Benzene guideline

Hazardous chemicals released from the petroleum-derived face mask can be inhaled by wearers and cause adverse health effects. Here, we first used headspace solid-phase microextraction coupled with GC-MS to comprehensively analyze the volatile organic compounds (VOCs) released from 26 types of face masks. The results showed that total concentrations and peak numbers ranged from 3.28 to 197 μg/mask and 81 to 162, respectively, for different types of mask. Also, light exposure could affect the chemical composition of VOCs, particularly increasing the concentrations of aldehydes, ketones, organic acids and esters...

This report presents the findings of the concentrations, distributions and health risks assessment of heavy metals (HMs) and volatile organic compounds (VOCs) in topsoils of two typical automobile mechanic villages (MVs) situated within Ogun State, Nigeria. One of the MVs is located in basement complex terrain (Abeokuta), while the second is in the sedimentary formation (Sagamu). Ten composite samples were collected at depth of 0-30 cm with the aid of soil auger from spent oil-contaminated spots within the two MVs...

Indoor air quality (IAQ) has attracted a lot of attention due to its complexity and direct effect on human health. Indoor settings in libraries entail various volatile organic compounds (VOCs) linked to the aging and degradation of print material. The effect of the storage environment on paper life expectancy was investigated by targeting the VOC emissions of old and new books using headspace solid phase micro extraction-gas chromatography/mass spectrometry (HS-SPME-GC/MS) analysis. "Sniffing" of book degradation markers showed both ubiquitously and infrequently occurring VOCs...

Health, environmental and ethical concerns have resulted in a dramatic increase in demand for plant-based dairy analogues. While the volatile organic compounds (VOCs) responsible for the characteristic flavours of dairy-based products have been extensively studied, little is known about how to reproduce such flavours using only plant-based substrates. As a first step in their development, this review provides an overview of the VOCs associated with fermented (bacteria and/or fungi/yeast) vegetable and fruit substrates...

Salvadora persica (SP) is an important medicinal plant. Numerous articles have been conducted on the leaf, the roots, and the stem of the plant, but there is little information about the seed. Thus, the present work tries to identify the chemical composition of SP seed bio-oil and investigates its use as an adsorbent for cyclohexane removal. This study extracted bio-oil from seeds using different polar and non-polar organic solvents. Two techniques have been used to determine the chemical composition of the bio-oil extracted: FTIR and GC-MS...

The present work is considered to investigate the sources, concentration, and composition of polycyclic aromatic hydrocarbons (PAHs) and associated health risk assessment of road dust in Riyadh City, Saudi Arabia. The study region included an urban area, strongly affected by traffic, a bare and an industrial area. A total of 50 locations were selected for sampling and 16 different PAHs were determined. The concentration of PAHs in road dust and their estimated lifetime average daily dose (LADD) for adults (human) ranged from 0...

This review article aims to study how phytochemists have reacted to green chemistry insights since 1990, the year when the U.S. Environmental Protection Agency launched the "Pollution Prevention Act". For each year in the period 1990 to 2019, three highly cited phytochemistry papers that provided enough information about the experimental procedures utilized were sampled. The "greenness" of these procedures was assessed, particularly for the use of solvents. The highly hazardous diethyl ether, benzene, and carbon tetrachloride did not appear in the papers sampled after 2010...

Increased oil production in Canada has resulted in proposals to extend or develop new oil pipelines. Many of these proposals have been met by concerns from the public over potential environmental impacts related to construction and the potential for oil spills to negatively affect groundwater quality. Crude oil sourced from the Alberta oil sands represents a significant proportion of this increase in production. This crude oil is produced as bitumen, which is subsequently diluted with light hydrocarbons to lower viscosity to allow for pipeline transport producing diluted bitumen...

Thermally activated delayed fluorescence (TADF) and hybridized local and charge transfer (HLCT) emitters are two types of highly efficient electroluminescent materials which could improve their internal quantum efficiency (IQE) by converting triplet excitons to singlet ones. However, the molecular designs of TADF and HLCT materials are usually carried out separately because of their distinct emission mechanisms. In this work, we report a rational design strategy for the realization of switching between HLCT and TADF emissions in structurally similar donor-acceptor (D-A) type molecules, which are constructed with the same electron donors (benzo- or naphtho-carbazole) and acceptors with tunable electron-withdrawing abilities (benzonitrile (BN) and benzene-1,2,3,4,5-pentacarbonitrile (BPN))...

Anaerobic degradation is the major pathway for microbial degradation of benzene, toluene, ethylbenzene, and xylenes (BTEX) under electron acceptor lacking conditions. However, how exogenous electron acceptors modulate BTEX degradation through shaping the microbial community structure remains poorly understood. Here, we investigated the effect of various exogenous electron acceptors on BTEX degradation as well as methane production in anaerobic microbiota, which were enriched from the same contaminated soil...

The aim of this study was to evaluate the levels of inorganic and organic substances as well as microbial contaminants in bottled drinking water on a global scale. The findings were compared to WHO guidelines, EPA standards, European Union (EU) directive, and standards drafted by International Bottled Water Association (IBWA). Our review showed that 46% of studies focused on the organic contaminants, 25% on physicochemical parameters, 12% on trace elements, 7% on the microbial quality, and 10% on microplastics (MPs) and radionuclides elements...

The GuLF Study is investigating adverse health effects from work on the response and clean-up after the Deepwater Horizon explosion and oil release. An essential and necessary component of that study was the exposure assessment. Bayesian statistical methods and over 135 000 measurements of total hydrocarbons (THC), benzene, ethylbenzene, toluene, xylene, and n-hexane (BTEX-H) were used to estimate inhalation exposures to these chemicals for >3400 exposure groups (EGs) formed from three exposure determinants: job/activity/task, location, and time period...

Biocontrol agents serve as a sustainable means of controlling wilt caused by the widespread plant pathogen, Fusarium oxysporum f. sp. lycopersici. The present study aimed to develop water dispersible granules (WDG) using response surface methodology (RSM) for Bacillus subtilis MTCC 2274 and Trichoderma harzianum MTCC 3928, and to compare their antifungal efficacy with other formulations. Further, characterization of the bioactive metabolites responsible for biocontrol was performed. A new microbial formulation, WDG, was developed in the present study with talcum powder (substrate), alginic acid (dispersing agent) and acacia gum (wetting agent) (suspensibility 82...

Three lactone-based rigid semiconducting polymers were designed to overcome major limitations in the development of n-type organic thermoelectrics, namely electrical conductivity and air stability. Experimental and theoretical investigations demonstrated that increasing the lactone group density by increasing the benzene content from 0 % benzene (P-0), to 50 % (P-50), and 75 % (P-75) resulted in progressively larger electron affinities (up to 4.37 eV), suggesting a more favorable doping process, when employing (N-DMBI) as the dopant...

BACKGROUND: We examined sperm quality in a cohort of city policemen in Ostrava at the end of a period with high concentrations of air pollutants (winter) and in the same cohort at the end of a relatively low exposure period (summer). METHODS: The study group was comprised of 54 nonsmoking city policemen living and working in Ostrava, Czech Republic. Average daily air-pollutant concentrations recorded by stationary monitoring for 90 days preceding the collection of semen samples were evaluated for different city districts of Ostrava...

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...

Our aim was to analyze the effects of benzene exposure on hematotoxicity in workers, with a focus on gender differences. The study was divided into three parts, and the survey included 218,061 workers. Since 2017, some workers are selected from the total workers each year to explore the possible influencing factors (age, duration of benzene exposure, TWA (8-h time-weighted average) of benzene, SPMA (S-phenylmercapturic acid), MDA (malondialdehyde), 8-OHdG (8-hydroxy-2'-deoxyguanosine) of different hematotoxicity of different genders)...

A respiratory syncytial virus (RSV) is the major cause of respiratory tract infection in children under 5 years. However, RSV infection in the European Region of the World Health Organization has not been systematically reviewed. The aim was to determine the prevalence and factors associated with RSV in children under 5 years of age in European regions. A systematic review and meta-analysis was performed. CINAHL, Medline, LILACS, ProQuest, SciELO, and Scopus databases were consulted for studies published in the last 5 years, following Preferred Reporting Items for Systematic Reviews and Meta-analysis guidelines...

We reviewed 47 documents published 1967-2019 that reported measurements of volatile organic compounds (VOCs) on commercial aircraft. We compared the measurements with the air quality standards and guidelines for aircraft cabins and in some cases buildings. Average levels of VOCs for which limits exist were lower than the permissible levels except for benzene with average concentration at 5.9 ± 5.5 μg/m3 . Toluene, benzene, ethylbenzene, formaldehyde, acetaldehyde, limonene, nonanal, hexanal, decanal, octanal, acetic acid, acetone, ethanol, butanal, acrolein, isoprene and menthol were the most frequently measured compounds...

Objective: This study was designed to conduct a retrospective and systematic occupational health risk assessment (OHRA) of enterprises that used benzene, toluene, and xylene (BTX) in Shanghai, China. Methods: All data for the study were obtained from 1,705 occupational health examination and evaluation reports from 2013 to 2017, and a semiquantitative model following Chinese OHRA guidelines (GBZ/T 298-2017) was applied for the assessment. Results: The selected enterprises using BTX were mainly involved in manufacturing of products...