Application of the multimedia fugacity model in predicting the environmental behaviors of PCBs: Based on field measurements and level III fugacity model simulation.

The comprehensive understanding of PCBs' fate has been impeded by the lack of simultaneous monitoring of PCBs in multiple environmental media in the background areas, which were considered long-term sinks for highly chlorinated PCBs. To address this gap, this study analyzed soils, willow tree barks, water, suspended particulate matter (SPM), and sediment samples collected from the middle reach of the Huaihe River in China for 27 PCBs. The results showed that the levels of ∑27PCBs in the soils were comparable to or lower than the background values worldwide. There were no significant correlations between organic matter and ∑27PCB concentrations in the soils and sediments. Additionally, the contamination of dioxin-like PCBs in the aquatic environment of the study area deserves more attention than in the soils. Applying the level III fugacity model to PCB 52, 77, 101, and 114 revealed that the soil was the primary reservoir, and air-soil exchange was the dominant intermedia transfer process, followed by air-water exchange. Furthermore, simulated results of air-soil and air-water diffusion were compared with those calculated from the field concentrations to predict the potential environmental behaviors of PCBs. Results indicated that the studied river would be a "secondary source" for PCB 52, 77, and 101. However, PCB 52, 77, 101, and 114 would continue to transfer from the air to the soil. This study combines multimedia field measurements and the fugacity model, providing a novel approach to predicting the potential environmental behaviors of PCBs.

Selenium and toxic metals in human hair of the Dashan Region, China: Concentrations, sources, and antagonism effect.

The Dashan Region was a Se-rich region of China. In this study, 131 residents' human hair samples were collected. The concentrations of Se and toxic metals were analyzed, and the health risk was estimated using the concentration data. Cd and As concentrations were significantly higher than in East China. Se and most toxic metal concentrations increased with age (except for the aged people). Furthermore, gender and smoking habits might have a significant impact on toxic metals and Se levels. Multivariable statistics analysis revealed that Se and toxic metals primarily originate in the environment and are then transferred to the human body via the food chain. Dietary habits had an effect on the Se and As concentrations in hair, according to the results of stable isotope analysis. To assess detoxification ability, the Se/ toxic metal molar ratio was used as an indicator. The results demonstrated that the antagonistic effect of Se and Cd, As, Cr, and Hg (molar ratio > 1) could effectively protect residents in the study area from Cd and As pollution in daily life.

Polycyclic aromatic hydrocarbons (PAHs) in urban stream sediments of Suzhou Industrial Park, an emerging eco-industrial park in China: Occurrence, sources and potential risk.

In this study, urban stream sediment samples were collected in the Suzhou Industrial Park (SIP), one of the earliest national demonstration eco-industrial parks of China. PAHs were analyzed in these sediments, and concentrations of total PAHs were 180-81,000 ng g-1 (5700 ± 14,000 ng g-1). Medium molecular weight (4- ring) PAHs were predominant (42 ± 12%), followed by high molecular weight (5- and 6- ring) PAHs (31 ± 10%). No correlation was found between concentrations of PAHs and land uses of SIP in this study. Diagnostic ratios and a positive matrix factorization (PMF) model indicated that coal/biomass combustion might be the primary PAH source (61%), followed by non-combustion sources (21%) and vehicular emission (18%). According to the spatial analysis, PAHs in the sediments of SIP might be mainly associated with the coal/biomass combustion in the northeast industrial zone. Residential & commercial activities seem not to be the major causes of PAH contamination. Total PAH toxic equivalent concentrations, effect range low/effect range median values, and mean effects range-median quotient all showed that PAHs were present at a low toxicity risk level in most regions of the SIP. However, vigilance is required at some sampling sites with extremely high PAH concentrations or high mean effects range-median quotient.

Spatial Variability and Source Apportionment of Aliphatic Hydrocarbons in Sediments from the Typical Coal Mining Area.

Fifty-four surface sediments from the typical coal mining area were analyzed for pristane, phytane and C8-C40 n-alkanes using gas chromatography-mass spectrometry (GC-MS). The spatial distribution, homolog profiles and source apportionment of aliphatic hydrocarbons were investigated. Bimodal distribution pattern, centered at C16-C20 and C27-C33 n-alkanes, were observed in all sediment samples with an obvious dominance of low molecular weight homologues. Principal component analysis-multiple linear regression (PCA-MLR) was used to predict the contributions of different sources. The result implied that natural input was the main source, contribution of which accounted for 60.8%, and the contributions of different sources were estimated as follow: 21.8% for terrestrial higher plants, 24.1% for algae and photosynthetic bacteria, 14.9% for submerged/floating macrophytes, 23.5% for fossil fuel combustion and 15.7% for petroleum hydrocarbons. Moreover, relatively high median concentrations of fossil fuel combustion were observed in Shou County and Fengtai County, indicating the high contribution of fossil fuel combustion in these two areas.

Polybrominated Diphenyl Ethers in Surface Soils from the Yellow River Delta Natural Reserve, China: Occurrence, Sources, and Potential Risk.

A total of 39 lower brominated PBDE congeners in surface soils from the Yellow River Delta Natural Reserve (YRDNR) were analyzed in the present study. The total concentrations of PBDEs (ΣPBDEs) ranged from "not detected" to 0.732 ng g-1, with a mean concentration of 0.142 ng g-1. The concentrations of the ΣPBDEs displayed no correlation with the content of the total organic carbon in the YRDNR. The ΣPBDEs concentrations in the Experimental Area were significantly higher than that of the Buffer Area and Core Area, and ΣPBDEs in soils in the North were lower than that of the South. PentaBDEs and HexaBDEs were the most abundant homologues, and the occurrence of PBDEs in the YRDNR may be attributed to the debromination and long range transport of DecaBDEs. Even though the cancer risk and mass inventory of PBDEs in the present study area were estimated to be very low, due to the widespread presence of PBDEs and the particularity of the natural reserve, vigilance should not be let up on the issue of environmental contamination caused by these compounds despite the gradual phase out of their commercial products in the world.

Occurrence and Potential Risk of Polychlorinated Biphenyls in Surface Soils from the Yellow River Delta Natural Reserve, China.

A total of 28 PCB congeners were determined using gas chromatography-mass spectrometry (GC-MS) in 46 surface soils collected from the Yellow River Delta Natural Reserve (YRDNR) and its adjacent area, China. The total concentrations of PCBs in the YRDNR ranged from 0.149 to 4.32 ng/g, with a mean concentration of 0.802 ng/g. Light PCB congeners predominated in the present research area, which may be attributed to the atmospheric transportation and were also associated with the recent contamination of unintentionally produced PCBs from industrial processes. In addition, PCB 126 and PCB 169 were found to be the major toxicity contributors of dioxin-like PCBs in the YRDNR, which should require special focus.

n-Alkanes in sediments from the Yellow River Estuary, China: Occurrence, sources and historical sedimentary record.

A total of 21 surface sediments from the Yellow River Estuary (YRE) and a sediment core from the abandoned Old Yellow River Estuary (OYRE) were analyzed for n-alkanes using gas chromatography-mass spectrometry (GC-MS). n-Alkanes in the range C12-C33 and C13-C34 were identified in the surface sediments and the core, respectively. The homologous series were mainly bimodal distribution pattern without odd/even predominance in the YRE and OYRE. The total n-alkanes concentrations in the surface sediments ranged from 0.356 to 0.572mg/kg, with a mean of 0.434mg/kg on dry wt. BASIS: Evaluation of n-alkanes proxies indicated that the aliphatic hydrocarbons in the surface sediments were derived mainly from a petrogenic source with a relatively low contribution of submerged/floating macrophytes, terrestrial and emergent plants. The dated core covered the time period 1925-2012 and the mean sedimentation rate was ca. 0.5cm/yr. The total n-alkanes concentrations in the core ranged from 0.0394 to 0.941mg/kg, with a mean of 0.180mg/kg. The temporal evolution of n-alkanes reflected the historical input of aliphatic hydrocarbons and was consistent with local and regional anthropogenic activity. In general, the investigation on the sediment core revealed a trend of regional environmental change and the role of anthropogenic activity in environmental change.

Concentration and fractionation of heavy metals in the old yellow river estuary, china.

A sequential extraction procedure was applied to determine the concentration and fractionation characteristics of eight heavy metals (HMs) (Cu, Zn, Pb, Cd, Cr, Fe, Mn, and Ni) in a sediment core collected from the old Yellow River Estuary, China. The results revealed that the mean deposition rate of this sediment core, which spanned 87 yr (1925-2012), was approximately 0.5 cm yr. The mean concentrations and ranges of HMs were Cu: 26.9 (18.3-38.5), Zn: 76.4 (51.0-107), Pb: 37.3 (17.8-53.8), Cd: 0.23 (0.20-0.27), Cr: 84.7 (45.5-116), Fe: 24,000 (16,500-31,700), Mn: 709 (388-1020), and Ni: 36.1 (24.8-47.2) mg kg (dry weight). Six HMs (Cu, Zn, Cr, Cd, Fe, and Ni) were present in their highest proportion in the residual fraction; their lowest proportion was observed in the exchangeable fraction. Lead primarily existed in the oxidizable or residual fraction. Manganese was mainly presented in the exchangeable fraction. The risk assessment code results revealed that the sediments displayed a low risk for Cu, Zn, Pb, Cr, Cd, Fe, Mn, and Ni. The HMs Cu, Zn, Cr, Cd, Mn, and Ni displayed minor enrichment in the sediment core, whereas for Pb, moderate contamination enrichment was observed. Overall, an increase in and total concentration of HMs occurred since 1925 and reached a maximum value around 1980, after which there was a larger fluctuation or decline until 2012. We also found that the degree of HM pollution during the 1976-1996 period was less serious than before 1976. All the sediment samples exceeded the effect range low (ERL) for Ni, whereas 56.1, 7.32, and 17.1% exceeded the ERL values for Cr, Cu, and Pb; no samples exceeded the ERL for Zn or Cd.

Occurrence, sources, and potential toxicity of polycyclic aromatic hydrocarbons in surface soils from the Yellow River Delta Natural Reserve, China.

A total of 46 surface soil samples collected from the experimental area, buffer area, and core area of the Yellow River Delta Natural Reserve (YRDNR), China, and an adjacent area outside the reserve were analyzed for 23 PAHs including highly carcinogenic dibenzopyrene isomers. The total concentrations ranged from 87.2 to 319 ng/g for ∑23PAHs and 79.2 to 311 ng/g for ∑16PAHs with average concentrations of 133 and 119 ng/g, respectively. Pearson correlation analysis implied that the total polycyclic aromatic compound (PAH) concentrations had a significant positive correlation with the total organic carbon content on the condition that four sites with abnormal values were removed. Low molecular-weight 2- to 3-ring PAHs predominated in the present study. Source diagnostics based on PAHs isomer ratios, principal component analysis, and multiple linear regression suggested that petroleum contributed most to the PAH contamination in the YRDNR, whereas a potential toxicity assessment using BaPeq indicated that the four dibenzopyrenes were the major carcinogenic PAH contributors in the area under investigation, although their concentrations only represented a small proportion of the total PAH concentrations.

Analysis of HCHs and DDTs in a sediment core from the Old Yellow River Estuary, China.

The present study analyzed the distribution of HCHs and DDTs in a sediment core from the Old Yellow River Estuary, China. The OCP levels were detected by Soxhlet extraction followed by gas chromatography (GC) using a mass-selective detector. Sediment age was analyzed for (210)Pb using an Ortec GWL HPGe gamma spectrometer. The results indicated that the concentrations of ∑DDT in the sediment core were much lower than those of ∑HCH. Compared with the other estuarine and coastal regions in Chinese rivers, HCHs levels in this area were higher or similar, while DDTs levels were lower. The compositional analysis indicated that ß-HCH and p, p'-DDD were the predominant species. The temporal trends indicated that levels of HCHs and DDTs were related with their historical usage, emission and soil residues. According to the analysis of the ratio, HCHs in this area was mainly due to the technical historical residue and recent lindane. DDTs was mainly due to historical residue. The biodegradation conditions for DDTs were anaerobic. The dicofol-type DDTs application occurred in this area.

Polycyclic aromatic hydrocarbons in sediments from the Old Yellow River Estuary, China: occurrence, sources, characterization and correlation with the relocation history of the Yellow River.

The levels of 16 USEPA priority PAHs were determined in surface sediments and one dated sediment core from the abandoned Old Yellow River Estuary, China. Total PAH concentrations in the surface sediments ranged from 100.4 to 197.3 ng g(-1) dry weight and the total toxic equivalent quantity (TEQ(carc)) values of the carcinogenic PAHs were very low. An evaluation of PAH sources based on diagnostic ratios and principal component analysis suggested that PAHs in the surface sediments mainly derived from combustion sources. The total PAH concentrations altered significantly with year of deposition and showed quite different patterns of change compared with other studies: it is hypothesized that the principal cause of these changes is the relocation of the course of the Yellow River to the sea in 1976 and 1996.

Distribution and assessment of Pb in the supergene environment of the Huainan Coal Mining Area, Anhui, China.

Coal mining area is highly subject to lead (Pb) pollution from coal mining activities. Several decades of coal mining and processing practices in dozens of coal mines in the Huainan Coal Mining Area (HCMA) have led to the accumulation of massive amounts of coal gangue, which piled in dumps. In order to investigate the impacts of coal gangue dumps on Pb level in the supergene media of the HCMA, a systematic sampling campaign comprising coal gangue, soil, wheat, and earthworm samples was conducted. The average Pb content in the coal mining area soil is 24 mg/kg, which is slightly higher than the associated coal gangues (23 mg/kg) and markedly higher than reference region soil (12.6 mg/kg). Soil in the HCMA present a slight to moderate Pb contamination, which might be related to the weathering and leaching of coal gangue dumps. Lateral distribution of Pb in HCMA soil differed among individual coal mines. The soil profile distribution of Pb depends on both natural and anthropogenic contributions. Average Pb content is higher in roots than in stems, leaves, and wheat husks, while the Pb level in seeds exceeded the maximum Pb allowance for foods (Maximum Levels of Contaminants in Foods of China, GB 2762-2012). Earthworms in the selected area are significantly enriched in Pb, suggesting higher bio-available Pb level in soil in the HCMA.

Residual levels, phase distributions, and human health risks of OCPs in the middle reach of the Huai River, China.

Are the residues of organochlorine pesticides (OCPs) in freshwater in China still of concern after prohibition and restriction for decades? The scarcity of monitoring data on OCPs in freshwater in China over the past few years has hampered understanding of this issue. In this study, water and suspended particulate matter (SPM) samples were collected from the middle reach of the Huai River for OCP analyses. Residues of ∑OCPs in water and SPM ranged from ND to 8.6 ng L-1 and 0.50 to 179 ng L-1, with mean concentrations of 1.7 ± 1.3 ng L-1 and 6.1 ± 31 ng L-1, respectively. ∑HCHs (α-, ß-, γ-, and δ-HCH) and ∑HEPTs (heptachlor and heptachlor epoxide) were the most predominant pesticides in the dissolved phase and SPM, respectively, accounting for 43 ± 35% and 27 ± 29% of ∑OCPs. HCHs and heptachlor epoxide mainly existed in the dissolved phase, while heptachlor mainly existed in SPM. The isomeric composition pattern of HCHs in water differed from that in SPM. Briefly, ß-HCH dominated in water, while δ-HCH dominated in SPM. However, the composition pattern of DDT and its metabolites in water was similar to that in SPM. o,p'-DDD and p,p'-DDE dominated in both water and SPM. The ratios of α-/γ-HCH and (DDD + DDE)/DDTs indicated that HCHs and DDTs were mainly derived from historical residues. Risk assessments indicated that OCPs may not pose carcinogenic and non-carcinogenic risks to residents.

Aliphatic and polycyclic aromatic compounds in coal and coal-based solid wastes: Relationship with coal-forming paleoenvironment and implications for environmental pollution.

In this study, coal and coal-based solid wastes (coal gangue, fly ash, bottom ash, desulfurized gypsum and tar residue) were collected from major coal mines, power plants and coking plants in Lianghuai mining area (LH), China, and were analyzed for 76 polycyclic aromatic compounds (PACs), 27 n-alkanes and 2 isoprenoids (phytane and pristane). The total n-alkanes concentrations and ∑76 PACs in raw coals (640 ± 600 and 180 ± 87 µg/g) were higher than those in coal-based solid wastes (47 ± 40 and 24 ± 25 µg/g), but were lower than those in tar residue (3700 and 63,000 µg/g). It was discovered that the depositional paleoenvironment in LH was mostly a lacustrine and freshwater environment with oxidizing conditions and mixed organic matter input, but the Huainan coalfield had stronger oxidizing conditions and more input of terrestrial organic matter than that of the Huaibei coalfield. Alkylated PACs made up 56 ± 12 % of the ∑76PACs in raw coals, whereas solid wastes mainly consisted of 16 EPA PAHs (66 ± 16 %). Coal combustion and gangue weathering altered the structural properties of n-alkanes and PACs, resulting in a significant loss of n-alkanes and PACs, a higher proportion of parent PACs, and an increased abundance of short n-alkanes in the products (No apparent change of n-alkanes composition was observed through gangue weathering). The toxicity of PACs in raw coal and its solid wastes in LH from high to low was tar residue, raw coal, coal gangue, and coal-fired products. This investigation further confirmed that traditional diagnostic ratios may distort source information, and that they should not be used to assess PACs sources from raw coal particles or coal gangues, but rather to identify combustion sources near the point source. In addition, Retene/(Retene + Chrysene) < 0.03 may indicate direct contamination of raw coal particles.

p-phenylenediamines (PPDs) and PPD-quinones (PPD-Qs) in human urine and breast milk samples: Urgent need for focus on PPD-Qs and the establishment of health threshold criteria.

PPDs and their oxidation products, PPD-Qs, are emerging environmental contaminants arising from the addition and oxidation of rubber products. Although numerous studies have been conducted to elucidate their risks, the primary focus has been on 6PPD and 6PPD-Q, with limited attention given to other PPDs and especially other PPD-Qs. This study comprehensively examines the occurrences of frequently used PPDs and their degradation products, PPD-Qs, in human urine and breast milk samples. The average concentrations of ΣPPDs and ΣPPD-Qs in urine were 27 ± 78 ng/mL and 16 ± 12 ng/mL, respectively. IPPD and DNPD were the predominant PPDs, while DPPD-Q, CPPD-Q, and IPPD-Q were the predominant PPD-Qs. Notably, the concentrations of 6PPD, CPPD, and DPPD were significantly lower than their oxidized quinone products. Weak or no correlations were observed between most PPDs and their corresponding PPD-Qs, suggesting that PPD-Qs in the human body are primarily derived from direct environmental intake rather than in vivo conversion of PPDs. PPDs and PPD-Qs were widely detected in breast milk, exhibiting concentrations and patterns similar to those found in urine, with comparable major pollutants. Estimated daily intakes of PPDs + PPD-Qs for infants were several µg/(kg·day), with the 95th percentile intake approaching 10 µg/(kg·day).

Matching-Adjusted Indirect Comparison of the Efficacy and Safety of Erdafitinib vs Enfortumab Vedotin in Patients with Locally Advanced Metastatic Urothelial Carcinoma.

Background: For patients with locally advanced or metastatic urothelial carcinoma (la/mUC), prognosis is poor and effective treatment options are limited. Erdafitinib is an oral fibroblast growth factor receptor (FGFR) kinase inhibitor approved by the FDA for the treatment of adults with la/mUC harboring FGFR alterations whose disease progressed following at least 1 prior line of therapy, including a PD-1 or PD-L(1) inhibitor, based on the phase 3, randomized THOR trial (NCT03390504, Cohort 1). Objective: To compare the efficacy and safety of erdafitinib vs enfortumab vedotin-ejfv (EV) in the absence of head-to-head comparison via an anchored matching-adjusted indirect comparison (MAIC). Methods: An anchored MAIC was conducted according to the National Institute for Health and Care Excellence Decision Support Unit guidance, with physician's choice of chemotherapy (docetaxel/paclitaxel and vinflunine) as the common comparator. Individual patient data from THOR were adjusted to match published key eligibility criteria and average baseline characteristics of EV-301, such as Bellmunt risk score, liver or visceral metastases, primary site, among others. Erdafitinib was then indirectly compared with EV using the relative treatment effects for the reweighted THOR population and those published for EV-301. Results: After matching, the effective sample size for THOR was 126 patients. The MAIC-recalculated hazard ratio (95% credible interval) for erdafitinib vs EV was 0.92 (0.54, 1.57) for overall survival and 0.93 (0.55, 1.56) for progression-free survival, yielding Bayesian probabilities of erdafitinib being better than EV of 62.1% and 60.5%, respectively. For response outcomes, the MAIC-recalculated risk ratio was 1.49 (0.56, 3.90) for confirmed objective response rate and 2.89 (0.27, 30.33) for confirmed complete response with probabilities of 72.6% and 81.3% for erdafitinib being better than EV, respectively. For safety, MAIC-yielded risk ratios of 1.09 (0.99, 1.21) for any treatment-related adverse events, 0.86 (0.57, 1.28) for grade 3+ TRAEs, and 1.02 (0.98, 1.06) for any treatment-emergent adverse events. Conclusion: The MAIC indicates comparable efficacy of erdafitinib vs EV for overall survival and progression-free survival, with erdafitinib showing a higher probability of achieving deep responses. While erdafitinib is associated with slightly more adverse events compared with EV, these events seem to be less severe.

It's time to reevaluate the list of priority polycyclic aromatic compounds: Evidence from a large urban shallow lake.

Monitoring only 16 priority PAHs (Pri-PAHs) may greatly underestimate the pollutant load and toxicity of polycyclic aromatic compounds (PACs) in aquatic environments. There is an urgent need to reevaluate the list of priority PACs. To determine which PACs deserve priority monitoring, the occurrence, sources, and toxicity of 78 PACs, including 24 parent PAHs (Par-PAHs), 49 alkylated PAHs (Alk-PAHs), 3 oxygenated PAHs (OPAHs), carbazole, and dibenzothiophene were investigated for the first time in Lake Chaohu sediments, China. Concentrations of ∑Par-PAHs, ∑Alk-PAHs, and ∑OPAHs ranged from 35 to 165, 3.4-26, and 7.7-26 ng g-1, respectively. Concentrations of 16 Pri-PAHs have decreased by 1-2 orders of magnitude compared to a decade ago, owing to the effective implementation of PAHs emission control measures. Comparisons with the sediment quality guidelines indicated that 16 Pri-PAHs have negligible adverse effects on benthic organisms. Positive matrix factorization (PMF) model results showed that coal combustion was the major source of PACs (accounting for 23.5 %), followed by traffic emissions (23.4 %), petroleum volatilization (21.9 %), wood/biomass combustion (18.2 %), and biological/microbial transformation (13.1 %). The toxicity of PACs was assessed by calculating the BaP toxic equivalent concentrations (TEQBaP) and toxic units. It was found that Par-PAHs were the predominant toxic substances. In addition, monomethyl-BaPs, OPAHs, BeP, and 7,12-DMBaA should be prioritized for monitoring due to their noticeable contributions to overall toxicity. The contributions of different sources to the toxicity of PACs were determined based on PMF model results and TEQBaP values, which revealed that combustion sources mainly contributed to the comprehensive toxicity of PACs in Lake Chaohu sediments.

[The spectrum studies of structure characteristics in magma contact metamorphic coal].

The structural parameters evolution of coal due to the influence of intrusions of hot magma was investigated and analyzed. X-ray diffraction and laser confocal microscope Raman spectroscopy were used to test and analyze 4 coal samples undergoing varying contact-metamorphism by igneous magmas in borehole No. 13-4 of Zhuji coal mine, Huainan coalfield. The result showed that coal XRD spectrum showed higher background intensity, with the 26 degrees and 42 degrees nearby apparent graphite diffraction peak. Two significant vibration peaks of coal Raman spectra were observed in the 1 000-2 000 cm(-1) frequency range: broad "D" peak at 1 328-1 369 cm(-1) and sharp "G" peak at 1 564-1 599 cm(-1). With the influence of magma intrusion, the relationship between coal structural parameters and coal ranks was excellent.

Prioritization, sources, and ecological risk of typical antibiotics in the Huai River, a Chinese major river: a warning about aquaculture.

This is the first comprehensive report on antibiotics in the Huai River, a major Chinese river. To illuminate the concentrations, prioritization, spatial distributions, sources, and ecological risks of antibiotics, surface water samples were collected and three types of most widely used antibiotics (16 sulfonamides, 8 tetracyclines, and 14 quinolones) were analyzed. The results indicated that concentrations of ∑quinolones (86 ± 31 ng/L) > ∑tetracyclines (20 ± 13 ng/L) > ∑sulfonamides (11 ± 3.7 ng/L). Oxolinic acid (OXA), cinoxacin(CINX), norfloxacin (NFX), and methacycline (MTC) were the priority antibiotics with mean concentrations > or close to 10 ng/L, however, they were rarely included as target compounds in most previous Chinese investigations. Different spatial distributions of antibiotics were discovered across three reaches separated by two sluices, demonstrating that the sluices may impact antibiotic dissemination. According to the results of the source analysis, the aquaculture industry was the major source of observed antibiotics (49%), followed by livestock & poultry farming (26%) and mixed sources (25%). Because commercial fishing in the Huai River has been prohibited, the aquaculture industry will expand in the next years, and antibiotic contamination caused by the aquaculture industry deserves more attention. The risk quotients were calculated by comparing observed antibiotics to predicted no-effect concentrations, and the results showed that observed antibiotics posed negligible or low integrated risks for Green algae, and medium or low integrated risks for Daphnia magna.

Polycyclic aromatic compounds (PACs) in tree barks and tree cores of a national large-scale coal-fired power base of China: Sources, atmospheric toxicities, and pollution histories.

Polycyclic aromatic compounds (PACs) are important hazardous air pollutants in China due to the country's coal-dominant energy structure. In order to reveal the pollution characteristics, sources, toxicity, and pollution historical trends of PACs in the atmosphere of the middle reach of the Huaihe River (MRHR), a large-scale coal-fired power base of China, tree barks and tree cores were collected and employed as passive air samplers and historical trend recorders, and 76 PACs were identified for the first time. ΣPACs in tree barks ranged from 170 to 3800 ng g-1 (mean = 700 ± 720 ng g-1), with the high concentrations observed mainly in the coal-mining and coal-bearing area. 16 priority PAHs (PriPAHs) were the predominant substances and accounted for 59 ± 8.3 % of ΣPACs. The combustion of coal and fuel oil was the most significant source of PACs, accounting for 43 % of ΣPACs, followed by the combustion of biomass (30 %) and non-combustion sources (27 %). Based on a bark-air partitioning model, volumetric air concentrations for ΣPACs were calculated to be 450-11,000 ng m-3 (mean = 1600 ± 2000 ng m-3). The BaP-toxic equivalent concentrations (TEQBaP) of ΣPACs (mean = 9.7 ± 15 ng m-3) were significantly higher than the Chinese guideline (1 ng m-3) and were mostly caused by coal & fuel oil combustion (55 ± 13 %). High molecular weight PACs were detected in lower percentages in tree cores than in tree barks, indicating that PACs in the particle phase were difficult to enter the tree core. Major PACs decreased in tree core samples between 2000 and 2020 as pollution control efforts improved, however, some PACs showed different trends when influenced by point sources.