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This study reported the distribution patterns of ten typical phthalic acid esters (PAEs) in personal care products (PCPs) available in Vietnam, with a focus in source apportionment and ecological risk assessment. Total of PAE concentrations in PCPs was 352–83500 µg/g (mean/median: 10900/6050), with di-(2-ethyl)hexyl phthalate (DEHP) being the dominant compound (115–36300 µg/g; mean/median: 6110/3780), diethyl phthalate (mean/median: 2000/n.d.; range: n.d.–75300 µg/g), and diisobutyl phthalate (mean/median: 1040/130; range: n.d.–13800 µg/g) were also present in significant concentrations. Total PAE concentrations in untreated municipal wastewater samples from Hanoi were significantly higher than those from Thaibinh, with a mean concentration approximately 3.7 times greater. DEHP was also found to have the highest frequency and levels in wastewater, with mean/median concentrations of 3260/2830 and 598/557 µg/L in samples collected from Hanoi and Thaibinh, respectively. Seasonal variation was observed, with higher concentrations in the dry season. The ecological risk due to the distribution of individual PAEs in wastewater was moderate, except for DEHP, with risk quotients ranging from 5.98 to 24.8 for algae. These findings underscore the need for regulatory interventions to mitigate PAE contamination in urban environments. Highlights: High levels of PAEs were found in PCPs available in Vietnam. DEHP was measured at the highest levels in both PCPs and untreated municipal wastewater. Strong correlations existed between the distribution of PAEs in PCPs and wastewater. The risk quotient (RQ) for DEHP was high for algae and crustaceans. [ABSTRACT FROM AUTHOR]

Data on particulate matter, gaseous pollutants, and AQI values from three cities (Haikou, Sanya, and Danzhou) between January 2018 and December 2022 were obtained in order to analyze the spatiotemporal distribution characteristics of air pollution, the correlation between pollutants with meteorological conditions, and the potential sources in Hainan Island. The spatiotemporal distribution's characteristics demonstrated that the annual mean concentrations of SO2, NO2, CO, O3, PM10 and PM2.5 were 4.34 ± 1.11 μg m−3, 9.87 ± 1.87 μg m−3, 0.51 ± 0.06 mg m−3, 73.04 ± 6.36 μg m−3, 27.31 ± 3.63 μg m−3, and 14.01 ± 2.02 μg m−3, respectively. The yearly mean concentrations were trending downward in the past few years and were below the National Ambient Air Quality Standard (NAAQS) Grade II. Summer was the season with the lowest concentrations of all pollutants (3.84 μg m−3, 7.34 μg m−3, 0.42 mg m−3, 52.80 μg m−3, 18.67 μg m−3 and 8.67 μg m−3 for SO2, NO2, CO, O3, PM10 and PM2.5, respectively), and afternoons were the time with the lowest concentrations of pollutants (except for 78.04 μg m−3 for O3). The influence of meteorological conditions on pollutants was examined: there was a prominent positive correlation between temperature and O3 in summer, and relative humidity largely influenced the concentrations of PM. The pollution in Hainan was affected more by regional transport; according to the backward trajectory results, Hainan is susceptible to air masses from Guangdong and Fujian to the northeast, the Indochina Peninsula to the southwest, and the South China Sea to the southeast. The results of PSCF and CWT analyses indicated that Guangdong, Jiangxi, Hunan, and Fujian were the primary potential sources of PM2.5 and O3. [ABSTRACT FROM AUTHOR]

To observe the long-term variations in halocarbons in the Yangtze River Delta (YRD) region, this study analyzes halocarbon concentrations and composition characteristics in Shanxi from 2018 to 2020, exploring their origins and the health effects. The total concentration of halocarbons has shown an overall increasing trend, which is driven by both regulated substances (CFC-11 and CFC-113) and unregulated substances, such as dichloromethane, chloromethane and chloroform. The results of the study also reveal that dichloromethane (1.194 ± 1.003 to 1.424 ± 1.004 ppbv) and chloromethane (0.205 ± 0.185 to 0.666 ± 0.323 ppbv) are the predominant halocarbons in Shanxi, influenced by local and northwestern emissions. Next, this study identifies that neighboring cities in Zhejiang Province and other YRD areas are potentially affected by backward trajectory models. Notably, chloroform and 1,2-dichloroethane have consistently surpassed acceptable thresholds, indicating a significant carcinogenic risk associated with solvent usage. This research sheds light on the evolution of halocarbons in the YRD region, offering valuable data for the control and reduction in halocarbon emissions. [ABSTRACT FROM AUTHOR]

Antibiotic contamination poses a significant global concern due to its far-reaching impact on public health and the environment. This comprehensive review delves into the prevalence of various antibiotic classes in environmental pollution and their interactions with natural ecosystems. Fluoroquinolones, macrolides, tetracyclines, and sulphonamides have emerged as prevalent contaminants in environmental matrices worldwide. The concentrations of these antibiotics vary across diverse environments, influenced by production practices, consumer behaviours, and socio-economic factors. Low- and low-middle-income countries face unique challenges in managing antibiotic contamination, with dominant mechanisms like hydrolysis, sorption, and biodegradation leading to the formation of toxic byproducts. Ecotoxicity reports reveal the detrimental effects of these byproducts on aquatic and terrestrial ecosystems, further emphasizing the gravity of the issue. Notably, monitoring the antibiotic parent compound alone may be inadequate for framing effective control and management strategies for antibiotic pollution. This review underscores the imperative of a comprehensive, multi-sectoral approach to address environmental antibiotic contamination and combat antimicrobial resistance. It also advocates for the development and implementation of tailored national action plans that consider specific environmental conditions and factors. Thus, an approach is crucial for safeguarding both public health and the delicate balance of our natural ecosystems. [ABSTRACT FROM AUTHOR]

The shelf‐margin deltas are the primary 'sources' of interest in siliceous submarine fan source‐to‐sink systems. However, less has yet to be discovered about the roles and effects of the shallow water platform situated on continental slopes. Using the Miocene sediments of the Ledong‐Lingshui Sag in the western part of the Qiongdongnan Basin (QDNB), this paper studies the YC35 coarse‐grained submarine fan that developed in the Meishan Formation (Fm.). The material sources, depositional characteristics, and developmental mechanisms of this fan were investigated. The restored palaeogeomorphology, based on high‐resolution 3D seismic data, shows that a shallow water platform exists. According to geochemical palaeoenvironmental data, the shallow water platform was ideal for forming carbonate deposits in the Meishan Fm., owing to the warm and humid palaeoclimate and the shifting trend in palaeowater depth. Based on the combined source tracing of heavy minerals, coherence slices, and seismic profiles, the shallow water platform and the Ningyuan River source on Hainan Island contributed to the YC35 coarse‐grained submarine fan. Compared to submarine fans formed during different periods, coarse‐grained fan stands out due to its distinct sedimentary structure, rock composition, and microlithological characteristics. Aside from not following the usual Bowmar sequence, there is an excess of gravel and no clear bedding or lamination. A large number of rock fragments, mostly granite and sedimentary rock (carbonatite), make up the rock composition. According to these results, the shallow water platform significantly affects submarine fan material composition. In addition, the attribute slice based on the root mean square reveals that shallow water platforms moderate peripheral deposition. We attribute the development and proximal supply of the shallow water platform to diapirism and forced regression. Our research provides novel insights and comprehension into the investigation of submarine fan sedimentary systems. [ABSTRACT FROM AUTHOR]

Given the widespread use as flame retardants, plasticizers, and organophosphate esters (OPEs) received increasing scientific interests on their occurrence and ecotoxicological research progress. This review comprehensively conducted bibliometric analysis and surveyed the OPEs occurrence in aquatic ecosystem (water, sediment, and aquatic organisms) and human-related (drinking water and sewage) over the past decade to unraveling knowledge gaps. The OPEs concentrations in water, sediment were at the range of not detected (n.d.) or several to hundreds ng/g or ng/L and exhibited landuses-specific characteristics. The electronic waste (e-waste) processing activities and sewage discharge were identified as point sources of OPEs in aquatic environment. Emission source intensity, water chemistry, and content of organic carbon were important for the partition and transfer processes of OPEs in the water, as well as hydrophobicity of OPEs dominating the absorption on the organic matter. Degradation, especially photodegradation and reductive degradation, has application potential in improving removal efficiencies of chlorinated-OPEs (Cl-OPEs) being reluctant to degrade. Generally, most surveyed OPEs have negligible ecological and health risks, whereas those OPEs with moderate threats or chronic effects on aquatic ecosystem should gain more attention. This review elucidates the status of OPEs pollution in water and highlights the need for more transport and degradation studies on traditional and emerging OPEs and metabolites to further identify potential threats on aquatic ecosystem. [ABSTRACT FROM AUTHOR]

To observe the long-term variations in halocarbons in the Yangtze River Delta (YRD) region, this study analyzes halocarbon concentrations and composition characteristics in Shanxi from 2018 to 2020, exploring their origins and the health effects. The total concentration of halocarbons has shown an overall increasing trend, which is driven by both regulated substances (CFC-11 and CFC-113) and unregulated substances, such as dichloromethane, chloromethane and chloroform. The results of the study also reveal that dichloromethane (1.194 ± 1.003 to 1.424 ± 1.004 ppbv) and chloromethane (0.205 ± 0.185 to 0.666 ± 0.323 ppbv) are the predominant halocarbons in Shanxi, influenced by local and northwestern emissions. Next, this study identifies that neighboring cities in Zhejiang Province and other YRD areas are potentially affected by backward trajectory models. Notably, chloroform and 1,2-dichloroethane have consistently surpassed acceptable thresholds, indicating a significant carcinogenic risk associated with solvent usage. This research sheds light on the evolution of halocarbons in the YRD region, offering valuable data for the control and reduction in halocarbon emissions.

Due to the difference of industrialization degree and meteorological conditions, there are obvious differences in the composition of air pollution between islands and inland areas. With Zhoushan (ZS) and Nanjing (NJ) representing islands and inland cities in the Yangtze River Delta, the differences in vertical distribution of atmospheric components were investigated. A combination of multi-axial differential optical absorption spectroscopy (MAX-DOAS), weather research and forecasting (WRF), and potential source contribution function (PSCF) models were used to obtain vertical distribution data for aerosols, nitrogen dioxide (NO2) and formaldehyde (HCHO), meteorological factors, and pollution sources in summer 2019. The findings indicate that, except for the aerosol extinction coefficient (AE), the atmospheric composition at the ZS site was not significantly stratified. However, the AE, NO2, and HCHO at NJ all displayed a decreasing trend with altitude. Here is the interesting finding that the ZS site has a higher AE value than the NJ site, while NJ displays higher NO2 and HCHO columns than the ZS site. This discrepancy was primarily attributable to Zhoushan City's extremely low traffic emissions when compared to inland cities. In addition, HCHO in the YRD region was significantly affected by human activities. Analysis of potential pollution sources found that regional transport contributed to differences in atmospheric composition at different altitudes in different regions. Aerosols, NO2, and HCHO in Nanjing were significantly affected by transport in inland areas. Aerosols in Zhoushan were easily affected by transport in the Yellow Sea and East China Sea, and NO2 and HCHO were significantly affected by transport contributions from surrounding areas in inland areas. The study strongly suggests that land and sea breezes play an important role in the vertical distribution of aerosols over island regions. [ABSTRACT FROM AUTHOR]

Black carbon (BC), an important component of atmospheric aerosol, plays a significant role in regional climate, hydrological cycle, variation of monsoon rainfall, and human health. The 40-year detailed atmospheric BC over China from 1981 to 2020 is systematically investigated through the MERRA-2 reanalysis dataset. MERRA-2 BC generally showed a good correlation (R = 0.68) compared with 673 monthly samples from ground-based observation at 35 stations around China. The overall annual average of MERRA-2 BC concentration over China is 1.15 μg/m3, with a fast growth rate during 1981–2007 and a relatively slow decrease after that. The winter season has the highest mean concentration of BC, followed by autumn and spring, whereas summer shows relatively weaker values. The order of annual average BC concentrations during 1981–2020 is Beijing-Tianjin-Hebei region (BTH, 4.02 μg/m3) > Sichuan Basin (SB, 3.94 μg/m3) > Yangtze River Delta (YRD, 2.68 μg/m3) > Pearl River Delta (PRD, 1.47 μg/m3). The monthly mean BC concentrations over the BTH, YRD, PRD and SB are estimated to be smallest 3.18 μg/m3 in May, 1.94 μg/m3 in August, 0.82 μg/m3 in July, 3.04 μg/m3 in June, respectively, whilst largest consistently in December with 5.09 μg/m3, 3.83 μg/m3, 2.12 μg/m3, and 5.41 μg/m3, respectively. Our study indicates the primary potential source areas for BC are concentrated in the research city and its surroundings. Beijing and Chengdu are more BC-polluted areas than Shanghai and Guangzhou. Long-distance, regional transfer from south BTH contributes importantly to BC pollution in Beijing under the influence of prevailing southerly winds. The geographical location of Chengdu causes the transport and accumulation of BC inside the SB. [ABSTRACT FROM AUTHOR]

Microplastics (MPs) as emerging contaminants have become a major global concern, however, the distribution and origin of MPs in Qinghai-Tibet Plateau (QTP) and their impacts on ecosystem are poorly known. Hence, we systematically evaluated the profile of MPs on the representative metropolitan locations of Lhasa and Huangshui Rivers and the scenic sites of Namco and Qinghai Lake. The average abundance of MPs in the water samples was 7020 items/m3, which was 34 and 52 times higher than those for the sediment (206.7 items/m3) and soil samples (134.7 items/m3), respectively. Huangshui River had the highest levels, followed by Qinghai Lake, Lhasa River and Namco. Human activities rather than altitude and salinity impacted the distribution of MPs in those areas. Besides the consumption of plastic products by locals and tourists, laundry wastewater and exogenous tributary inputs, the unique prayer flag culture also contributed to the MPs emission in QTP. Notably, the stability and fragment of MPs were crucial for their fate. Multiple assessment models were employed to evaluate the risk of MPs. PERI model took MP concentration, background value and toxicity into account, comprehensively describing the risk differences of each site. The large PVC proportion in Qinghai Lake posed the highest risk. Furthermore, concerns should be raised about PVC, PE and PET in Lhasa and Huangshui Rivers, and PC in Namco Lake. Risk quotient suggested that aged MPs in sediments slowly released biotoxic DEHP and should be cleaned up promptly. The findings offer baseline data of MPs in QTP and ecological risks, providing important support for the prioritization of future control measures.

Bacterial loading aggravates the harm of particulate matter (PM) to public health and ecological systems, especially in operations of concentrated animal production. This study aimed to explore the characteristics and influencing factors of bacterial components of inhalable particles at a piggery. The morphology and elemental composition of coarse particles (PM10, aerodynamic diameter ≤ 10 µm) and fine particles (PM2.5, aerodynamic diameter ≤ 2.5 µm) were analyzed. Full-length 16 S rRNA sequencing technology was used to identify bacterial components according to breeding stage, particle size, and diurnal rhythm. Machine learning (ML) algorithms were used to further explore the relationship between bacteria and the environment. The results showed that the morphology of particles in the piggery differed, and the morphologies of the suspected bacterial components were elliptical deposited particles. Full-length 16 S rRNA indicated that most of the airborne bacteria in the fattening and gestation houses were bacilli. The analysis of beta diversity and difference between samples showed that the relative abundance of some bacteria in PM2.5 was significantly higher than that in PM10 at the same pig house (P

The spatio-temporal variation of aerosol size distribution, which indicates the primary and secondary sources of atmospheric aerosols, can reflect the dynamic and chemical processes that they were subjected to. A wide-range particle size spectrometer was used to observe the aerosol size distributions（10 nm-10 μm） in Litang county of Sichan province over the eastern Qinghai-Tibet Plateau from July 6 to August 3, 2017. Combining with the data of six atmospheric pollutants(PM2.5, PM10, SO2, NO2, CO, and O3), meteorological elements, trajectory model of HYSPLIT, potential source contribution function（PSCF） and concentration-weighted trajectory（CWT） analysis, the size distributions, potential sources and affecting areas of aerosols on the eastern margin of Qinghai-Tibet Plateau were discussed. The results show that the average aerosol number concentration is 4 660.3 cm-3 in Litang area, and mainly concentrates below 500 nm, which accounts for 99.95% of total number concentration; the aerosol number concentrations in different modes of particle vary greatly, that of nucleation mode, Aitken mode, accumulation mode, and coarse mode of particle are 391.9, 4 218.0, 50.1, and 0.4 cm-3, respectively; meanwhile, the diurnal variations of aerosol number concentration in different modes of particle are all bimodal distributions, with a discrepancy in the peak time, which is located at 12:00 and 19:00 for the nucleation mode of particle, and at 08:00 and 20:00 for the Aitken mode, accumulation mode and coarse mode of particle; the spectrum of aerosol number concentration and surface area concentration has both unimodal distributions with peaks at 50 nm and 170 nm, respectively, the peak concentrations of which are 7 361.9 cm-3·nm-1 and 215.5 μm²·cm-3·nm-1, accordingly. Finally, the potential sources of aerosol number concentration with high PSCF values in Litang area include two areas, which are a local polluted region in the northeast and a foreign region in the southwest triggered by the long range transport process. Conversely, the affecting areas of the aerosol number concentration in the eastern Qinghai-Tibet Plateau are mainly in the domestic region, and the affecting areas with high PSCF value are relatively scattered. [ABSTRACT FROM AUTHOR]

Rapid social development has led to serious air pollution problems in cities, and air pollutants, including gaseous pollutants and particulate matter, have an important impact on climate, the environment, and human health. This study analyzed the characteristics, potential sources, and causes of air pollution in the Wu-Chang-Shi urban cluster. The results showed that NO2, CO, SO2, PM10, and PM2.5 had a tendency to decrease, while O3 showed an increasing trend. The concentrations of SO2, NO2, CO, PM2.5, and PM10 showed the highest values in winter and the lowest values in summer, with similar seasonal variations. However, the concentration of O3 was highest in the summer and lowest in the winter. Compared with the pollutant concentrations in other Chinese cities, PM2.5, PM10, and NO2 are more polluted in the Wu-Chang-Shi urban. Meteorological factors have a greater impact on pollutant concentrations, with higher concentrations of major pollutants observed when wind speeds are low and specific wind directions are observed, and higher secondary pollutant O3 concentrations observed when wind speeds are low and specific wind directions are observed. The backward trajectory and concentration weighting analysis show that the particulate pollutants in the Wu-Chang-Shi urban in winter mainly come from Central Asia and surrounding cities. O3 showed an increasing trend before and after the novel coronavirus outbreak, which may be related to changes in NOX, volatile organic compounds, and solar radiation intensity, and the concentrations of SO2, NO2, CO, PM10, and PM2.5 showed an overall decreasing trend after the outbreak and was smaller than before the outbreak, which is related to the reduction of industrial and anthropogenic source emissions during the outbreak. [ABSTRACT FROM AUTHOR]

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Global climate change is becoming increasingly crucial. With the continuous strengthening of environmental supervision and governance in China, the haze （O 3 ） weather mainly caused by PM 2.5 pollution has gradually improved, while the emissions of invisible ozone pollutants have been increasing annually. In particular, the problem of near-ground ozone pollution is more crucial, which poses a severe threat to urban production, life, and health of people. To gain a deeper understanding of the pollution characteristics of ozone, this study was conducted based on ozone monitoring, ground meteorological, and global data assimilation system （GDAS） meteorological data from January 2020 to February 2023 in Tianshan District, Urumqi City, to explore the characteristics of ozone mass concentration changes and potential source areas in Urumqi City at different time scales using the cluster analysis of the backward trajectory model （HYSPLIT） and trajectory （Tianshan District） and the concentration weight trajectory analyses （CWT）. The results showed that： ① The maximum 8-hour O 3 （O 3-8h ） mass concentration in Tianshan District of Urumqi City had been increasing yearly from 2020 to 2022 and had obvious seasonal variation characteristics, with summer （110.33 μg·m -3 ） > spring （87.67 μg·m -3 ） > autumn （64.33 μg·m -3 ） > winter （39.67 μg·m -3 ）. ② The temperature, relative humidity, and air pressure of each season had a significant impact on O 3-8h mass concentration, with correlation coefficients r of 0.871,-0.752, and 0.644 （ P < 0.01）, respectively. The annual wind speed variation was relatively low, which was a secondary meteorological factor and had no significant impact on ozone mass concentration. ③ The HYSPLIT clustering analysis results showed that overseas long-distance transportation had less impact on the O 3-8h mass concentration in Tianshan District, Urumqi City. The CWT results indicated that ozone pollution sources were mainly concentrated in the northern area of Urumqi in Xinjiang and the high-value areas in summer [O 3-8h mass concentration > 70 μg·m -3 ] mainly appeared in areas with higher temperatures in Urumqi, Changji, Altay, and Tacheng. ④ Especially in autumn, the pollutants emitted by local anthropogenic activities had a great influence. To summarize, spatiotemporal concentration changes were observed in ozone pollution in Urumqi and the prevention and control of urban ozone pollution in Urumqi requires strengthening the emission of ozone precursors while considering implementing coordinated emission reduction measures for surrounding areas.

The presence of polyhalogenated carbazoles (PHCZs), which are emerging as dioxin-like contaminants, in remote polar regions has not been reported. This study investigated 11 target PHCZs (Σ 11 PHCZs) and 25 unknown PHCZs (Σ 25 UNPs) in soil and sediment samples collected from Ny-Ålesund in the Arctic. The findings revealed that Σ 11 PHCZs concentrations reached 165.6 ng/g dry weight (dw), with 3,6-dichlorocarbazole and 3-chlorocarbazole being the predominant congeners. The Σ 25 UNPs concentrations ranged from 1.4 to 92.4 ng/g dw (median: 17.0 ng/g dw), primarily comprising a 1,3,6,8-tetrabromocarbazole isomer. The sediment contained ∼6 times more Σ 25 UNPs than Σ 11 PHCZs. Long-range atmospheric transport, oceanic transport, and human activity can potentially affect soils and sediments concurrently. For the first time, halogen substitution patterns in PHCZs, including ClI, ClI 2 , and ClI 3 , were detected in soil and sediment. Using the toxic equivalent (TEQ) approach, the potential toxic effects linked to the target PHCZ levels were assessed. The TEQ PHCZs in Arctic soils and sediments indicated low risk, ranging from 8.0 × 10 -3 to 17 pg TEQ/g dw (median: 2.8 pg TEQ/g dw) and 0.1 to 0.4 pg TEQ/g dw (median: 0.3 pg TEQ/g dw), respectively. This study marks the first report on the occurrence, composition, sources, and potential risks posed by PHCZs in the Arctic region.

Air pollution is one of the leading causes for global deaths and understanding pollutant emission sources is key to successful mitigation policies. Air quality data in the urban, suburban, industrial, and rural areas (UA, SA, IA, and RA) of Jining, Shandong Province in China, were collected to compare the characteristics and associated health risks. The average concentrations of PM2.5, PM10, SO2, NO2, and CO show differences of −3.87, −16.67, −19.24, −15.74, and −8.37% between 2017 and 2018. On the contrary, O3 concentrations increased by 4.50%. The four functional areas exhibited the same seasonal variations and diurnal patterns in air pollutants, with the highest exposure excess risks (ERs) resulting from O3. More frequent ER days occurred within the 25–30°C, but much larger ERs are found within the 0–5°C temperature range, attributed to higher O3 pollution in summer and more severe PM pollution in winter. The premature deaths attributable to six air pollutants can be calculated in 2017 and 2018, respectively. Investigations on the potential source show that the ER of O3 (r of 0.86) had the tightest association with the total ER. The bivariate polar plots indicated that the highest health-based air quality index (HAQI) in IA influences the HAQI in UA and SA by pollution transport, and thus can be regarded as the major pollutant emission source in Jining. The above results indicate that urgent measures should be taken to reduce O3 pollution taking into account the characteristics of the prevalent ozone formation regime, especially in IA in Jining.

This study aims to investigate the spatial and temporal characteristics, pollution degrees, and potential ecological risks of mercury (Hg) in urban lake waters and sediments in Guangzhou, where is a typical area of Hg emission and population-economic-industrial concentration in South China. In different districts of this city, the water from 15 lakes were collected continuously from June 2020 to May 2021, and the sediments from 9 lakes were collected in 2015 and 2021. The seasonal changes of Hg concentration (Hg-C) in the water were found to be high in winter and low in summer. The spatial distribution of Hg-C in sediments showed that it was high in urban central areas and low in suburbs. The Nemero index and geological accumulation index showed that there were uncontaminated of Hg in the collected lake water, and above moderately contaminated in the lake sediments in urban center, respectively. The Hg pollution potential ecological risk index showed that there was low risk in the collected water, high and extremely high risk in the lake sediments in urban center, respectively. The principal component analysis (PCA) and correlation analysis (CA) of Hg and meteorological factors showed that precipitation, temperature, and vapor pressure had negative effects on the seasonal changes of Hg-C in water, and air pressure and wind direction had positive effects. The PCA and CA of Hg and other geochemical elements showed that anthropogenic emissions may be the main sources of Hg in sediments, which was also supported by the data of population density, road density, and motor vehicles per 1000 people. This study provided a reference for urban lake pollution treatment, resident health, and ecological environment protection. [ABSTRACT FROM AUTHOR]

In the Beijing-Tianjin-Hebei (BTH) urban agglomeration, the atmospheric particulate matter (PM) pollution has become exacerbated year by year. In an attempt to understand the current condition of aerosol particulate pollution in the BTH region, the temporal and spatial distribution, future trend changes, and potential source areas of absorbing aerosols in the BTH region from 2005 to 2019 were analyzed based on Ozone Monitoring Instrument/Aura Near UV Aerosol Optical Depth and Single Scattering Albedo 1-orbit L2 Swath 13 × 24 km V003 (OMAERUV) daily product data; besides, relevant influencing factors were explored in this study. As per the analysis of results, the ultraviolet aerosol index (UVAI) increased by 3.03% in the time series from 2005 to 2019. Spatially, the absorbing aerosol in the North China Plain was always maintained in a high-value area, and the15-year average annual UVAI value has been as high as 0.45. In the monthly time series, a "V" shape started from January. The peak value of seasonal characteristics reached the highest in winter, followed by autumn and spring, and the lowest in summer. The external potential sources in the BTH region are mainly sand and dust sources generated in the northwest, while those of absorbing aerosols are mainly carbon sources in spring, with the lowest external absorbing aerosols in summer. The potential sources of absorbing aerosols in autumn are relatively complicated. The potential sources of absorbing aerosols are mainly sand and dust sources in the north. The time series of absorbing aerosols mainly showed an anti-continuous rise, and 54.23% of absorbing aerosols indicated an upward trend that would occur in the future. The relationship between absorbing aerosols and PM2.5 is mutual conversion. According to the path coefficient, industrial production activities are important sources of atmospheric absorbing aerosols, and precipitation can reduce the content of absorbing aerosols in the atmosphere caused by industrial production. [ABSTRACT FROM AUTHOR]

Based on the environmental monitoring data and meteorological observational data in Hainan Island from 2015 to 2021, the PM 2.5 -polluted characteristics, influencing factors, and potential contributing regions were analyzed using the backward trajectory simulation, cluster analysis, potential source analysis function （PSCF）, and concentration weight trajectory （CWT） methods. The results showed that PM 2.5 in Hainan Island had an obvious seasonal variation, with the highest in winter （22.6 μg·m -3 ）, followed by that in autumn and spring （17.38 and 16.53 μg·m -3 , respectively）, with the lowest in summer （9.79 μg·m -3 ）. In the past seven years, there were 30 days in Hainan Island in which PM 2.5 concentration exceeded the standard. The annual average and four seasons of PM 2.5 showed a significant downward trend, and the climatic change rates were -0.97 （annual mean）, -1.09 （spring）, -0.61 （summer）, -0.83 （autumn）, and -1.25 （winter） μg·（m 3 ·a） -1 . PM 2.5 in Hainan Island was highly correlated with gaseous pollutants, with correlation coefficients of 0.471 （SO 2 ）, 0.633 （NO 2 ）, 0.479 （CO）, and 0.773 （O 3 -8h）, all passing a significance level of 0.01. PM 2.5 was positively correlated with average wind speed and atmospheric pressure and negatively correlated with precipitation, relative humidity, sunshine duration, average temperature, and total solar radiation. Among them, average temperature, relative humidity, and total solar radiation were the main dominant meteorological factors on PM 2.5 in Hainan Island. Backward trajectory and potential source analysis revealed that PM 2.5 concentration was high （≥20 μg·m -3 ） in winter and autumn, which was influenced by airflow from inland regions, and Fujian, Zhejiang, Hunan, Jiangxi, Guangdong, and Guangxi provinces were the main potential sources of PM 2.5 in Hainan Island.

In this study, air pollutants were analyzed at a low-industry city on the Silk Road Economic Belt of Northwestern China from 2015 to 2018. The results show that SO2 and CO had a decreasing trend and NO2, O3, PM2.5, and PM10 had an increasing trend during the study period. The primary characteristic pollutants were PM2.5 and PM10, which were higher than China’s Grade II standard. SO2, NO2, CO, PM2.5, and PM10 concentrations showed similar seasonal variation patterns: the highest pollutant concentration was in winter and the lowest in summer. Those pollutants showed a similar diurnal pattern with two peaks, one at 7:00 to 9:00 and another at 21:00 to 22:00. However, O3 concentration was highest in summer and lowest in winter, with a unimodal diurnal variation pattern. The annual average pollution concentrations in Tianshui in 2017 were substantially lower than the concentrations reported by most cities in China. By examining the meteorological conditions at a daily scale, we found that Tianshui was highly influenced by local emissions and a southwest wind. Potential source contributions and concentration weighted trajectory analyses indicated that the pollution from Gansu, Sichuan, Qinghai, and Shaanxi Province could affect the pollution concentration in Tianshui. The results provide directions for the government to take in formulating regional air pollution prevention and control measures and to improve air quality.

Linfen in China's Shanxi Province suffers severe air pollution in winter. Understanding the characteristics of air pollution and providing scientific support to mitigate such pollution are urgent matters. This study investigated the variations of PM2.5, PM10, NO2, SO2, O3, and CO in Linfen between December 1, 2019 and February 29, 2020. The mean concentrations of PM2.5, PM10, NO2, SO2, MDA8 (the maximum daily 8-h average) O3, and CO were 106.2, 139.4, 47.2, 41.0, 57.0 μg m−3, and 1.8 mg m−3, respectively. Large amounts of pollutants emitted by coal burning, industry, vehicles, and residents contributed to air pollution. Unfavorable meteorological conditions, such as lower temperature, weaker wind, higher relative humidity, and reduced planetary boundary layer height, made the situation worse. Fireworks and firecrackers set off to celebrate traditional Chinese festivals caused the concentration of PM pollutants to spike, with the maximum daily mean concentration of PM2.5 reached 314 μg m−3 and the peak hourly value reached 378.0 μg m−3. Suspensions of commercial and social activities due to COVID-19 reduced anthropogenic emissions, mainly from industry and transportation, which decreased the level of air pollutants other than O3. Analyses involving backward trajectory cluster, the potential source contribution function, and concentration weighted trajectory demonstrated that PM2.5 pollution mainly came from local emissions in Shanxi Province and regional transport from Inner Mongolia, Shaanxi, Hebei, Henan, and Gansu provinces. Shanxi and its surrounding provinces should adopt measures such as tightening environmental management standards, promoting the use of renewable energy, and adjusting the transportation structure to reduce regional emissions. This study will help policy-makers draft plans and policies to reduce air pollution in Linfen. [ABSTRACT FROM AUTHOR]

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The synthesis of polycyclic aromatic hydrocarbon (PAH) data allows us to quantify and gain insights into the spatiotemporal dynamics of PAH contamination in marine bays. Here, a data synthesis framework was developed to understand data-driven insights into the spatiotemporal levels, compositional profiles, and potential sources of PAHs in water and sediment of marine bays. PAHs were detected in 69 bays worldwide, with contamination hotspots located in Asian bays. PAH concentrations in pre-2000 were significantly lower than those in the 2000s and post-2010, while the dominant species in water and sediment were 2-3 ring and 4-6 ring PAHs, respectively. The composition patterns of PAHs included 2-3 ring, 3-5 ring, and 4-5 ring dominant categories, but no significant distance decay relationship was found in the composition similarity due to international energy trade. Temporal dynamic patterns of concentrations included Descending-, Ascending-, and Inverted V-type, whereas over longer time spans, the pattern is more similar to the Inverted V-type owing to the reductions in emission intensity. PAHs were derived from both petrogenic and pyrolytic sources, with combustion from both coal and petroleum being the dominant source. These data-driven discoveries provide quantitative insights into the spatiotemporal patterns in the concentration and composition of PAHs, contributing to the mitigation of PAH contamination.

To investigate the secondary formation and pollution sources of atmospheric particles in urban Beijing, PM 2.5 and its chemical components were collected and determined by URG-9000D ambient ion monitor (AIM) from March 2016 to January 2017. Among water-soluble ions (WSIs), NO 3 −, SO 4 2- and NH 4 + (SNA) had the largest proportion (77.8%) with the total concentration of 23.8 μg/m3. Moreover, as fine particle pollution worsened, the NO 3 −, SO 4 2- and NH 4 + concentrations increased basically, which revealed that secondary aerosols were the main cause of particle pollution in Beijing. Furthermore, the particle neutralization ratio (1.1), the ammonia to sulfate molar ratio (3.4) and the nitrate to sulfate molar ratio (2.2) showed that secondary aerosols are under ammonium-rich conditions with the main chemical forms of NH 4 NO 3 and (NH 4) 2 SO 4 , and vehicle emission could be the main anthropogenic source of secondary aerosols in Beijing. Source analysis further indicated that secondary aerosols, solid fuel combustion, dust and marine aerosol were the principal pollution sources of PM 2.5 , accounting for about 46.1%, 22.4% and 13.0%, respectively, and Inner Mongolia and Hebei Provinces could be considered as the main potential sources of PM 2.5 in urban Beijing. In addition, secondary formation process was closely related with gaseous precursor emission amounts (SO 2 , NO 2 , NH 3 and HONO), atmospheric ozone concentration (O 3), meteorological conditions (temperature and relative humidity) and particle components. Sensitive analysis of the thermodynamic equilibrium model (ISORROPIA II) revealed that controlling total nitrate (TN) is the effective measure to mitigate fine particle pollution in Beijing. Image, graphical abstract [ABSTRACT FROM AUTHOR]

Copyright of Research of Environmental Sciences is the property of Research of Environmental Sciences Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Black carbon (BC) significantly affects climate, environmental quality, and human health. This study utilised Modern-Era Retrospective Analysis for Research and Applications, version 2 (MERRA-2), which can compensate for the shortcomings of ground BC monitoring in spatial-temporal distribution to study the pollution characteristics of BC and potential pollution sources in a typical industrial city (Xinxiang) with serious air pollution in northern China. The results showed that average daily ground observation and MERRA-2 concentration of BC of 7.33 μg m−3 and 9.52 μg m−3. The mean BC concentration derived from MERRA-2 reanalysis data was higher than ground measurement due to resolution limitations and pollution from the northern regions. The reliability of the MERRA-2 data was confirmed through correlation analysis. Consideration of the spatial distribution of BC from MERRA-2 and incorporating the potential source contribution function (PSCF), concentration-weighted trajectory (CWT), and emission inventory, other possible source areas and primary sources of BC in Xinxiang were investigated. The results indicated that implementing transportation and residential emission control measures in Henan Province and its surrounding provinces, such as Hebei Province, will effectively decrease the BC level in Xinxiang City. A passively smoked cigarettes model was used to evaluate the risk of BC exposure. The percentage of lung function decrement (PLFD) was the highest in school-age children, while the impact on lung cancer (LC) health risk was comparatively lower. Notably, the BC health risk in Xinxiang was lower than in most cities across Asia. [Display omitted] • The atmospheric BC pollution characteristic of Xinxiang was analyzed based on MERRA-2. • The relationship between BC and meteorological factors were explained. • The potential sources of BC in Xinxiang were clarified. • The BC different health terminals risks were assessed by using equal amounts of negative smoking model. [ABSTRACT FROM AUTHOR]

Atmospheric PM 10 (particulate matter with aerodynamic diameter <10 μm) samples were collected in the cities along the Bohai Sea Rim during heating and non-heating periods, and ionic per - and polyfluoroalkyl species (PFASs) in the PM 10 were measured. The total concentration of ionic PFASs ranged from 21.8 to 87.0 pg/m3, and the mean concentration of ionic PFASs during the day (42.6 pg/m3) was slightly higher than that at night (35.1 pg/m3). Generally, diurnal variations in the levels of ionic PFASs were consistent with those in the PM 10 concentrations. Perfluorooctanoic acid (PFOA, 23.5–33.7%), perfluoropentanoic acid (PFPeA, 28.3–39.9%) and perfluorobutyric acid (PFBA, 17.1–20.1%) accounted for the dominant compositional contributions. Significant positive correlations (p < 0.05) between the main components of PFASs and O 3 implied that oxidative degradation (O 3 served as the main oxidant) in the period of non-heating may affect the short-chain PFASs. The clustering analysis of a 72-h backward trajectory indicated that cross-provincial transport contributed to ionic PFASs at the sampling sites. Compared with ingestion via daily diet, the inhalation of PM 10 exhibited an insignificant contribution to the estimated average daily intakes (ADI s) of PFASs by different age groups. In addition, the calculated hazard ratios (HR s) for the non-cancer respiratory risk, based on the air concentrations of PFOA and perfluorooctane sulfonate (PFOS), also manifested lower non-cancer risk through inhalation exposure. The effects of heating and non-heating activity and diurnal variation on the concentrations of PFASs, dominated by PFOA, PFPeA, and PFBA in PM 10 , were determined, and atmospheric trans-provincial input served as an important source. Unlabelled Image • Heating activity and diurnal variation affected the levels of PFASs in PM 10. • PFOA, PFPeA and PFBA were determined to be the dominant species. • Backward trajectory indicated fluorine chemical plant as a main source of PFASs. • No strong health risks by inhalation exposure to PFOA and PFOS were estimated. [ABSTRACT FROM AUTHOR]

Bacteria are ubiquitous throughout the earth's lower atmosphere. Bacteria, especially pathogenic bacteria, play an important role in human health. The diversity, composition, and dynamics of airborne bacteria has been widely studied; however, the characteristics of pathogenic bacteria remain poorly understood. In this study, a high throughput sequencing method was used to explore the airborne opportunistic pathogenic bacteria during autumn and winter in Xi'an, China. An aggregated boosted tree (ABT) was developed to determine the relative influence of environmental factors on the proportions of opportunistic pathogenic bacteria. Results showed that significantly more opportunistic pathogenic bacteria were found in winter than in autumn, and more opportunistic pathogenic bacteria were found in fine particulate matters (<2.5 μm) than in PM 10 (<10 μm). However, the composition of opportunistic pathogenic bacteria varied in autumn and winter. PM was the main factor affecting the proportions of opportunistic pathogenic bacteria, and air contaminants (PM, sulfur dioxide, nitrogen oxide, carbon monoxide, and ozone) influenced the proportion of opportunistic pathogenic bacteria more than meteorological factors (relative humidity, temperature, and wind speed). Different factors may be responsible for the variances in opportunistic pathogenic bacterial communities in different seasons. This study may provide a reference to support the control of pathogenic bacteria in urban environments during haze events. The release, suspension and human health risk of opportunistic pathogenic bacteria. Unlabelled Image • The relative abundance of potential pathogenic bacteria increased notably in winter. • More opportunistic pathogenic bacteria were observed in PM 2.5 than in PM 10. • Air contaminants had more impact on opportunistic pathogenic bacteria. • Opportunistic pathogenic bacteria were mainly from nearby soil and leaf-surfaces. [ABSTRACT FROM AUTHOR]

Beijing, the capital city of China, has achieved remarkable progress in terms of an improvement in air quality under strict control policies in the past 10 years from various sources. In this paper, the characteristics of fine particulate matter (PM2.5) and O3 in January 2013 and 2018 in Beijing are discussed on the basis of daily sample analysis and hourly monitoring data. It was found that the PM2.5 pollution for the month of January in Beijing has been greatly curbed. The SO42− concentration and proportion of PM2.5 decreased, while the proportions of NO3− and NH4+ increased. Organic matter represented the major component during the two periods with the proportions of 31.7% ± 8.2% and 31.4% ± 9.8%. The results of the Hybrid Single Particle Lagrangian Integrated Trajectory (Hysplit) model and Potential Source Contribution Function (PSCF) method showed that air mass from southern nearby regions accounted for 34% and 10% in 2013 and 2018, respectively, which was closely related to the pollution period. Thus, the input direction of air mass in January 2018 was more conducive to the diffusion of pollutants. Modeling results of the Weather Research and Forecasting model (WRF) coupled with Comprehensive Air Quality Model Extensions (CAMx) indicated that the contribution of industry sources to PM2.5 and O3 decreased from 2013 to 2018, while mobile sources increased. This was mainly due to the different control policies on various emission sources. In terms of O3 sources, more control measurements should be taken on volatile organic compounds (VOCs) due to its prominent effect on O3 concentration in both periods. The reduction in emissions and the meteorological conditions both contributed effectively to the sharp decrease in PM2.5 concentration. However, the change in weather conditions had the greater impact on the decrease in PM2.5 concentration, while the reduction in emissions was weakened as a function of this change.

Ferromanganese nodules and crusts contain relatively high concentration of rare earth elements (REE) and yttrium (REY), with a growing interest in exploitation as an alternative to land-based REY resources. On the basis of comprehensive geochemical approach, the abundance and distribution of REY in the ferromanganese nodules from the South China Sea are analyzed. The results indicate that the REY contents in ferromanganese deposits show a clear geographic regularity. Total REY contents range from 69.1×10-6 to 2 919.4×10-6, with an average value of 1 459.5×10-6. Especially, the enrichment rate of Ce content is high, accounting for almost 60% of the total REY. This REE enrichment is controlled mainly by the sorption of ferromanganese oxides and clay minerals in the nodules and crusts. Moreover, the total REY are higher in ferromanganese deposits of hydrogenous origin than of diagenetic origin. Finally, Light REE (LREE) and heavy REE (HREE) oxides of the ferromanganese deposits in the study area can be classified into four grades: non-enriched type, weakly enriched type, enriched type, and extremely enriched type. According to the classification criteria of rare earth resources, the Xisha and Zhongsha platform-central deep basin areas show a great potential for these rare earth metals. [ABSTRACT FROM AUTHOR]

Ambient air samples were collected simultaneously at three sites in northern Taiwan using high-volume samplers during winter and summer to evaluate the atmospheric PCN characteristics including concentration, distribution, potential sources and gas/particle partitioning. The average concentration (Σ73 PCNs from di-to octa-CN) observed at industrial site is the highest (172 ± 111 pg m −3 ), while PCN levels measured at urban and rural sites are comparable (45.2 ± 8.20 and 45.9 ± 24.4 pg m −3 , respectively). The PCN concentrations are higher in summer compared with those measured in winter for all three sampling sites. Gas-phase PCNs predominate in ambient air, accounting for 94 ± 6.0% of total concentration. Homologue distributions of PCNs measured at industrial site are different from two other sites for both gas and particulate phases, suggesting that different sources contribute to PCNs collected at industrial site. Based on the ratios of characteristic PCN congeners and fraction of Σcombustion-related PCNs/ΣPCNs, thermal processes are identified as major sources of PCNs at industrial site. PCNs collected at urban and rural sites are mixed sources of thermal emissions and evaporation, however, more influence of thermal sources in winter and more impact of evaporation sources in summer are observed. Results of the logK p -logP L relationship indicate that both adsorption and absorption govern gas/particle partitioning of atmospheric PCNs in northern Taiwan. Furthermore, the relationship between logK p and logK OA reveals that absorption is more important in governing gas/particle partitioning of PCNs in winter compared to summer. [ABSTRACT FROM AUTHOR]

Airborne pollutant characteristics, potential sources, and variation trends of cause are investigated based on the hourly air concentrations of gaseous pollutants and particulate matter from 2013 to 2016 in Lanzhou. The mean concentration of SO2, NO2, CO, 8-hO3, PM2.5, and PM10 was 25.2 ± 16.0 μg m−3, 46.5 ± 21.1 μg m−3, 1.3 ± 0.7 mg m−3, 77.8 ± 45.5 μg m−3, 58.7 ± 32.9 μg m−3, and 131.1 ± 86.2 μg m−3, respectively. The concentrations of SO2, PM10, and PM2.5 present decreasing trends while NO2, CO, and O3 present increasing trends. PM is the most frequent major pollutants with much higher value than standard limit. However, NO2 pollution had obvious trends to reach the limit and was more serious in Lanzhou compared with other Chinese cities. Relationship between air pollutants and meteorological parameters suggested that lower primary pollutants were associated with higher wind speed from north and west. Modeled back trajectory demonstrated that the transport of air masses from the Hexi Corridor and Inner Mongolia was responsible for the high concentrations of the air pollutants in wintertime, and high PM10 level in springtime was related to long-range transport of dust from desert areas of the Sinkiang and the Central Asia. Effects of local pollutant emissions and meteorological condition were preliminary analyzed. Improvement of air quality might be related to the decreasing of pollutant emissions due to strict emissions controls, and the contribution of meteorological condition was not explicit and should be further investigated. [ABSTRACT FROM AUTHOR]