfer and developmental toxicity 6PPDQ are unknown. Here, we treated C57Bl/6 mice with 4 mg/kg or investigate urine excretion transfer. Female male exhibited sex difference profiles 6PPDQ. Urine concentrations were one order magnitude lower than those 6PPD, suggesting higher bioaccumulation In from embryonic day 11.5 15.5, showed ∼1.5–8 times placenta, embryo body, brain, Using vitro dual-luciferase reporter assays, revealed that activated human retinoic acid receptor α (RARα) retinoid X (RXRα) at as low 0.3 μM, which was ∼10-fold detected urines. RXRα 1.2 μM. These results demonstrate exposure risks during pregnancy emphasize need for further toxicological epidemiological investigations.

Язык: Английский

---