Search Results (515)

To investigate the characteristics and sources of volatile organic compounds (VOCs) as well as their impacts on secondary organic aerosols (SOAs) formation during high-incidence periods of PM_2.5 pollution, a field measurement was conducted in December 2019 in Hefei, a typical city of the Yangtze River Delta (YRD). During the whole process, the mixing ratios of VOCs were averaged as 21.1 ± 15.9 ppb, with alkanes, alkenes, alkyne, and aromatics accounting for 59.9%, 15.3%, 15.0%, and 9.8% of the total VOCs, respectively. It is worth noting that the contributions of alkenes and alkyne increased significantly during PM_2.5 pollution periods. Based on source apportionment via the positive matrix factorization (PMF) model, vehicle emissions, liquefied petroleum gas/natural gas (LPG/NG), and biomass/coal burning were the main sources of VOCs during the research in Hefei. During pollution periods, however, the contribution of biomass/coal burning to VOCs increased significantly, reaching as much as 47.6%. The calculated SOA formation potential (SOAFP) of VOCs was 0.38 ± 1.04 µg m⁻³ (range: 0.04–7.30 µg m⁻³), and aromatics were the dominant contributors, with a percentage of 96.8%. The source contributions showed that industrial emissions (49.1%) and vehicle emissions (28.3%) contributed the most to SOAFP during non-pollution periods, whereas the contribution of biomass/coal burning to SOA formation increased significantly (32.8%) during PM_2.5 pollution periods. These findings suggest that reducing VOCs emissions from biomass/coal burning, vehicle, and industrial sources is a crucial approach for the effective control of SOA formation in Hefei, which provides a scientific basis for controlling PM_2.5 pollution and improving air quality in the YRD region. Full article

To establish and implement effective policies for controlling fine particle matters (PM_2.5), which is associated with high-risk diseases, continuous research on identifying PM_2.5 sources was conducted. This study utilized the positive matrix factorization (PMF) receptor model to estimate the sources and characteristics of PM_2.5 between Baengnyeong Island (BNI) and the Seoul Metropolitan Area (SMA). We conducted PMF modeling and backward trajectory analysis using the data on PM_2.5 and its components collected from 2020 to 2021 at the Air quality Research Centers (ARC). The PMF modeling identified nine pollution sources in both BNI and the SMA, including secondary sulfate, secondary nitrate, vehicles, biomass burning, dust, industry, sea salt particles, coal combustion, and oil combustion. Secondary particulate matter, vehicles, and biomass burning were found to be major contributors to PM_2.5 concentrations in both regions. A backward trajectory analysis indicated that air masses, passing through BNI to the SMA, showed higher concentrations and contributions of ammonium nitrate, vehicles, and biomass burning in the SMA site compared to BNI site. These findings suggest that controlling nitrogen oxides (NOx) and ammonia emissions in the SMA, as well as monitoring the intermediate products that form aerosols, such as HNO₃, are needed. Full article

This study assessed the presence of potentially toxic elements (PTEs) in China’s northeastern black soil belt, an area with limited prior research. We collected 304 soil samples (0–20 cm) from Gonghe Town, Hailun City, and analyzed the PTE contamination degree using the single-factor pollution index and Nemerow pollution index. The results demonstrated that the mean concentrations of arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), mercury (Hg), nickel (Ni), lead (Pb), and zinc (Zn) were 11.16, 0.11, 65.29, 22.56, 0.03, 27.07, 26.09, and 66.01 mg/kg, respectively. Source apportionment was conducted via correlation analysis, principal component analysis, and positive matrix factorization, identifying four main sources: natural (33.2%), irrigation (29.5%), fuel (23.4%), and fertilizer (13.2%). The ecological risk index indicated a slight ecological risk, while the human health risk showed that non-carcinogenic risks were negligible and carcinogenic risks were acceptable. Our findings emphasize the need to prioritize controlling PTEs from fertilizer, particularly cadmium, and to a lesser extent, irrigation and fuel sources, focusing on As, Pband Hg. This research provides critical insights for policymakers aiming to manage PTE contamination in black soils. Full article

The key to a sustainable future is the reduction in humankind’s impact on natural systems via the development of new technologies and the improvement in source apportionment. Although days, years and seasons are arbitrarily set, their mechanisms are based on natural cycles driven by Earth’s orbital periods. This is not the case for weeks, which are a pure anthropic category and are known from the literature to influence emission cycles and atmospheric chemistry. For the first time since it started data gathering operations, CO (carbon monoxide), CO₂ (carbon dioxide), CH₄ (methane) and eBC (equivalent black carbon) values detected by the Lamezia Terme WMO/GAW station in Calabria, Southern Italy, have been evaluated via a two-pronged approach accounting for weekly variations in absolute concentrations, as well as the number of hourly averages exceeding select thresholds. The analyses were performed on seven continuous years of measurements from 2016 to 2022. The results demonstrate that the analyzed GHGs (greenhouse gasses) and aerosols respond differently to weekly cycles throughout the seasons, and these findings provide completely new insights into source apportionment characterization. Moreover, the results have been combined into a new parameter: the hereby defined WDWO (Weighed Distribution of Weekly Outbreaks) normalizes weekly trends in CO, CO₂, CH₄ and eBC on an absolute scale, with the scope of providing regulators and researchers alike with a new tool meant to better evaluate anthropogenic pollution and mitigate its effects on the environment and human health. Full article

Fluoride and nitrate contamination in groundwater is a global concern due to their toxicity and associated negative health effects. This study incorporated a comprehensive methodology, including hydrogeochemical analysis, drinking and irrigation water quality assessment, source apportionment, and health risk estimation of groundwater fluoride and nitrate in a lithium ore deposit basin in western Serbia. Groundwater major ion hydrogeochemistry was governed by water–rock interactions, with Ca-Mg-HCO₃ identified as the predominant groundwater type. The entropy-weighted water quality index (EWQI), sodium adsorption ratio (SAR), and sodium percentage (%Na) revealed that 95% of the samples were of excellent to good quality for both drinking and irrigation. Moreover, the results showed that fluorides were of geogenic origin, whereas nitrates originated from agricultural activities. Although the fluoride and nitrate levels in groundwater were relatively low, averaging 1.0 mg/L and 11.1 mg/L, respectively, the results of the health risk assessment revealed that the ingestion of such groundwater can still lead to non-cancerous diseases. The threshold of one for the hazard index was exceeded in 15% and 35% of the samples for adults and children, respectively. Children were more vulnerable to non-carcinogenic risk, with fluorides being the primary contributing factor. The study outcomes can serve as a reference for other lithium-bearing ore areas and guide the management of regional groundwater resources. Full article

Contamination with potentially toxic elements (PTEs) frequently occurs in surface water in coal mining areas. This study analyzed 34 surface water samples collected from the Yunnan–Guizhou Plateau for their hydrochemical characteristics, spatial distribution, source apportionment, and human health risks. Our statistical analysis showed that the average concentrations of PTEs in the surface water ranked as follows: Fe > Al > Zn > Mn > Ba > B> Ni > Li > Cd > Mo > Cu > Co > Hg > Se > As > Pb > Sb. The spatial analysis revealed that samples with high concentrations of Fe, Al, and Mn were predominantly distributed in the main stream, Xichong River, and Yangchang River. Positive matrix factorization (PMF) identified four sources of PTEs in the surface water. Hg, As, and Se originated from wastewater discharged by coal preparation plants and coal mines. Mo, Li, and B originated from the dissolution of clay minerals in coal seams. Elevated concentrations of Cu, Fe, Al, Mn, Co, and Ni were attributed to the dissolution of kaolinite, illite, chalcopyrite, pyrite, and minerals associated with Co and Ni in coal seams. Cd, Zn, and Pb were derived from coal melting and traffic release. The deterministic health risks assessment showed that 94.12% of the surface water samples presented non-carcinogenic risks below the health limit of 1. Meanwhile, 73.56% of the surface water samples with elevated As posed level III carcinogenic risk to the local populations. Special attention to drinking water safety for children is warranted due to their lower metabolic capacity for detoxifying PTEs. This study provides insight for PTE management in sustainable water environments. Full article

Recent advances in sensor technology for air pollution monitoring open new possibilities in the field of environmental epidemiology. The low spatial resolution of fixed outdoor measurement stations and modelling uncertainties currently limit the understanding of personal exposure. In this context, air quality sensor systems (AQSSs) offer significant potential to enhance personal exposure assessment. A pilot study was conducted to investigate the feasibility of the NO₂ sensor model B43F and the particulate matter (PM) sensor model OPC-R1, both from Alphasense (UK), for use in epidemiological studies. Seven patients with chronic obstructive pulmonary disease (COPD) or asthma had built-for-purpose sensor systems placed inside and outside of their homes at fixed locations for one month. Participants documented their indoor activities, presence in the house, window status, and symptom severity and performed a peak expiratory flow test. The potential inhaled doses of PM_2.5 and NO₂ were calculated using different data sources such as outdoor data from air quality monitoring stations, indoor data from AQSSs, and generic inhalation rates (IR) or activity-specific IR. Moreover, the relation between indoor and outdoor air quality obtained with AQSSs, an indoor source apportionment study, and an evaluation of the suitability of the AQSS data for studying the relationship between air quality and health were investigated. The results highlight the value of the sensor data and the importance of monitoring indoor air quality and activity patterns to avoid exposure misclassification. The use of AQSSs at fixed locations shows promise for larger-scale and/or long-term epidemiological studies. Full article

This study was aimed at monitoring the occurrence and potential sources of emerging contaminants in water sources within the Modder River catchment. Selected water quality indicators were analysed by Hanna multi-parameter meters. Emerging contaminants such as acetaminophen, carbamazepine, ibuprofen, atrazine, simazine, metolachlor, terbuthylazine, 17-alpha-ethinyl-estradiol, estradiol, progesterone, and testosterone were analysed by high performance liquid chromatography mass spectrometry. The sources of emerging contaminants were determined by statistical methods such as Pearson correlation and hierarchical cluster analysis. Results showed that all the sampled water sources have some level of questionable drinking water quality and necessitate some amount of treatment to reduce the contamination before consumption, especially DO, EC, and pH. The 17-alpha-ethinyl-estradiol mean values in rivers (7.79 and 31.55 µg/L), dams (1.83 and 6.90 µg/L), and treated drinking water (0.2 and 0.73 µg/L) were the highest in summer and autumn seasons, respectively. Wastewater effluents, domestic sewage, urban surface runoff, agricultural runoff, and illegal dumping were identified as the possible sources of emerging contaminants pollution. Waste management education, proper application of herbicides, and advance wastewater treatment methods were some of the suggested mitigation strategies. The outcomes may be relevant for environmental protection and water sustainability in the catchment. Full article

Permafrost-affected regions in the Russian Arctic are a critical study area for studying the sources of metal elements (MEs) in soils originating from geological/pedogenic processes or from anthropogenic sources via atmospheric transport. In the Nadym region of the Yamalo-Nenets Autonomous District, we investigated the contents of soil organic carbon (SOC), total nitrogen (TN), and MEs across different soil types and horizons, explored the source apportionment of MEs, and assessed local ecological risks of potentially toxic elements (PTEs). The results showed that (1) the contents of SOC and TN in Histic Cryosols (8.59% and 0.27%) were significantly higher than in Plaggic Podzols (Arenic, Gelic, and Turbic) (2.28% and 0.15%) and in Ekranic Technosols (Umbric) (1.32% and 0.09%); (2) the concentrations of MEs in the Nadym region were lower than in other Arctic regions; (3) the primary sources of MEs were identified as geological processes (36%), atmospheric transport (23%), agricultural activities (21%), and transportation (20%); and (4) the permafrost-affected soils in the Nadym region exhibited low ecological risks from PTEs. These results underscore the critical role of geological and anthropogenic factors in shaping soil conditions and highlight the relatively low ecological risk from PTEs, providing a valuable benchmark for future environmental assessments and policy development in Yamal permafrost regions. Full article

In recent years, the widespread application of antibiotics has raised global concerns, posing a severe threat to ecological health. In this study, the occurrence, source, and ecological risks of 39 antibiotics belonging to 5 classes in mangrove sediments from Lianzhou Bay, China, were assessed. The total concentrations of the antibiotics (∑39 antibiotics) ranged from 65.45 to 202.24 ng/g dry weight (dw), with an average of 142.73 ± 36.76 ng/g dw. The concentrations of these five classes of antibiotics were as follows: Sulfonamides (SAs) > Tetracyclines (TCs) > Fluoroquinolones (QUs) > Penicillin (PCs) > Macrolides (MLs). The spatial distribution of antibiotics varied as high tidal zone > middle tidal zone > low tidal zone. The total organic carbon (TOC), pH, nitrate (NO₃⁻-N), and nitrite (NO₂⁻-N) of the sediment significantly influenced the distribution of antibiotics (p < 0.05). A source analysis identified untreated sewage from aquaculture as the primary source of antibiotics in the local mangrove. A risk assessment revealed that ciprofloxacin, norfloxacin, ofloxacin of QUs, and tetracycline of TCs exhibited medium risks to algae in certain sampling sites, while other antibiotics exhibited low or no risks to all organisms. Nevertheless, the total risk of all the detected antibiotics to algae was medium in 95% of the sites. The overall ecological risk level of antibiotics in the middle tidal zone was slightly lower than in the high tidal zone and the lowest in the low tidal zone. In summary, the experimental results provided insights into the fate and transport behaviors of antibiotics in mangrove sediments from Lianzhou Bay. Full article

This study leveraged 2019 online data of particulate matter (PM_2.5) and volatile organic compounds (VOCs) in Tianjin to analyze atmospheric pollution characteristics. PM_2.5 was found to be primarily composed of water-soluble ions, with nitrates as the dominant component, while VOCs were predominantly alkanes, followed by alkenes and aromatic hydrocarbons, with notable concentrations of propane, ethane, ethylene, toluene, and benzene. The receptor model identified six major sources of PM_2.5 and seven major sources of VOCs. The secondary source is the main contribution source, while motor vehicles and coal burning are important primary contribution sources in PM_2.5. And, industrial processes and natural gas volatilization were considered major contributors for VOCs. A health risk assessment indicated negligible non-carcinogenic risks but potential carcinogenic risks from trace metals As and Cr, and benzene within VOCs, underscoring the necessity for focused public health measures. A risk attribution analysis attributed As and Cr in PM to coal combustion and vehicular emissions. Benzene in VOCs primarily originates from fuel evaporation, and industrial and vehicular emissions. These findings underscore the potential for reducing health risks from PM and VOCs through enhanced regulation of emissions in coal, industry, and transportation. Such strategies are vital for advancing air quality management and safeguarding public health. Full article

In this study, online ambient volatile organic compounds (VOCs) were collected at an urban site of Zhengzhou in Central China during February 2018. The VOCs characteristics, source contributions and the Chinese New Year (CNY) effects have been investigated. During the sampling period, three haze periods have been identified, with the corresponding VOCs concentrations of (92 ± 45) ppbv, (62 ± 18) ppbv and (83 ± 34) ppbv; in contrast, the concentration during non-haze days was found to be (57 ± 27) ppbv. In addition, the festival effects of the CNY were investigated, and the concentration of particulate matter precursor decreased significantly. Meanwhile, firework-displaying events were identified, as the emission intensity had been greatly changed. Both potential source contribution function (PSCF) and the concentration weighted trajectory (CWT) models results indicated that short-distance transportation was the main influencing factor of the local VOCs pollution, especially by transport from the northeast. Source contribution results by the positive matrix factorization (PMF) model showed that vehicle exhaust (24%), liquid petroleum gas and natural gas (LPG/NG, 23%), coal combustion (21%), industrial processes (16%) and solvent usages (16%) were the major sources of ambient VOCs. Although industry and solvents have low contribution to the total VOCs, their secondary organic aerosol (SOA) contribution were found to be relatively high, especially in haze-1 and haze-3 periods. The haze-2 period had the lowest secondary organic aerosol potential (SOAp) during the sampling period; this is mainly caused by the reduction of industrial and solvent emissions due to CNY. Full article

To measure the long-range transport of PCDD/Fs, a background sampling site at Mt. Lulin station (Taiwan) was selected based on meteorological information and its location relative to burning events in Southeast Asia. During regular sampling periods, a higher concentration of PCDD/Fs was recorded in 2008 at Mt. Lulin station during La Niña events, with levels reaching 390 fg I-TEQ/m³. In contrast, a higher concentration of 483 fg I-TEQ/m³ was observed in 2013 during biomass burning events. This indicates that La Niña affects the ambient PCDD/F concentrations. The ratio of ΣPCDD/ΣPCDF was 0.59, suggesting significant long-range transport contributions from 2007 to 2023. From 2007 to 2015, the predominant species was 2,3,4,7,8-PCDF, accounting for 25.3 to 39.6% of the total PCDD/Fs. From 2018 onward, 1,2,3,7,8-PCDD became more dominant, accounting for 15.0 to 27.1%. According to the results from the receptor model PMF (n = 150), the sources of PCDD/Fs were identified as dust storms and monsoon events (19.3%), anthropogenic activity (28.5%), and biomass burning events (52.2%). The PSCF values higher than 0.7 highlighted potential PCDD/F emission source regions for Mt. Lulin during biomass burning events, indicating high PSCF values in southern Thailand, Cambodia, and southern Vietnam. Full article

Soil heavy metal pollution is one of the hottest topics in soil environmental research. There are a large number of small abandoned metal mines in China. Due to the lack of timely restoration and treatment, the heavy metal concentration in the soil within these mining areas often exceeds the local background levels, facilitating pollution spread to other natural factors such as precipitation, resulting in a wider extent of continuous contamination. This paper investigates the current status of heavy metal pollution in an abandoned small lead-zinc mine, particularly examining the concentrations of 10 specific heavy metals (V, Cr, Ni, Zn, As, Cd, Hg, Pb, Cu, Co) in soil samples. Additionally, it explores the extent of contamination caused by these heavy metals within the area. Besides, principal component analysis and positive matrix factorization model (PMF) were adopted to determine the sources of these heavy metals. The risk assessment of the pollution status was also carried out. The provision of a scientific basis for mining area management under similar conditions holds significant importance. The results indicate a significant positive correlation among the majority of these 10 heavy metals in soil. The presence of these heavy metals in the soil within the concentrator and tailings reservoir area primarily stems from mining operations, construction activities, and discharges from the power system. Hg, Pb, Zn, and As in the surrounding agricultural land mainly come from the heavy metal spillover from the mining area. Furthermore, the area is plagued by severe contamination from As and Pb. The Nemerow comprehensive index method has confirmed substantial pollution in both the concentrator and tailings reservoir. Additionally, there exists a substantial ecological risk ranging from moderate to high. Full article

The airport and its surrounding areas are home to a variety of pollution sources, and air pollution is a recognized health concern for local populated regions. Submicron particulate matter (PM₁ with an aerodynamic diameter of <1 mm) is a typical pollutant at airports, and the enrichment of heavy metals (HMs) in PM₁ poses a great threat to human health. To comprehensively assess the source-specific health effects of PM₁-bound HMs in an airport community, PM₁ filter samples were collected around the Tianjin Binhai International Airport for 12 h during the daytime and nighttime, both in the spring and summer, and 10 selected HMs (V, Cr, Mn, Co, Ni, Cu, Zn, As, Cd, and Pb) were analyzed. The indicatory elements of aircraft emissions were certified as Zn and Pb, which accounted for more than 60% of the sum concentration of detected HMs. The health risks assessment showed that the total non-cancer risks ($TNCRs$) of PM₁-bound HMs were 0.28 in the spring and 0.23 in the summer, which are lower than the safety level determined by the USEPA, and the total cancer risk ($TCR$) was 2.37 × 10⁻⁵ in the spring and 2.42 × 10⁻⁵ in the summer, implying that there were non-negligible cancer risks in the Tianjin Airport Community. After source apportionment with EF values and PMF model, four factors have been determined in both seasons. Consequently, the source-specific health risks were also evaluated by combining the PMF model with the health risk assessment model. For non-cancer risk, industrial sources containing high concentrations of Mn were the top contributors in both spring (50.4%) and summer (44.2%), while coal combustion with high loads of As and Cd posed the highest cancer risk in both seasons. From the perspective of health risk management, targeted management and control strategies should be adopted for industrial emissions and coal combustion in the Tianjin Airport Community. Full article