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1.
J Environ Sci (China) ; 109: 26-35, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34607671

RESUMO

Microcosmic experiments were performed under a simulated marine environment to investigate the natural attenuation of C9 aromatics using nine components (propylbenzene, isopropylbenzene, 2-ethyltoluene, 3-ethyltoluene, 4-ethyltoluene, 1,2,3-trimethylbenzene, 1,2,4-trimethylbenzene, 1,3,5-trimethylbenzene, and indene). This research aims to assess the contribution of biodegradation and abiotic activity to total attenuation of C9 aromatics and ascertain the changes in the comprehensive toxicity of seawater in the natural environment. The process of natural attenuation indicates the agreement with pseudo-first-order kinetics for all nine components in microcosmic experiments. The half-lives of the nine main compounds in C9 aromatics ranged between 0.34 day and 0.44 day under optimal conditions. The experiments showed that the natural attenuation of nine aromatic hydrocarbons mainly occurred via abiotic processes. Seawater samples significantly inhibited the luminescence of P. phosphoreum (the luminescence inhibition ratio reached 100%) at the beginning of the experiment. In addition, the toxicity declined slowly and continued for 25 days. The attenuation kinetics and changes in toxicity could be applied to explore the natural attenuation of C9 aromatics in the marine environment.


Assuntos
Benzeno , Água do Mar , Biodegradação Ambiental , Cinética
2.
Anal Chim Acta ; 1179: 338835, 2021 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-34535252

RESUMO

Although electron impact ionization (EI) remains the standard ionization source for GC-MS, it presents extensive fragmentation as its main limitation. The potential of a novel plasma-based soft ionization source named controlled-atmosphere flexible microtube plasma (CA-FµTP) has been evaluated in this work for the determination of monoaromatic volatile BTEX group (namely benzene, toluene, ethylbenzene, and o-, m- and p-xylenes) in olive oil, based on headspace technique. The obtained results show an attractive advantage over EI due to no fragmentation was observed. A nitrosated ion [M + NO]+ is obtained as the most abundant species. Thus, the BTEX mass spectrum identification can be carried out without major effort. In general, the sensitivity for CA-FµTP was comparable to those obtained by EI, achieving LODs ranged from 0.6 to 1.0 µg kg-1. The potential usefulness of GC-CA-FµTP-MS for the detection of BTEX was demonstrated by analyzing olive oil samples and identifying traces of these compounds in one sample. Therefore, the proposed plasma-based soft ionization is suitable for BTEX analysis in fatty complex matrixes as olive oil.


Assuntos
Derivados de Benzeno , Xilenos , Atmosfera , Benzeno/análise , Derivados de Benzeno/análise , Cromatografia Gasosa-Espectrometria de Massas , Espectrometria de Massas , Azeite de Oliva , Tolueno/análise , Xilenos/análise
3.
J Hazard Mater ; 416: 126208, 2021 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-34492969

RESUMO

Aromatic hydrocarbon is a representative type of VOCs, which causes adverse effects to human health. The degradation stability of aromatic hydrocarbon is of vital importance to commercializing a photocatalyst for its practical application. The most commonly used titanium dioxide photocatalyst (P25) was deactivated rapidly in the photocatalytic VOCs degradation process. In this work, the indium hydroxide (In(OH)3) photocatalyst was developed, which exhibited not only higher efficient activity but also ultra-stable stability for degradation of benzene, toluene and their mixtures. The origin of the activity difference between two catalysts was investigated by combined experimental and theoretical ways. Based on in situ DRIFTS and GC-MS, it was revealed that benzoic acid and carbonaceous byproducts were specifically formed and accumulated on P25, which were responsible for deactivation of photocatalyst. In contrast, as revealed by both DFT calculations and experimental results, the reaction pathway with byproducts blocking the active sites can be thermodynamically avoided on In(OH)3. This rendered high durability to In(OH)3 photocatalyst in degradations of aromatic pollutants. The elucidation of deactivation-resistant effect and reaction mechanism as an ideal photocatalyst for practical usage were provided.


Assuntos
Benzeno , Tolueno , Catálise , Humanos , Hidróxidos , Fotólise , Titânio
4.
Nature ; 597(7874): 33-34, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34471278
5.
J Org Chem ; 86(17): 11545-11556, 2021 09 03.
Artigo em Inglês | MEDLINE | ID: mdl-34479410

RESUMO

α,ß-Unsaturated carbonyl compounds are significant moieties in many biological molecules and have attracted considerable attention in organic synthetic chemistry. A Pd-catalyzed cascade cyclization for the synthesis of (E)-α,ß-unsaturated carbonyl compounds with the sequential formation of C-C bonds was developed. This method offers high efficiency, good functional group tolerance, and moderate to excellent yields and generally displays high stereoselectivity.


Assuntos
Benzeno , Paládio , Catálise , Ciclização , Estereoisomerismo
6.
Analyst ; 146(20): 6239-6244, 2021 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-34528640

RESUMO

Hazardous volatile organic compounds (VOCs) can significantly impact human health and the environment. Hence, the detection of VOCs is of foremost importance. A quinoxaline-based fluorimetric probe (1) unveils a notable "turn-on" fluorescence response towards mesitylene in the presence of other VOCs and common interfering ions in aqueous media. The sensing phenomenon involves specific 1 : 1 stoichiometric binding of the probe with mesitylene with a ∼2.66 ppm detection limit. Furthermore, the probe experiences morphological transformations from a fibril-network to a stone-shaped hetero-structure upon treatment with mesitylene, indicating mesitylene induced self-assembly. The detection induced self-assembly of the probe was further corroborated by dynamic-light-scattering (DLS) and fluorescence microscopy study. Importantly, this proposed approach is applicable to detect mesitylene in natural water sources and in the vapor phase using portable, low-cost filter paper strips.


Assuntos
Compostos Orgânicos Voláteis , Benzeno , Humanos , Íons , Quinoxalinas , Espectrometria de Fluorescência
7.
Chemosphere ; 282: 131110, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34470162

RESUMO

Fibrous activated carbon has attracted emerging research interests due to its remarkable adsorption performance for volatile organic compounds (VOCs). Though this adsorption behavior for VOCs is closely related to the pore structure on the surface of activated carbon fiber (ACF), few researchers paid attentions to the influence of textural properties of this adsorption process. Especially, cotton-based activated carbon fiber (CACF) for adsorbing benzene pollutant is rarely reported. Herein, in order to develop a high-performance adsorbent for the removal of VOCs pollutants, this work studied the influence of textural properties of CACF on the adsorption of benzene. The results showed that the increase of carbonization temperature would lead to the reduction of mesopores but the increase of micropores for CACF; the embedment of phosphoric acid and its derivatives into the carbon layers contributed to the formation of pore structure for CACF; furthermore, specific surface area of CACF can also be enlarged by increasing the concentration of phosphoric acid. More importantly, it was found that the adsorption capacity of CACF for benzene was strongly dependent on the specific surface area and volume of micropores within CACF because micropores can provide more favorable binding sites. This adsorption process preferred to occur on the wall of micropores, then the accumulated benzene would slowly fill the pores. Interestingly, the decrease of pore size of micropores can unexpectedly improve the affinity of CACF to benzene on the contrary. This work provides a new strategy to develop porous structured ACF materials for the high-performance adsorption of VOCs.


Assuntos
Benzeno , Carvão Vegetal , Adsorção , Fibra de Carbono , Porosidade
8.
Talanta ; 235: 122722, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34517590

RESUMO

In-vehicle air pollution has become a major concern to public health in recent years. The traditional analytical methods for detection of volatile organic compounds (VOCs) pollutants in air are based on gas chromatography - mass spectrometry (GC-MS) or high-performance liquid chromatography (HPLC), including complicated pretreatment and separation procedures, which are not only time-consuming and labor-intensive, but also incapable of simultaneously measuring both aldehydes and benzenes. In this work, a new photoionization-induced NO+ chemical ionization time-of-flight mass spectrometry (PNCI-TOFMS) was developed for real-time and continuous measurement of aldehydes and benzenes in vehicles. High-intensity NO+ reactant ions could be generated by photoionization of NO reagent gas, and efficient chemical ionization between NO+ reactant ions and analyte molecules occurred to produce adduct ions M·NO+ at an elevated ion source pressure of 800 Pa. Consequently, the achieved LODs for aldehydes and benzenes were down to sub-ppbv within 60 s. The analytical capacity of this system was demonstrated by continuous and online monitoring of in-vehicle VOCs in a used car, exhibiting broad potential applications of the PNCI-TOFMS in air pollutants monitoring and in-vehicle air quality analysis.


Assuntos
Poluentes Atmosféricos , Compostos Orgânicos Voláteis , Poluentes Atmosféricos/análise , Aldeídos , Benzeno , Cromatografia Gasosa-Espectrometria de Massas , Compostos Orgânicos Voláteis/análise
9.
J Hazard Mater ; 418: 126405, 2021 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-34351297

RESUMO

Hydrogels are often claimed as optimal adsorbents for water treatment; however, their efficiency towards the removal of hydrophobic pollutants is still limited. As an alternative, hydrogels prepared from polymers functionalized with siliceous materials can overcome this issue. Here, a composite hydrogel (denoted as GEL-SBA15) was prepared using alginate grafted with mesoporous silica (SBA15) and poly(vinyl alcohol) for benzene and toluene adsorption from aqueous solutions. Adsorption studies demonstrated that a low dosage of GEL-SBA15 (10 mg) has a high adsorption capacity for benzene (1482.8 mg/g) and toluene (596.6 mg/g) under mild experimental conditions (pH 7.0, at 25 °C). Besides, the adsorption capacities of GEL-SBA15 for both pollutants were enhanced compared to the conventional hydrogel. Kinetic analysis showed that the adsorption of benzene and toluene follows a pseudo-second order model, while the experimental adsorption data were well-fitted by the Freundlich isotherm. According to this isotherm, the adsorption occurs via a collaborative process, and weak physical forces (π-π interactions, van der Waals and hydrophobic) are involved. Hence, the post-utilized GEL-SBA15 can be recycled and reused up to 6 times without losing adsorption performance. Although hydrogels are not common adsorbents for aromatic hydrocarbons, the results reported here rank GEL-SBA15 as a promising adsorbent for the removal of these pollutants from water.


Assuntos
Poluentes Químicos da Água , Purificação da Água , Adsorção , Alginatos , Benzeno , Hidrogéis , Cinética , Dióxido de Silício , Tolueno , Poluentes Químicos da Água/análise
10.
J Phys Chem Lett ; 12(32): 7701-7707, 2021 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-34355903

RESUMO

The resolving power of solid-state nuclear magnetic resonance (NMR) crystallography depends heavily on the accuracy of computational predictions of NMR chemical shieldings of candidate structures, which are usually taken to be local minima in the potential energy. To test the limits of this approximation, we systematically study the importance of finite-temperature and quantum nuclear fluctuations for 1H, 13C, and 15N shieldings in polymorphs of three paradigmatic molecular crystals: benzene, glycine, and succinic acid. The effect of quantum fluctuations is comparable to the typical errors of shielding predictions for static nuclei with respect to experiments, and their inclusion improves the agreement with measurements, translating to more reliable assignment of the NMR spectra to the correct candidate structure. The use of integrated machine-learning models, trained on first-principles energies and shieldings, renders rigorous sampling of nuclear fluctuations affordable, setting a new standard for the calculations underlying NMR structure determinations.


Assuntos
Benzeno/química , Glicina/química , Ácido Succínico/química , Isótopos de Carbono/química , Cristalografia/métodos , Hidrogênio/química , Aprendizado de Máquina , Espectroscopia de Ressonância Magnética , Isótopos de Nitrogênio/química
11.
Environ Pollut ; 289: 117893, 2021 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-34385133

RESUMO

Health risks of typical benzene series and halocarbons (BSHs) in a densely populated area near a large-scale chemical industrial park were investigated. Ambient and indoor air and tap water samples were collected in summer and winter; and the concentration characteristics, sources, and exposure risks of typical BSH species, including five benzene series (benzene, toluene, ethylbenzene, o-xylene, m,p-xylene) and five halocarbons (dichloromethane, trichloromethane, trichloroethylene, tetrachloromethane, and tetrachloroethylene), were analysed. The total mean concentrations of BSHs were 53.32 µg m-3, 36.29 µg m-3, and 26.88 µg L-1 in indoor air, ambient air, and tap water, respectively. Halocarbons dominated the total BSHs with concentrations relatively higher than those in many other industrial areas. Industrial solvent use, industrial processes, and vehicle exhaust emissions were the principal sources of BSHs in ambient air. The use of household products (e.g., detergents and pesticides) was the principal source of indoor BSHs. Inhalation is the primary human exposure route. Ingestion of drinking water was also an important exposure route but had less impact than inhalation. Lifetime non-cancer risks of individual and cumulative BSHs were below the threshold (HQ = 1), indicating no significant lifetime non-cancer risks in the study area. However, tetrachloromethane, benzene, trichloromethane, ethylbenzene, and trichloroethylene showed potential lifetime cancer risk. The cumulative lifetime cancer risks exceeded the tolerable benchmark (1 × 10-4), indicating a lifetime cancer risk of BSHs to residents near the chemical industry park. This study provides valuable information for the management of public health in chemical industrial parks.


Assuntos
Poluentes Atmosféricos , Benzeno , Poluentes Atmosféricos/análise , Benzeno/análise , Derivados de Benzeno/análise , Monitoramento Ambiental , Humanos , Tolueno/análise , Emissões de Veículos/análise
12.
Microbes Environ ; 36(3)2021.
Artigo em Inglês | MEDLINE | ID: mdl-34433738

RESUMO

Current challenges in the anaerobic bioremediation of benzene are the lack of capable cultures and limited knowledge on the biodegradation pathway. Under methanogenic conditions, benzene may be mineralized by syntrophic interactions between microorganisms, which are poorly understood. The present study developed an optimized formula for anoxic medium to successfully promote the growth of the putative benzene degrader Deltaproteobacterium Hasda-A and enhance the benzene degradation activity of methanogenic enrichment cultures. Within 70| |d of incubation, the benzene degradation activity and relative abundance of Hasda-A in cultures in the new defined medium increased from 0.5 to >3| |mg L-1 d-1 and from 2.5% to >17%, respectively. Together with Hasda-A, we found a strong positive relationship between the abundances of superphylum OD1 bacteria, three methanogens (Methanoregula, Methanolinea, and Methanosaeta) and benzene degradation activity. The syntrophic relationship between these microbial taxa and Hasda-A was then demonstrated in a correlation analysis of longitudinal data. The involvement of methanogenesis in anaerobic benzene mineralization was confirmed by inhibition experiments. The high benzene degradation activity and growth of Hasda-A were quickly recovered in successive dilutions of enrichment cultures, proving the feasibility of using the medium developed in the present study to produce highly capable cultures. The present results will facilitate practical applications in bioremediation and research on the molecular mechanisms underlying benzene activation and syntrophic interactions in benzene mineralization.


Assuntos
Benzeno/metabolismo , Meios de Cultura/química , Deltaproteobacteria/metabolismo , Metano/metabolismo , Methanosarcinales/metabolismo , Anaerobiose , Biodegradação Ambiental , Crescimento Quimioautotrófico , Técnicas de Cocultura , Meios de Cultura/metabolismo , Deltaproteobacteria/crescimento & desenvolvimento , Methanosarcinales/crescimento & desenvolvimento
13.
Sci Total Environ ; 800: 149484, 2021 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-34392216

RESUMO

Organic pollutants are common in the environment, very difficult to remove, and pose a serious threat to human health. Probabilistic risk assessment advances conservative single-point estimation and brings a new perspective to risk assessment. From 2009 to 2019, we monitored the distribution of major pollutants in an industrial park in Northeastern China. The result showed the maximum concentration of benzene reached 73,680 µg/L in 2009, benzo[a]pyrene reached 36.80 ng/L in 2016. These concentrations are significantly above the levels set by Chinese regulatory agencies. The single-factor index increases year by year, and pollutants gradually spread from the pollution leakage source to surrounding areas. A new method was used to quantify the human health risk from groundwater organic pollution accurately, based on the triangular fuzzy numbers coupled with the Monte Carlo simulation. The Monte Carlo simulation was used to simulate the triangular fuzzy numbers. This simplified the operation between the triangular fuzzy numbers and their function successfully and obtained the risk as a set of values. The results indicated that non-carcinogenic risk was negligible in all age groups (children, adolescents, and adults). Conversely, when it comes to carcinogenic risks, adults were about 50-270 times the tolerable level of risk due to long exposure years and wide skin contact areas. Oral ingestion played an essential role in total exposure (>90%) compared to dermal contact. Control of exposure duration and intake should be prioritized when making decisions to reduce risk uncertainty. Monte Carlo simulation-triangular fuzzy numbers can effectively reduce the risk of uncertainty and reflect the complex conditions of the groundwater environment for small amounts of data or inaccurate data.


Assuntos
Água Subterrânea , Poluentes Químicos da Água , Adolescente , Adulto , Benzeno , Criança , China , Monitoramento Ambiental , Humanos , Medição de Risco , Poluentes Químicos da Água/análise
14.
Toxicol Appl Pharmacol ; 428: 115682, 2021 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-34418406

RESUMO

Benzene, an important and widely used industrial chemical, is the cause of different types of blood disorders. However, the mechanisms of benzene-induced hematotoxicity are still unclear. This study aimed to explore the effects of benzene on metabolism, especially in amino acid metabolism, in human peripheral blood B lymphocyte cells (AHH-1 cells) treated with 1,4-benzoquinone (1,4-BQ) and in benzene-exposed population based on the un-targeted and targeted metabolomics platforms. The results showed that 1,4-BQ disturbed the metabolic activity, such as arginine biosynthesis, citrate cycle, glycine, serine, and threonine metabolism pathways, and significantly upregulated the ratio of sarcosine/glycine in vitro. Meanwhile, the targeted metabolomics further showed that the ratio of sarcosine/glycine was also increased in the benzene exposure population. Notably, the expression of glycine N-methyltransferase (GNMT), an enzyme catalyzing the transformation of glycine to sarcosine, was upregulated both in 1,4-BQ treated AHH-1 cells and benzene-exposed workers. These results imply that the glycine/GNMT/sarcosine axis was involved in benzene-induced hematotoxicity. Such evidence will help to develop a better understanding of the underlying mechanism of benzene-induced hematotoxicity at the level of amino acid metabolism.


Assuntos
Linfócitos B/metabolismo , Benzeno/toxicidade , Doença Hepática Induzida por Substâncias e Drogas/sangue , Glicina N-Metiltransferase/sangue , Exposição Ocupacional/efeitos adversos , Sarcosina/sangue , Adulto , Linfócitos B/efeitos dos fármacos , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/fisiologia , Doença Hepática Induzida por Substâncias e Drogas/diagnóstico , Relação Dose-Resposta a Droga , Feminino , Humanos , Masculino
15.
J Phys Chem B ; 125(31): 8855-8861, 2021 08 12.
Artigo em Inglês | MEDLINE | ID: mdl-34339214

RESUMO

The pressure dependence of the solubility of hydrophobic solutes in aqueous solutions is equivalent to volume changes upon hydrophobic hydration. This phenomenon has been attributed to the packing effects induced by the van der Waals volume difference between the solute and water. However, the volume changes may also be related to the chemical properties of the solute. In this study, we investigated hydrophobic hydration using a series of halogenated benzenes. Solution density measurements revealed negative volume changes for benzene, fluorobenzene, and chlorobenzene, whereas those for bromobenzene and iodobenzene were positive. Subsequent volumetric analyses demonstrated that the relationship between the excess particle number for hydration water and the van der Waals volume for bromobenzene and iodobenzene significantly deviated from the universal line for hydrophobic solutes. This behavior suggests that the volume changes are due to factors other than the packing effect with bromo and iodine functional groups acting as modulators of the hydration structure, resulting in enhanced water depletion.


Assuntos
Benzeno , Água , Halogenação , Solubilidade , Soluções
16.
Environ Pollut ; 285: 117491, 2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-34380213

RESUMO

The utility of metal-organic frameworks (MOFs) such as the CUK family (CUK - Cambridge University-KRICT) has been explored intensively for adsorption/separation of airborne volatile organic compounds (VOCs). In this article, three M-CUK analogs (M = Mg, Co, or Ni) were synthesized hydrothermally under similar conditions to assess the effects of their isostructural properties and metal centers on adsorption of benzene vapor (0.05-1 Pa). A list of performance metrics (e.g., breakthrough volume (BTV) and partition coefficient (PC)) were used to assess the role of the metal type (in M-CUK-1s) in the adsorption of VOCs. Specifically, Co-CUK-1 (average pore size of 8.98 nm) showed 2-3 times greater performance (e.g., in terms of 10% BTV (2012 L atm g-1) and PC (6 mol kg-1 Pa-1)) over other analogs when exposed up to 0.05 Pa benzene vapor. The superiority of mesoporous Co-CUK-1 (e.g., enhanced adsorption diffusion mechanism through favorable metal-π and π- π interactions) can be attributed to the presence of cobalt metal centers (e.g., in reference to Mg- or Ni-CUK-1).


Assuntos
Estruturas Metalorgânicas , Compostos Orgânicos Voláteis , Adsorção , Benzeno , Gases , Humanos
17.
Environ Pollut ; 285: 117678, 2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-34380234

RESUMO

Toluene/o-Xylene Monooxygenase (ToMO) is equipped with a broad spectrum of aromatic substrate specificity (such as BTEX; benzene, toluene, ethylbenzene, and isomers of xylenes). TOMO has can hydroxylate more than a single position of aromatic rings in two consecutive monooxygenation reactions. Catechol 1,2-dioxygenase (C1,2D) is an iron-containing enzyme able to cleave the ring of catechol (the converted product from ToMO) for complete detoxification of BTEX. In this study, cold-active ToMO and C1,2D were produced using newly isolated psychrophilic Pseudomonas S2TR-14 in the minimal salt medium supplemented with crustacean waste and different concentrations of used motor oil (0.2-2% (v/v)). Crude ToMO and C1,2D were immobilized into micro/nano biochar-chitosan matrices and used for BTEX biodegradation. The results showed that the highest enzyme production (12 U/mg for ToMO and 22 U/mg for C1,2D) was achieved at the presence of 0.5% v/v used motor oil compared to the control group without motor oil (0.07 and 0.06 U/mg). High immobilization yield was achieved due to covalent bonding of ToMO (92.26% for micro matrix and 77.20% for nano matrix) and C1,2D (87.57% for micro matrix and 74.79% for nano matrix) with matrices. FTIR spectra confirmed the immobilization of enzymes on the surface of microbiochar and nanobiochar-chitosan matrices as proper support. The immobilization increased the storage stability of the enzymes with more than 50% residual activity after 30 days at 4 ± 1 °C, while the free form of enzymes had less than 10% of its activity. Immobilized enzymes degraded more than 80% of BTEX (~200 mg/L in groundwater and ~10,000 mg/kg in soil) at 10 ± 1 °C in groundwater and soil. Therefore, integrated use of microbiochar and nanobiochar with chitosan for co-immobilization of ToMO and C1,2D can be a potential way to remove petroleum hydrocarbons with higher efficiency from contaminated groundwater and soil.


Assuntos
Pseudomonas , Xilenos , Benzeno , Derivados de Benzeno , Biodegradação Ambiental , Tolueno
18.
Artigo em Inglês | MEDLINE | ID: mdl-34360380

RESUMO

Indoor air pollution has obtained more attention in a moment where "stay at home" is a maximum repeated for the entire world. It is urgent to know the sources of pollutants indoors, to improve the indoor air quality. This study presents some results obtained for twelve incense products, used indoors, at home, and in temples, but also in spa centers or yoga gymnasiums, where the respiratory intensity is high, and the consequences on health could be more severe. The focus of this study was the gaseous emissions of different types of incense, performing a VOC screening and identifying some specific VOCs different from the usual ones, which are known or suspected to cause severe chronic health effects: carcinogenic, mutagenic, and reprotoxic. Thirteen compounds were selected: benzene, toluene, styrene, naphthalene, furfural, furan, isoprene, 2-butenal, phenol, 2-furyl methyl ketone, formaldehyde, acetaldehyde, and acrolein. The study also indicated that incense cone type shows a higher probability of being more pollutant than incense stick type, as from the 12 products tested, four were cone type, and three of them were in the group of the four higher polluters. Benzene and formaldehyde presented worrying levels in the major part of the products, above guideline values established by the WHO. Unfortunately, there are no limit values established for indoor air for all the compounds studied, but this fact should not exempt us from taking action to alert the population to the potential dangers of using those products. From this study, acetaldehyde, acrolein, furfural, and furan emerge as compounds with levels to deserve attention.


Assuntos
Poluentes Atmosféricos , Poluição do Ar em Ambientes Fechados , Poluentes Ambientais , Compostos Orgânicos Voláteis , Poluentes Atmosféricos/análise , Poluentes Atmosféricos/toxicidade , Poluição do Ar em Ambientes Fechados/análise , Benzeno/análise , Formaldeído/análise , Formaldeído/toxicidade , Humanos , Compostos Orgânicos Voláteis/análise , Compostos Orgânicos Voláteis/toxicidade
19.
Talanta ; 234: 122641, 2021 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-34364450

RESUMO

In the present study, 12 volatile benzene and naphthalene derived co-formulants were identified by suspect screening and unknown analysis in 14 plant protection products (PPPs) corresponding to several types of formulations, as emulsifiable concentrates (EC), suspension concentrates (SC), dispersible concentrates (DC) and ZC, which is a mixture of a capsule suspension (CS) in an SC, containing either difenoconazole or chlorantraniliprole as main active ingredients. The selected technique was gas chromatography coupled to Q-Orbitrap high resolution mass accuracy spectrometry (GC-Q-Orbitrap-MS), providing efficient separation and detection of all identified compounds. Finally, 42 compounds were tentatively identified, and 12 of them were confirmed and quantified using analytical standards. Results showed that the applied methodology was able to detect these co-formulants at concentrations as low as 0.03 g/L (tert-butylbenzene), encompassing a wide concentration range, up to 9.63 g/L (pentamethylbenzene). Pentamethylbenzene was the only compound detected in all studied samples.


Assuntos
Benzeno , Cromatografia Gasosa-Espectrometria de Massas , Espectrometria de Massas , Análise Espectral
20.
Environ Res ; 200: 111745, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34303681

RESUMO

This study focused on the measurement of BTEX (benzene, toluene, ethylbenzene and xylene) concentrations in the air of various regions and indoor-outdoor environments in Bandar Abbas, Iran. Air samples were taken actively and analyzed by gas chromatography-mass spectrometry (GC-MS) during two one-month periods i.e., Feb 2020 (period I) and Sep/Oct 2020 (period II). The mean air temperature and the levels of all BTEX compounds were higher in period II. The highest total BTEX (t-BTEX) levels (median [min-max]) were found in the urban region (18.00 [5.21-67.24] µg m-3), followed by industrial region (7.00 [2.05-14.76] µg m-3) and rural region (2.81 [ND-7.38] µg m-3). The significant positive correlations between all BTEX compounds and T/B ratio >1 indicated the vehicular traffic as the main source of emission. At 95th percentile probability, the non-cancer risk of t-BTEX in urban region was only less than one order of magnitude below the threshold level of unity (1.91E-01) and the cancer risk of benzene exceeded the recommended level of 1.0E-06 by U.S. EPA in urban (7.69E-06) and industrial (2.97E-06) regions. It was found that the indoor/outdoor ratio of BTEX concentration in beauty salon and hospital was greater than 1. Overall, the current levels of BTEX in the ambient air of study area, especially near urban roadside and in some indoor environments, should not be overlooked and appropriate mitigation actions should be undertaken.


Assuntos
Poluentes Atmosféricos , Poluição do Ar em Ambientes Fechados , Poluentes Atmosféricos/análise , Poluição do Ar em Ambientes Fechados/análise , Benzeno/análise , Derivados de Benzeno/análise , Monitoramento Ambiental , Irã (Geográfico) , Medição de Risco , Tolueno/análise
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