Toxicological Impact Research Articles

Possibilities and Limitations of ICP-Spectrometric Determination of the Total Content of Tin and Its Inorganic and Organic Speciations in Waters with Different Salinity Levels-Part 2: Separate Determination of Inorganic and Organic Speciations of Tin.

In this study, determination of the inorganic and organic forms of tin in waters of different salinities is considered. The possibility of the separation of speciations of tin using liquid-liquid extraction (LLE); precipitation with fluorides, iodides, ammonia, and iron (III) chloride; and sorption of organotin compounds (OTCs) was studied. The LLE and analyte precipitation methods proved to be ineffective. Inorganic and organic forms of tin were separated by the sorption of OTCs using silica gel sorbent Diapak C18. Under optimized conditions, a technique for the separate determination of the forms of tin in natural waters was developed. The technique combines hydride generation and microwave mineralization of solutions followed by ICP spectrometry. The inorganic forms of tin were determined after their solid-phase separation from organotin compounds. The lower limits of analyte quantification were 0.03 μg/L (ICP-MS) and 0.05 μg/L (ICP-OES), which provide separate determinations of inorganic and organic forms of tin in waters with different salinities. The content of OTCs in water was determined by subtracting the inorganic concentration from the total concentration of tin. The technique will allow a comprehensive assessment of the toxicological impact of tin speciations on the aquatic ecosystem.

Alterations of Bax/Bcl-2 ratio contribute to NaAsO2 induced thyrotoxicity in human thyroid follicular epithelial cells and SD rats

The environmental toxicant arsenic causes various human diseases and threatens millions of people worldwide. Recently, a limited number of studies have revealed that exposure to arsenic is associated with thyroid dysfunction, indicating its toxicological impact on the thyroid gland, however, its precise forms of damage and underlying mechanisms remain largely unknown. Here, we sought to observe the thyrotoxicity of sodium arsenite (NaAsO2) on human thyroid follicular epithelial cells (Nthy-ori 3–1) and SD rats, and explore the role of Bax/Bcl-2 ratio in the above process. Our results displayed that NaAsO2 exerted a dose-dependent inhibitory effect on the viability of Nthy-ori 3–1 cells. Alongside the increase doses of NaAsO2 exposure, morphological changes and elevated LDH levels were observed. Furthermore, apoptosis rates increased in a dose- and time-dependent manner, accompanied by a decrease in Bcl-2 and an opposite change in Bax expression. SD rats were treated with 0, 2.5, 5, and 10 mg/kg NaAsO2 for 36 weeks. Our findings revealed that NaAsO2 exposure resulted in arsenic accumulation in thyroid tissue, elevated ratio of Bax/Bcl-2, and histopathological changes of thyroid in rats, which accompanied by the decreased serum T3 and T4 levels and the increased serum TSH level. Furthermore, T3 and T4 levels were negatively correlated with Bax expression, whereas positively correlated with Bcl-2 expression. Collectively, our results suggest that NaAsO2 exposure induces cytotoxicity in Nthy-ori 3–1 cells, causes structural damages and dysfunction of thyroid in SD rats, in which the imbalance of Bax/Bcl-2 ratio may play a significant role.

P10-12: Toxicological impact of biogenic and anthropogenic secondary organic aerosols

P10-12: Toxicological impact of biogenic and anthropogenic secondary organic aerosols

Metoprolol elicits neurobehavioral insufficiency and oxidative damage in nontarget Nauphoeta cinerea nymphs.

Metoprolol, a drug for hypertension and cardiovascular diseases, has become a contaminant of emerging concern because of its frequent detection in various environmental matrices globally. The dwindling in the biodiversity of useful insects owing to increasing presence of environmental chemicals is currently a great interest to the scientific community. In the current research, the toxicological impact of ecologically relevant concentrations of metoprolol at 0, 0.05, 0.1, 0.25, and 0.5 μg/L on Nauphoeta cinerea nymphs following exposure for 42 consecutive days was evaluated. The insects' behavior was analyzed with automated video-tracking software (ANY-maze, Stoelting Co, USA) while biochemical assays were done using the midgut, head and fat body. Metoprolol-exposed nymphs exhibited significant diminutions in the path efficiency, mobility time, distance traveled, body rotation, maximum speed and turn angle cum more episodes, and time of freezing. In addition, the heat maps and track plots confirmed the metoprolol-mediated wane in the exploratory and locomotor fitness of the insects. Compared with control, metoprolol exposure decreased acetylcholinesterase activity in insects head. Antioxidant enzymes activities and glutathione level were markedly decreased whereas indices of inflammation and oxidative injury to proteins and lipids were significantly increased in head, midgut and fat body of metoprolol-exposed insects. Taken together, metoprolol exposure induces neurobehavioral insufficiency and oxido-inflammatory injury in N. cinerea nymphs. These findings suggest the potential health effects of environmental contamination with metoprolol on ecologically and economically important nontarget insects.

Rapid Chemical Screening of Microplastics and Nanoplastics by Thermal Desorption and Pyrolysis Mass Spectrometry with Unsupervised Fuzzy Clustering.

The transport and chemical identification of microplastics and nanoplastics (MNPs) are critical to the concerns over plastic accumulation in the environment. Chemically and physically transient MNP species present unique challenges for isolation and analysis due to many factors such as their size, color, surface properties, morphology, and potential for chemical change. These factors contribute to the eventual environmental and toxicological impact of MNPs. As analytical methods and instrumentation continue to be developed for this application, analytical test materials will play an important role. Here, a direct mass spectrometry screening method was developed to rapidly characterize manufactured and weathered MNPs, complementing lengthy pyrolysis-gas chromatography-mass spectrometry analysis. The chromatography-free measurements took advantage of Kendrick mass defect analysis, in-source collision-induced dissociation, and advancements in machine learning approaches for the data analysis of complex mass spectra. In this study, we applied Gaussian mixture models and fuzzy c-means clustering for the unsupervised analysis of MNP sample spectra, incorporating clustering stability and information criterion measurements to determine latent dimensionality. These models provided insight into the composition of mixed and weathered MNP samples. The multiparametric data acquisition and machine learning approach presented improved confidence in polymer identification and differentiation.

Avoidance behaviour and toxicological impact of sunscreens in the teleost Chelon auratus

There is increasing evidence that sunscreen, more specifically the organic ultra-violet filters (O-UVFs), are toxic for aquatic organisms. In the present study, we simulated an environmental sunscreen exposure on the teleost fish, Chelon auratus. The first objective was to assess their spatial avoidance of environmental concentrations of sunscreen products (i.e. a few μg.L−1 of O-UVFs). Our results showed that the fish did not avoid the contaminated area. Therefore, the second objective was to evaluate the toxicological impacts of such pollutants after 35 days exposure to concentrations of a few μg.L−1 of O-UVFs. At the individual level, O-UVFs increased the hepatosomatic index which could suggest pathological alterations of the liver or the initiation of the detoxification processes. At the cellular level, a significant increase of malondialdehyde was measured in the muscle of fish exposed to O-UVFs which suggests a failure of antioxidant defences and/or an excess of reactive oxygen species.

Toxicological assessment of pristine and degraded forms of graphene functionalized with MnOx nanoparticles using human in vitro models representing different exposure routes

The development of novel advanced nanomaterials (NMs) with outstanding characteristics for their use in distinct applications needs to be accompanied by the generation of knowledge on their potential toxicological impact, in particular, that derived from different occupational risk exposure routes, such as inhalation, ingestion, and skin contact. The harmful effects of novel graphene-metal oxide composites on human health are not well understood, many toxicological properties have not been investigated yet. The present study has evaluated several toxicological effects associated with graphene decorated with manganese oxide nanoparticles (GNA15), in a comparative assessment with those induced by simple graphene (G2), on human models representing inhalation (A549 cell line), ingestion (HT29 cell line) and dermal routes (3D reconstructed skin). Pristine and degraded forms of these NMs were included in the study, showing to have different physicochemical and toxicological properties. The degraded version of GNA15 (GNA15d) and G2 (G2d) exhibited clear structural differences with their pristine counterparts, as well as a higher release of metal ions. The viability of respiratory and gastrointestinal models was reduced in a dose-dependent manner in the presence of both GNA15 and G2 pristine and degraded forms. Besides this, all NMs induced the production of reactive oxygen species (ROS) in both models. However, the degraded forms showed to induce a higher cytotoxicity effect. In addition, we found that none of the materials produced irritant effects on 3D reconstructed skin when present in aqueous suspensions. These results provide novel insights into the potentially harmful effects of novel multicomponent NMs in a comprehensive manner. Furthermore, the integrity of the NMs can play a role in their toxicity, which can vary depending on their composition and the exposure route.

Toxicological Status of the Hydroethanolic Extract of <i>Piliostigma thonningii</i> Leaves in Female Wistar Rats

This study aims to evaluate the toxicological impact of Piliostigma thonningii leaves on liver and renal function in rats and the plant extract was screened for heavy metals. Rats were divided into four groups, comprising five animals each, with the control group receiving distilled water orally and the other groups receiving 50, 100, and 200 mg/kg doses of the plant extract, orally, for seven days. On the eighth day, animals were sacrificed, and liver and kidney function parameters were assessed. Heavy metal screening revealed the absence of chromium and nickel, while trace amounts of lead and cadmium were detected. The liver bodyweight ratio significantly increased (p<0.05) in rats treated with the plant extract at 100 and 200 mg/kg body weight. Liver functioning tests showed no significant (p>0.05) changes in total protein and albumin levels, suggesting no major adverse effects on protein metabolism or liver function. However, the significant (p<0.05) changes in Aspartate aminotransferase (AST), alanine aminotransferase (ALT), and Alkaline phosphatase (ALP) may be detrimental. Renal function tests revealed some variations, with significant (p<0.05) alterations in uric acid, creatinine, and urea levels which may affect renal function. The significant (p<0.05) decrease in phosphate ion and potassium ion levels further suggested potential side effects on renal functions.

Toxicological impact of microplastics and nanoplastics on humans: understanding the mechanistic aspect of the interaction.

Plastic is a pervasive material that has become an indispensable part of our daily lives and is used in various commercial products. However, plastic waste has significantly impacted the environment, accumulating in water and land ecosystems and harming all forms of life. When plastic degrades, it breaks down into smaller particles called microplastics (MPs), which can further breakdown into nanoplastics (NPs). Due to their small size and potential toxicity to humans, NPs are of particular concern. During the COVID-19 pandemic, the production of plastic had reached unprecedented levels, including essential medical kits, food bags, and personal protective equipment (PPE), which generate MPs and NPs when burned. MPs and NPs have been detected in various locations, such as air, food, and soil, but our understanding of their potential adverse health effects is limited. This review aims to provide a comprehensive overview of the sources, interactions, ecotoxicity, routes of exposure, toxicity mechanisms, detection methods, and future directions for the safety evaluation of MPs and NPs. This would improve our understanding of the impact of MPs and NPs on our health and environment and identify ways to address this global crisis.

Bioaccumulation and in vivo fate of toxic benzylalkyldimethylammonium chloride in rats via the radiotracer analysis

Benzylalkyldimethylammonium chloride (BAC), a quaternary ammonium compound (QAC), is utilized in industrial and biomedical applications for antimicrobial purposes. Since the coronavirus disease (COVID-19) outbreak, various types of BAC-containing household chemicals have been produced. BACs have several adverse effects; however, their biological uptake, translocation, and excretion in animal models (essential for better understanding in vivo behavior and toxicological impact) remain unclear. In this study, we performed the first biodistribution and whole-body imaging studies of BAC in male Sprague Dawley rats, using two different administration routes. Quantitative whole-body autoradiography (QWBA) data obtained for intranasal 14C-labeled BAC ([14C]C12-BAC) exposure showed substantial uptake values for the respiratory organs (e.g. 346 ng g−1 of lung at 3 h post administration) and the radiotracer was transported to other internal organs. The amount of radiotracer in the heart, adrenal gland, and pancreas were 198, 1410, and 186 ng g−1 tissue respectively at 168 h following exposure. Autoradiograms obtained after intravenous injection also showed high accumulation and slow excretion in these organs. The cumulative excretion analysis revealed that approximately 6.4% of the administered radioactivity remained in rats after a week. The results indicated that continuous inhalation exposure to BAC leads to potential toxic effects in extrapulmonary organs and the respiratory tract. Thus, the radiolabeling method utilized may help assess various synthetic QACs in living subjects.

Toxicological Effect of Green Tea (Camelia sinensis) on Haematological Parameters in Wistar Rats

Introduction: Green tea, derived from the leaves of Camellia sinensis, has gained significant attention due to its potential health benefits. It contains various bioactive compounds, such as polyphenols, flavonoids, and catechins, which have antioxidant, anti-inflammatory, and anticancer properties. Despite its widespread consumption and positive reputation, limited information is available regarding the potential toxicological effects of green tea. In this study, the toxicological impact of green tea extract on haematological parameters was investigated using Wistar rats as an animal model.
 Method: Forty-eight adult male rats were randomly divided into four groups (n=12 per group). The control group received a vehicle solution, while the treatment groups were orally administered different doses of green tea extract (low dose: 100 mg/kg, moderate dose: 200 mg/kg, high dose: 400 mg/kg) once daily for 28 consecutive days. Haematological analysis was performed at baseline (day 0) and on days 7, 14, 21, and 28 of the study. Blood samples were collected from the retro-orbital plexus under light isoflurane anaesthesia, and various haematological parameters were assessed using automated Hematology analyzers.
 Results: The results of the haematological analysis showed that the administration of green tea extract did not significantly affect haemoglobin levels, packed cell volume, red blood cell count, eosinophil count, lymphocyte count, and neutrophil count compared to the control group throughout the study period. However, the white blood cell (WBC) count and its differential count exhibited some variations among the treatment groups. The low and moderate doses of green tea extract resulted in a slight increase in the WBC count compared to the control group, although the difference was not statistically significant. On the other hand, the high dose of green tea extract led to a slight decrease in the WBC count compared to the control group. Regarding platelet count, the low and moderate doses of green tea extract resulted in a significant increase compared to the control group. In contrast, the high dose of green tea extract caused a significant decrease in platelet count.
 Conclusions: Based on the findings of this study, it can be concluded that the administration of green tea extract did not have significant adverse effects on the assessed haematological parameters in Wistar rats, except for some minor variations in the WBC count and platelet count at higher doses. These results suggest that green tea consumption may not cause significant haematological toxicity in rats. However, further studies are warranted to evaluate the long-term effects and safety of green tea consumption in humans.

Origin, dietary exposure, and toxicity of endocrine-disrupting food chemical contaminants: A comprehensive review

Endocrine-disrupting chemicals (EDCs) are a growing public health concern worldwide. Consumption of foodstuffs is currently thought to be one of the principal exposure routes to EDCs. However, alternative ways of human exposure are through inhalation of chemicals and dermal contact. These compounds in food products such as canned food, bottled water, dairy products, fish, meat, egg, and vegetables are a ubiquitous concern to the general population. Therefore, understanding EDCs' properties, such as origin, exposure, toxicological impact, and legal aspects are vital to control their release to the environment and food. The present paper provides an overview of the EDCs and their possible disrupting impact on the endocrine system and other organs.

(Eco)toxicological impact potential from inorganic substances in biosolids: Real data-based suggestions for regulatory improvements

Sewage sludge (SS) can be applied in soil for its nutrient recycling in agriculture and forestry, but the presence of toxic substances may prompt environmental and human health risks. Brazilian Resolution (CONAMA 498/2020) establishes thresholds for biosolid (i.e., treated sludge) quality for application in soils. We have evaluated the (eco)toxicological impact potential of such practice regarding the mentioned thresholds, and the concentration of inorganic substances in sludge from three different Wastewater Treatment Plants (WWTP) in São Paulo, Brazil. The assessment relied on USEtox®, a model that estimates the potential toxicological impact on humans and ecosystems. According to the evaluation of the regulatory thresholds, Zn are responsible for an ecotoxicological impact potential of 2.33E + 02 PAF.m3.day/kg (potentially affected species), which represents 48.2% of the aggregated impact for the scenario, while Hg potential is of 1.25E-04 cases/kg for non-cancerous diseases in humans – corresponding to 54% of this scenario. The assessment of the SS samples has confirmed to be critical for Zn, Hg, and Cr, and indicated potential ecotoxicological risks for concentrations found of Fe and Al, which do not have regulatory thresholds. Results were discussed along with related literature and international regulation. The study supports sustainable management of sewage in Brazil, and the analytical framework is replicable in other regions.

Microplastics and leachate materials from pharmaceutical bottle: An in vivo study in Donax faba (Marine Clam)

Most pharmaceuticals are stored in synthetic polymer bottles, manufactured using polyethylene as the base material. The toxicological impact of pharmaceutical container leachate was studied on Donax faba. Several organics and inorganics were identified from the leachate. The concentrations of heavy metals in the leachate was higher than standard reference value for drinking water. In the leachate treatment the protein concentration increased to 8.5% more than the control. The reactive oxygen species (ROS) level elevated by 3 folds and malondialdehyde (MDA) increased by 4.3% in comparison to the control. Superoxide dismutase (SOD) and catalase (CAT) showed a decrease by 14% and 70.5% respectively. The leachate affected the antioxidant machinery of D. faba. Similarly, these PET (polyethylene terephthalate) pharmaceutical containers could potentially leach additives into the drugs and may cause oxidative and metabolic damages to higher organisms including human beings.

Determination of mycotoxins and their dietary exposure assessment in pale lager beers using immunoaffinity columns and UPLC-MS/MS.

The use of contaminated raw materials can lead to the transfer of mycotoxins into the final product, including beer. This study describes the use of the commercially available immunoaffinity column 11+Myco MS-PREP® and UPLC-MS/MS for the determination of mycotoxins in pale lager-type beers brewed in Czech Republic and other European countries. The additional aim of the work was to develop, optimize and validate this analytical method. Validation parameters such as linearity, limit of detection (LOD), limit of quantification (LOQ), precision and accuracy were tested. The calibration curves were linear with correlation coefficients (R2 > 0.99) for all mycotoxins under investigation. The LOD ranged from 0.1 to 50ng/L and LOQ from 0.4 to 167ng/L. Recoveries of the selected analytes ranged from 72.2 to 101.1%, and the relative standard deviation under conditions repeatability (RSDr) did not exceed 16.3% for any mycotoxin. The validated procedure was successfully applied for the analysis of mycotoxins in a total of 89 beers from the retail network. The results were also processed using advanced chemometric techniques and compared with similar published studies. The toxicological impact was taken into account.

Synthesis and Characterization of Silica, Silver-Silica, and Zinc Oxide-Silica Nanoparticles for Evaluation of Blood Biochemistry, Oxidative Stress, and Hepatotoxicity in Albino Rats.

Evaluation of nanoparticles (NPs) for biomedical applications has received a lot of attention for detailed study on pharmacokinetics prior to clinical application. In this study, pure C-SiO2 (crystalline silica) NPs and SiO2 nanocomposites with silver (Ag) and zinc oxide (ZnO) were prepared by utilizing different synthesis routes such as sol-gel and co-precipitation techniques. The prepared NPs showed highly crystalline nature as confirmed by X-ray diffraction analysis where average crystallite sizes of 35, 16, and 57 nm for C-SiO2, Ag-SiO2, and ZnO-SiO2 NPs, respectively, were calculated. Fourier transform infrared analysis confirmed the presence of functional groups related to the chemicals and procedures used for sample preparation. Due to agglomeration of the prepared NPs, the scanning electron microscope images showed large particle sizes when compared to their crystalline sizes. The optical properties of the prepared NPs such as absorption were obtained with UV-Vis spectroscopy. For in vivo biological evaluation, albino rats, both male and female, kept in different groups were exposed to NPs with 500 μg/kg dose. Hematological, serum biochemistry, histo-architecture, oxidative stress biomarkers, and antioxidant parameters in liver tissues along with various biomarkers for the evaluation of erythrocytes were estimated. The results on hemato-biochemistry, histopathological ailments, and oxidative stress parameters exhibited 95% alteration in the liver and erythrocytes of C-SiO2 NPs-treated rats while 75 and 60% alteration in the liver tissues of rats due to exposure to Ag-SiO2 and ZnO-SiO2 NPs, respectively, when compared with the albino rats of the control (untreated) group. Therefore, the current study showed that the prepared NPs had adverse effects on the liver and erythrocytes causing hepatotoxicity in the albino rats in respective order C-SiO2 > Ag SiO2 > ZnO-SiO2. As the C-SiO2 NPs appeared to be the most toxic, it has been concluded that coating SiO2 on Ag and ZnO reduced their toxicological impact on albino rats. Consequently, it is suggested that Ag-SiO2 and ZnO-SiO2 NPs are more biocompatible than C-SiO2 NPs.

Synthesized partially unzipped carbon nanotubes and potential DNA/CNTs interactions

Carbon nanotubes (CNTs) are structurally considered to be graphene nano-ribbons (GNRs) that rolled up into seamless tubes. While CNTs nanotechnology is advancing, synthesis of GNRs from CNTs is sought after for precise and integrative graphene applications. Acid treatment of CNTs can generate longitudinal unzipping in an effective, large scale and economic approach. However, further understanding of CNTs-to-GNRs degradation, which mimics biodegradation molecular processes by oxidants, can also aid to assess toxicological impact of biodegraded CNTs. In this study, unzipping of multi-wall carbon nanotubes (MWCNTs) was established using a strong oxidizing agent. The influence of oxidation on the morphological, crystalline quality and dielectric properties was investigated. In particular, partial unzipping of CNTs was confirmed by transmission electron microscopy (TEM), and scanning electron microscopy (SEM) images. Broad band dielectric spectroscopy (BDS) was utilized to depict the influence of the applied frequency on the dielectric properties. GNRs exhibited a lag in the drop of capacitance and impedance to higher values of frequency with respect to the starting MWCNTs. Furthermore, DNA interactions with partially unzipped carbon nanotubes, were computationally assessed by employing molecular docking. The obtained potential DNA-CNT molecular conformations were illustrated and their biomolecular implications were discussed.

Histological and hematological changes to Clarias gariepinus juveniles exposed to acute doses of Emamectin benzoate in a static bioassay.

Emamectin benzoate (EMB) is a potent neurotoxic pesticide, extensively used in agriculture and aquaculture in Nigeria. The knowledge of its toxicological impact to C. gariepinus in Nigeria is scarce. Thus, the investigation was designed to uncover its 96 h LC50, safe level to aquatic media, histological impact on fish liver, gill and hematological changes in the blood parameters. 96 h LC50 was 0.34 mg L-1. Safe level of EMB was 0.034 mg L-1. Dose dependent liver degenerations were characterized by; Congestion of the central vein by inflammatory cells, pyknotic nuclei of hepatocytes, coagulation necrosis, focal necrosis, dilations of sinusoidal spaces and infiltration of periportal regions by inflammatory cells. Dose dependent changes in gill were characterized by; mucus secretion, shrinkage of secondary lamellae, hyperplasia, occlusion of secondary lamellae, degeneration of gill cartilage, necrosis of respiratory epithelia and erosion of secondary lamellae. Red blood cell indices decreased minimally at the end of the 96 h exposure. White blood cell count (WBCC), mean corpuscular volume (MCV) and mean corpuscular hemoglobin (MCH) were significantly (p ≤ 0.05) elevated in three treatments. Neutrophils decreased significantly (p ≤ 0.05), basophils, eosinophils and monocytes showed mixed tendencies. The findings of this investigation imply that C. garipinus exposed to EMB may cause dose and time-dependent changes in the liver and gill histology as well as alterations in the fish's hematological profile, all of which were harmful to the fish's health. To avoid negative effects on fish in nearby aquatic settings, it is advised that the use of EMB be monitored and limited.

75 Effect of Atmospheric Aging on Soot Particle Toxicity in Airway Epithelial-Endothelial Co-Culture Models at the Air–Liquid Interface

Abstract Secondary organic aerosols (SOAs) formed from anthropogenic or biogenic volatile precursors in the atmosphere substantially contribute to the ambient fine particulate matter (PM2.5) burden, which has been associated with adverse human health effects. However, there is only limited evidence of their differential toxicological impact. To study those effects, we generated different aerosols by atmospheric aging of volatile biogenic (β-pinene) or anthropogenic (naphthalene) precursors of SOA that condensed on soot particles (SPs). In-depth, physicochemical aerosol characterization revealed very similar physical properties for SOAβPIN-SP and SOANAP-SP, but distinct differences in chemical composition. For example, SOANAP-SP was associated with the formation of more oxidized and more aromatic SOAs with a higher oxidative potential compared to β-pinene. By exposing a co-culture model system consisting of lung epithelial cells (A549) and endothelial cells (EA.hy926) at the air-liquid interface to different aerosol concentrations, we aimed to discriminate toxicological effects. Integrated transcriptomic and metabolomics analysis revealed induction of stress-related airways remodeling and an early type I immune response, for the A549 cells, especially after the exposure to SOANAP-SP. The underlying EA.hy926 cells showed similar transcriptomic changes in early response genes and genes related to cardiovascular pathologies after exposure to both SOA types, however to a greater extent after SOANAP-SP. While fresh SP without coating by SOA evinced only minor changes in both cell lines. Altogether, this supports the assumption of a pivotal role of atmospheric chemistry and the chemical PM composition on the toxicological outcomes and highlights the importance of organic compounds on cellular effects.

Evaluation of stormwater microbiomes for the potential biodegradation of tire wear particle contaminants

Stormwater is a major source of many contaminants of emerging concern, which can be toxic to both aquatic and terrestrial organisms. This project aimed to identify novel biodegraders of toxic tire wear particle (TWP) contaminants associated with coho salmon mortality. This study has (i) characterized the prokaryotic communities of stormwater in both urban and rural settings; (ii) evaluated the ability of stormwater isolates to degrade two model TWP contaminants, hexa(methoxymethyl)melamine and 1,3-diphenylguanidine; and (iii) evaluated the toxicological impact of these model contaminants on the growth of six model bacteria. Rural stormwater possessed a diverse microbiome dominated by Oxalobacteraceae, Microbacteriaceae, Cellulomonadaceae, and Pseudomonadaceae taxa, while urban stormwater showed much less microbial diversity overall. Additionally, multiple stormwater isolates appeared capable of using model TWP contaminants as their sole carbon source. Each model contaminant was also found to alter growth patterns of model environmental bacteria including, with 1,3-DPG appearing more acutely toxic at high concentrations. This study identified several stormwater isolates that have the potential to be used as a sustainable solution to stormwater quality management.