Long-term exposure to Volatile Organic Compounds (VOCs) is a health risk for citizens. In this study, the cumulative health risk of exposure to VOCs in Tehran was assessed by investigating the concentration of these pollutants in ambient air in a five-year period. Health risk assessment was calculated by the quantitative method and the carcinogenic risk level was determined using the lifetime carcinogenic risk (LCR) method. The average concentration of benzene, toluene, ortho-xylene, and ethylbenzene was 1.4-1.8, 4.8-5.4, 5-6.5, and 3.6-4 ppb, respectively. Although HQ was not greater than 1, but it was very close in the case of benzene, ortho-xylene, meta-xylene, and para-xylene. Benzene and ethylbenzene had the largest effect in the assessed health risk. So the long-term exposure of Tehran citizens to VOCs has serious health consequences for them, which could be different according to the exposure time and spatial variations.

Toluene is a widely used solvent whose many toxic effects include neurological and hematological damage. This study reviewed evidence about the effects of toluene exposure on platelet count in humans. Three electronic databases and a digital library of theses and dissertations were searched using a specific strategy, yielding 64 articles, of which 14 were selected. These studies assessed a total of 15,759 participants, including 13,297 exposed individuals, mainly women exposed in an environmental setting. The major findings were: (1) conflicting results (positive, inverse, or no association), (2) cross-contamination with other substances, which impaired assessment of the relationship, and (3) a lack of studies. Thus, further research is needed on this topic, especially toluene exposure in isolation from associated substances.
O tolueno é um solvente amplamente utilizado com múltiplos efeitos tóxicos, sobretudo sobre o sistema nervoso central, assim como efeitos hematológicos. Este estudo foi conduzido para revisar a evidência presente na literatura sobre a exposição humana ao tolueno e seu efeito na contagem de plaquetas. Em 3 bases de dados eletrônicas e 1 biblioteca digital de teses e dissertações foram pesquisadas utilizando uma estratégia de busca específica, da qual resultaram 64 artigos, dos quais 14 foram selecionados. Estes avaliaram 15.759 pessoas, com 13.297 indivíduos expostos, compostos principalmente de mulheres em um cenário ambiental. Foram encontrados 3 grandes resultados, os quais incluem a presença de relações conflitantes (positiva, inversa, sem associação), a presença frequente de outras substâncias afetando a análise da relação, e a falta de estudos. Portanto, nós recomendamos mais pesquisas no tópico, com ênfase na exposição ao tolueno sem substâncias associadas.

In this study, a string of Cr-Mn co-modified activated coke catalysts (XCryMn1-y/AC) were prepared to investigate toluene and Hg0 removal performance. Multifarious characterizations including XRD, TEM, SEM, in situ DRIFTS, BET, XPS and H2-TPR showed that 4%Cr0.5Mn0.5/AC had excellent physicochemical properties and exhibited the best toluene and Hg0 removal efficiency at 200℃. By varying the experimental gas components and conditions, it was found that too large weight hourly space velocity would reduce the removal efficiency of toluene and Hg0. Although O2 promoted the abatement of toluene and Hg0, the inhibitory role of H2O and SO2 offset the promoting effect of O2 to some extent. Toluene significantly inhibited Hg0 removal, resulting from that toluene was present at concentrations orders of magnitude greater than mercury\'s or the catalyst was more prone to adsorb toluene, while Hg0 almost exerted non-existent influence on toluene elimination. The mechanistic analysis showed that the forms of toluene and Hg0 removal included both adsorption and oxidation, where the high-valent metal cations and oxygen vacancy clusters promoted the redox cycle of Cr3+ + Mn3+/Mn4+ ↔ Cr6+ + Mn2+, which facilitated the conversion and replenishment of reactive oxygen species in the oxidation process, and even the CrMn1.5O4 spinel structure could provide a larger catalytic interface, thus enhancing the adsorption/oxidation of toluene and Hg0. Therefore, its excellent physicochemical properties make it a cost-effective potential industrial catalyst with outstanding synergistic toluene and Hg0 removal performance and preeminent resistance to H2O and SO2.

A series of Mn and Fe metal oxide catalysts loaded onto USY, as well as single metal oxides, were prepared and characterized. The effects of interactions between the catalytic components and the introduction of gas phase NO on the catalytic ozonation of toluene were investigated. Characterization showed that there existed strong interactions between MnOx, FeOx, and USY, which enhanced the content of oxygen vacancies and acid sites of the catalysts and thus boosted the generation of reactive oxygen species and the adsorption of toluene. The MnFeOx-USY catalyst with MnOx and FeOx dimetallic oxides exhibited the most excellent performance of catalytic ozonation of toluene. On the other hand, the presence of NOx in reaction gas mixtures significantly promoted both toluene conversion and mineralization, which was attributed to the formation of nitrate species on the catalysts surface and thus the increase of both acid sites and toluene oxidation sites. Meanwhile, the reaction mechanism between O3 and C7H8 was modified in which the strong interactions between MnOx, FeOx, and USY accelerated the reaction progress based on the L-H route. In addition, the formation of the surface nitrate species not only promoted reaction progress following the L-H route but also resulted in the occurrence of the reaction via the E-R route.

UNASSIGNED: Numerous physical and chemical agents can induce destructive effects on the brain tissue. Noise and toluene, which are some of these harmful agents, have significant adverse effects on the brain tissue. This work aimed to investigate the neurotoxic changes induced by co-exposure to toluene and noise.
UNASSIGNED: A total of 24 male white New Zealand rabbits were randomly segregated into four groups, including toluene exposure, noise exposure, co-exposure to noise and toluene, and control. This in vivo study tested the neurotoxic effects of exposure to 1000 ppm toluene and 100 dB noise during two weeks (8 h/day). The serum levels of brain-derived neurotrophic factor-α (BDNF-α), malondialdehyde (MDA), glutathione peroxidase (GPx), superoxide dismutase (SOD), and catalase and total antioxidant capacity (TAC) values in the brain tissue were measured. Moreover, hematoxylin and eosin (H&E) staining was utilized for brain pathological analysis.
UNASSIGNED: Exposure to noise increased TAC values in the cerebral cortex. Co-exposure to toluene and noise increased the serum levels of BDNF-α. Nevertheless, exposure to noise decreased the levels of BDNF-α in serum. On the other hand, histopathological examinations using H&E staining exhibited that different signs of inflammation, such as lymphocyte infiltration, pyknosis, vacuolization, and chromatolysis were induced by exposure to noise and toluene in the cerebellum, hippocampus, and frontal section in the brain tissue. In addition, simultaneous exposure to toluene and noise induced antagonistic and synergistic changes in some neurotoxic parameters.
UNASSIGNED: Exposure to noise and toluene, which caused inflammation in the brain tissue cells, could be a noticeable risk factor for the neurological system.
UNASSIGNED: Exposure to noise increased total antioxidant capacity.Exposure to toluene decreased brain-derived neurotrophic factor-α.Exposure to noise decreased brain-derived neurotrophic factor-α.Co-exposure to noise and toluene increased brain-derived neurotrophic factor-α.Noise and toluene induced some histopathological effects on the brain tissue.
UNASSIGNED: The brain tissue can be adversely affected by various agents, including noise and toluene. This study aimed to examine the effects of simultaneous exposure to noise and toluene on the nervous system. Twenty-four healthy male white New Zealand rabbits were randomly divided into four groups: control, noise, toluene, and simultaneous exposure to noise and toluene. The study involved a two-week in-vivo experiment, subjecting the rabbits to 100 dB noise and 1000 ppm toluene for eight hours per day. This study showed that exposure to noise and toluene changed different parameters relating to the neurological system. Furthermore, noise and toluene induced some adverse effects on the brain tissue. This study suggested that exposure to noise and toluene can lead to harmful effects on the brain tissue, posing a significant risk to the neurological system.

Here, the optical properties of the Nafion polymer membrane containing colloidal CdSe/CdS/ZnS nanocrystals embedded by diffusion have been studied. The CdSe/CdS/ZnS nanocrystals have a core/shell/shell appearance. All experiments were carried out at room temperature (22 ± 2) °C. A toluene solution was used to provide mobility to the active sulfone groups of the Nafion membrane and to embed the nanocrystals inside the membrane. The diffusion process of colloidal CdSe/CdS/ZnS nanocrystals into Nafion proton exchange membrane has resulted in a new molecular complex \"Nafion-colloidal CdSe/CdS/ZnS nanocrystals\". The kinetics of the nanocrystals embedding into the membrane matrix was investigated using luminescence analysis and absorption spectroscopy techniques. The embedding rate of CdSe/CdS/ZnS nanocrystals into the Nafion polymer membrane was approximately 4·10-3 min-1. The presence of new luminescence centers in the membrane was proved independently by laser emission spectroscopy. The luminescence spectrum of the resulting molecular complex contains intensity maxima at wavelengths of 538, 588, 643 and 700 nm. The additional luminescence maximum observed at the 643 nm wavelength was not recorded in the original membrane, solvent or in the spectrum of the semiconductor nanoparticles. The luminescence maximum of the colloidal CdSe/CdS/ZnS nanocrystals was registered at a wavelength of 634 nm. The intensity of the luminescence spectrum of the membrane with embedded nanocrystals was found to be higher than the intensity of the secondary emission peak of the initial nanocrystals, which is important for the practical use of the \"Nafion-colloidal nanocrystals\" complex in optical systems. The lines contained in the luminescence spectrum of the membrane, which has been in solution with colloidal nanocrystals for a long time, registered upon its drying, show the kinetics of the formation of the molecular complex \"Nafion membrane-nanocrystals\". Colloidal nanocrystals located in the Nafion matrix represent an analog of a luminescent transducer.

BACKGROUND: Volatile organic compounds (VOC) are major indoor air pollutants. Previous studies reported an association between VOC exposure and allergic diseases. Here, we aimed to explore the relationship between VOC exposure and atopic dermatitis (AD) in adults.
METHODS: We prospectively enrolled 31 adult AD patients and 11 healthy subjects as controls. Urine metabolite levels of VOCs, including 1.3-butadiene, acrylamide, benzene, toluene, and xylene, were all determined with liquid chromatography-mass spectrometry. The relationship between AD and log-transformed urine levels of VOC metabolites were examined using a multivariate linear regression model adjusted for age and sex. We also treated mouse bone marrow-derived cells (BMMCs) with 1,3-butadiene and toluene and measured the release of β-hexosaminidase.
RESULTS: Our results demonstrated that creatinine-corrected urine levels of N-Acetyl-S- (3,4-dihydroxybutyl)-L-cysteine (DHBMA), N-Acetyl-S-(2-carbamoyl-2-hydroxyethyl)-L-cysteine (GAMA), and N-Acetyl-S-(benzyl)-L-cysteine (BMA) were all elevated in AD patients compared with controls. In a multivariate linear regression model, creatinine-corrected urine levels of BMA (a toluene metabolite) and DHBMA (a 1,3-butadiene metabolite) appeared elevated in AD patients, although statistical significance was not reached after correction for multiple comparisons. In addition, 1,3-butadiene and toluene could stimulate BMMCs to degranulate as much as compound 48/80.
CONCLUSIONS: Some VOCs, such as 1,3-butadiene and toluene, might be associated with AD pathogenesis in adults.

With the increasing consumption of organic solvents in chemical and pharmaceutical industries, the environment pollution of volatile organic compounds (VOCs) has become an urgent problem. Therefore, the rapid-visual detection method is of great significance in the analysis of VOCs. Based on the fluorescence quenching/enhancement mechanism of carbon quantum dots (CQDs), with the help of carboxymethyl cellulose membrane with porous and large specific surface area structure, a series of green CQDs@carboxymethyl cellulose composite film (CQDs@CMC composite film) was prepared in this study. In the typical-targeted pollutants (toluene) detection application, a fluorescence spectroscopy method was established which could achieve the high sensitivity and strong specificity detection. The mainly conclusions were as follows: The fluorescence spectrometric detection method for toluene: A kind of hydrophobic Lmi/Bet CQDs@CMC composite film was prepared and characterized with imidazole/betaine CQDs and porous carboxymethyl cellulose composite film as raw materials. The toluene detection performance was studied, and the recognition mechanism was explored. The results showed that toluene enhanced the fluorescence of Lmi/Bet CQDs@CMC composite film. The fluorescence intensity of composite films was proportional to toluene concentration when the toluene concentration ranged from 200 to 2200 mg/L. The detection limit of toluene was 1.169 mg/L, which provides a theoretical basis for the detection of toluene by fluorescence spectrometry.

The preparation of nitrogen-doped TiO2 (i.e., N-TiO2) catalysts is a highly effective option to improve the photocatalytic activity of TiO2. Nonetheless, relatively little is known about the effects of dopant precursors selected for their preparation with regard to the photocatalytic efficacy. In this study, three types of dopants are selected and used as N sources (urea (U), melamine (M), and aqueous ammonia (A)) for N-TiO2 samples with the name codes of NTU, NTM, and NTA, respectively. The photocatalytic efficacy of these N-TiO2 samples is examined against toluene in a packed bed flow reactor. Under optimal conditions (e.g., relative humidity (RH) = 20% and gas hourly space velocity (GHSV) = 1698 h-1), the superiority of NTA is evident over others with a quantum efficiency (QE) of 7.03 × 10-4 molecules photon-1, a space time yield (STY) of 1.38 × 10-4 molecules photon-1 mg-1, and a specific clean air delivery rate (SCADR) of 1148.8 L g-1 h-1. The analysis based on in-situ diffuse reflectance infrared Fourier transform spectroscopy and gas chromatography-mass spectrometry confirms the formation of several intermediates such as benzyl alcohol, benzaldehyde, benzoic acid, and alkane species through ring opening reactions. In addition, the prepared NTA photocatalyst exhibits the highest toluene photocatalytic degradation efficiency among all TiO2-based catalysts surveyed to date. Overall, this study offers as a valuable guideline for the development of advanced TiO2 catalytic systems (such as N-TiO2) for the treatment of aromatic hydrocarbons in indoor air.

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