Solvent Vehicle Research Articles

Characteristics, Sources Analysis, and Environmental Impacts of VOCs Based on Photochemical Loss in Summer in Zhengzhou

To clarify the pollution characteristics and sources of atmospheric VOCs in Zhengzhou City in the summer, multi-site offline sampling and laboratory analyses of atmospheric VOCs in Zhengzhou were carried out in August 2022. The observed and initial VOC volume fraction levels, OFP, SOAFP, and sources were compared. During the study period, the average values of three-site observation and initial φ（VOCs） during the study period were （31.83 ±13.51）×10-9 and （35.92 ±15.30）×10-9,respectively. Olefins （52.5 %） and aromatic hydrocarbons （29.7 %） were the components with a higher photochemical loss rate, and the spatial variations of the observed TVOCs concentration at each site were： Zhengzhou University （ZZU） > Gangli Reservoir （GLR） > Jingkaiqu （JKQ）, and the concentrations of alkanes and OVOCs at each site were higher. Olefins and aromatic hydrocarbons were the components that contributed greatly to the formation of O3 and SOA. Motor vehicle sources, solvent-use sources, and industrial sources were the main contributing sources of atmospheric VOCs in Zhengzhou. Compared with the source analysis results based on the initial concentration, the contribution rates of motor vehicle sources, industrial sources, and solvent use sources were relatively high, and the contribution rates of combustion sources, plant sources, and oil and gas volatilization sources were relatively low.

Complexities of peroxyacetyl nitrate photochemistry and its control strategies in contrasting environments in the Pearl River Delta region

Peroxyacetyl nitrate (PAN) is a hazardous secondary pollutant and a nitrogen reservoir in the troposphere, while comprehensive studies on its spatiotemporal distribution, chemical sources, and control strategies are limited. This study addressed these issues based on 1-year multi-site observations in the Pearl River Delta region, showing a pattern of higher PAN levels in the cold season, particularly in coastal areas. Moreover, in situ modeling indicated a net photochemical PAN formation in the warm season, while PAN was dominated by regional transport in the cold season (i.e., rural and coastal areas), releasing NO2 and PA radicals and promoting ozone (O3) formation. In addition, the feasibility of joint control of PAN and O3 was confirmed by their isopleth diagrams. C7–C9 aromatics and C4–C5 alkenes, largely from vehicle exhaust and solvent usage, were identified as the predominant contributors to PAN formation in this region. Overall, this study deepens our understanding of PAN chemistry and provides valuable insights into its control measures.

Pollution Characteristics，Source Analysis，and Activity Analysis of Atmospheric VOCs During Winter and Summer Pollution in Zhengzhou

In order to study the pollution characteristics of volatile organic compounds （VOCs）， continuous monitoring of VOCs in two pollution processes was conducted in June and December 2021 in Zhengzhou. Combined with meteorological conditions， the pollution characteristics， source contributions， and reactivity of VOCs in winter and summer were compared and analyzed. The results showed that the volume fraction of atmospheric VOCs in two episodes were （27.92±12.68）×10-9 and （24.30±5.93）×10-9， respectively. The volume fraction of atmospheric VOCs in the haze pollution process in winter was larger than that in the ozone pollution process in summer. The analysis results of winter sources were as follows： industrial source （27.0%）， motor vehicle source （22.5%）， combustion source （20.1%）， solvent use source （16.3%）， and oil and gas volatilization source （14.1%）. The analysis results of summer sources were as follows： motor vehicle source （24.8%）， industrial source （24.1%）， solvent source （17.4%）， oil and gas volatilization source （14.2%）， combustion source （11.2%）， and plant source （8.4%）. The results of the smog production model showed that the proportion of days in the synergistic control zone of VOCs during the two pollution processes in summer （66.7%） was smaller than that in winter （100.0%）. The secondary reaction activity results showed that the average ·OH loss rate （L·OH） values in winter and summer were 4.12 s-1 and 4.75 s-1， respectively. The average ozone formation potential （OFP） values in summer were 108.36 μg·m-3. The olefins were dominant in the top ten species due to L·OH and OFP contributions in summer. The total SOAFP values in winter in Zhengzhou were 54.38 μg·m-3. Among the top ten species contributing to SOAFP in winter， nine were aromatic hydrocarbons.

Empagliflozin alone and in combination with metformin ameliorate diabetes type 2-oxidative stress

Currently, one of the major public health concerns is diabetes mellitus, which is known as a silent killer due to the failure to diagnose it at an early stage. A growing body of research indicates that metformin and empagliflozin have antioxidant properties in addition to their hypoglycemic properties. Our research looked into the potential antioxidant effects of metformin and empagliflozin on diabetic rats by decreasing oxidative stress. For eight weeks, 42 adult male Sprague Dawley rats were divided into six groups: normal control, diabetic control group, diabetic group received dimethyl sulfoxide as a vehicle(solvent) of the empagliflozin, 250 mg/kg metformin only, 10 mg/kg empagliflozin only and a combination of both. A single injection of 40 mg/kg streptozocin administered intraperitoneally was after administering 10% fructose in drinking water for two weeks to cause type 2 diabetes in rats. The evaluation of oxidative stress involved the quantification of serum malondialdehyde (MDA) and superoxide dismutase (SOD) levels upon completion of the experimental period. Additionally, blood glucose levels were determined using blood samples from the tail, and body weight was monitored on a weekly basis. Our findings showed that compared to the diabetic group, the therapy groups had considerably lower blood glucose, and serum MDA levels, while higher levels of SOD, and less decrease in body weight. Furthermore, even better results were obtained when empagliflozin and metformin were administered together. As a result of our findings, diabetic rats treated with empagliflozin and metformin had lower levels of oxidative stress.

Ames test study designs for nitrosamine mutagenicity testing: qualitative and quantitative analysis of key assay parameters.

The robust control of genotoxic N-nitrosamine (NA) impurities is an important safety consideration for the pharmaceutical industry, especially considering recent drug product withdrawals. NAs belong to the 'cohort of concern' list of genotoxic impurities (ICH M7) because of the mutagenic and carcinogenic potency of this chemical class. In addition, regulatory concerns exist regarding the capacity of the Ames test to predict the carcinogenic potential of NAs because of historically discordant results. The reasons postulated to explain these discordant data generally point to aspects of Ames test study design. These include vehicle solvent choice, liver S9 species, bacterial strain, compound concentration, and use of pre-incubation versus plate incorporation methods. Many of these concerns have their roots in historical data generated prior to the harmonization of Ames test guidelines. Therefore, we investigated various Ames test assay parameters and used qualitative analysis and quantitative benchmark dose modelling to identify which combinations provided the most sensitive conditions in terms of mutagenic potency. Two alkyl-nitrosamines, N-nitrosodimethylamine (NDMA) and N-nitrosodiethylamine (NDEA) were studied. NDMA and NDEA mutagenicity was readily detected in the Ames test and key assay parameters were identified that contributed to assay sensitivity rankings. The pre-incubation method (30-min incubation), appropriate vehicle (water or methanol), and hamster-induced liver S9, alongside Salmonella typhimurium strains TA100 and TA1535 and Escherichia coli strain WP2uvrA(pKM101) provide the most sensitive combination of assay parameters in terms of NDMA and NDEA mutagenic potency in the Ames test. Using these parameters and further quantitative benchmark dose modelling, we show that N-nitrosomethylethylamine (NMEA) is positive in Ames test and therefore should no longer be considered a historically discordant NA. The results presented herein define a sensitive Ames test design that can be deployed for the assessment of NAs to support robust impurity qualifications.

Dimethyl sulfoxide’s impact on epileptiform activity in a mouse model of chronic temporal lobe epilepsy

In the quest for novel treatments for patients with drug-resistant seizures, poor water solubility of potential drug candidates is a frequent obstacle. Literature indicated that the highly efficient solvent dimethyl sulfoxide (DMSO) may have a confounding influence in epilepsy research, reporting both pro- and antiepileptic effects. In this study, we aim to clarify the effects of DMSO on epileptiform activity in one of the most frequently studied models of chronic epilepsy, the intrahippocampal kainic acid (IHKA) mouse model, and in a model of acute seizures. We show that 100 % DMSO (in a volume of 1.5 µl/g corresponding to 1651 mg/kg) causes a significant short-term anti-seizure effect in epileptic IHKA mice of both sexes, but does not affect the threshold of acute seizures induced by pentylenetetrazol (PTZ). These findings highlight that the choice of solvent and appropriate vehicle control is crucial to minimize undesirable misleading effects and that drug candidates exclusively soluble in 100 % DMSO need to be modified for better solubility already at initial testing.

A comprehensive investigation on source apportionment and multi-directional regional transport of volatile organic compounds and ozone in urban Zhengzhou

To understand the characteristics, source apportionment, and regional transport of volatile organic compounds (VOCs) and ozone (O3) in a typical city with severe air pollution in central China, we observed and analyzed 115 VOC species at an urban site in Zhengzhou from 29 July to 26 September 2021. During this period, observation- and emission-based approaches revealed that Zhengzhou was in a VOC-limited regime. The average concentration of total VOCs (TVOCs) was 162.25 ± 71.42 μg/m3, dominated by oxygenated VOCs (OVOCs, 34.49%), alkanes (24.29%), and aromatics (19.49%). Six VOC sources were identified using positive matrix factorization (PMF) model, including paint solvent usage (25.32%), secondary production (24.11%), industrial production (19.22%), vehicle exhaust (16.18%), biogenic emission (8.87%), and combustion (6.30%). To assess the regional contribution and source apportionment of VOCs and O3, Comprehensive Air Quality Model with Extensions (CAMx) with the Ozone Source Apportionment Technology (OSAT) was used for simulation. Results showed that the VOCs were significantly affected by local emissions (about 70%), while O3 was mainly attributed to regional and super-regional transport. Regarding multi-directional regional transport of VOCs and O3, dominant contributions were from the northeast and east-northeast directions, and O3 contributions were also predominantly from the east and east-southeast directions. In terms of source apportionment, the transportation and industrial sectors (including solvent usage) were the major contributors to O3 and VOCs. To alleviate VOCs and O3 pollution, transportation and industrial emission reduction should be strengthened, and regional coordination, especially from the northeast to east-southeast directions, should be emphasized in addition to local management.

VOCs sources and roles in O3 formation in the central Yangtze River Delta region of China

Surface ozone (O3) pollution has become a prominent air quality problem in the Yangtze River Delta (YRD) region of China in recent years. Since O3 is non-linearly related to its precursors (volatile organic compounds (VOCs), nitrogen oxides (NOx)), identifying the characteristics of VOCs is significant for the control of O3 pollution. In this study, online observation of ambient VOCs from August to October 2018 was conducted at 2 sites in Changzhou, an industrial city located in the central YRD region, to investigate the O3 pollution characteristics, sources of VOCs, and their roles in O3 formation. The average concentration of VOCs in Changzhou during the observational period was 39.52 ± 23.14 ppb. Alkanes, oxygenated VOCs (OVOCs), and halocarbons were the main contributors to the total VOCs concentration, with the average relative contributions of 39.4%, 23.1%, and 16.1%, respectively. An observation-based model (OBM) was used to investigate the sensitivity of O3 formation to VOCs and NOx. Results of relative incremental reactivity (RIR) of individual VOC and empirical kinetics modeling approach (EKMA) showed that the O3 formation in Changzhou was within the VOCs-limited regime. Anthropogenic VOCs with the largest RIR values were xylenes and propene, respectively. The positive matrix factorization (PMF) model was applied to quantitatively identify the sources of VOCs. Six factors were resolved, including vehicle exhaust, gasoline evaporation, paint and solvent usage, electronic manufacturing, petrochemical industry, and biogenic source & secondary formation. The average relative contribution of traffic-related emissions to the total VOCs mass concentration was about 49.5%, followed by electronic manufacturing (22.9%), paint and solvent usage (14.7%), and petrochemical industry (7.1%). The average relative contributions of individual sources for xylenes and propene were further compared. Xylenes were mainly emitted from paint and solvent usage (60%), electronic manufacturing (17%), and vehicle exhaust (16%). Petrochemical industry (67%) and vehicle exhaust (30%) were the major sources of propene. Therefore, VOCs from industrial emissions and traffic-related emissions should be given priority for the control of O3 pollution in the central YRD region.

Variations, sources, and effects on ozone formation of VOCs during ozone episodes in 13 cities in China

In recent years, ozone (O3) pollution has worsened in China and contributes frequently to air pollution problems. To support the implementation of coordinated control for ozone and fine particulate matter, it is essential to study the chemical compositions and sources of volatile organic compounds (VOCs), which are the crucial precursor of both ozone and fine particulate matter. In this study, 117 volatile organic compounds were monitored in 13 cities in Beijing-Tianjin-Hebei Urban Agglomeration and Fenwei plain. Concentrations of total volatile organic compounds ranged from 42 to 279 μg/m3 during the monitoring episode. In all 13 cities, alkanes, halogenated hydrocarbons, aromatics and oxygenated volatile organic compounds (OVOCs) were the dominant volatile organic compounds. Contributions of alkanes, halogenated hydrocarbons, aromatics and oxygenated volatile organic compounds to total ozone formation potential (OFP) were 21.7%–32.6%, 21.0%–27.9%, 24.3%–50.8% and 28.6%–52.3%, respectively. Furthermore, the results of source apportionment by positive matrix factorization (PMF) model indicated that solvent usage, gasoline evaporation, vehicle emissions, petrochemical industry and combustion were essential volatile organic compounds sources in 13 cities. Moreover, the sensitivity of ozone production was studied using an Empirical Kinetic Modeling Approach (EKMA) model, and it was found that ozone formation was volatile organic compounds limited in all 13 cities.

Variation Characteristics and Source Apportionment of Atmospheric VOCs at Multi-sites in Zhengzhou

From July 2020 to June 2021, monthly offline sampling of atmospheric VOCs was carried out and analyzed at three urban sites and one suburban site in Zhengzhou. Then, the volume fraction levels, composition characteristics, reactivity, and source apportionment of atmospheric VOCs were discussed. The results showed that the volume fraction of atmospheric VOCs in Zhengzhou was (37.50±14.30)×10-9 during the sampling period, and the proportion of components was represented by alkanes (33%)>OVOCs (24%)>halogenated hydrocarbons (23%)>aromatic hydrocarbons (8%)>alkenes (7%)>alkynes (4%)>sulfides (1%). The seasonal variation characteristics were winter>autumn>summer>spring, and the monthly average value of VOCs had the highest value in January and the lowest value in May; the spatial variation characteristics were Zhengzhou University (ZD)>Jiancezhan (JCZ)>Jingkaiqu (JKQ)>Gangli Reservoir (GLR). The average·OH loss rate (L·OH) was 4.24 s-1, and the average ozone formation potential (OFP) was 172.27 μg·m-3; the top ten species of L·OH and OFP at each site and in each season were dominated by alkenes, OVOCs, and aromatic hydrocarbons. The results of positive matrix factorization (PMF) showed that the main sources of VOCs were vehicle emissions (28%), solvent utilization (24%), industrial emissions (24%), and oil and gas volatilization (19%) and plant emissions (5%).

Characteristics, sources and health risk assessment of atmospheric carbonyls during multiple ozone pollution episodes in urban Beijing: Insights into control strategies

Carbonyls have attracted continuous attention due to their critical roles in atmospheric chemistry and their potential hazards to the ecological environment and human health. In this study, atmospheric carbonyls were measured during several ground-level-ozone (O3) pollution episodes at three urban sites (CRAES, IEP and BJUT) in Beijing in 2019 and 2020. Comparative analysis revealed that the carbonyl concentrations were 20.25 ± 6.91 ppb and 13.43 ± 5.13 ppb in 2019 and 2020 in Beijing, respectively, with a significant spatial trend from north to south, and carbonyl levels in urban Beijing were in an upper-intermediate range in China, and higher than those in other countries reported in the literature. A particularly noteworthy phenomenon is the consistency of carbonyl concentrations with variations in O3 concentrations. On O3 polluted days, the carbonyl concentrations were 1.3–1.5 times higher than those on non-O3 polluted days. Secondary formation contributed more to formaldehyde (FA) and acetaldehyde (AA) on O3 polluted days, while the anthropogenic emissions were more significant for acetone (AC) on non-O3 polluted days. Vehicle exhaust and solvent utilization were the main primary contributors to carbonyls. Due to reduced anthropogenic emissions caused by the COVID-19 lockdown and the “Program for Controlling Volatile Organic Compounds in 2020” in China, the contributions of primary emissions to carbonyls decreased in 2020 in Beijing. Human cancer risks to exposed populations from FA and AA increased with elevated O3 levels, and the risks still remained on non-O3 polluted days. The residents around the BJUT site might experience relatively higher human cancer risks than those around the other two sites. The findings in this study confirmed that atmospheric carbonyl pollution and its potential human health hazards cannot be ignored in urban Beijing; therefore, more strict control strategies for atmospheric carbonyls are urgently needed to better protect human health in Beijing in the future.

Measurement report: Intra- and interannual variability and source apportionment of volatile organic compounds during 2018–2020 in Zhengzhou, central China

Abstract. Ambient volatile organic compounds (VOCs) were measured continuously from January 2018 to December 2020 at an urban site in Zhengzhou (China) to investigate their characteristics, sources, atmospheric oxidation capacity (AOC), and chemical reactivity. During the sampling period, the total concentration of observed VOCs was 94.3±53.1 µg m−3, and alkanes were the major VOC species, accounting for 58 % of the total. During the sampling period, the interannual variation in VOCs gradually reduced from 113.2±65.2 µg m−3 in 2018 to 90.7±52.5 µg m−3 in 2019 and 79.1±41.7 µg m−3 in 2020. Ethane and propane were the top two most abundant species during the 3-year observation period. Results showed that the total AOC, dominated by OH radical reactions, was 7.4×107 molec. cm−3 s−1. Total OH reactivity was 45.3 s−1, and it was mainly contributed by NOx. The AOC and ⚫OH reactivity both exhibited well-defined seasonal and interannual patterns. Therefore, control strategies should focus on the key species given their interannual and seasonal variations. Meanwhile, diagnostic ratios of VOC species indicated that VOCs in Zhengzhou were greatly affected by vehicle emissions and liquid petroleum gas/natural gas (LPG/NG). Positive matrix factorization analysis identified six sources: industrial sources, solvent use, vehicle emissions, LPG/NG, fuel burning, and biogenic sources. Vehicle emissions and industrial sources made the largest contributions to VOC emissions in each of the 3 years. The proportion of the contributions of vehicle emissions and LPG/NG increased with each passing year. However, the proportion of industrial and solvent sources presented a decreasing trend, which reflects the remarkable effect of control policies. The effect of VOCs on O3 formation suggests that vehicle emissions and solvent use remain key sources. Therefore, it is necessary to formulate effective strategies for reducing ground-level O3, and those sources mentioned above should be strictly controlled by the regulatory authorities.

Non-growth inhibitory doses of dimethyl sulfoxide alter gene expression and epigenetic pattern of bacteria.

Although dimethyl sulfoxide (DMSO) is a widely used solvent in scientific research, drug screening settings, and biomedical applications, its solvent (vehicle) effects on biological processes are overlooked. Using Escherichia coli as a model, we aimed to investigate and evaluate the effects of low-dose DMSO-driven changes in bacterial cells in a comprehensive and multifaceted manner by combining Fourier transform infrared spectroscopy analyses, analytical cell-biology approaches, and high-throughput sequencing. Here, we show that the non-toxic (1.0 and 2.5%, v/v) DMSO doses reduce the cellular levels of reactive oxygen species, change the cellular nucleic acid content and DNA topology, affect the global 5-methylcytosine pattern of the genome, and modulate gene transcription. These results indicate that even at non-toxic concentrations, DMSO is not inert: it can alter validity by changing or masking the assessed activity of the analyte. Besides, this manuscript does not only highlight that the low, non-toxic solvent doses of DMSO impinge on biological processes, including genome structure and function, but also, the high-throughput sequence data obtained during the study offer a platform for future research to elucidate the mechanism of epigenetically regulated genes in bacteria. KEY POINTS: •A clear-cut differentiation between the low-dose DMSO-treated and -untreated bacteria by PCA and LDA. •Drastic alterations in the DNA topology and nucleic acids of DMSO-treated bacteria. •Changes in transcriptome and epigenetic signatures with the low-dose DMSO.

Analysis of a Typical Ozone Pollution Process in Guangzhou in Winter

This study focused on an ozone pollution event occurring in winter (January) in Guangzhou. Various influencing factors were analyzed, including various atmospheric trace gases, meteorological conditions during the whole pollution process, as well as the characteristics of the main O3 precursor volatile organic compounds (VOCs). The main sources of VOCs and the O3 formation regime were analyzed using an array of tools:the ozone potential formation (OFP), positive matrix factorization (PMF) model, and empirical kinetic modeling approach (EKMA) curve. Feasible strategies for O3 control were suggested. The results showed that O3 and NO2 exceeded the corresponding standards in this winter pollution event, when the concentrations of PM10 and PM2.5 were also high, differing from the air pollution characteristics in summer and autumn. Low boundary layer height (<75 m) and high atmospheric stability at night exacerbated the accumulation of ozone precursors and fine particles. Meteorological conditions such as the increased daytime temperature (5℃), stronger solar radiation (10%), and low horizontal wind speed (<1 m·s-1) favored photochemical reactions and promoted the formation of ozone and fine particles. VOCs were mainly composed of alkanes, and the proportions of alkanes and alkynes in winter were higher than those in the other seasons. Aromatics (xylenes and toluene) and propylene were the key VOCs species leading to O3 formation. The main VOCs sources were vehicle exhaust (22.4%), solvent usage (20.5%), and industrial emissions (17.9%); however, the source with highest OFP was identified as solvent usage. O3 formation in this event was in the VOCs-limited regime, and reducing O3 precursors in the VOCs/NOx ratio of 3:1 was effective and feasible for O3 control. This study explored the causes of an O3 pollution event in winter, which will serve as reference for the synergistic control of O3 and PM2.5 in heavy pollution seasons.

Species profile and reactivity of volatile organic compounds emission in solvent uses, industry activities and from vehicular tunnels

A survey was conducted of the volatile organic compounds (VOCs) released from sources of solvent use, industry activities and vehicle emissions in Guiyang, a capital city of China. Samples were collected by canisters and analyzed by GC-MS-FID. The species profiles of VOCs emitted from sources were obtained. Results showed that xylenes, ethylbenzene, acetone and dichloromethane were the characteristics species for painting, 2-propanol and ethyl acetate for printing, α-pinene for solid wood furniture manufacturing, and 2-butanone for biscuit baking. These characteristics species could be as tracers for the sources respectively. In most of samples from the solvent use, the benzene/toluene (B/T) ratio was less than 0.3, indicating that the ratio could be as the indicator for tracing the solvent use related sources. The results also suggested that the toluene/xylene (T/X) ratio be as the indicator to distinguish the VOCs sources of painting (<2) from the printing (>2). Aromatics contributed the most to ozone formation potential (OFP) of most painting and non-paper printing sources, and oxygen-containing VOCs (OVOCs) were major species contributing to OFP of the sources from food production and paper printing. The OFP of the VOCs emissions from vehicle in tunnels and from other manufactures were dominated by both aromatics and alkenes. The α-pinene could explain 56.94% and 32.54% of total OFP of the VOCs sources from filing cabinet and solid wood furniture manufacturing, which was rarely been involved in previous studies of VOCs source profiles, indicating that the species of concern for VOCs sources are still insufficient at present.

Characteristics and sources analysis of ambient volatile organic compounds in a typical industrial park: Implications for ozone formation in 2022 Asian Games

In this study, volatile organic compounds (VOCs) at a major industrial park in Yangtze River Delta Region, China, along with an urban site had been investigated for three years (2018–2020). The daily-mean concentration of total 97 VOCs in the industrial park (224.3 ± 139.1 μg/m3) was about twice that of urban site (112.0 ± 64.2 μg/m3). Halohydrocarbons were predominant VOCs species at both sites accounting for 39.0 % and 32.2 % in industrial and urban sites, respectively. Annual-average concentrations of total VOCs slowed down gradually in industrial park, while that of the urban site increased annually. Evident seasonal and diurnal variations were observed for VOCs concentration in both sites. Higher VOCs concentrations appeared in summer for industrial park, and high concentrations generally appeared at 8:00 and 19:00–20:00 in two sites. Diagnostic ratios of m/p-xylene to ethylbenzene indicated vehicle emissions and solvent volatilization were main sources of VOCs in industrial site during winter. Further positive matrix factorization identified fuel usage and industry source as major sources in industrial park and urban site, respectively. Ozone formation potential calculations showed aromatics contributed most to ozone formation, and benzyl chloride was a key species when its concentration was high. Further empirical kinetic modeling approach revealed ozone formation in industrial park was in VOCs-limited regime. Through air mass trajectory analysis, air pollutants especially ozone from industrial park will be transported to stadiums by northeast wind during the 2022 Asian Games. The reductions in VOCs emissions from industrials are highly recommended for ozone control in 2022 Asian Games.

Characteristics and sources of volatile organic compounds (VOCs) in Xinxiang, China, during the 2021 summer ozone pollution control

Real-time monitoring of volatile organic compounds (VOCs) was conducted in Xinxiang, China, during the implementation of Xinxiang's ozone pollution control period (CP) in June 2021. To evaluate the effectiveness of the control measures, three study periods were determined by combining meteorological conditions and the implementation time of the control measures: before, during, and after the CP of ozone pollution (BCP, CP, and ACP, respectively). The average concentrations of VOCs during the three periods were 41.20 ± 4.99 ppbv, 33.64 ± 5.65 ppbv, and 37.42 ± 2.59 ppbv, respectively, with the same top three components, namely oxygenated VOCs (OVOCs), alkanes, and halogenated hydrocarbons (XVOCs). However, the concentrations of these three components decreased substantially during the CP (by 19 %, 18 %, and 11 %, respectively). The ozone formation potential (OFP) during the BCP was 144.47 ppbv, which was 1.2 times and 1.3 times higher than those during the ACP and CP periods, respectively. During the CP, the proportion of alkenes that contributed to the OFP decreased significantly by 24 %. Five types of VOCs sources were determined by positive matrix factorization (PMF): (1) solvent use, (2) biogenic, (3) secondary formation, (4) industrial process, and (5) vehicle exhaust and fuel evaporation sources. The VOCs emissions from industrial processes decreased by 54 % during the CP, whereas those from vehicle exhaust and fuel evaporation sources decreased by 36 %, indicating the effectiveness of emission control measures and the importance of these two sources for VOCs control in Xinxiang. In terms of regional transport, the results of the spatial analysis revealed that Hebi and Anyang in the northeast and Zhengzhou and Pingdingshan in the southwest, affected significantly the VOCs of Xinxiang. These results highlight the importance of controlling VOCs emissions in Xinxiang. Furthermore, attention should be paid to controlling the regional transport of surrounding cities.

Ecotoxic effects of the vehicle solvent dimethyl sulfoxide on Raphidocelis subcapitata, Daphnia magna and Brachionus calyciflorus

ABSTRACT Dimethyl sulfoxide (DMSO) is widely used as a vehicle solvent in ecotoxicity bioassays.Despite its frequent use, it could be toxic for organisms at some concentrations. Hence, this study aims to investigate the effects of DMSO on the model organisms: microalgae Raphidocelis subcapitata, microcrustacean Daphnia magna, and rotifer Brachionus calyciflorus. DMSO was applied to the organisms in concentrations ranging from 0.031% to 4%. For R. subcapitata the lowest observed effect concentration (LOEC) after 72 h of exposure was 0.125% DMSO. The 50% effective concentration (EC50) was 2.138 ± 0.372%. In D. magna, significant differences in the mobility after 24 h or 48 h of exposure were observed for 1% DMSO being 1.712 ± 0.207% and 1.167 ± 0.220% DMSO the EC50 observed for 24 h and 48 h exposure, respectively. For B. calyciflorus, it was not possible to validate the tests performed, as there were insufficient animals alive in the control conditions at the end of the exposure period. Therefore, we recommended avoiding DMSO as a vehicle in assays using B. calyciflorus, and to use final DMSO concentrations in an experimental solution not exceeding 0.125% for R. subcapitata and 0.5% for D. magna. Finally, using a maximum of 0.01% DMSO is safe for the organisms tested. The effects of the vehicle solvent dimethyl sulfoxide (DMSO) were investigated in three aquatic model organisms, the microalgae Raphidocelis subcapitata, the microcrustacean Daphnia magna and the rotifer Brachionus calyciflorus. As a result, negative effects on growth rate for the algae population, immobilisation of daphnids and inhibition of rotifer reproduction was observed obtaining EC50 close to 1% of DMSO for all these cases.

Mice behavioural models with pooled data analysis of Gelsemium studies and new findings about Ignatia and Aconitum

Objective: We investigated the effects of three different homeopathic medicines in several dilutions/dynamizations on mice, using validated models which explore anxiety-like and emotional symptoms. Two complete series of investigations were performed in order to assess the activity of Gelsemium sempervirens; furthermore, we investigated Ignatia amara and Aconitum napellus in the same model systems.&#x0D; Methods: Mice of CD1 strain were randomized in different cages (minimum 8 mice per treated group in each experiment) and treatment solutions were coded in such a way that all protocols were carried out fully in blind. The indicated compounds at various centesimal dilutions/dynamizations, a control solution (the solvent vehicle of drugs, which was succussed before administration) or the reference drugs diazepam (1 mg/kg body weight) or buspirone (5 mg/kg body weight) diluted in the same succussed solvent were delivered intraperitoneally (0.3 ml/mice) for 9 days. A series of changes of animal behavior were assessed by the Light-Dark (LD) choice test and the Open-Field (OF) exploration test. Two series of studies with little technical differences, exploiting a total of 14 separate experiments, were carried out with Gelsemium, five complete experiments with Ignatia and four complete experiments with Aconitum. &#x0D; Results: In both series of experiments Gelsemium showed anxiolytic-like effects using both OF test (permanence and movement in centre area of field) and LD test (time spent in lit area and number of light-dark transitions). However, due to high variability of animal responses and possibly to some minor differences in protocols, those effects reached the threshold of statistical significance only in OF in the first series and only in LD in the second series. Cumulative analysis of the two series demonstrated a highly significant (p

Characteristics and Source of VOCs During O3 Pollution Between August to September, Langfang Development Zones

A total of 99 volatile organic compound(VOC) species were detected the Langfang development zones based on continuous monitoring using a ZF-PKU-1007 between August 25 and September 30, 2018. The concentrations, reactivity, and sources of VOCs were studied under different O3 concentrations using compositional analysis. The results showed that the average VOCs concentration during the research period was(75.17±38.67)×10-9, and was(112.33±30.96)×10-9, (66.25±34.84)×10-9 on pollution days and cleaning days, respectively(VOCs concentrations were 69.6% higher on pollution days). The contribution of VOCs species to the ozone formation potential(OFP) were ranked in the order aldehydes > aromatics > alkenes > alkanes. In the case of L·OH, the main contributions were from aromatics(30.0%) and alkenes(25.8%) on pollution days, while the contribution from aromatic alkenes(29.8%) was a slightly higher than aromatics(28.0%) on cleaning days. By applying the positive matrix factorization(PMF) model, five major VOCs sources were extracted, namely vehicle emissions(34.4%), solvent usage and evaporation(31.7%), the petrochemical industry(15.7%), combustion(11.1%), and plant emissions(7.9%). The contributions of solvent usage and evaporation and plant emission sources on pollution days were 13.1% and 1.2% higher than on cleaning days, respectively, which was likely due to relatively higher temperatures on these days. Therefore, vehicle emissions and solvent usage and evaporation should be priorities in VOCs control strategies for the Langfang development zones between August to September.