Temperature dependence of the rain-gas and snow-gas partition coefficients for nearly a thousand chemicals.

Compared to the particle-gas partition coefficients (KPG), the rain-gas (KRG) and snow-gas (KSG) partition coefficients are also essential in studying the environmental behavior and fate of chemicals in the atmosphere. While the temperature dependence for the KPG have been extensively studied, the study for KRG and KSG are still lacking. Adsorption coefficients between water surface-air (KIA) and snow surface-air (KJA), as well as partition coefficients between water-air (KWA) and octanol-air (KOA) are vital in calculating KRG and KSG. These four basic adsorption and partition coefficients are also temperature-dependent, given by the well-known two-parameters Antoine equation logKXY = AXY+BXY/T, where KXY is the adsorption or partition coefficients, AXY and BXY are Antoine parameters (XY stand for IA, JA, WA, and OA), and T is the temperature in Kelvin. In this study, the parameters AXY and BXY are calculated for 943 chemicals, and logKXY can be estimated at any ambient temperature for these chemicals using these Antoine parameters. The results are evaluated by comparing these data with published experimental and modeled data, and the results show reasonable accuracy. Based on these coefficients, temperature-dependence of logKRG and logKSG is studied. It is found that both logKRG and logKSG are linearly related to 1/T, and Antoine parameters for logKRG and logKSG are also estimated. Distributions of the 943 chemicals in the atmospheric phases (gas, particle, and rain/snow), are illustrated in a Chemical Space Map. The findings reveal that, at environmental temperatures and precipitation days, the dominant state for the majority of chemicals is the gaseous phase. All the AXY and BXY values for logKSG, logKRG, and basic adsorption and partition coefficients, both modeled by this study and collected from published work, are systematically organized into an accessible dataset for public utilization.

Analysis of the Sputum Culture Spectrum of Children with Respiratory Tract Infection in Wuxi Between 2014 and 2021.

Objective: We retrospectively analysed related clinical data to determine the influencing factors to better prevent and treat children's respiratory tract infection. Methods: The study participants were children with respiratory tract infection who had sputum cultured in our hospital between 2014 and 2021. Sputum samples were extracted using negative suction pressure and sent to the hospital microbiological laboratory for testing. The testing results were analysed. Results: A total of 4610 sputum samples were collected, and 508 positive samples were detected. The positive rate of pathogenic bacteria was 11.02%. Escherichia coli infection was more common in male patients (11.11%), whereas Haemophilus influenzae infection was more common in female patients (17.54%); the infection rates of these 2 bacteria are increasing annually. There were 304 (59.84%) strains of gram-negative bacteria, 172 (33.86%) strains of gram-positive bacteria and 32 (6.3%) strains of fungi. In children between 0 and 3 years old, the proportions of gram-negative bacteria were significantly higher than those of gram-positive bacteria in 2016-2017, 2018-2019 and 2020-2021 (p < 0.01). In every age group, the constituent ratio of gram-negative bacteria was significantly higher than that of gram-positive bacteria (p < 0.01) except for the 3-6-year age group. The proportion of Staphylococcus aureus in 2014-2015, 2016-2017, 2018-2019 and 2020-2021 was 25.64%, 25.20%, 22.98% and 16.44%, respectively. The proportion of H. influenzae in 2014-2015 was significantly lower than that in other years (p < 0.01). Haemolyticus staphylococcus and E. coli were more common in newborns, accounting for 19.12%. Conclusion: The pathogens of respiratory tract infection in children change dynamically. There are significant differences in pathogens of respiratory tract infections among different age groups, years and seasons. Clinicians should pay attention to changes in the pathogen spectrum and improve drug resistance monitoring.

Bioaccumulation of novel brominated flame retardants in crucian carp (Carassius auratus): Implications for electronic waste recycling area monitoring.

Bioaccumulation factor (BAF) of pollutants is an important parameter for evaluating their bioaccumulation potential and an important indicator for evaluating their environmental risks. However, little study exits on the BAF of novel brominated flame retardants (NBFRs). The present study determined 17 NBFRs in 24 water samples in dissolved phase and 93 crucian carp samples collected from an electronic waste recycling site in northern China, in order to examine their contamination, distribution and bioaccumulation. The results showed that the targeted NBFRs were widely detectable in the dissolved phase and crucian carps. In dissolved phase, allyl 2,4,6-tribromophenyl ether (ATE) had the highest detectable rate (100%) and concentration (mean: 1.3 ± 0.62 ng/L), but in crucian carp, hexachlorocyclopentenyl-dibromocyclooctane (HCDBCO) was the one with the highest detectable rate (89%) and concentration (mean: 16 ± 9.2 ng/g wet weight (ww)) among all 17 NBFRs. The discharge and water solubility of NBFRs determined their concentration in the dissolved phase, while the concentration of NBFRs in crucian carp was the results of their discharge and food exposure. The estimated BAFs exceeded 5000 L/kg for petabromoethylbenzene (PBEB), pentabromotoluene (PBT), HCDBCO, pentabromobenzyl acrylate (PBBA), 1,2,3,4,5-pentabromobenzene (PBBZ), 2,3-dibromopropyl-2,4,6-tribromophenyl ether (DPTE), hexabromobenzene (HBBZ), and α-1,2,5,6-tetrabromocyclooctane (α-TBCO), suggesting that these compounds were above the hazard standard of bioaccumulation. Although the BAFs of 2,3,5,6-tetrabromo-p-xylene (p-TBX), 1,2-bis(2,4,6-tribromophenoxy)-ethane (BTBPE), α-/ß-tetrabromoethylcyclohexane (α-/ß-TBECH) and ATE were less than 5000, the potential of bioaccumulation cannot be ignored. The log BAF of tested NBFRs showed a pattern of first increasing and then decreasing with the increase of log KOW, the water solubility of NBFRs, the exposure to fish, the uptake and depuration of fish were the key factor to this pattern. To our knowledge, the BAF values of the most of NBFRs calculated in this study were not reported in the published work previously.

PM2.5 exposure promotes asthma in aged Brown-Norway rats: Implication of multiomics analysis.

Children are disproportionately represented among those who suffer asthma, which is a kind of chronic airway inflammation. Asthma symptoms might worsen when exposed to the air pollutant particulate matter 2.5 (PM2.5). However, it is becoming more prevalent among older adults, with more asthma-related deaths occurring in this pollution than in any other age group, and symptoms caused by asthma can reduce the quality of life of the elderly, whose asthma is underdiagnosed due to physiological factors. Therefore, in an effort to discover a therapy for older asthma during exposure to air pollution, we sought to ascertain the effects of pre-exposure (PA) and persistent exposure (PAP) to PM2.5 in aged asthma rats. In this study, we exposed aged rats to PM2.5 at different times (PA and PAP) and established an ovalbumin-mediated allergic asthma model. The basic process of elderly asthma caused by PM2.5 exposure was investigated by lung function detection, enzyme-linked immunosorbent assay (ELISA), histopathology, cytology, cytokine microarray, untargeted metabolomics, and gut microbiota analysis. Our findings demonstrated that in the PA and PAP groups, exposure to PM2.5 reduced lung function and exacerbated lung tissue damage, with varying degrees of effect on immunoglobulin levels, the findings of a cytological analysis, cytokines, and chemokines. The PA and PAP rats had higher amounts of polycyclic aromatic hydrocarbons (PAHs), such as naphthalene, 2-methylNaphthalene, 1-methylNaphthalene and flourene. Moreover, exposure to PM2.5 at different times showed different effects on plasma metabolism and gut microbiota. Bioinformatics analysis showed a strong correlation between PAHs, cytokines, and gut microbiota, and PAHs may cause metabolic disorders through the gut microbiota. These findings point to a possible mechanism for the development of asthma in older people exposure to PM2.5 that may be related to past interactions between PAHs, cytokines, gut microbiota, and plasma metabolites.

Influence on the levels of PAHs and methylated PAHs in surface soil from pollution control in China: Evidence in 2019 data compared with 2005 and 2012 data.

To comprehensively clarify the pollution characteristics of persistent toxic substances, the Soil and Air Monitoring Program Phase III (SAMP-III) was conducted in 2019 in China. In total, 154 surface soil samples were collected across China, and 30 unsubstituted polycyclic aromatic hydrocarbons (U-PAHs) and 49 methylated PAHs (Me-PAHs) were analyzed in this study. The mean concentrations of total U-PAHs and Me-PAHs were 540 ± 778 and 82.0 ± 132 ng/g dw, respectively. Northeastern China and Eastern China are the two regions of concern with high PAH and BaP equivalency levels. Compared with SAMP-I (2005) and SAMP-II (2012), an obvious upward temporal trend followed by a downward trend of PAH levels was observed in the past 14 years for the first time. The mean concentrations of 16 U-PAHs were 377 ± 716, 780 ± 1010, and 419 ± 611 ng/g dw in surface soil across China for the three phases, respectively. Considering rapid economic growth and energy consumption, an increasing trend from 2005 to 2012 was expected. From 2012 to 2019, the PAH levels in soils across China decreased by 50 %, which was consistent with the decline in PAH emissions. The period of reduction of PAHs in surface soil coincided with the implementation of Air and Soil Pollution Control Actions in China after 2013 and 2016, respectively. Along with the pollution control actions in China, the pollution control of PAHs and the increase in soil quality can be expected in the near future.

Characterization of Volatile Profiles and Correlated Contributing Compounds in Pan-Fried Steaks from Different Chinese Yellow Cattle Breeds through GC-Q-Orbitrap, E-Nose, and Sensory Evaluation.

This study focused on characterizing the volatile profiles and contributing compounds in pan-fried steaks from different Chinese yellow cattle breeds. The volatile organic compounds (VOCs) of six Chinese yellow cattle breeds (bohai, jiaxian, yiling, wenshan, xinjiang, and pingliang) were analyzed by GC-Q-Orbitrap spectrometry and electronic nose (E-nose). Multivariate statistical analysis was performed to identify the differences in VOCs profiles among breeds. The relationship between odor-active volatiles and sensory evaluation was analyzed by partial least square regression (PLSR) to identify contributing volatiles in pan-fried steaks of Chinese yellow cattle. The results showed that samples were divided into two groups, and 18 VOCs were selected as potential markers for the differentiation of the two groups by GC-Q-Orbitrap combined multivariate statistical analysis. YL and WS were in one group comprising mainly aliphatic compounds, while the rest were in the other group with more cyclic compounds. Steaks from different breeds were better differentiated by GC-Q-Orbitrap in combination with chemometrics than by E-nose. Six highly predictive compounds were selected, including 3-methyl-butanal, benzeneacetaldehyde, 2-ethyl-6-methyl-pyrazine, 2-acetylpyrrole, 2-acetylthiazole, and 2-acetyl-2-thiazoline. Sensory recombination difference and preference testing revealed that the addition of highly predictive compounds induced a perceptible difference to panelists. This study provides valuable data to characterize and discriminate the flavor profiles in pan-fried steaks of Chinese yellow cattle.

Occurrence of Phthalates in Bottled Drinks in the Chinese Market and Its Implications for Dietary Exposure.

Ubiquitous occurrences of phthalic acid esters (PAEs) or phthalates in a variety of consumer products have been demonstrated. Nevertheless, studies on their occurrence in various types of bottled drinks are limited. In this study, fifteen PAEs were analyzed in six categories of bottled drinks (n = 105) collected from the Chinese market, including mineral water, tea drinks, energy drinks, juice drinks, soft drinks, and beer. Among the 15 PAEs measured, DEHP was the most abundant phthalate with concentrations ranging from below the limit of quantification (LOQ) to 41,000 ng/L at a detection rate (DR) of 96%, followed by DIBP (DR: 88%) and DBP (DR: 84%) with respective concentration ranges of below LOQ to 16,000 and to 4900 ng/L. At least one PAE was detected in each drink sample, and the sum concentrations of 15 PAEs ranged from 770 to 48,004 ng/L (median: 6286 ng/L). Significant differences with respect to both PAE concentrations and composition profiles were observed between different types of bottled drinks. The median sum concentration of 15 PAEs in soft drinks was over five times higher than that detected in mineral water; different from other drink types. Besides DEHP, DBIP, and DBP, a high concentration of BMEP was also detected in a tea drink. The estimated daily dietary intake of phthalates (EDIdrink) through the consumption of bottled drinks was calculated based on the concentrations measured and the daily ingestion rates of bottled drink items. The EDIdrink values for DMP, DEP, DIBP, DBP, BMEP, DAP, BEEP, BBP, DCP, DHP, BMPP, BBEP, DEHP, DOP, and DNP through the consumption of bottled mineral water (based on mean concentrations) were 0.45, 0.33, 12.5, 3.67, 2.10, 0.06, 0.32, 0.16, 0.10, 0.09, 0.05, 0.81, 112, 0.13, and 0.20 ng/kg-bw/d, respectively, for Chinese adults. Overall, the EDIdrink values calculated for phthalates through the consumption of bottled drinks were below the oral reference doses suggested by the United States Environmental Protection Agency (U.S. EPA).

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.

Brominated flame retardants (BFRs) in marine food webs from Bohai Sea, China.

In this study, brominated flame retardants (BFRs), including 13 polybrominated diphenyl ethers (PBDEs) and 17 novel brominated flame retardants (NBFRs) are determined in 18 species (including plankton, invertebrate, and fish) from Bohai Sea, China. Trophic transfer of these compounds is also assessed in the marine food web. Significant trophic magnification (p < 0.01) for 11 PBDE congeners (BDE-17, BDE-28, BDE-47, BDE-49, BDE-66, BDE-85, BDE-99, BDE-100, BDE-153, BDE154 and BDE-183) is observed. No significant correlation is observed for BDE-138 (p = 0.06), and significant trophic dilution is observed for BDE-209 (p < 0.0001). In PBDEs, BDE-66 has the highest TMF value of 3.9 (95% confidence interval (CI): 3.2-4.7), followed by BDE-47 (TMF: 3.8, 95% CI: 2.6-5.4) and BDE-28 (3.0, 2.2-4.1). For NBFRs, ATE, TBECH (include α- and ß-isomer), PBBZ, TBCO (include α- and ß-isomer), PBT, DPTE, HBBZ, PBBA, BTBPE, PBEB and HCDBCO are observed significant trophic magnification (p < 0.01), significant trophic dilution is observed for BATE (p < 0.01), DBDPE (p < 0.001) and OBIND (p < 0.0001), no significant correlation is observed for p-TBX (p = 0.77). In NBFRs, PBT has the highest TMF value of 4.5 (95% CI: 3.1-6.3), followed by PBEB (TMF: 4.0, 95% CI: 2.1-7.6) and HCDBCO (3.9, 3.1-5.0). Regression analysis between KOW and TMF values of BFRs suggest that TMF values have a trend of first rising and then falling against the values of log KOW. Generally, chemicals with higher KOW value have stronger trophic magnification capacity than those with lower ones, but due to the influence of bioavailability, the trophic magnification ability of the superhydrophobic compounds may be inhibited. To our best knowledge, this is the first report of trophic transfer of NBFRs in marine food web and trophic transfer of 9 NBFRs (α-TBECH, p-TBX, BATE, PBBZ, α-TBCO, ß-TBCO, DPTE, OBIND, and HCDBCO) in aquatic food web.

Comparison of super-mini-PCNL and flexible ureteroscopy for the management of upper urinary tract calculus (1-2 cm) in children.

OBJECTIVES: To retrospectively evaluate the efficacy and safety of super-mini percutaneous nephrolithotomy (SMP) and retrograde intrarenal surgery (RIRS) for children with upper urinary tract calculus (1-2 cm). PATIENTS AND METHODS: Children with upper urinary tract calculus (1-2 cm) who underwent the SMP or RIRS were enrolled in this study. Patients were divided into two groups: group SMP, 36 patients; and group RIRS, 25 patients. Patients were evaluated with KUB radiography or CT after 1 month. The collected data were analyzed. RESULTS: The mean stone size was 14.18 mm in group SMP, and 14.00 mm in group RIRS (p = 0.812). Group RIRS compared to group SMP showed longer operating time [76.3 vs 53.9 min (p = 0.002)], and postoperative hospital stay [4.2 vs 2.9 days (p = 0.011)]. The overall stone-free rate (SFR) was 94.4% for group SMP, and 60.0% for group RIRS in 1 month after operation (p = 0.001). The re-treatment rate was significantly higher in group RIRS compared to group SMP [20.0% vs 0.0% (p = 0.009)]. The complication rate was 5.6%, and 24.0% for groups SMP, and RIRS, respectively (p = 0.036). CONCLUSIONS: SMP was more effective than RIRS to obtain a better SFR, less re-treatment rate, and complication rate in children with upper urinary tract calculus (1-2 cm).

Slopes and intercepts from log-log correlations of gas/particle quotient and octanol-air partition coefficient (vapor-pressure) for semi-volatile organic compounds: II. Theoretical predictions vs. monitoring.

The logarithm of gas/particle (G/P) partition quotient (logKP) has been found to have a linear relationship with logKOA (octanol-air partition coefficient) with slope mo and intercept bo and logPL (subcooled liquid vapor pressure) with slope mp and intercept bp. In the sister paper of the present work, analytical equations to predict the slope mo and intercept bo based on logKOA and predict the slope mp and intercept bp based on logPL are developed using steady state theory. In this work, the equations are evaluated using world-wide monitoring data (262 pairs for mo and bo values and 292 pairs for mp and bp values produced from more than 10,000 monitiring data worldwide) for selected seven groups of semi-volatile organic compounds (SVOCs), including polybrominated diphenyl ethers (PBDEs), polychlorinated dibenzo-p-dioxins and polychorinated dibenzofurans (PCDD/Fs), polyclorinated biphenyl (PCBs), polycyclic aromatic hydrocarbons (PAHs), polychlorinated naphthalenes (PCNs), organochlorinated pesticides (OCPs), novel brominated flame retardants (NBFRs), and other selected halogenated flame retardants. The slopes and intercepts predicted by the steady state equations reproduce the trends observed in monitoring regression results for the seven SVOC groups, with 44.4% of the variation of monitoring mo values accounted for by logKOA and 48.2% of the variation of monitoring mp values accounted for by logPL. Theoretically, the values of mo can be any value between 0 and 1 dependent on the values of KOA, and are not constrained to 1 as in equilibrium theory. Likewise, the values of mp can be any value between 0 and -1 dependent on the values of PL, and not constrained to -1 predicted by the equilibrium theory. The influence of sampling artifacts on the G/P partitioning of SVOCs has most likely been overemphasized by the equilibrium theory. Thus, the equilibrium approach should be abandoned in favor of the steady state approach for calculating the G/P partition quotients for SVOCs with high KOA values (>1011.38) or low PL values (<10-4.92).

Construction and Validation of a Robust Cancer Stem Cell-Associated Gene Set-Based Signature to Predict Early Biochemical Recurrence in Prostate Cancer.

BACKGROUND: Postoperative early biochemical recurrence (BCR) was an essential indicator for recurrence and distant metastasis of prostate cancer (PCa). The aim of this study was to construct a cancer stem cell- (CSC-) associated gene set-based signature to identify a subgroup of PCa patients who are at high risk of early BCR. METHODS: The PCa dataset from The Cancer Genome Atlas (TCGA) was randomly separated into discovery and validation set. Patients in discovery set were divided into early BCR group and long-term survival group. Propensity score matching analysis and differentially expressed gene selection were used to identify candidate CSC-associated genes. The LASSO Cox regression model was finally performed to filter the most useful prognostic CSC-associated genes for predicting early BCR. RESULTS: By applying the LASSO Cox regression model, we built a thirteen-CSC-associated gene-based early BCR-predicting signature. In the discovery set, patients in high-risk group showed significantly poorer BCR free survival than that patients in low-risk group (HR: 4.91, 95% CI: 2.75-8.76, P < 0.001). The results were further validated in the internal validation set (HR: 2.99, 95% CI: 1.34-6.70, P = 0.005). Time-dependent ROC at 1 year suggested that the CSC gene signature (AUC = 0.800) possessed better predictive value than any other clinicopathological features in the entire TCGA cohort. Additionally, survival decision curve analysis revealed a considerable clinical usefulness of the CSC gene signature. CONCLUSIONS: We successfully developed a CSC-associated gene set-based signature that can accurately predict early BCR in PCa cancer.

PAHs in Chinese atmosphere Part II: Health risk assessment.

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous pollutants in atmosphere, which attracted more attentions due to their influence on human health. In this study, a national scale cancer risk (CR) assessment with atmospheric PAHs were conducted based on one year monitoring program at 11 cities across China. The annual mean concentrations of benzo[a]pyrene (BaP) and BaP equivalency (BaPeq) were 4.56 ± 7.78 ng/m3 and 8.45 ± 14.1 ng/m3, respectively, which were both higher than the new ambient air quality standards of China (GB 3095-2012, 1 ng/m3). Concentrations of BaP and BaPeq in northern Chinese cities were almost 2 times higher than those in southern Chinese cities. The CR values induced by the dermal contact exposure were two orders of magnitude higher than that by the inhalation exposure. Children and adults were the most sensitive age groups with the dermal contact exposure and the inhalation exposure to atmospheric PAHs, respectively. For the total CR values, 99.7% of its values were higher than the reference level of 10-6. No significant difference of the total CR values was observed between northern Chinese and southern Chinese cities for children and adults. In order to quantify the uncertainties of CR assessment, Monte Carlo Simulation was applied based on the specific distributions of the exposure factors cited from the Exposure Factors Handbook of Chinese Population. The results indicated that almost 90% probability of the total CR values were higher than 10-6, indicating potential cancer risk. Sensitive analysis indicated that atmospheric concentration, outdoor exposure fraction, particle amount adhered to skin, and cancer slope factor should be carefully considered in order to increase the accuracy of CR assessment with PAHs in atmosphere.

Distribution, seasonal trends, and lung cancer risk of atmospheric polycyclic aromatic hydrocarbons in North China: A three-year case study in Dalian city.

Atmospheric monitoring data of polycyclic aromatic hydrocarbons (PAHs) over a three-year period were collected from an urban site in Dalian, northeast China. The status of PAHs in the atmosphere in Dalian were evaluated by assessing concentration levels, congener profiles, seasonal trends, primary source, inhalation exposure and the risk of developing lung cancer risk. Average concentrations were recorded for 53 PAHs (95 ± 40 ng/m3), 16 EPA priority PAHs (68 ± 33 ng/m3), 26 alkylated PAHs (17 ± 7.6 ng/m3) and 4 high-molecular-weight (302 Da) PAHs (1.3 ± 1.3 ng/m3). Atmospheric PAH concentrations in winter were almost twice as high as those recorded in the summer, possibly due to enhanced local emissions and long-range transport of atmospheric PAHs during the winter. PAH congeners were dominated by phenatherene, fluoranthene, pyrene and fluorene, accounting for 46.0% of total ∑53PAH concentrations. Ship/vehicle emission and mixed combustion were identified as the main sources of PAHs using diagnostic PAH concentration ratios and principal component analysis-multiple linear regression. Benzo(a)pyrene toxicity equivalent concentration had an average content of 32 ± 37 ng/m-3 over the sampling period, with dibenzo(a,h)anthracene (50.7%) and dibenzo(a,l)pyrene (26.4%) being the largest contributors. The risk of developing lung cancer due to inhalation exposure to outdoor PAHs was calculated at 12.0‰ using the overall population attributable fraction (PAF). Our results estimate that, due to PAH exposure in Dalian, the average excess lung cancer risk during a person's lifetime is 35.7 cancer cases per one million inhabitants.

Soil concentrations and soil-air exchange of polycyclic aromatic hydrocarbons in five Asian countries.

The Asia Soil and Air Monitoring Program (Asia-SAMP) is a large-scale monitoring program spanning China, Japan, South Korea, Vietnam and India. 47 polycyclic aromatic hydrocarbons (PAHs) were analyzed in 169 concurrently collected surface soil samples across the five study regions. Total PAH concentrations (∑47PAHs) ranged from 13.1 to 7310 ng/g dry weight, with a median value of 272 ng/g dry weight. Higher concentrations of ΣPAHs were recorded in soils from urban areas, followed by soils from rural areas and background soils. Low correlation coefficients were found between PAHs concentrations with population density, surface air temperature and soil organic content. A trend of depleting high molecular weight PAHs and enrichment of low molecular weight PAHs occurred from east to west in Chinese soils. Based on atmospheric PAHs detected in almost the same sampling sites, the equilibrium status of PAHs in the atmosphere and on the ground was investigated. Sample sites with a soil-air equilibrium status for different PAH congeners recorded differences, and differences were recorded between seasons. 2-ring PAHs were mainly volatilized, and 5- & 6-ring PAHs were mainly deposited in all seasons and across all study regions. 3- & 4-ring PAHs were more affected by soil-air transfer, showing a tendency to accumulate in soils in cold regions/seasons and to be re-volatilized into the atmosphere in warm regions/seasons. Partitioning and exchange of PAHs among soil and air were significantly affected by the air temperature.

Uptake, depuration, bioaccumulation, and selective enrichment of dechlorane plus in common carp (Cyprinus carpio).

Dechlorane plus (DP) is a chlorinated flame retardant with high production volume (HPV) and is widely used in our daily necessities. In the present study, a laboratory-scale microcosm was built up to simulate the uptake, depuration, bioaccumulation, and stereoselective enrichment of DP in a lower concentration and equilibration condition. Common carp (Cyprinus carpio) were used for 32 days exposure and 32 days depuration. The concentration ratios of syn-DP to total DP (fsyn values) in fish examined were lower than that in commercial products. Rate constants of uptake (kS) and elimination (ke) for the syn- and anti-DP were calculated using a first-order kinetic model. The uptake rate constants of syn- and anti-DP were 0.63 and 0.89 day-1, respectively. The depuration rate constants of syn-DP (0.11 day-1) were similar to anti-DP (0.096 day-1), suggesting that anti-DP is absorbed faster than syn-DP by common carp. The estimated bioconcentration factors for both syn-DP (5700 L/kg) and anti-DP (9300 L/kg) were higher than the bioconcentration hazard criteria outlined in the Stockholm Convention, suggesting the bioconcentration potential to aquatic organisms for DP.

PAHs in Chinese atmosphere: Gas/particle partitioning.

The gas/particle (G/P) partitioning behavior is an important factor for the environmental fate of polycyclic aromatic hydrocarbons (PAHs) in atmosphere. Based on one year monitoring program at 11 urban sites across China, 7647 pairs of gaseous and particulate concentrations were obtained for 16 priority PAHs, which provided a good opportunity to study the G/P partitioning behavior of PAHs. The concentrations of PAHs in both gas and particle phases were not in the same level among the 11 sites with a difference of more than one orders of magnitude. Along with the increase of molar weight of PAHs, the proportion of concentration in particle phase was increasing. In particle phase, the concentrations of ∑16PAHs in northern Chinese cities were significantly (p < 0.05) higher than those in southern Chinese cities with the average concentrations of 83.4 ±â€¯151 ng/m3 and 33.4 ±â€¯45.5 ng/m3, respectively. However, non-significant difference was found with ∑16PAHs in gas phase. The values of log KP (the G/P partitioning coefficient/quotient) ranged from -5.65 m3/µg to 2.34 m3/µg, with the mean value of -2.01 ±â€¯1.65 m3/µg for the 16 PAHs. The values of log KP for individual PAHs at the 11 sites were not in the same level. Furthermore, significant difference (p < 0.05) with log KP of the 16 PAHs was found between northern Chinese cities and southern Chinese cities except for Acy, Flu and DahA. More than one orders of magnitude difference with KP were observed for different congeners and different rings PAHs, which are mainly caused by their physical-chemical properties. The results of this study provided large database of KP, which is necessary and important to the research field of the G/P partitioning of PAHs.

Trophic transfer of cyclic methyl siloxanes in the marine food web in the Bohai Sea, China.

Trophic transfer of cyclic methyl siloxanes (CMS) in aquatic ecosystems is an important criterion for assessing its environmental risks. This study researched the trophic transfer of four CMS (octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), dodecamethylcyclohexasiloxane (D6), and tetradecamethylcycloheptasiloxane (D7)) in marine food web from zooplankton up to seabirds in the Chinese Bohai Sea. In the zooplankton-invertebrate-fish-seabird based food web, the significant trophic magnifications were found for D4 to D6 (D4: R2 = 0.040, p < 0.05, D5: R2 = 0.26, p < 0.0001, D6: R2 = 0.071, p < 0.001), and the significant trophic dilution was found for D7 (R2 = 0.026 and p < 0.05). The trophic magnification factors (TMF) for D4 to D7 were 1.7 (95% confidence interval: 1.1-2.6), 3.5 (2.5-5.0), 1.8 (1.3-2.6), and 0.63 (95% CI: 0.40-0.99) respectively. In the zooplankton-invertebrate-fish based food web, both significant trophic magnification for D5 (R2 = 0.16, p < 0.0001, TMF = 3.0) and significant trophic dilution for D7 (R2 = 0.073, p < 0.01, TMF = 0.4) were found, but for D4 and D6, the trophic magnifications were not significant (D4: R2 = 0.010, p = 0.23, D6: R2 = 0.010, p = 0.23). The trophic transfer of the legacy contaminant BDE-47 and BDE-99 were also conducted as the benchmark chemicals and significant positive correlation was found. As far as we know, this is the first research on the trophic transfer of CMS in the zooplankton-invertebrate-fish-bird food chain which provided new insight of these compounds in the area.

The fabrication of an Ni6MnO8 nanoflake-modified acupuncture needle electrode for highly sensitive ascorbic acid detection.

The current work describes the use of a steel acupuncture needle as an electrode substrate in order to construct an Ni6MnO8 nanoflake layer-modified microneedle sensor for highly sensitive ascorbic acid detection. For the purpose of constructing the functionalized acupuncture needle, first, a carbon film was layered on the needle surface as the seed layer. Subsequently, a straightforward hydrothermal reaction-calcination process was employed for the growth of Ni6MnO8 nanoflakes on the needle to function as a sensing interface. Electrochemical investigations illustrated the fact that the Ni6MnO8 nanoflake-altered acupuncture needle electrode manifested outstanding efficiency toward the amperometric identification of ascorbic acid. In addition, the electrode manifested elevated sensitivity of 3106 µA mM-1 cm-2, detection limit of 0.1 µM, and a broad linear range between 1.0 µM and 2.0 mM. As demonstrated by the results, the Ni6MnO8 nanoflake-modified acupuncture needle constitutes a potentially fresh platform to construct non-enzymatic ascorbic acid sensors.