The ESG performance influence mechanism analysis-based on empirical analysis.

ESG has emerged as a prominent method for evaluating enterprises, gaining increasing importance in recent years. It assesses a company's ability to promote sustainable economic development and fulfill its social responsibilities, encompassing three non-financial dimensions: environmental, social, and corporate governance. Regulatory authorities, industry associations, and investment institutions worldwide have placed growing emphasis on a company's ESG performance. From the perspective of career concern, this study conducted a multiple regression analysis using data from Chinese A-share companies listed in Shanghai and Shenzhen from 2011 to 2020. It used CEO shareholding and CEO political affiliation as moderating variables to examine the impact of CEO career concerns on the corporate environment, society, and corporate governance performance. Empirical testing of whether CEO career concerns promote or suppress the ESG performance in enterprises. The findings of this study reveal that CEOs with heightened career concerns tend to impede the ESG performance of their respective enterprises. Additionally, CEO shareholding and political affiliations exert a negative moderating influence on the relationship between CEO career concerns and ESG performance. This research significantly extends the investigation into factors influencing ESG performance, offering fresh perspectives that could inform improved CEO oversight, foster corporate transformation, and enhance ESG performance.

Seasonal patterns, fate and ecological risk assessment of pharmaceutical compounds in a wastewater treatment plant with Bacillus bio-reactor treatment.

Pharmaceutical compounds (PhCs) pose a growing concern with potential environmental impacts, commonly introduced into the environment via wastewater treatment plants (WWTPs). The occurrence, removal, and season variations of 60 different classes of PhCs were investigated in the baffled bioreactor (BBR) wastewater treatment process during summer and winter. The concentrations of 60 PhCs were 3400 ± 1600 ng/L in the influent, 2700 ± 930 ng/L in the effluent, and 2400 ± 120 ng/g dw in sludge. Valsartan (Val, 1800 ng/L) was the main contaminant found in the influent, declining to 520 ng/L in the effluent. The grit chamber and BBR tank were substantially conducive to the removal of VAL. Nonetheless, the BBR process showcased variable removal efficiencies across different PhC classes. Sulfadimidine had the highest removal efficiency of 87 ± 17% in the final effluent (water plus solid phase). Contrasting seasonal patterns were observed among PhC classes within BBR process units. The concentrations of many PhCs were higher in summer than in winter, while some macrolide antibiotics exhibited opposing seasonal fluctuations. A thorough mass balance analysis revealed quinolone and sulfonamide antibiotics were primarily eliminated through degradation and transformation in the BBR process. Conversely, 40.2 g/d of macrolide antibiotics was released to the natural aquatic environment via effluent discharge. Gastric acid and anticoagulants, as well as cardiovascular PhCs, primarily experienced removal through sludge adsorption. This study provides valuable insights into the intricate dynamics of PhCs in wastewater treatment, emphasizing the need for tailored strategies to effectively mitigate their release and potential environmental risks.

Artificial intelligence technology in Alzheimer's disease research.

Alzheimer's disease is a neurocognitive disorder and one of the contributing factors to dementia. According to the World Health Organization, this disease has a sig-nificant impact on the global population's health, with the number of affected individuals steadily increasing each year. Amidst rapid technological development, the use of artificial intelligence has significantly expanded into the field of medical diagnostics, encompassing areas such as the analysis of medical images, drug development, design of personalized treatment plans, and disease prediction and treatment. Deep learning, which is an important branch in the field of artificial intelligence, is playing a key role in solving several medical challenges by providing important technical support for the early detection, diagnosis, and treatment of Alzheimer's disease. Given this context, this review aims to explore the differences between conventional methods and artificial intelligence techniques in Alzheimer's disease research. Additionally, it aims to summarize current non-invasive and portable techniques for detection of Alzheimer's disease, offering support and guidance for the future prediction and management of the disease.

Design of a simple and low-cost solid-state ultra-fast high-voltage switch.

Ultra-fast high-voltage switches (UFHVSs) are a core component of time-of-flight mass spectrometers for realizing high accuracy ion acceleration, deceleration, and temporal focusing. The desirable features of high performance UFHVSs include a large range of adjustability of pulse width, a high maximum output amplitude, and minute rising and falling times. Besides the simplicity of the driver circuit, the total cost of the whole device is also critical to its practical applications. In this work, we present a low-cost and easy-fabrication 5000 V bipolar solid-state UFHVS for a high-resolution mass spectrometer. A double-pulse transformer isolates the circuit's high- and low-voltage sides and synchronously drives series-connected cascode SiC FETs to form its push-pull topology. This scheme allows transmitting drive signals with long widths but without the magnetic saturation of the transformer. Testing results show that output pulses reach a maximum voltage of 5000 V and a width of 150 µs, with rising and falling times of 8.5 and 18.3 ns, respectively. More importantly, they have nearly no voltage decay.

Building Low-Cost, High-Performance Flexible Photodetector Based on Tetragonal Phase VO2 (A) Nanorod Networks.

We present a straightforward and cost-effective method for the fabrication of flexible photodetectors, utilizing tetragonal phase VO2 (A) nanorod (NR) networks. The devices exhibit exceptional photosensitivity, reproducibility, and stability in ambient conditions. With a 2.0 V bias voltage, the device demonstrates a photocurrent switching gain of 1982% and 282% under irradiation with light at wavelengths of 532 nm and 980 nm, respectively. The devices show a fast photoelectric response with rise times of 1.8 s and 1.9 s and decay times of 1.2 s and 1.7 s for light at wavelengths of 532 nm and 980 nm, respectively. In addition, the device demonstrates exceptional flexibility across large-angle bending and maintains excellent mechanical stability, even after undergoing numerous extreme bending cycles. We discuss the electron transport process within the nanorod networks, and propose a mechanism for the modulation of the barrier height induced by light. These characteristics reveal that the fabricated devices hold the potential to serve as a high-performance flexible photodetector.

Assessment of degradability and endothelialization of modified poly L-lactic acid (PLLA) atrial septal defect (ASD) occluders over time in vivo.

OBJECTIVE: To evaluate the fiber-degradation and endothelialization of a modified poly L-lactic acid (PLLA) atrial septal defect (ASD) occluder for a long time in vivo. METHODS: A total of 57 New Zealand rabbits were selected to establish the vasculature implantation model, which would be used to characterize the mechanical properties and pathological reaction of PLLA filaments (a raw polymer of ASD occluder). In total, 27 Experimental piglets were used to create the ASD model for the catheter implantation of PLLA ASD occluders. Then, X-ray imaging, transthoracic echocardiography, histopathology, and scanning electron microscope (SEM) were performed in the experimental animals at 3, 6, 12, and 24 months after implantation. RESULTS: In the rabbit models, the fibrocystic grade was 0 and the inflammatory response was grade 2 at 6 months after vasculature implantation of the PLLA filaments. The mass loss of PLLA filaments increased appreciably with the increasing duration of implantation, but their mechanical strength was decreased without broken. In the porcine models, the cardiac gross anatomy showed that all PLLA ASD occluders were stable in the interatrial septum without any vegetation or thrombus formation. At 24 months, the occluders had been embedded into endogenous host tissue nearly. Pathological observations suggested that the occluders degraded gradually without complications at different periods. SEM showed that the occluders were endothelialized completely and essentially became an integral part of the body over time. CONCLUSION: In the animal model, the modified PLLA ASD occluders exhibited good degradability and endothelialization in this long-term follow-up study.

Association Between Urinary Bisphenols and Body Composition Among American Adults: Cross-Sectional National Health and Nutrition Examination Survey Study.

BACKGROUND: Bisphenol A (BPA), bisphenol S (BPS), and bisphenol F (BPF) are widely used in various consumer products. They are environmental contaminants with estrogenic properties that have been linked to various health outcomes. Understanding their impact on body composition is crucial for identifying potential health risks and developing preventive strategies. However, most current studies have only focused on their relationship with BMI. OBJECTIVE: This study aimed to investigate the association between urinary levels of BPA, BPS, and BPF and body composition, including BMI, lean mass, and fat mass, in a large population-based sample. METHODS: We conducted a cross-sectional analysis using data from the National Health and Nutrition Examination Survey 2003-2016. Body composition data were assessed using dual-energy X-ray absorptiometry, which provided precise measurements of lean mass, fat mass, and other indicators. We used multivariate linear regression models to estimate the associations, adjusting for potential confounders such as age, gender, race, socioeconomic factors, and lifestyle variables. RESULTS: The results revealed significant associations between bisphenol exposure and body composition. After adjusting for covariates, BPS showed a positive association with BMI, with quartiles 3 and 4 having 0.91 (95% CI 0.34-1.48) and 1.15 (95% CI 0.55-1.74) higher BMI, respectively, compared with quartile 1 (P<.001). BPA was negatively associated with total lean mass (TLM) and appendicular lean mass, with quartiles 2, 3, and 4 having -7.85 (95% CI -11.44 to -4.25), -12.33 (95% CI -16.12 to -8.54), and -11.08 (95% CI -15.16 to -7.01) lower TLM, respectively, compared with quartile 1 (P<.001). BPS was negatively associated with TLM, with quartiles 3 (ß=-10.53, 95% CI -16.98 to -4.08) and 4 (ß=-11.14, 95% CI -17.83 to -4.45) having significantly lower TLM (P=.005). Both BPA and BPS showed a positive dose-response relationship with trunk fat (BPA: P=.002; BPS: P<.001) and total fat (BPA: P<.001; BPS: P=.01). No significant association was found between BPF and any body composition parameter. CONCLUSIONS: This large-sample study highlights the associations between urinary levels of BPA and BPS and alterations in body composition, including changes in lean mass, fat mass, and regional fat distribution. These findings underscore the importance of understanding the potential health risks associated with bisphenol exposure and emphasize the need for targeted interventions to mitigate adverse effects on body composition.

Soil Chromium Accumulation in Industrial Regions across China: Pollution and Health Risk Assessment, Spatial Pattern, and Temporal Trend (2002-2021).

This study conducted a nationwide specific assessment of soil chromium (Cr) contamination status in 506 of China's industrial regions. The overall soil Cr concentrations were 0.74-37,967.33 mg/kg, and the soil Cr content in 4.15% of the regions exceeded the reference screening value (2500 mg/kg). Geochemical accumulation index (Igeo) and monomial potential ecological risk index (E) revealed Cr salt production and tanning were the primary control industries. The non-carcinogenic risks posed by Cr salt production and tanning industries were higher than the national average values, and children were the most vulnerable groups. The heavily polluted regions were mainly located at the Yangtze River Delta, the Bohai Rim, the Pearl River Delta, the Yangtze River Basin, and the Yellow River Basin. The Yangtze River Delta was further identified as the high priority control area based on the class distribution of Igeo and E. Regression analysis showed the soil Cr concentrations in industrial regions increased during 2002-2009 and then turned into a declining trend in 2009-2021. This paper gives detailed insights into soil Cr pollution status in industrial regions across China and the results may serve as references for formulating tailored control measures for different industries and areas.

What Do Local People Really Need from a Place? Defining Local Place Qualities with Assessment of Users' Perceptions.

China is facing a serious urban regeneration issue in which replicable international-style locations are losing their socio-cultural adaptability, especially in anonymous residential neighbourhoods. This study defines the key location qualities from local literature and then refines these qualities through observation investigations and statistical analysis (n = 180) to establish links between theories and contemporary uses. Based on the results, a correlation analysis of local place qualities was assessed from users' perceptions (n = 180) to identify the interactional influences between each indicator of local place qualities. Finally, local place qualities were scored to address their level of impact on users' perceptions. The results highlighted health, enjoyment, and social dependence as the most concerning factors in site investigations based on local cognitions. They are strongly associated with key local place qualities (naturality, functionality, cosmological cognitions, and interdependent sociability), directly and indirectly resulting in different levels of impact on users' perceptions at different scales.

Modeling historical budget for ß-Hexachlorocyclohexane (HCH) in the Arctic Ocean: A contrast to α-HCH.

The historical annual loading to, removal from, and cumulative burden in the Arctic Ocean for ß-hexachlorocyclohexane (ß-HCH), an isomer comprising 5-12% of technical HCH, is investigated using a mass balance box model from 1945 to 2020. Over the 76 years, loading occurred predominantly through ocean currents and river inflow (83%) and only a small portion via atmospheric transport (16%). ß-HCH started to accumulate in the Arctic Ocean in the late 1940s, reached a peak of 810 t in 1986, and decreased to 87 t in 2020, when its concentrations in the Arctic water and air were ∼30 ng m-3 and ∼0.02 pg m-3, respectively. Even though ß-HCH and α-HCH (60-70% of technical HCH) are both the isomers of HCHs with almost identical temporal and spatial emission patterns, these two chemicals have shown different major pathways entering the Arctic. Different from α-HCH with the long-range atmospheric transport (LRAT) as its major transport pathway, ß-HCH reached the Arctic mainly through long-range oceanic transport (LROT). The much higher tendency of ß-HCH to partition into the water, mainly due to its much lower Henry's Law Constant than α-HCH, produced an exceptionally strong pathway divergence with ß-HCH favoring slow transport in water and α-HCH favoring rapid transport in air. The concentration and burden of ß-HCH in the Arctic Ocean are also predicted for the year 2050 when only 4.4-5.3 t will remain in the Arctic Ocean under the influence of climate change.

Research on Carbon Emission Efficiency Space Relations and Network Structure of the Yellow River Basin City Cluster.

The Yellow River Basin serves as China's primary ecological barrier and economic belt. The achievement of the Yellow River Basin's "double carbon" objective is crucial to China's green and low-carbon development. This study examines the spatial link and network structure of city cluster carbon emission efficiency in the Yellow River Basin, as well as the complexity of the network structure. It focuses not only on the density and centrality of the carbon emission efficiency network from the standpoint of city clusters, but also on the excellent cities and concentration of the city cluster 's internal carbon emission efficiency network. The results show that: (1) The carbon emission efficiency of the Yellow River Basin has been dramatically improved, and the gap between city clusters is narrowing. However, gradient differentiation characteristics between city clusters show the Matthew effect. (2) The distribution of carbon emission efficiency in the Yellow River Basin is unbalanced, roughly showing a decreasing trend from east to west. Lower-level efficiency cities have played a significant role in the evolution of carbon emissions efficiency space. (3) The strength of the carbon emission efficiency network structure in the Yellow River Basin gradually transitions from weakly correlated dominant to weakly and averagely correlated dominant. Among them, the Shandong Peninsula city cluster has the most significant number of connected nodes in the carbon emission efficiency network. In contrast, the emission efficiency network density of the seven city clusters shows different changing trends. Finally, this study suggests recommendations to improve carbon emission efficiency by adopting differentiated governance measures from the perspective of local adaptation and using positive spatial spillover effects.

Development and Validation of a Risk Assessment Tool for Gaming Disorder in China: The Gaming Hazard Assessment Scale.

Despite the growing research interest in gaming disorder, risk screening tools developed specifically for the Chinese population are still lacking. This study aimed to construct a screening tool to evaluate the risk of gaming disorder (GD) development, by assessing the severity of GD symptoms among Chinese gamers, based on clinical expert interviews, structured interviews with GD patients, a background literature review, and IGD/GD criteria proposed by the DSM-5 and ICD-11. It introduced the Gaming Hazard Assessment Scale-a multidimensional GD risk screening tool-and evaluated the dimension structure, reliability, and validity of the scale among 959 Chinese gamers. A three-level structure, consisting of 18 items scored from 0 to 54, ultimately indicated satisfactory reliability, good validity, and acceptable model fit. The scale will help large-scale initial screening and early identification of patients with a high risk of GD. Further evaluation of the Gaming Hazard Assessment Scale in clinical settings is highly recommended.

A Simple and Low-Cost Strategy to Improve Conidial Yield and Stress Resistance of Trichoderma guizhouense through Optimizing Illumination Conditions.

Light is perceived by photoreceptors in fungi and further integrated into the stress-activated MAPK HOG pathway, and thereby potentially activates the expression of genes for stress responses. This indicates that the precise control of light conditions can likely improve the conidial yield and stress resistance to guarantee the low cost and long shelf life of Trichoderma-based biocontrol agents and biofertilizers. In this study, effects of wavelengths and intensities of light on conidial yield and stress tolerance to osmotic, oxidative and pH stresses in Trichoderma guizhouense were investigated. We found that 2 µmol photons/(m2 × s) of blue light increased the conidial yield more than 1000 folds as compared to dark condition and simultaneously enhanced conidial stress resistance. The enhanced conidial stress resistance is probably due to the upregulated stress-related genes in blue light, which is under the control of the blue light receptor BLR1 and the MAP kinase HOG1.

Fate, source and mass budget of sedimentary microplastics in the Bohai Sea and the Yellow Sea.

As reservoirs for pollutants transported via the Yangtze and Yellow Rivers, the Bohai Sea (BS) and Yellow Sea (YS) play an important role in transporting microplastics (MPs) to the Pacific Ocean. The fate, sources and mass budget of MPs in the BS and the YS were investigated by Pearson correlation, principal component analysis-multilinear regression analysis (PCA-MRLA) and a mass balance model to sedimentary MPs data. Average MP abundances were 137 and 119 items kg-1 in the Bohai and Yellow Seas, respectively. MPs <1000 µm exhibited similar distribution patterns to total organic carbon and fine-grained sediments, while MPs >1000 µm were confined in the BS and exhibited a strong positive correlation with chlorophyll-a and polyethylene terephthalate, suggesting that larger MPs might deposit faster due to biofouling or when comprised of high density polymers. PCA-MLRA analysis indicated land-based inputs (packing materials, textile material and daily commodities) were dominant in the BS, while maritime activities (fishing and mariculture) were the main source of MPs in the YS. The mass balance model revealed that the total MP input and output to the BS and the YS was 3396.92 t yr-1 and 3814.81 t yr-1, respectively. The major input pathway of MPs to the BS and the YS were river discharge and air deposition, respectively. Notably, 94% of MPs in the BS and the YS were deposited to sediments. This study revealed that BS and YS sediments play an important role in preventing MPs from being further transported to the Pacific Ocean, thus more attention should be paid to local ecological risk assessment.

Concentration profiles of a typical ultraviolet filter benzophenone-3 and its derivatives in municipal sewage sludge in China: Risk assessment in sludge-amended soil.

The widespread occurrence of benzophenones in various environmental matrices is a public health concern due to their endocrine-disrupting effects. Nevertheless, information on the exposure and health risk of benzophenones derived from sludge-amended soil is scarce. Herein, we measured a typical ultraviolet filter benzophenone-3 (BP-3) and its four derivatives in sewage sludges from different regions of China. BP-3 was the most abundant benzophenone analog in sludge (range: 0.581-305 ng/g dw), whereas no difference was found for BP-3 in sludge from different regions (p > 0.05). The sum concentration range of the four BP-3 derivatives in sludge was 0.128-74.2 ng/g dw. The mass loading and per capita daily release were calculated to determine the environmental release of benzophenones. The highest mass loading of benzophenones was found in Eastern China (20.9 kg/yr), followed by Northeast China (8.41 kg/yr) and Northwest China (8.13 kg/yr). The per capita daily release value of benzophenones via sludge was estimated as 100 ng/day/person. Calculation of the risk quotients (RQs) of BP-3 and its derivatives showed that benzophenones in sludge-amended soils had low environmental risks (RQs < 0.1) in all geographic regions. This nationwide study provides information outlining the environmental release of benzophenones through sludge composting and potential ecological risk from sludge-amended soil.

Real-world cost-effectiveness analysis of the fracture liaison services model of care for hip fracture in Taiwan.

BACKGROUND: This study was to perform an economic evaluation to understand clinical outcomes and health resource use between hip fracture patients receiving hospital-based postfracture fracture liaison service (FLS) care and those receiving usual care (UC) in Taiwan. METHODS: This cohort study included hospital-based data of 174 hip fracture patients who received FLS care (FLS group) from National Taiwan University Hospital, and 1697 propensity score-matched patients who received UC (UC group) of National Health Insurance claim-based data. Two groups had similar baseline characteristics but differed in hip fracture care after propensity score matching. Clinical outcomes included refracture-free survival (RFS), hip-refracture-free survival (HRFS), and overall survival (OS). Health resource use included inpatient, outpatient, and pharmacy costs within 2 years follow-up after the index of hip fracture. The economic evaluation of the FLS model was analyzed using the net monetary benefit regression framework based on the National Health Insurance perspective. RESULTS: The FLS group had longer RFS than the UC group, with an adjusted difference of 44.3 days (95% confidence interval: 7.2-81.4 days). Two groups did not differ in inpatient and outpatient costs during follow-up, but the FLS group had a higher expenditure than the UC group on osteoporosis-related medication. The probability of FLS being cost-effective was >80% and of increasing RFS, HRFS, and OS was 95%, 81%, and 80%, respectively, when the willingness-to-pay threshold was >USD 65/gross domestic product per day. CONCLUSION: FLS care was cost-effective in reducing refracture occurrence days for patients initially diagnosed with hip fractures.

Global, regional, and national prevalence, disability adjusted life years, and time trends for refraction disorders, 1990-2019: findings from the global burden of disease study 2019.

BACKGROUND: To evaluate global burden of refraction disorders by year, age, region, gender, socioeconomic status and other national characteristics in terms of disability adjusted life years (DALYs) and prevalence from Global Burden of Disease (GBD) study 2019 and World Bank Open Data 2019. METHODS: Global, regional, and national DALY numbers, crude DALY rates, age-standardized DALY and prevalence rates of refraction disorders were acquired from the GBD study 2019. Mobile cellular subscriptions, urban population, GDP per capita, access to electricity and total fertility rate were obtained from the World Bank to explore the factors that influenced the health burden of refraction disorders. Kruskal-Wallis test, linear regression and multiple linear regression were performed to evaluate the associations between the health burden with socioeconomic levels and other national characteristics. Wilcoxon Signed-Rank Test was used to investigate the gender disparity. RESULTS: Globally, age-standardized DALY rates of refraction disorders decreased from 88.9 (95% UI: 60.5-120.3) in 1990 to 81.5 (95% UI: 55.0-114.8) in 2019, and might fall to 73.16 (95% UI: 67.81-78.51) by 2050. Age-standardized prevalence rates would also reduce to 1830 (95% UI: 1700-1960) by 2050, from 2080 (95% UI: 1870-2310) in 1990 to 1960 (95% UI: 1750-2180) in 2019. In low SDI region, age-standardized DALY rates (equation: Y = 114.05*X + 27.88) and prevalence rates (equation: Y = 3171.1*X + 403.2) were positively correlated with SDI in linear regression respectively. East Asia had the highest blindness rate caused by refraction disorders in terms of age-standardized DALY rates (11.20, 95% UI: 7.38-16.36). Gender inequality was found among different age groups and SDI regions. CONCLUSION: Health burden of refraction disorders decreased in recent years, and may continue to alleviate in the next three decades. Older ages, females and lower socioeconomic status were associated with higher refraction disorders health burden.

Fate processes of Parabens, Triclocarban and Triclosan during wastewater treatment: assessment via field measurements and model simulations.

The high levels of parabens (including methyl-, ethyl- and propyl congeners), triclocarban (TCC) and triclosan (TCS) used every year in China might be a problem to the typical wastewater treatment plant (WWTP). This study addresses measurements of parabens, TCC and TCS Northern China WWTP and a modelling assessment on the occurrence, fate and removal pathways in WWTP. Per-capita emissions of the three parabens, TCC and TCS to the WWTP were estimated as 0.41, 0.11 and 0.07 mg/d. After the wastewater treatment processes, 94, 92 and 87% of parabens, TCC and TCS were removed. The major removal pathway of parabens was biodegradation while that of TCC and TCS were sorption to sludge. Computer simulations on the fate processes of parabens, TCC and TCS in the WWTP using the SimpleTreat 4.0 model suggested the model could generally reproduce the measurements with root mean squared errors (RMSEs) of less than 10 ng/L. However, the model underestimated the removal of TCC and TCS from water to sludge in the primary tank. These discrepancies were attributed to the uncertainty of the predicted organic carbon-water partition coefficients (Koc) to which the modelling results are highly sensitive. The model predictions using updated Koc became more accurate and RMSEs of TCC and TCS were reduced by 40 and 80%, respectively. The modelling assessment suggests that the SimpleTreat, as a generic model to simulate chemical fate processes in WWTPs, has the potential to be applied to other similar WWTPs in China for estimating environmental releases of parabens, TCC and TCS at a larger spatial scale.

Assessment bioaccumulation factor (BAF) of methyl siloxanes in crucian carp (Carassius auratus) around a siloxane production factory.

Methyl siloxanes are identified as emerging persistent toxic compounds and the ecological environment risks of these compounds have been caused of great concern worldwide. In this study, the concentrations of methyl siloxanes were reported in dissolved water and crucian carp around a methyl siloxane production factory located in Liaoning Province, Northeast China. D4, D5, D6, D7, L4, L5 and L6 were detectable both in dissolved water and crucian carp. The total concentrations of 7 methyl siloxanes (Σ7MS) were 14 ± 6.3 ng/L in dissolved water and 43 ± 22 ng/g ww in crucian carp, respectively. D5 has the highest concentration both in dissolved water (5.5 ± 3.5 ng/L) and crucian carp (17 ± 11 ng/g ww). Based on the monitoring values, bioaccumulation factor (BAF) of these compounds were calculated. Significant bioaccumulation potential was observed for D4 (BAF = 5900 ± 3500 L/kg) based on the bioaccumulation criteria suggested by USEPA and EU (BAF > 5000 L/kg). To our understanding, this is the first report of BAF values of methyl siloxane in field study, which will provide important support for further assessment of bioaccumulation of these compounds.

Occurrence, variations, and risk assessment of neonicotinoid insecticides in Harbin section of the Songhua River, northeast China.

Neonicotinoid insecticides (NNIs) have been intensively used and exploited, resulting in their presence and accumulation in multiple environmental media. We herein investigated the current levels of eight major NNIs in the Harbin section of the Songhua River in northeast China, providing the first systematic report on NNIs in this region. At least four NNIs in water and three in sediment were detected, with total concentrations ranging from 30.8 to 135 ng L-1 and from 0.61 to 14.7 ng g-1 dw, respectively. Larger spatial variations in surface water NNIs concentrations were observed in tributary than mainstream (p < 0.05) due to the intensive human activities (e.g., horticulture, urban landscaping, and household pet flea control) and the discharge of wastewater from many treatment plants. There was a significant positive correlation (p < 0.05) between the concentrations of residual imidacloprid (IMI), clothianidin (CLO), and Σ4NNIs in the sediment and total organic carbon (TOC). Due to its high solubility and low octanol-water partition coefficient (K ow), the sediment-water exchange behavior shows that NNIs in sediments can re-enter into the water body. Human exposure risk was assessed using the relative potency factor (RPF), which showed that infants have the highest exposure risk (estimated daily intake (ΣIMIeq EDI): 31.9 ng kg-1 bw·d-1). The concentration thresholds of NNIs for aquatic organisms in the Harbin section of the Songhua River were determined using the species sensitivity distribution (SSD) approach, resulting in a value of 355 ng L-1 for acute hazardous concentration for 5% of species (HC5) and 165 ng L-1 for chronic HC5. Aquatic organisms at low trophic levels were more vulnerable to potential harm from NNIs.