Risk Of Volatile Organic Compounds Research Articles

Effects of different inhibitors on emission characteristics, environmental impact and health risk of volatile organic compounds from asphalt binder

Volatile organic compounds (VOCs) of asphalt will cause adverse environmental impact and workers’ health risk, inhibitors can be used to reduce the emission of VOCs from asphalt. Three inhibitors, including activated carbon (AC), expanded graphite (EG) and hydrotalcite (MA), were used to modified asphalt in this work. The effects of inhibitors on the VOCs emission characteristics of asphalt were investigated at multiple levels of VOCs total concentration, groups distribution and components characteristics. 101 asphalt VOCs components were detected, among which alkane accounted for more than 50% of the total concentration, followed by aldehyde and benzene. AC with the largest specific surface area and pore capacity exhibited the best inhibitory effect on the emission of VOCs with total concentration inhibition rate of 45.58%, followed by MA, while excessive MA would have adverse effect. Over 90% of VOCs components emissions had been suppressed by AC and EG. And inhibitors had the best inhibitory effect on the emission of olefin and aldehyde in VOCs, followed by ketone, but had the worst inhibitory effect on alkane, which was due to the weak interactions between non-polar alkane and polar hydroxyl on the surface of inhibitors. Furthermore, the effects of different inhibitors on the environmental impact and health risk of VOCs from asphalt were also systematically studied. The highest total inhibition rate of OFP and SOAP from asphalt VOCs by AC was only 58.3% and 21.7%, which was ascribed to the limited suppression on OFP and SOAP generated by alkane and benzene. Meanwhile, the non-carcinogenic risk from asphalt VOCs was mainly caused by acrolein with a contribution rate of 80.0%, AC and EG can completely inhibit the emission of acrolein in asphalt VOCs, while MA showed the poor performance. The contribution rate of acetaldehyde to the carcinogenic risk of asphalt VOCs reached 93.7%, while inhibitors had limited inhibitory effects on its emissions. This study contributes to a deeper understanding of the correlation mechanism between inhibitors, emission reduction characteristics of asphalt VOCs and environmental-health benefits, which could provide theoretical support for the design of bituminous material with low environmental-health load.

Emission characteristics and probabilistic health risk of volatile organic compounds from leather sofa

Furniture is identified as a vital volatile organic compound (VOC) emission source in the indoor environment. Leather has become the most common raw and auxiliary fabric material for upholstered furniture, particularly with extensive consumption in sofas, due to its abundant resources and efficient functions. Despite being widely traded across the world, little research has been conducted on the VOCs released by leather materials and their health risk assessment in the indoor environment. Accordingly, this study investigated the VOC emissions of leather with different grades and the health risk of the inhalation exposure. Based on the ultra-fast gas phase electronic nose (EN) and GC-FID/Qtof, the substantial emissions of aliphatic aldehyde ketones (Aks), particularly hexanal, appear to be the cause of off-flavor in medium and low grade (MG and LG) sofa leathers. The health risk assessment indicated that leather materials barely pose non-carcinogenic and carcinogenic effects to residents. Given the abundance of VOC sources and the accumulation of health risks in the indoor environment, more stringent specifications concerning qualitative and quantitative content should be extended to provide VOC treatment basic for the manufacturing industry and obtain better indoor air quality.

Exploring the release of hazardous volatile organic compounds from face masks and their potential health risk

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. Of these detected VOCs, 142 substances were matched to a reported database of chemicals associated with plastic packaging; 30 substances were identified by the International Agency for Research on Cancer (IARC) as potential carcinogenic to humans; 6 substances were classified in the European Union as persistent, bioaccumulative, and toxic, or very persistent, very bioaccumulative substance. Reactive carbonyls were ubiquitous in masks, especially after exposure to light. The potential risk of VOCs released from the face masks were then accessed by assuming the extreme scenario that all the VOC residues were released into the breathing air within 3 h. The result showed that the average total concentration of VOCs (17 μg/m3) was below the criterion for hygienic air, but seven substances, 2-ethylhexan-1-ol, benzene, isophorone, heptanal, naphthalene, benzyl chloride, and 1,2-dichloropropane exceeded the non-cancer health guidelines for lifetime exposure. This finding suggested that specific regulations should be adopted to improve the chemical safety of face masks.

Multiple source apportionments, secondary transformation potential and human exposure of VOCs: A case study in a megacity of China

The Central Plain City Cluster represented by Zhengzhou is one of the most haze-polluted regions, especially for the heating period. As critical precursors of Secondary Organic Aerosol (SOA) and Ozone, the ambient Volatile Organic Compounds (VOCs) emitted from anthropogenic activities have aroused widespread concern. This study provided a revealing insight on the concentration level, chemical composition, multiple source apportionments (SAs), SOA formation potential (SOAp) and exposed health risk of VOCs before and during heating periods at a megacity site. The average concentrations of TVOCs during clear days before heating, pollution days before heating, clear days during heating, and pollution days during heating were 37.81 ± 17.21, 54.48 ± 17.83, 39.27 ± 16.38 and 63.98 ± 22.42 ppbv, respectively. Compared with the before heating period, the concentration of TVOCs increased by 3.9% and 17.4% on clear days and polluted days during the heating period, respectively. Among them, alkanes were the most abundant species of VOCs, followed by halocarbons and alkenes. The multiply SAs methods were applied to identify potential sources, and the contributions of source structures were reasonable and credible by comparing PMF and emission inventory. Vehicular exhaust was the largest contributor during the non-heating period (33.2%), while for the heating period, combustion source contributed the most to VOCs emission (24.2%). In terms of the contribution to SOAp formation, aromatics were the most abundant VOCs species, and combustion (29.4%) was the major source, followed by solvent usage (26.5%) and vehicular exhaust (24.6%). The non-carcinogenic risks of VOCs sources were significantly lower than the acceptable safety threshold, while all the specific VOCs sources posed carcinogenic risks except for biogenic emission. The ways of analysis and assessment in this study can highlight the need for more effective control strategies related to VOCs anthropogenic activities during the heating period in megacities of Central China.

Generation characteristics and spreading risk of VOCs released from a biological fermentation pharmaceutical factory.

Pharmaceutical factories produce a large amount of volatile organic compounds (VOCs), which may pose a potential health threat to the environment, workers, and nearby residents. Sampling points were set up in the tylosin biological fermentation workshop (FW) and sewage treatment station (STS) of a pharmaceutical factory in a central city in northern China to collect VOCs and study their generation characteristics and diffusion. The results indicated that with the increase in fermentation time, VOC production decreased gradually, and the decline was rapid. The main VOCs produced by the FW are oxygen-containing organics and nitrogen-containing organics including 1-heptyladehyde (8.86 × 102 mg m-3), 1-methyl-2-pyrrolidone (6.36 × 102 mg m-3) and benzene (5.85 × 102 mg m-3). The STS mainly produces nitrogen-containing organics and oxygen-containing organics including 1-methyl-2-pyrrolidone (3.38 × 103 mg m-3), diethyl amine (9.60 × 102 mg m-3) and methyl ethyl ketone (2.98 × 102 mg m-3). VOCs produced by biopharmaceutical factories can diffuse for a long distance in the atmosphere. The highest concentration of chlorinated organic compounds can spread to 11.43 kilometers in the horizontal direction and 3 kilometers in the vertical direction. Acetaldehyde, butyraldehyde, diethylamine, butyl acetate and methyl ethyl ketone are odorous gases detected in the FW and STS, respectively. Benzene, carbon tetrachloride and acetaldehyde are the main carcinogenic VOCs produced in the fermentation process of tylosin. The research elucidated production characteristics, diffusion and health risks of VOCs in the FW, which provided a reference for the control of VOCs.

Preliminary Assessment of Occurrence, Potential Origin, and Human Health Risk of Volatile Organic Compounds in Uncontrolled Springs, North Morocco.

In recent years, with the drastic increase in worldwide pollution rates, considerable attention has been paid to the volatile organic compounds (VOCs) that might lead to serious health problems, e.g., cancer. As there appears to be a notable lack of research on the pollution (specifically, VOCs) of water bodies in Morocco, we aimed to assess the occurrence of VOCs in some uncontrolled springs in the north of Morocco that have not been previously investigated. We also discuss the estimation of health risks posed by ingestion and dermal contact as well as the different potential origins of these pollutants. For this purpose, water samples were collected from twenty-six sampling sites and were analyzed via headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry (HS-SPME-GC-MS). Out of the 60 suspected VOCs, a total of 15 compounds belonging to five distinct groups were identified and quantified. Among them, fumigants, solvents, and gasoline hydrocarbons were the most abundant groups, with proportions of 40%, 26.7%, and 20%, respectively. A heatmap clustered the provinces based on their degree of pollution, while a dendrogram was used to classify the studied springs into six main groups. Regarding carcinogenic risk, all the samples were safe for consumption as well as for dermal contact, except for S17, S18, and S8, and S19, which might present a severe threat to inhabitants due to their contents of, respectively, naphthalene (2.1 × 10-3), chloroform (2.5 × 10-4), and cis and trans-dichlropropene (1.61 × 10-4 and 1.11 × 10-4). Our investigation revealed several anthropogenic sources of water contamination, which could aid authorities in limiting contamination spread in water bodies.

Emission behavior and impact assessment of gaseous volatile compounds in two typical rural domestic waste landfills

Landfill sites are sources of gaseous volatile compounds. The dumping area (LDA) and leachate storage pool (LSP) of two typical rural domestic waste landfill sites in north China (NLF) and southwest China (SLF) were investigated. We found that 45, 46, 61 and 68 volatile organic compounds (VOC) were present in the air of NLF-LDA, NLF-LSP, SLF-LDA, and SLF-LSP, respectively. And there were 27, 29, 35 and 37 kinds of odorous compounds being detected. Oxygenated compounds (>48.88%), chlorinated compounds (>6.85%), and aromatics (>5.46%), such as organic acid, 1-chlorobutane, and benzene, were the most abundant compounds in both landfills. The SLF-LDA had the highest olfactory effect, with a corresponding total odor activity value of 29,635.39. The ozone-formation potential analysis showed that VOCs emitted from SLF landfills had significantly higher potential for ozone formation than those from NLF landfills, with ozone generation potentials of 166.02, 225.86, 2511.82, and 1615.99 mg/m3 for the NLF-LDA, NLF-LSP, SLF-LDA, and SLF-LSP, respectively. Higher chronic toxicity and cancer risk of VOCs were found in the SLF according to method of Risk Assessment Information System. Based on the sensitivity analysis by the Monte Carlo method, concentrations of benzene, propylene oxide, propylene, trichloroethylene, and N-nitrosodiethylamine, along with exposure duration, daily exposure time, and annual exposure frequency, significantly impacted the risk levels. We provide a scientific basis, which reflects the need for controlling and reducing gaseous pollutants from landfills, particularly rural residential landfills, which may improve rural sanitation.

Modeling of Inhalation Health Risk of Volatile Organic Compounds in the Vicinity of Maptaphut Petroleum and Petrochemical Industrial Estate, Thailand

The purpose of this research was to explicate a human health risk assessment that can be employed with inhalation risk estimates to provide a screening level of risks. Model input parameters provide reasonable values with the site- and compound-specific values relied on by the Human Health Risk Assessment Protocol (HHRAP). This method uses a generic risk assessment, consisting of air dispersion and deposition modeling followed by risk modeling. An intensive evaluation was conducted in the surrounding area of the largest petroleum and petrochemical estate in Thailand, the Maptaphut industrial area, where a large volume of VOCs was emitted, with an increasing negative health impact on the local population. The potential inhalation health risk assessment showed that the lifetime cancer risk in all residential areas is higher than the health benchmarks. The highest cancer risk was 7.82 × 10−2 in children and 3.91 × 10−1 in adults. The inhalation effects are based on the specific emission rates, the united concentrations and deposition fluxes, and the emission phase. The results revealed that four VOCs (benzene, 1,3-butadiene, vinyl chloride, and 1,2-dichloroethane) should be given priority when controlling for sustainable health risk management through the comprehensive analysis of the integrated analysis of air dispersion and health risk mathematical models.

Species profiles, in-situ photochemistry and health risk of volatile organic compounds in the gasoline service station in China

Accompanying with increases in vehicle population and gasoline consumption, gasoline evaporation accounted for an enlarged portion of total volatile organic compound (VOC) emissions in China, raising increasing environmental concerns especially in megacities. In this study, an intensive sampling campaign was performed in a gasoline service station, to reveal emission characteristics, environmental and health impacts of VOCs. It was strikingly found that 24 % of air samples exceeded the national standard of 4 mg/m3 for non-methane hydrocarbons (NMHCs) on the boundary of the station, with the equipment of Stage I and II controls. VOC groups and species profiles showed that alkanes dominated total VOCs. As typical markers of evaporative loss of gasoline, C4–5 species (i-pentane, n-pentane and n-butane) as well as methyl tert-butyl ether (MTBE) accounted for 49.6 % of VOCs. Species profile and diagnostic ratios indicated the prominent contribution of gasoline evaporative losses from refueling or breathing processes, as well as the interference of vehicle exhaust in the ambient air at the site. Intensive O3 production was reproduced by the photochemical box model, demonstrating that O3 formation was co-limited by both VOCs (especially trans-2-butene) and NOx. Inhalation health risk assessment proved that exposure to hazardous VOCs caused non-cancer risk (HQ = 3.08) and definitely posed cancer risks at a probability of 1.3 × 10−4 to workers. Remarkable health risks were mainly imposed by halocarbons, aromatics and alkenes, in which 1,2-dichloropropane caused the highest non-cancer risk (HQ = 1.3) and acted as the primary carcinogen (ICR = 5.1 × 10−5). This study elucidated the high unqualified rate in gasoline service stations after the implementation of latest standards in China, where new regulations targeted halocarbons and updates in existing vapor recovery systems were suggested for VOC mitigation.

Pollution characteristics and risk assessment of air multi-pollutants from typical e-waste dismantling activities

This study investigated the characteristics of air multi-pollutants emitted during typical electronic waste (e-waste) dismantling processes and assessed their risks to the environment and human health. Concentrations of total volatile organic compounds (TVOCs), polybrominated diphenyl ethers (PBDEs), and polycyclic aromatic hydrocarbons (PAHs) in a typical e-waste dismantling workshop were 137 μg/m3, 135 ng/m3 and 42 ng/m3, respectively, which were lower than those without emission control measures. The partial removal of pollutants due to the emission control measures also decreased the ozone formation potential and non-cancer risk of volatile organic compounds (VOCs). In the workshop, the lifetime cancer risk (LCR) of VOCs (8.1 × 10−5) was close to the recommended values. Conversely, the LCR of PAHs (3.6 × 10−5) and the total exposure index of PBDEs (19 ng/d) were remarkably lower than the recommended values of 10−3 and that without emission control measures, respectively. Meanwhile, the concentrations of TVOCs, polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs), PBDEs, and PAHs in the outlet were approximately 10–30 times higher than those in the workshop. In addition, the LCR of TVOCs within a 5-km radius area remained higher than the accepted value (10−6), and the inhalation exposure risk of PCDD/Fs within a 20-km radius area was five times higher than the recommended value. Therefore, the emissions from e-waste recycling processes should be considered as an important source of air pollution, and more efficient control measures should be taken in the future.

Source, temporal variation and health risk of volatile organic compounds (VOCs) from urban traffic in harbin, China.

The main of this work investigated the levels, emission sources, and associated health risks of ambient volatile organic compounds (VOCs) closed urban traffic trunk from June 2017 to November 2018. The seasonal variation trend for total VOCs (TVOCs) concentrations was autumn>winter>summer>spring. During the daily fluctuations in summer, the TVOC concentrations appeared to be the highest at midnight and the lowest at 14:00. In spring, autumn, and winter, the concentrations of TVOCs reached the highest levels at 06:00 and dropped to the lowest levels at 14:00 to 15:00; then, the levels increased after 20:00. Aromatics were the most important types of ambient VOCs for the formation of secondary organic aerosols (SOAs). The Positive Matrix Factorization (PMF) source analysis indicated that the traffic emission accounted for 28.9% of TVOCs, followed by combustion (24.7%), industrial (21.3%), gasoline volatilization (12.4%), and solvent (11.7%) sources. Carcinogenic and non-carcinogenic risks via inhalation exposure to the selected 10 toxic VOCs may be of more concern for residents nearby traffic trunk in Harbin in autumn.

Emission Characteristics and Risk Assessment of Volatile Organic Compounds from Typical Factories in Zhengzhou

To understand the characteristics and potential hazards of volatile organic compounds (VOCs) emitted from different industrial factories in Zhengzhou, several representative factories have been selected for sample collection using canisters; the samples were subsequently analyzed by GC-MS/FID system, from which the composition and risk of VOCs are discussed in this study. It was found that OVOCs, especially ethyl acetate and isopropanol, were the most important species originating from printing factories, which accounted for more than 93.1% of total VOCs. The major components related to manufacturing industries, including automobile, furniture, and coating, were aromatics, mainly m/p-xylene, o-xylene, and ethylbenzene, which contributed 33.5%-90.0% to VOCs. Halogenated hydrocarbons made the largest contribution (52.3%) to VOCs in the food processing industry. The main components of VOCs were halogenoalkanes (25.5%) and alkanes (28.8%) in rubber factories. As for graphite carbon factories, the main components of VOCs were aromatics (28.5%) and alkanes (24.1%). Compared with previous studies, the VOC emission characteristics of factories involving solvent usage in Zhengzhou are consistent with those in other cities, but the compositional information of VOCs varies across different factories, even within the same industry, due to the different production processes and raw materials used. Risk assessment showed that the concentration of VOCs emitted from solvent factories are positively correlated with ozone formation potential (OFP) and the hazard index (HI). Specifically, benzene, toluene, ethylbenzene, xylene, and other C6-C8 aromatic hydrocarbons contributed significantly to OFP and HI. The HI values were 1.18 and 2.74 in automobile manufacturing factory NO.3 and wooden furniture factory NO.5, respectively, which were higher than the limits stated by EPA regulations because of the different production processes and raw materials, and the VOCs of the factories were mainly composed of aromatics; in particular, C6-C9 benzene series contributed significantly to HI and OFP. Therefore, it is necessary to control VOCs originating from industries involving solvent usage.

Characteristics of exposure and health risk air pollutants in public buses in Korea.

The objective of this study was to estimate the concentrations of indoor air pollutants in unregulated public transport means in Korea and to determine the factors affecting the air quality as well as to assess the harmful effects of indoor air pollutants on the health of passengers. The correlation between particulate matter (PM10) and number of passengers on intra-city buses, express buses, town shuttle buses, or rural buses was insignificant whether it was during rush hours or non-rush hours. In regard to PM10 on express buses, there was no case where the standard limit was exceeded during the winter and summer seasons. In winter, however, the average concentration of PM10 increased by the travel distance. In regard to CO2, there was a statistically significant correlation (p < 0.05) between CO2 concentrations and the number of passengers, owing to human respiration. Unlike the case of PM10, there was a difference between rush hours and non-rush hours. Regarding volatile organic compounds (VOCs) and aldehydes, the values were high among recently manufactured vehicles regardless of bus types. The standard limit was exceeded during the summer season, which seemed to be related to the temperature and humidity in both indoor and outdoor. The results of this study indicate that the excess mortality resulting from PM10 was as high as the safety margin during both non-rush hours and rush hours among all unregulated public transportation means. The excess cancer risk and non-cancer risk of VOCs and aldehydes were as high as the safety margin during both non-rush hours and rush hours.

Quantitative structure activity relationship (QSAR) modelling of the degradability rate constant of volatile organic compounds (VOCs) by OH radicals in atmosphere

The reaction with hydroxyl radicals (•OH) is an important way to remove the most volatile organic compounds (VOCs) in atmospheric environment. Thus, the reaction rate constant (kOH) is important for assessing the persistence and exposure risk of VOCs, and is of great significance in evaluating the ecological risk of volatile organic chemicals. Fukui indices and bond order have a large effect on the degradation of VOCs, but so far, quantitative structure activity relationship (QSAR) models for VOCs degradation have rarely been considered these two factors. In this study, these two momentous factors will be considered along with other relevant quantitative parameters. A total of 180 substances are divided into training set (144 substances) and test set (36 substances), which are used to build and validate quantitative structure activity relationship (QSAR) models, respectively. Internal, external verification and y-randomization tests showed that the established model had excellent stability and reliability. The energy of the highest occupied molecular orbital (EHOMO), the possibility of being attacked by radicals (f (0)n) and the breaking of chemical bonds (BOx) are the main factors affecting VOCs removal. Finally, the scope of the application domain was determined and the robustness of the model was further verified.

Distribution Characteristics of Volatile Organic Compounds and Contribution to Ozone Formation in a Coking Wastewater Treatment Plant.

Ozone pollution, which can be caused by photochemical reactions, has become a serious problem. The ozone formation potential (OFP) is used to describe the photochemical reactivity. Volatile organic compounds (VOCs) are main precursors of ozone formation, and wastewater treatment plants (WWTPs) are important sources of VOCs. Therefore, it is necessary to study the concentration level and OFP of VOCs from WWTPs. In this work, a coking WWTP with anaerobic-oxic-oxic (A/O/O) processes in Shaoguan city, Guangdong province, China, was selected to investigate the characteristics of VOCs at wastewater treatment areas and office areas. The OFP of VOCs was estimated by the maximum incremental reactivity (MIR) coefficient method. Results showed that 17 VOCs were detected, and the total concentration of VOCs was the highest at the raw water tank (857.86 μg m−3). The benzene series accounted for 69.0%–86.9% and was the main component of VOCs in the WWTP. Based on OFP data, the top six VOCs contributing most to the OFP were m-xylene, toluene, p-xylene, o-xylene, styrene, and benzene. This study provides field data and information on the environmental risk of VOCs for coking companies and environmental departments. We found that the priority control sources of VOCs were wastewater treatment units because of their larger OFP contributions.

Environmental impact and health risk assessment of volatile organic compound emissions during different seasons in Beijing

Volatile organic compounds (VOCs) are major contributors to air pollution. Based on the emission characteristics of 99 VOCs that daily measured at 10 am in winter from 15 December 2015 to 17 January 2016 and in summer from 21 July to 25 August 2016 in Beijing, the environmental impact and health risk of VOC were assessed. In the winter polluted days, the secondary organic aerosol formation potential (SOAP) of VOC (199.70 ± 15.05 μg/m3) was significantly higher than that on other days. And aromatics were the primary contributor (98.03%) to the SOAP during the observation period. Additionally, the result of the ozone formation potential (OFP) showed that ethylene contributed the most to OFP in winter (26.00% and 27.64% on the normal and polluted days). In summer, however, acetaldehyde was the primary contributor to OFP (22.00% and 21.61% on the normal and polluted days). Simultaneously, study showed that hazard ratios and lifetime cancer risk values of acrolein, chloroform, benzene, 1,2-dichloroethane, acetaldehyde and 1,3-butadiene exceeded the thresholds established by USEPA, thereby presenting a health risk to the residents. Besides, the ratio of toluene-to-benzene indicated that vehicle exhausts were the main source of VOC pollution in Beijing. The ratio of m-/p-xylene-to-ethylbenzene demonstrated that there were more prominent atmospheric photochemical reactions in summer than that in winter. Finally, according to the potential source contribution function (PSCF) results, compared with local pollution sources, the spread of pollution from long-distance VOCs had a greater impact on Beijing.

Emission characteristics and associated health risk assessment of volatile organic compounds from a typical coking wastewater treatment plant.

Coking wastewater is a typical industrial wastewater and contains a number of toxic and harmful organic pollutants which threaten human health. However, emission of volatile organic compounds (VOCs) from coking wastewater treatment plants (WWTPs) is rarely studied. Here, the emission characteristics of VOCs were investigated in a full-scale coking WWTP composed of an anaerobic-oxic-oxic (A-O1-O2) treatment system. Furthermore, the potential health risks were assessed in this study. VOC emission rates were estimated at each unit of the coking WWTP and the influencing factors of emissions were discussed. Seventeen VOCs were identified in the air phase by gas chromatography-mass spectrometry combined with Tenax adsorption-thermal desorption method; benzene, toluene, and xylenes were predominant, and the concentration of total VOCs decreased gradually from the raw water tank (857.86 ± 131.30 μg m-3) to the effluent tank (28.56 ± 3.96 μg m-3). The total VOC emission rate from all units was 1773.42 g d-1, corresponding to an annual emission of 0.65 tons year-1. Since the treatment capacity of this coking WWTP was about 1500 m3 d-1, it was estimated that 1.18 g of VOCs are emitted during the treatment of 1 m3 wastewater. Influencing factors of VOC emission mainly include the background concentration of VOCs in wastewater, operational parameters of the treatment processes, and physicochemical properties of VOCs. The carcinogenic risk of VOCs for workers in this coking WWTP ranged from 3.0 × 10-5 to 7.8 × 10-4, which exceeded an acceptable level (1.0 × 10-6). The non-carcinogenic risk hazard ratio of benzene exceeded 1, indicating that benzene has an obvious non-carcinogenic risk. Understanding VOCs emission characteristics and emission rates can help to identify the adverse effects of coking WWTPs on human health and provide relevant information for policy-making.

Emission sources and probabilistic health risk of volatile organic compounds emitted from production areas in a petrochemical refinery in Hainan, China

The emission sources and health risks of volatile organic compounds (VOCs) were analyzed and evaluated in a typical petrochemical refinery in Hainan, China. The sources and levels of 9 VOCs in five production areas were identified and qualified, and the probabilistic risk assessment method was employed to obtain more reasonable and scientific outcomes specifically realized by inhalation risk model and Monte Carlo simulation. Sensitivity and uncertainty analysis were also conducted to determine the influential factors in the risk evaluation process. The results indicated that for the refinery benzene, toluene, ethyl benzene, and xylene were the primary pollutants in these production areas, where the aromatic hydrocarbon extraction device (AHED) and xylene fractionation device areas are main contributors. In terms of non-carcinogenic risk, the largest hazard index existed in AHED area. The non-carcinogenic risk values for all production areas were not more than 1. The risk value of substances such as benzene still exceed the carcinogenic risk value of 10−6, indicating these substances existed potential carcinogenic risk to workers. Meanwhile, the findings can help to accumulate basic data for VOCs research in different installations of refineries, and provide evidence for VOCs pollution prevention and control.

Emission characteristics and probabilistic health risk of volatile organic compounds from solvents in wooden furniture manufacturing

The sources, levels and health risks of volatile organic compounds emitted from the entire furniture manufacturing process in workshops were investigated. A probabilistic health assessment model was established to estimate the health risks of workers and managers caused by VOCs (volatile organic compounds) based on the inhalation risk model and the Monte Carlo method. Sensitivity analyses and uncertainty analyses were implemented to screen out the crucial input parameters and to identify the possible influential factors in the evaluation process. The results demonstrate that the highest concentration of VOCs occurs in the topcoating process, followed by the veneering, undercoating, edge bonding, polishing varnish, drying, and paint mixing processes. Overall, a total of 17 VOCs, including aromatic hydrocarbons, alkanes, halogenated alkanes, ketones, and saturated aliphatic esters, exist in 7 VOC emission processes in the wood processing workshop and the painting workshop. For health impacts, workers in the topcoating, undercoating, and veneering positions suffer the greatest carcinogenic risks, with mean values above 1.00E-05, which mainly originate from ethylbenzene, dichloromethane, and benzene. The carcinogenic risks in other positions are relatively lower and are in the sequence of polishing varnish, paint mixing, drying, and edge bonding. Sensitivity analyses indicated that exposure duration had the greatest impact on carcinogenic and non-carcinogenic risk, with an average contribution of 0.78 and 0.93, respectively. These comprehensive evaluations for exposure level and health risk can yield insight into the occupational hazards of VOC emissions and will contribute to informed decision-making related to abatement measures and risk management in furniture manufacturing workplaces.

Measurement of volatile organic compounds and associated risk assessments through ingestion and dermal routes in Dongjiang Lake, China

This study aims to investigate the occurrence, distribution and risk assessment of volatile organic compounds (VOCs) in Dongjiang Lake of China. Twenty two kinds of VOCs were detected, and the major VOCs were alkene compounds. The total concentration of VOCs (∑VOCs) ranged from 2.93 to 4.69 µg/L, and none of the VOCs detected in Dongjiang Lake exceeded the concentration limits set in the National Drinking Water Quality Standards (GB5749-2006) or the National Environmental Quality Standards for Surface Water (GB3838-2002) of China. Risk quotients (RQ) model, Multimedia Environment Pollutant Assessment System (MEPAS) and value of odor hazard index (OHI) were used to assess the ecological risk, lifetime carcinogenic risk and olfactory risk of VOCs in Dongjiang Lake, respectively. The RQtotal values varied from 3.95 × 10−3 to 0.34 and the RQ values for all the 22 detected VOCs in 12 sample locations of Dongjiang Lake were below 0.01, which means negligible risk to aquatic organisms. The cancerous and non-cancerous risk indices were in the range of 2.31 × 10−9–5.16 × 10−7 and 1.68 × 10−7–1.45 × 10−2, respectively. Bromodichloromethane and 1,1-dichloroethene were associated with the highest and lowest carcinogenic risks in all 12 sample locations. Results also demonstrated that the olfactory risk in Dongjiang Lake is negligible. These data suggest that the VOCs in Dongjiang Lake may not lead great ecological and health risks for organism and human.