Investigation of health risk assessment and odor pollution of volatile organic compounds from industrial activities in the Yangtze River Delta region, China

Research on pollution identification and safety thresholds based on the olfactory effect on a halogenated hydrocarbon contaminated site

To effectively address odor control issues at sites contaminated with halogenated hydrocarbons, it is essential to establish an odor risk prediction system for evaluating potential risks that may impact future planning. This research focuses on a representative halogenated hydrocarbon-contaminated site, examining the spatial and temporal distribution characteristics of key pollutants in soil gas. By analyzing odor contribution rates, the study identifies significant odorants in soil gas, which enables the derivation of both probabilistic and deterministic safety thresholds for soil and groundwater based on olfactory effects. The findings indicate that 1,1-dichloroethylene, vinyl chloride, chloroform, and 1,1-dichloroethane are prevalent throughout the contaminated site, displaying elevated concentration levels and substantially influencing the overall contamination extent. These substances are highlighted as critical pollutants requiring attention. Correlation analysis (P < 0.05) reveals a strong relationship between the concentrations of vinyl chloride, 1,1-dichloroethane, and chloroform with groundwater depth and air temperature. Additionally, the analysis of odor activity values (OAV) identified 1,1-dichloroethene, 1,4-dichlorobenzene, chlorobenzene, chloroform, and vinyl chloride as key olfactory factors at the site. The corresponding probabilistic safety thresholds are 0.68, 1.65, 0.50, 7.87, and 3.72 mg kg-1 for soil, and 9.29, 3.46, and 1.09, 69.55, and 47.01 mg L-1 for groundwater, respectively. Among them, the odor risks of chlorobenzene and 1,1-dichloroethylene warrant more attention than soil contamination risks; regarding 1,4-dichlorobenzene, it is recommended to concurrently consider odor risks during human health risk assessment; as for vinyl chloride and chloroform, their odor risks can be largely eliminated based on human health-oriented pollution management.

Derivation of human health and odor risk control values for soil ammonia nitrogen by incorporating solid-liquid partitioning, ammonium/ammonia equilibrium: A case study of a retired nitrogen fertilizer site in China

Nitrogen fertilizer supports agricultural intensification, but its manufacturing results in substantial contaminated sites. Ammonia nitrogen is the main specific pollutant in retired nitrogen fertilizer sites with potential human health and odor risks. However, few studies focus on ammonia nitrogen risk assessment at contaminated sites, particularly considering its solid-liquid partitioning process (Kd) and ammonium/ammonia equilibrium process (R) in the soil. This study took a closed nitrogen fertilizer factory site as an example and innovatively introduced Kd and R to scientifically assess the human health and odor risk of ammonia nitrogen. The risk control values (RCVs) of ammonia nitrogen based on human health and odor risk were also derived. The maximum concentration of ammonia nitrogen was 3380 mg/kg in the unsaturated soil, which was acceptable for human health because the health RCVs were 5589 ∼ 137,471 mg/kg in various scenarios. However, odor risk was unacceptable for RCVs were 296 ∼ 1111 mg/kg under excavation scenarios and 1118 ∼ 35,979 mg/kg under non-excavation scenarios. Of particular concern, introducing Kd and R in calculation increased the human health and odor RCVs by up to 27.92 times. Despite the advancements in ammonia risk assessment due to the introduction of Kd and R, odor risk during excavation remains a vital issue. These findings inform a more scientific assessment of soil ammonia risk at contaminated sites and provide valuable insights for the management and redevelopment of abandoned nitrogen fertilizer plant sites.

Unlocking the secrets: Volatile Organic Compounds (VOCs) and their devastating effects on lung cancer

Lung cancer (LCs) is still a serious health problem globally, with many incidences attributed to environmental triggers such as Volatile Organic Compounds (VOCs). VOCs are a broad class of compounds that can be released via various sources, including industrial operations, automobile emissions, and indoor air pollution. VOC exposure has been linked to an elevated risk of lung cancer via multiple routes. These chemicals can be chemically converted into hazardous intermediate molecules, resulting in DNA damage and genetic alterations. VOCs can also cause oxidative stress, inflammation, and a breakdown in the cellular protective antioxidant framework, all of which contribute to the growth of lung cancer. Moreover, VOCs have been reported to alter critical biological reactions such as cell growth, apoptosis, and angiogenesis, leading to tumor development and metastasis. Epidemiological investigations have found a link between certain VOCs and a higher probability of LCs. Benzene, formaldehyde, and polycyclic aromatic hydrocarbons (PAHs) are some of the most well-researched VOCs, with comprehensive data confirming their cancer-causing potential. Nevertheless, the possible health concerns linked with many more VOCs and their combined use remain unknown, necessitating further research. Identifying the toxicological consequences of VOCs in LCs is critical for establishing focused preventative tactics and therapeutic strategies. Better legislation and monitoring mechanisms can limit VOC contamination in occupational and environmental contexts, possibly reducing the prevalence of LCs. Developing VOC exposure indicators and analyzing their associations with genetic susceptibility characteristics may also aid in early identification and targeted therapies.

Significance of Volatile Organic Compounds to Secondary Pollution Formation and Health Risks Observed during a Summer Campaign in an Industrial Urban Area

The chemical complexity and toxicity of volatile organic compounds (VOCs) are primarily encountered through intensive anthropogenic emissions in suburban areas. Here, pollution characteristics, impacts on secondary pollution formation, and health risks were investigated through continuous in-field measurements from 1-30 June 2020 in suburban Nanjing, adjacent to national petrochemical industrial parks in China. On average, the total VOCs concentration was 34.47 ± 16.08 ppb, which was comprised mostly by alkanes (41.8%) and halogenated hydrocarbons (29.4%). In contrast, aromatics (17.4%) dominated the ozone formation potential (OFP) and secondary organic aerosol formation potential (SOAFP) with 59.6% and 58.3%, respectively. Approximately 63.5% of VOCs were emitted from the petrochemical industry and from solvent usage based on source apportionment results, followed by biogenic emissions of 22.3% and vehicle emissions of 14.2%. Of the observed 46 VOC species, hexachlorobutadiene, dibromoethane, butadiene, tetrachloroethane, and vinyl chloride contributed as high as 98.8% of total carcinogenic risk, a large fraction of which was ascribed to the high-level emissions during ozone pollution episodes and nighttime. Therefore, the mitigation of VOC emissions from petrochemical industries would be an effective way to reduce secondary pollution and potential health risks in conurbation areas.

Emission characteristics, environmental impact, and health risk assessment of volatile organic compounds (VOCs) during manicure processes

In recent years, the nail industry has been widely popular in China, and the use of nail care products has also significantly increased. Due to its high content of volatile solvents, the released VOCs not only have a negative impact on indoor air quality but also pose a health threat to nail salon workers who are highly exposed to such environments. The objectives of this research were to characterize VOCs emissions from detailed manicure processes and to evaluate the impact on the environment and health risks. Results showed that the VOCs concentration in the anti-warping treatment process was much higher than that in other manicure steps, at 360.69 mg/m3, making its contributions of OFP and SOA equally prominent. The trend of concentration contribution was similar to that of OFP, and OVOCs were the most significant contributor to the VOCs components in the whole manicure process. Since organic solvent nail gels were also frequently used in most steps, the main VOCs were methanol, ethanol and ethyl acetate. Aromatics were the component that contributed the most to SOA, and its contributions in all processes were >85 %. Health risk assessments performed in our study indicated that acrolein was the main non-carcinogen, and the carcinogenic risk of this study could be ignored. The results of this study can be used as a basis for controlling VOCs emission and reducing exposure to VOCs in nail salons.

Process-specific volatile organic compounds emission characteristics, environmental impact and health risk assessments of the petrochemical industry in the Beijing-Tianjin-Hebei region

Volatile organic compounds (VOCs) concentration, source profiles, O3 and SOA formation, and health risks were investigated in the petrochemical industry in Beijing-Tianjin-Hebei. The results showed that total VOCs concentrations were 547.1-1956.5 μg·m-3, and alkanes were the most abundant group in all processes (31.4%-54.6%), followed by alkenes (20.6%-29.2%) and aromatics (10.1%-25.1%). Moreover, ethylene (11.3%), iso-pentane (7.1%), n-hexane (5.1%), benzene (4.9%) and 2,2-dimethylbutae (4.8%) were identified as the top five species released for the whole petrochemical industry. The coefficient of divergence between the source profiles from different processes was 0.49-0.73, indicating that most source profiles must not be similar. Moreover, because of the different raw materials and technologies used, the source profiles in this study are significantly different from those of other regions. The ozone and secondary organic aerosol formation potentials (OFPs and SOAPs) were evaluated, suggesting that ethylene, propylene, 1-butene, m,p-xylene, and 1,3-butadiene should be preferentially controlled to reduce OFPs. That benzene, toluene, ethylbenzene, m,p-xylene, isopropylbenzene, o-ethyltoluene, and 1,3,5-trimethylbenzene should be priority control compounds for SOAPs. Additionally, the total hazard ratio for non-cancer risk ranged from 0.9 to 7.7, and only living area was unlikely to be related to adverse health effects. Cancer risks associated with organic chemicals, rubber synthesis, oil refining, and wastewater collection and treatment have definite risks, whereas other processes have probable risks. This study provides a scientific basis for VOCs emission control and management and guides human health in the petrochemical industry.

An Analysis of the Spatial Characteristics and Transport Fluxes of BTEX in Soil and Atmospheric Phases at a Decommissioned Steel Mill Site in China with a Long History

BTEX (benzene, toluene, ethylbenzene, and xylene), as characteristic pollutants in chemical plant sites, are widely present in the environment and pose a serious threat to the health and safety of nearby residents. Studying the spatial distribution characteristics and transport fluxes of BTEX in soil and air at contaminated sites and the health risks they pose to humans is of great significance for fine pollution control and environmental management. This study took a typical decommissioned steel plant as a case study. A total of 23 soil and air samples were collected from different locations to investigate the spatial distribution characteristics of BTEX in soil and air. The transport and fate of BTEX in soil and air were evaluated using the fugacity model, and finally, a human health risk assessment was conducted. The results indicate a relatively severe level of benzene pollution in both soil and air. The maximum exceedance factor of benzene in soil samples is 31.5, with the concentration exceedance depth at 1.5 m. The maximum concentration of benzene in air samples is 4.98 μg·m-3. Benzene, at 5.9% of the site, shows a low flux with negative values, while other components at various locations all exhibit a trend of transport from the soil phase to the atmospheric phase. Benzene is the pollutant that contributes the most to the transport flux from soil to air within the site. The coking area and sewage treatment area are key areas within the steel mill where BTEX accumulate easily in the soil. The non-carcinogenic risk values of the individual components of BTEX in the soil are below the acceptable risk level. However, the carcinogenic risk value of benzene in the children's exposure scenario exceeds the carcinogenic risk level of 10-6. The carcinogenic risk range of various components of BTEX in the air is 2.63 × 10-6~3.88 × 10-5, with 28.6% of the locations exceeding the threshold of 10-6. The range of the total HI (hazard index) is 2.08 × 10-4~1.81 × 10-1, all of which is below the safety threshold of 1. The results of this study will provide scientific support for the fine pollution control and environmental management of industrial contaminated sites with BTEX as their typical pollutants.

Identification of priority pollutants at an integrated iron and steel facility based on environmental and health impacts in the Yangtze River Delta region, China

Emissions from the iron and steel industry are a major source of air pollution. To investigate the composition characteristics, estimate the secondary transformation potential, and assess the ecological risk and human health risks of air pollutants from iron and steel industry, field measurements of volatile organic compounds (VOCs) and trace metals (TMs) were conducted simultaneously from 2020 to 2022 in the Yangtze River Delta (YRD) region, China. The average mixing concentration of VOCs (Σ64VOCs) was 58.2 ppbv. Alkanes, alkenes and aromatics were the major components. Benzene and ethylene were the most abundant VOC species. In the O3 season, the calculated OH loss rates (LOH) and ozone formation potential (OFP) were 10.87 S-1 and 181.74 ppbv, respectively, which increased 39.54% and 21.51% compared to the non-O3 season. Furthermore, the O3-VOCs-NOx sensitivity indicated that O3 formation was under the VOCs-limited regime. The average concentration of total 10 trace metals (Σ10TMs) was 226.8 ng m-3, Zn, Pb and Mn were the top abundant TM species. The results also found that Se was extremely contaminated; Pb and Zn was heavily to extremely contaminated; Cu, As and Ni were moderately to heavily contaminated. For lifetime cancer risk, the cumulative carcinogenic risks were 1.84E-5 for children, 6.14E-5 for adults and 1.83E-5 for workers. The carcinogenic risks of individual chemicals cannot be ignored, especially for Cr, Ni, benzene and 1,3-butadiene. The hazard index values for workers and residents were 0.53 and 2.23, respectively, suggesting a high non-carcinogenic risks to the exposed population. These findings deepen the understanding of the pollutant character of the iron and steel industry, and provide theoretical support for policy development on O3 pollution treatment and human health in the YRD region, China. For the study area, we recommend utilizing high-quality raw coal, reducing the volatile hydrocarbon content in the sinter feed, and installing absorption device for highly reactive VOC components at the exhaust outlet.

Real-time emission characteristics, health risks, and olfactory effects of VOCs released from soil disturbance during the remediation of an abandoned chemical pesticide industrial site

Volatile organic compounds (VOCs) released along with soil disturbance during the remediation of abandoned industrial sites have attracted great attention due to their possible toxicity and odour. However, the real-time emission characteristics of these VOCs and their subsequent effects on health and olfaction are less understood. In this study, the gaseous VOCs released from soil disturbance by excavators and drilling rigs at an abandoned chemical pesticide plant were monitored online with a laboratory-built single photoionization time-of-flight mass spectrometer (SPI-TOFMS). Twelve main VOCs with total mean concentrations ranging from 2350 to 3410 μg m-3 were observed, with dichloromethane (DCM) having a significant contribution. The total concentrations of the remaining 11 VOCs increased substantially during soil disturbance, with the total mean concentrations increasing from 18.65-39.05 to 37.95-297.94 μg m-3 and those of peak concentrations increasing from 28.46-58.97 to 88.38-839.13 μg m-3. This increase in VOC concentrations during soil disturbance leads to an enhanced heath risk for on-site workers. The distinctive difference between the mean and peak concentrations of VOCs indicates the importance of using mean and peak concentrations, respectively, for risk and olfactory evaluation due to the rapid response of the human nose to odours. As a result, the cumulative noncarcinogenic risk at the relatively high pollutant plot was higher than the occupational safety limit, while the total carcinogenic risks at all monitored scenarios exceeded the acceptable limit. Among the VOCs investigated, DCM and trichloroethylene (TCE) were determined to be crucial pollutants for both noncarcinogenic and carcinogenic risks of VOCs. With regard to olfactory effects, organic sulphides, including dimethyl disulphide (DMDS), dimethyl sulphide (DMS), and dimethyl trisulphide (DMTS) were identified as dominant odour contributors (78.28-92.11%) during soil disturbance.

A critical review on odor measurement and prediction

Odor pollution has become a global environmental issue of increasing concern in recent years. Odor measurements are the basis of assessing and solving odor problems. Olfactory and chemical analysis can be used for odor and odorant measurements. Olfactory analysis reflects the subjective perception of human, and chemical analysis reveals the chemical composition of odors. As an alternative to olfactory analysis, odor prediction methods have been developed based on chemical and olfactory analysis results. The combination of olfactory and chemical analysis is the best way to control odor pollution, evaluate the performances of the technologies, and predict odor. However, there are still some limitations and obstacles for each method, their combination, and the prediction. Here, we present an overview of odor measurement and prediction. Different olfactory analysis methods (namely, the dynamic olfactometry method and the triangle odor bag method) are compared in detail, the latest revisions of the standard olfactometry methods are summarized, and the uncertainties of olfactory measurement results (i.e., the odor thresholds) are analyzed. The researches, applications, and limitations of chemical analysis and odor prediction are introduced and discussed. Finally, the development and application of odor databases and algorithms for optimizing odor measurement and prediction methods are prospected, and a preliminary framework for an odor database is proposed. This review is expected to provide insights into odor measurement and prediction.

Fugitive emissions of volatile organic compounds from the pharmaceutical industry in China based on leak detection and repair monitoring, atmospheric prediction, and health risk assessment

In this study, a leak detection and repair program was conducted on five pharmaceutical factories in China to analyze the volatile organic compounds (VOCs) emission characteristics of leaking equipment. The results indicated that the monitored components were mainly flanges, accounting for 70.23% of the total, and open-ended lines were the components most prone to leaks. The overall percentage of VOCs emissions reduction after the repair was 20.50%, and flanges were the most repairable components, with an average emission reduction of 47.5 kg/a for each flange. In addition, atmospheric predictions were conducted for the VOCs emissions before and after the repair of the components at the research factories. The atmospheric predictions showed that emissions from equipment and facilities have a noticeable impact on VOCs concentration at boundary and the emissions are positively correlated with the pollution source strength. The hazard quotient of the investigated factories was lower than the acceptable risk level set by the US Environmental Protection Agency (EPA). The quantitative assessment of the lifetime cancer risk showed that the risk levels of factories A, C, and D exceeded the EPA's acceptable risk level, and the on-site workers were exposed to inhalation cancer risk.

Improving VOC control strategies in industrial parks based on emission behavior, environmental effects, and health risks: A case study through atmospheric measurement and emission inventory

Industrial parks have a very important impact on regional economic development, but the extremely complex and relatively concentrated volatile organic compound (VOC) emissions from industrial parks also result in it being difficult to control VOCs. In this study, we took a large integrated industrial park in the upper reaches of the Yangtze River as an example, conducted a 1-year monitoring campaign of ambient air VOCs, and established a speciated VOC emission inventory based on the measured chemical profiles of the key industries. The comprehensive control index (CCI) of 125 VOCs was evaluated using the entropy weighting method based on comprehensive consideration of three aspects, namely, emission behavior, environmental effects, and health risks of VOCs, to identify priority VOC species and their key sources for VOC control in industrial parks. The total estimated VOC emissions in the industrial park in 2019 were 6446.96 t. Steel production, sewage treatment, natural gas chemical industry, pharmaceuticals, and industrial boilers were the main sources of VOC emissions. In terms of VOC components, halocarbons, aromatics, and OVOCs were the largest groups of VOCs emitted from the industrial park, accounting for 73.75 % of the total VOC emissions. Using the entropy weighting method, we evaluated the index weights of five parameters: emissions, ozone formation potential, secondary organic aerosol formation potential, hazard quotient, and lifetime cancer risk. Based on the CCI, five control levels for VOC species were further established. The VOC species in Level I and Level II, which contain species such as naphthalene, 2-chlorotoluene, benzene, acrolein, and chloroform, should be considered as extremely important priority control species. These results serve as a reference for the development of precise control strategies for VOCs in industrial parks.

Spatial characterization of HCHO and reapportionment of its secondary sources considering photochemical loss in Taiyuan, China

Formaldehyde (HCHO) plays an important role in atmospheric ozone (O₃) formation. To accurately identify the sources of HCHO, carbonyls and volatile organic compounds (VOCs) were measured at three urban sites (Taoyuan, TY-U; Jinyuan, JY-U; Xiaodian, XD-U) and a suburban site (Shanglan, SL-B) in Taiyuan during a high O₃ period (from July 20 to August 3, 2020). The average mixing ratio of HCHO at XD-U (8.1 ± 2.8 ppbv) was comparable to those at TY-U (7.4 ± 2.1 ppbv) and JY-U (7.0 ± 2.3 ppbv) but higher (p < 0.01) than that at SL-B (4.9 ± 2.3 ppbv). HCHO contributed to 54.3-59.9 % of the total ozone formation potentials (OFPs) of non-methane hydrocarbons (NMHCs) at four sites. The diurnal variation of HCHO concentrations reached a peak value at 12:00-15:00, which may be attributed to the strong photochemical reaction. To obtain more accurate source results of HCHO under the condition of photochemical loss, the initial concentrations of NMHCs were estimated based on photochemical age parameterization and incorporated into the positive matrix factorization (PMF) model (termed IC-PMF). According to the IC-PMF results, secondary formation (SF) contributed the most to HCHO at XD-U (35.6 %) and SL-B (25.1 %), whereas solvent usage (SU) (40.9 %) and coking sources (CS) (36.0 %) were the major sources at TY-U and JY-U, respectively. Compared to the IC-PMF, the conventional PMF analysis based on the observed data underestimated the contributions of SU (100.5-154.2 %) and biogenic sources (BS) (28.5-324.7 %). Further reapportionment of secondary HCHO by multiple linear regression indicated that SU dominated the sources of HCHO at SL-B (28.3 %) and TY-U (41.7 %), while industrial emissions (IE) and CS contributed the most to XD-U (26.6 %) and JY-U (43.0 %) in Taiyuan from north to south, respectively.

Preparation of combined hydrogel solution that is suitable to control the emission of odor pollutants from brownfield site and its control effects

Odor pollution caused by brownfield site has attracted increasing attention. However, to date, fewer suitable materials can be used to control the emission of odor pollutant from brownfield site during remediation. This study prepared a kind of combined hydrogel solution based on sodium alginate and carboxymethyl cellulose sodium (CHS-SC) and tested the possibility of its membrane in controlling the emission of three odor pollutants (trichloroethylene, dimethyl disulfide, and p-xylene) from polluted soil. Our results showed that CHS-SC membrane could effectively control the emission of three odor pollutants from polluted soil. Comparatively, CHS-SC membrane had higher control rates for three odor pollutants at high ambient temperature (32 °C), short storage time of CHS-SC (5 days, 25 °C), and low odor pollutant concentration (2 ml/kg soil) than at low ambient temperature (2 °C), long storage time of CHS-SC (10 d, 25 °C), and high odor pollutant concentration (4 ml/kg soil), respectively. CHS-SC membrane was degraded by 79.23% after 150 days in soil and slightly changed soil bacterial community, indicating that it had good biodegradability and environmental friendliness. In addition, CHS-SC cost was the lowest among the products with similar function. This study shows that CHS-SC is effective in short-timely controlling the emission of odor pollutants from brownfield site.

Ambient volatile organic compounds in urban and industrial regions in Beijing: Characteristics, source apportionment, secondary transformation and health risk assessment

Field measurements of volatile organic compounds (VOCs) were conducted simultaneously at an urban site and one industrial park site in Beijing in summer. The VOCs concentrations were 94.3 ± 157.8 ppbv and 20.7 ± 8.9 ppbv for industrial and urban sites, respectively. Alkanes and aromatics were the major contributors to VOCs in industrial site, while oxygenated volatile organic compounds (OVOCs) contributed most in urban site. The most abundant VOC species were n-pentane and formaldehyde for industrial site and urban site, respectively. The calculated ozone formation potential (OFP) and OH loss rates (L_OH) were 621.1 ± 1491.9 ppbv (industrial site), 102.9 ± 37.3 ppbv (urban site), 22.0 ± 39.0 s^-1 (industrial site) and 5.3 ± 2.2 s^-1 (urban site), respectively. Based on the positive matrix factorization (PMF) model, solvent utilization I (34.1 %), solvent utilization II (27.9 %), mixture combustion source (19.3 %), OVOCs related source (9.6 %) and biogenic source (9.1 %) were identified in the industrial site, while OVOCs related source (27.8 %), vehicle exhaust (22.1 %), solvent utilization (19.3 %), coal combustion (16.0 %) and biogenic source (14.8 %) were identified in the urban site. The results of O₃-VOCs-NOx sensitivity indicated that O₃ formation were respectively under the VOC-limited and NOx-limited conditions in Beijing urban and industrial regions. Additionally, aromatics accounted remarkable SOA formation ability both in the two sites, and SOA potentials of xylene, toluene and ethylbenzene as the indicator species for the solvent utilization in industrial site were remarkable higher than those obtained in urban regions. The hazard index values in the industrial and urban sites were 1.72 and 3.39, respectively, suggesting a high non-carcinogenic risks to the exposed population. Formaldehyde had the highest carcinogenic risks in the two sites, and the cumulative carcinogenic risks in the industrial site and urban site were 1.95 × 10^-5 and 1.21 × 10^-5, respectively.

Chemical Characteristics and Source-Specific Health Risks of the Volatile Organic Compounds in Urban Nanjing, China

This work comprehensively investigated the constituents, sources, and associated health risks of ambient volatile organic compounds (VOCs) sampled during the autumn of 2020 in urban Nanjing, a megacity in the densely populated Yangtze River Delta region in China. The total VOC (TVOC, sum of 108 species) concentration was determined to be 29.04 ± 14.89 ppb, and it was consisted of alkanes (36.9%), oxygenated VOCs (19.9%), halogens (19.1%), aromatics (9.9%), alkenes (8.9%), alkynes (4.9%), and others (0.4%). The mean TVOC/NO_x (ppbC/ppbv) ratio was only 3.32, indicating the ozone control is overall VOC-limited. In terms of the ozone formation potential (OFP), however, the largest contributor became aromatics (41.9%), followed by alkenes (27.6%), and alkanes (16.9%); aromatics were also the dominant species in secondary organic aerosol (SOA) formation, indicative of the critical importance of aromatics reduction to the coordinated control of ozone and fine particulate matter (PM_2.5). Mass ratios of ethylbenzene/xylene (E/X), isopentane/n--pentane (I/N), and toluene/benzene (T/B) ratios all pointed to the significant influence of traffic on VOCs. Positive matrix factorization (PMF) revealed five sources showing that traffic was the largest contributor (29.2%), particularly in the morning. A biogenic source, however, became the most important source in the afternoon (31.3%). The calculated noncarcinogenic risk (NCR) and lifetime carcinogenic risk (LCR) of the VOCs were low, but four species, acrolein, benzene, 1,2-dichloroethane, and 1,2-dibromoethane, were found to possess risks exceeding the thresholds. Furthermore, we conducted a multilinear regression to apportion the health risks to the PMF-resolved sources. Results show that the biogenic source instead of traffic became the most prominent contributor to the TVOC NCR and its contribution in the afternoon even outpaced the sum of all other sources. In summary, our analysis reveals the priority of controls of aromatics and traffic/industrial emissions to the efficient coreduction of O₃ and PM_2.5; our analysis also underscores that biogenic emissions should be paid special attention if considering the direct health risks of VOCs.

Characteristics of volatile organic compounds in the metropolitan city of Seoul, South Korea: Diurnal variation, source identification, secondary formation of organic aerosol, and health risk

Atmospheric volatile organic compounds (VOCs) in Seoul, the capital of South Korea, have attracted increased attention owing to their emission, secondary formation, and human health risk. In this study, we collected 24 hourly samples once a month at an urban site in Seoul for a year (a total of 288 samples) using a sequential tube sampler. Analysis results revealed that toluene (9.08 ± 8.99 μg/m³) exhibited the highest annual mean concentration, followed by ethyl acetate (5.55 ± 9.09 μg/m³), m,p-xylenes (2.79 ± 4.57 μg/m³), benzene (2.37 ± 1.55 μg/m³), ethylbenzene (1.81 ± 2.27 μg/m³), and o-xylene (0.91 ± 1.47 μg/m³), indicating that these compounds accounted for 77.8-85.6% of the seasonal mean concentrations of the total (Σ₅₉) VOCs. The concentrations of the Σ₅₉ VOCs were statistically higher in spring and winter than in summer and fall because of meteorological conditions, and the concentrations of individual VOCs were higher during the daytime than nighttime owing to higher human activities during the daytime. The conditional bivariate probability function and concentration weighted trajectory analysis results suggested that domestic effects (e.g., vehicular exhaust and solvents) exhibited a dominant effect on the presence of VOCs in Seoul, as well as long-range atmospheric transport of VOCs. Further, the most important secondary organic aerosol formation potential (SOAFP) compounds included benzene, toluene, ethylbenzene, and m,p,o-xylenes, and the total SOAFP of nine VOCs accounted for 5-29% of the seasonal mean PM_2.5 concentrations. The cancer and non-cancer risks of the selected VOCs were below the tolerable (1 × 10^-4) and acceptable (Hazard quotient: HQ < 1) levels, respectively. Overall, this study highlighted the feasibility of the sequential sampling of VOCs and hybrid receptor modeling to further understand the source-receptor relationship of VOCs.

Health risk assessment of volatile organic compounds (VOCs) in a refinery in the southwest of Iran using SQRA method

Oil industries, such as oil refineries, are important sources of volatile organic compound production. These compounds have significant health effects on human health. In this study, a health risk assessment is carried out on volatile organic compounds (VOCs) in the recovery oil plant (ROP) unit of a refinery in southwest Iran. It was performed using the SQRA method including respiratory risk for chronic daily intake (CDI) of VOCs and cancer risk and non-cancer risk indices. Five locations in the area of oil effluents and five locations in the refinery area (control samples) were considered for evaluation. The sampling was done according to the standard NIOSH-1501 and SKC pumps. The gas chromatography/flame ionization detector (GC/FID) method was used to extract VOCs. The cancer slope factor (CSF) and respiratory reference dose (RFC) were calculated in addition to the respiratory risk (CDI). The end result shows that a significant difference was observed between the concentrations of volatile organic compounds in the two groups of air (P < 0.05). The SQRA risk assessment showed that the risk levels of benzene for workers in the pit area were very high (4-5). Health hazard levels were also evaluated as high levels for toluene (2-4) and moderate levels for xylene and paraxylene (1-3). The cancer risk assessment of volatile organic compounds recorded the highest level of cancer risk for benzene in the range of petroleum effluents (>1). Also, a non-cancer risk (HQ) assessment revealed that benzene had a significant health risk in the range of oil pits (2-3). Based on the results, petroleum industries, including refineries, should conduct health risk assessment studies of volatile organic compounds. The units that are directly related to the high level of VOCs should be considered sensitive groups, and their employees should be under special management to reduce the level of exposure to these compounds and other hazardous compounds.

Contamination of 16 priority polycyclic aromatic hydrocarbons (PAHs) in urban source water at the tidal reach of the Yangtze River

To explore the occurrence, source, and risk of 16 priority polycyclic aromatic hydrocarbons (PAHs) in urban source water at the tidal reach of the Yangtze River, eighty-nine surface water samples were collected in 8 field campaigns from July 2018 to November 2019. Fifteen of 16 PAHs except for dibenz(a,h)anthracene (DBA) were found in the water. Detection frequencies were observed between 53 and 72% for PAHs with 4 rings, while most of other PAHs were less detected, e.g., benzo(a)pyrene (BaP) in 31% of samples. The total concentrations of 16 priority PAHs reached up to 2.8 µg·L^-1 and increased during the tidal transitions from flood to ebb. The average concentrations of PAHs in ebb tides were higher than those in flood tides. PAH concentrations and compositions showed great variation with different sampling campaigns, and higher levels and more components were observed in the rainy months and cold months. Those priority PAHs in the tidal water source are mainly from combustion activities (especially fossil fuel combustion), but the contribution from oil spills/leakage is also important in rainy months. High-molecular-weight PAHs in this tidal water source may pose risks to aquatic life, while they pose no carcinogenic risk to human health via ingestion of drinking water.

Emission Characteristics and Health Risks of Volatile Organic Compounds (VOCs) Measured in a Typical Recycled Rubber Plant in China

The continued development of the automotive industry has led to a rapid increase in the amount of waste rubber tires, the problem of “black pollution” has become more serious but is often ignored. In this study, the emission characteristics, health risks, and environmental effects of volatile organic compounds (VOCs) from a typical, recycled rubber plant were studied. A total of 15 samples were collected by summa canisters, and 100 VOC species were detected by the GC/MS-FID system. In this study, the total VOCs (TVOCs) concentration ranged from 1000 ± 99 to 19,700 ± 19,000 µg/m³, aromatics and alkanes were the predominant components, and m/p-xylene (14.63 ± 4.07%–48.87 ± 3.20%) could be possibly regarded as a VOCs emission marker. We also found that specific similarities and differences in VOCs emission characteristics in each process were affected by raw materials, production conditions, and process equipment. The assessment of health risks showed that devulcanizing and cooling had both non-carcinogenic and carcinogenic risks, yarding had carcinogenic risks, and open training and refining had potential carcinogenic risks. Moreover, m/p-xylene and benzene were the main non-carcinogenic species, while benzene, ethylbenzene, and carbon tetrachloride were the dominant risk compounds. In the evaluation results of L_OH, m/p-xylene (25.26–67.87%) was identified as the most key individual species and should be prioritized for control. In conclusion, the research results will provide the necessary reference to standardize the measurement method of the VOCs source component spectrum and build a localized source component spectrum.

Investigation of VOC characteristics, source analysis, and chemical conversions in a typical petrochemical area through 1-year monitoring and emission inventory

To effectively investigate the characteristics, source analysis, and chemical conversions of volatile organic compounds (VOCs) pollution in a typical petrochemical area, 81 VOC species from nine sampling sites were collected from 1st January to 31th December 2019 in Jinshan District. Results showed the concentration of VOCs was 51.63 ± 36.05 ppbv, and VOCs were dominated by alkane (40.10%) and alkenes (39.91%). The temporal variations of VOCs showed that the highest average VOC concentration appeared in July, and the lowest concentration of VOCs was in February. The concentration of VOCs was mainly connected with industrial processes and was transported to other areas through the downwind direction. Six PMF-derived sources including petrochemical industry, solvent utilization, vehicle exhaust, fuel evaporation, combustion, and other industry processes, contributing 37.08%, 16.74%, 16.69%, 14.99%, 9.53%, and 4.97%, respectively. Meanwhile, an anthropogenic VOC emission inventory was established by emission factors and the activity statistics for 2019, results indicated that the total emission of VOCs was estimated as 6.22 kt, petrochemical industry was the most important contributor of human-produced VOCs. The L_OH concentration was 396.12 ppbv via OH radical loss rate method, and the OFP was 210.44 ppbv based on the MIR factor. Alkenes and aromatics were the important components of O₃ formation. This study provides effective information for corresponding governments to establish VOCs contamination control directives.

An integrated strategy by using long-term monitoring data to identify volatile organic compounds of high concern near petrochemical industrial parks

Exposure to ambient volatile organic compounds (VOCs) is associated with a risk of cancer in the residents living near petrochemical facilities. However, research on the contribution of different VOCs to the lifetime cancer risk remains inconclusive. The variability in source emissions, geographical locations, seasons, and meteorological conditions can be assessed through long-term measurement of ambient VOCs with a wide spatial distribution, thus reducing the uncertainty of health risk assessment from source emissions. This study analyzed comprehensive measurement data of 109 VOCs at 17 monitoring stations around petrochemical industrial parks, collected once every six days during 2015-2018 by the Taiwan Environmental Protection Agency. We calculated the annual mean concentration of selected VOCs and then integrated the probability risk assessment (PRA) and positive matrix factorization (PMF) models to identify the sources of VOCs of high concern. First, we prioritized 12 out of 23 carcinogenic VOCs based on the PRA results. Further, the results obtained from the PMF model revealed that petrochemical industrial parks contributed to more than 50% of the emissions of six VOCs, namely 1,3-butadiene, benzene, 1,2-dichloroethane, chloroform, vinyl chloride, and acrylonitrile, measured at a few monitoring stations. This integrated approach can help regulatory agencies to efficiently propose control strategies on the emissions of VOCs of high concern, thereby reducing the population's health risk.

Human health risk assessment and distribution of VOCs in a chemical site, Weinan, China

The study assessed the volatile organic compound (VOC) pollution characteristics in a chemical site in Weinan, China. The results indicated that chloroform, benzene, trichloroethylene, 1,2-dichloroethane, ethylbenzene, 1,2-dichloropropane, and 1,2,3-Trichloropropane exceeded the soil standard limit for soil contamination of development land (GB36600, PRC). Using pollution index, ambient severity, and correlation coefficient revealed industrial production and relocation activities as sources of VOCs contamination in the site. The carcinogenic risk assessed by human exposure to site VOCs through ingestion, respiration, exposure, etc., exceeded the potentially acceptable level (1.0 × 10−6). 1,2,3-trichloropropane has the highest carcinogenic risk across all pathways, regions, and populations. The long-term exposure and emission of VOCs in the investigated sites could likely pose an adverse health risk to site staff and the surrounding sensitive groups. Therefore, it is necessary to carry out strict investigation and evaluation of the site, and timely repair and control to protect the water, soil, and air environment and to avoid the long-term cumulative exposure risk to human health caused by VOCs emission.

1,3-Butadiene: a ubiquitous environmental mutagen and its associations with diseases

1,3-Butadiene (BD) is a petrochemical manufactured in high volumes. It is a human carcinogen and can induce lymphohematopoietic cancers, particularly leukemia, in occupationally-exposed workers. BD is an air pollutant with the major environmental sources being automobile exhaust and tobacco smoke. It is one of the major constituents and is considered the most carcinogenic compound in cigarette smoke. The BD concentrations in urban areas usually vary between 0.01 and 3.3 μg/m³ but can be significantly higher in some microenvironments. For BD exposure of the general population, microenvironments, particularly indoor microenvironments, are the primary determinant and environmental tobacco smoke is the main contributor. BD has high cancer risk and has been ranked the second or the third in the environmental pollutants monitored in most urban areas, with the cancer risks exceeding 10^-5. Mutagenicity/carcinogenicity of BD is mediated by its genotoxic metabolites but the specific metabolite(s) responsible for the effects in humans have not been determined. BD can be bioactivated to yield three mutagenic epoxide metabolites by cytochrome P450 enzymes, or potentially be biotransformed into a mutagenic chlorohydrin by myeloperoxidase, a peroxidase almost specifically present in neutrophils and monocytes. Several urinary BD biomarkers have been developed, among which N-acetyl-S-(4-hydroxy-2-buten-1-yl)-L-cysteine is the most sensitive and is suitable for biomonitoring BD exposure in the general population. Exposure to BD has been associated with leukemia, cardiovascular disease, and possibly reproductive effects, and may be associated with several cancers, autism, and asthma in children. Collectively, BD is a ubiquitous pollutant that has been associated with a range of adverse health effects and diseases with children being a subpopulation with potentially greater susceptibility. Its adverse effects on human health may have been underestimated and more studies are needed.

VOCs characteristics and their ozone and SOA formation potentials in autumn and winter at Weinan, China

Frequent ozone and fine particulate matter (PM_2.5) pollution have been occurring in the Guanzhong Plain in China. To effectively control the tropospheric ozone and PM_2.5 pollution, this study performed measurements of 102 VOCs species from Sep.19-25 (autumn) and Nov.27-Dec. 8, 2017 (winter) at Weinan in the central Guanzhong Plain. The total volatile organic compounds (TVOCs) concentrations were 95.8 ± 30.6 ppbv in autumn and 74.4 ± 37.1 ppbv in winter. Alkanes were the most abundant group in both of autumn and winter, accounting for 33.5% and 39.6% of TVOCs concentrations, respectively. The levels of aromatics and oxygenated VOCs were higher in autumn than in winter, mainly due to changes in industrial activities and combustion strength. Photochemical reactivities and ozone formation potentials (OFPs) of VOCs were calculated by applying the OH radical loss rate (L_OH) and maximum incremental reactivity (MIR) method, respectively. Results showed that Alkenes and aromatics were the key VOCs in term ozone formation in Weinan, which together contributed 59.6% ̶ 65.3% to the total L_OH and OFP. Secondary organic aerosol formation potentials (SOAFP) of the measured VOCs were investigated by employing the fractional aerosol coefficient (FAC) method. Aromatics contributed 94.9% and 96.2% to the total SOAFP in autumn and winter, respectively. The regional transport effects on VOCs and ozone formation were investigated by using trajectory analysis and potential source contribution function (PSCF). Results showed that regional anthropogenic sources from industrial cities (Tongchuan, Xi'an city) and biogenic sources from Qinling Mountain influenced VOCs levels and OFP at Weinan. Future studies need to emphasize on meteorological factors and sources that impact on VOCs concentrations in Weinan.

Odor-active volatile organic compounds along the seafront of Thessaloniki, Greece. Implications for sources of nuisance odor

Volatile organic compounds (VOCs) have long been associated with odor nuisance at urban sites close to emission sources. Sulfur containing volatile organic compounds (VOSCs) in particular, constitute a major category of malodorous compounds since some of them are characterized by intense odor and low odor thresholds. VOSCs have both, anthropogenic and biogenic sources. The purpose of this study was to assess the concentration levels of a variety of VOCs (mercaptans, sulfides, thiophenes, aromatics and aldehydes) along the seafront of the city of Thessaloniki, northern Greece, a city with frequent citizen complaints for nuisance odor. 1-Hour sampling on adsorption tubes was carried out concurrently at 3 sites along the seafront of the city (EAST, CENTER and WEST) three times during the day in winter and summer 2020. VOCs analysis, performed on a Thermal Desorption - Gas Chromatography/Mass Spectroscopy (TD-GC/MS) system. Diurnal and seasonal variations, and correlations with prevailing meteorological conditions were investigated. Concentrations found along the seafront were compared to previous data from inner-city sites affected by urban and/or industrial activities. Most VOCs were found at lower concentrations at the seafront in comparison to inner-city sites demonstrating better air quality. Typical biogenically-deriving VOSCs such as carbonyl sulfide and dimethyl sulfide were found at the seafront either at higher or at similar levels with inner city thus suggesting negligible contribution from biogenic sources. Odor activity values were further calculated and assessed. Odor nuisance at all seafront sites was significantly higher in winter, being in both seasons maximum at the WEST seafront that is closer to port activities, polluted creek estuaries and industrial facilities. Mercaptans were identified as the major contributors to odor pollution followed by aldehydes. The new findings described in this study might contribute to the better understanding of the odor pollution from VOCs at coastal urban sites.

Occurrence and risk assessment of volatile organic compounds in multiple drinking water sources in the Yangtze River Delta region, China

Volatile organic compounds (VOCs) are widely present in water environment, which can threaten ecological sustainability and human health. The concentrations of VOCs and their ecological risks in drinking water are of great concern to human beings. Therefore, 54 kinds of VOCs were investigated from 58 locations of the Yangtze River Delta Region (Yangtze River, Qiantang River, Huangpu River, Taihu Lake and Jiaxing Urban River). Out of 54 target compounds, only 31 VOCs were detected, with total concentrations ranging from 0.570 to 46.820 μg/L from 58 locations of all drinking water sources. Among all detected VOCs compounds, only toluene and styrene can cause high-level ecological risk at location TH-2 of Taihu Lake. According to the carcinogenic and non-carcinogenic risk index, compounds such as 1,2-dichloroethane, bromodichloromethane and 1,1,2-trichloroethane posed a higher carcinogenic risk, and 1,2-dichloroethane, trichloroethylene and toluene posed a higher non-carcinogenic risk. Olfactory risks of water bodies in the Yangtze River Delta region are negligible. Although the concentrations of VOCs in the Yangtze River Delta region did not exceed national standards in China and guidelines of the World Health Organization (WHO) for drinking water, the presence of some ecological and health risks indicated that future monitoring studies and control practices are important to ensure ecological safety of drinking water sources.

Investigation on Distribution and Risk Assessment of Volatile Organic Compounds in Surface Water, Sediment, and Soil in a Chemical Industrial Park and Adjacent Area

The occurrences, distributions, and risks of 55 target volatile organic compounds (VOCs) in water, sediment, sludge, and soil samples taken from a chemical industrial park and the adjacent area were investigated in this study. The Σ₅₅-VOCs concentrations in the water, sediment, sludge, and soil samples were 1.22–5449.21 μg L⁻¹, ND–52.20 ng g⁻¹, 21.53 ng g⁻¹, and ND–11.58 ng g⁻¹, respectively. The main products in this park are medicines, pesticides, and novel materials. As for the species of VOCs, aromatic hydrocarbons were the dominant VOCs in the soil samples, whereas halogenated aliphatic hydrocarbons were the dominant VOCs in the water samples. The VOCs concentrations in water samples collected at different locations varied by 1–3 orders of magnitude, and the average concentration in river water inside the park was obviously higher than that in river water outside the park. However, the risk quotients for most of the VOCs indicated a low risk to the relevant, sensitive aquatic organisms in the river water. The average VOCs concentration in soil from the park was slightly higher than that from the adjacent area. This result showed that the chemical industrial park had a limited impact on the surrounding soil, while the use of pesticides, incomplete combustion of coal and biomass, and automobile exhaust emissions are all potential sources of the VOCs in the environmental soil. The results of this study could be used to evaluate the effects of VOCs emitted from chemical production and transportation in the park on the surrounding environment.

Compositions, sources, and potential health risks of volatile organic compounds in the heavily polluted rural North China Plain during the heating season

Severe volatile organic compound (VOC) pollution has become an urgent problem during the heating season in the North China Plain (NCP), as exposure to hazardous VOCs can lead to chronic or acute diseases. A campaign with online VOC measurements was conducted at a rural site in Wangdu, NCP during the 2018 heating season to characterize the compositions and associated sources of VOCs and to assess their potential health risks. The total concentration of VOCs with 94 identified species was 77.21 ± 54.39 ppb. Seven source factors were identified by non-negative matrix factorization, including coal combustion (36.1%), LPG usage (21.1%), solvent usage (13.9%), biomass burning and secondary formation (14.2%), background (7.0%), industrial emissions (4.5%), and vehicle emissions (3.3%). The point estimate approach and Monte Carlo simulation were used to estimate the carcinogenic and non-carcinogenic risks of harzadous VOCs. The results showed that the cumulative health risk of VOCs was above the safety level. Acrolein, 1.2-dichloroethane, 1,2-dichloropropane, chloroform, 1,3-butadiene, and benzene were identified as the key hazardous VOCs in Wangdu. Benzene had the highest average carcinogenic risk. Solvent usage and secondary formation were the dominant sources of adverse health effects. During the Spring Festival, most sources were sharply reduced; and VOC concentration declined by 49%. However, coal and biomass consumptions remained relatively large, probably due to heating demand. This study provides important references for the control strategies of VOCs during the heating season in heavily polluted rural areas in the NCP.