[Pollution Assessment and Source Analysis of Heavy Metals in Atmospheric Deposition in a Lead-zinc Smelting City Based on PMF Model].

To explore the pollution characteristics and sources of heavy metals in atmospheric deposition in a typical lead-zinc smelting city, 511 effective atmospheric deposition samples from 22 points in different functional areas of a city in Henan Province were collected monthly during 2021. The concentrations and spatial-temporal distribution of heavy metals were analyzed. The geo-accumulation index method and health risk assessment model were utilized to evaluate the heavy metal pollution degree. The sources of heavy metals were quantitatively analyzed using a positive matrix factorization (PMF) model. The results showed that the average concentrations of ω(Pb), ω(Cd), ω(As), ω(Cr), ω(Cu), ω(Mn), ω(Ni), and ω(Zn) in atmospheric deposition samples were 3185.77, 78.18, 273.67, 149.50, 453.60, 810.37, 54.38, and 2397.38 mg·kg-1, respectively, which were all higher than the soil background values of Henan Province. All heavy metals except Mn had significant seasonal variation characteristics. The concentrations of Pb, Cd, As, and Cu in the industrial area with lead-zinc smelting were significantly higher than those in other functional areas, and the concentration of Zn was the highest in the residential mixed area. The results of the geo-accumulation index showed that the pollution of Cd and Pb were the most serious, followed by that of Zn, Cu, and As, which belonged to the serious-extreme pollution category. The main exposure route of non-carcinogenic risk was hand-mouth intake. Pb and As posed the greatest non-carcinogenic risk to children in all functional areas. The carcinogenic risks of Cr, As, Cd, and Ni through the respiratory system to humans were all below the threshold values. The analysis of the PMF model showed that the main sources of heavy metals in atmospheric deposition were industrial pollution sources (39.7%), transportation sources (28.9%), secondary dust sources (14.4%), incineration and coal combustion sources (9.3%), and natural sources (7.8%).

[Ecological Toxic Effect of Perfluorinated Compounds on Fish Based on Meta-analysis].

Perfluoroalkyl and polyfluoroalkyl substances (PFAS) are refractory organic pollutants, which are characterized by ubiquity, bioaccumulation, and biological toxicity. To explore the biotoxic effects of PFAS on fish, this study reviewed 64 publications. The toxicity of PFAS on functional traits of fish exposed to PFAS was analyzed based on Meta-analysis combined with effect sizes, which provided reference for the toxicity assessment of PFAS and was conducive to the priority control and management of PFAS pollution. The results showed that:① of the 12 functional traits studied, seven were found to be vulnerable in fish; the order of toxicity response was malformation (lnRR=-2.5599), development (lnRR=-0.4103), cell damage (lnRR=-0.3962), reproduction (lnRR=-0.3724), thyroid response (lnRR=-0.2492), growth (lnRR=-0.2194), and survival (lnRR=-0.2192). ② The aquatic toxicity of PFAS was significantly affected by the sex and developmental stage of fish. PFAS tended to have adverse effects on female fish (lnRR=-0.1628), and the physiological function of embryos was most significantly affected by PFAS (lnRR=-0.3553). ③ A total of 13 PFAS were involved in the study, among which PFAS with sulfonate groups and long-chains were more likely to have significant toxicity to the functional traits of fish (P<0.05).④ Existing data revealed that PFAS tended to produce acute toxicity to fish at medium and low concentrations (0.01-10 mg·L-1, P<0.05).

lncRNA DLEU2 acts as a miR-181a sponge to regulate SEPP1 and inhibit skeletal muscle differentiation and regeneration.

Sarcopenia is a serious public health problem associated with the loss of muscle mass and function. The purpose of this study was to identify molecular markers and construct a ceRNA pathway as a significant predictor of sarcopenia. We designed a prediction model to select important differentially expressed mRNAs (DEMs), and constructed a sarcopenia associated ceRNA network. After correlation analysis of each element in the ceRNA network based on clinical samples and GTEX database, C2C12 mouse myoblasts were used as a model to verify the identified ceRNA pathways. A new model for predicting sarcopenia based on four molecular markers SEPP1, SV2A, GOT1, and GFOD1 was developed. The model was used to construct a ceRNA network and showed high accuracy. Correlation analysis showed that the expression levels of lncDLEU2, SEPP1, and miR-181a were closely associated with a high risk of sarcopenia. lncDLEU2 inhibits muscle differentiation and regeneration by acting as a miR-181a sponge regulating SEPP1 expression. In this study, a highly accurate prediction tool was developed to improve the prediction outcomes of sarcopenia. These findings suggest that the lncDLEU2-miR-181a-SEPP1 pathway inhibits muscle differentiation and regeneration. This pathway may be a new therapeutic target for the treatment of sarcopenia.

Vertical and temporal distribution of nitrogen and phosphorus and relationship with their influencing factors in aquatic-terrestrial ecotone: a case study in Taihu Lake, China.

Vertical and temporal distributions of N and P in soil solution in aquatic-terrestrial ecotone (ATE) of Taihu Lake were investigated, and the relations among N, P, ORP (oxidation reduction potential), TOC, root system biomass and microorganism were studied. As a whole, significant declines in TN, NO3- -N, DON (dissolved organic nitrogen) and TP concentration in soil solution have occurred with increase of the depth, and reached their minima at 60 cm depth, except for NH4+ -N, which increased with depth. The concentration of TP increased gradually from spring to winter in the topsoil, the maximum 0.08 mg/L presented in the winter while the minimum 0.03 mg/L in spring. In the deeper layer, the concentration value of TP fluctuated little. As for the NO3- -N, its seasonal variation was significant at 20 cm depth, its concentration increased gradually from spring to autumn, and decreased markedly in winter. Vertical and temporal distribution of DON is contrary to that of NO3- -N. The results also show that the variation of N and P in the percolate between adjacent layers is obviously different. The vertical variation of TN, TP, NO3- -N, NH4+ -N and DON is significant, of which the variation coefficient of NO3- -N along the depth reaches 100.23%, the highest; while the variation coefficient of DON is 41.14%, the smallest. The results of correlation analysis show that the concentration of nitrogen and phosphorus correlate significantly with TOC, ORP, root biomass and counts of nitrifying bacteria. Most nutrients altered much from 20 to 40 cm along the depth. However, DON changed more between 60 and 80 cm. Results show that soil of 0-60 cm depth is active rhizoplane, with strong capability to remove the nitrogen and phosphorus in ATE. It may suggest that there exists the optimum ecological efficiency in the depth of above 60 cm in reed wetland. This will be very significant for ecological restoration and reestablishment.

Water quality characteristics along the course of the Huangpu River (China).

Huangpu River is about 114.5 km from upriver Dianfeng to downriver Wusong, near the estuary of the Yangtze River. It plays a key role in supplying water for production, life, shipment and irrigation. With the industrial development, the pollution of the Huangpu River has become serious recently. The biological oxygen demand (BOD), total nitrogen (TN), total phosphorus (TP), oil, phenol and suspended solids (SS) were lower in the upstream sites than in the downstream sites, indicating pollutants being input along its course. Water quality was the worst in the Yangpu site, near the center of Shanghai City. Dissolved oxygen (DO) content was less than 2 mg/L in the site of Yangpu in July. Among relations between thirteen characteristics, relations between BOD, DO, TN, TP, NH4(+)-N, NO3(-)-N and the count of total bacteria or Escherichia coli were significant and interdependent. Inner relationships between these main characteristics in the Huangpu River were studied. High nutrient concentration led to growth of microorganisms, including E. coli. Degradation of organic matters and respiration of bacteria made oxygen concentration decreased in the water body, and DO was a key factor for nitrification-denitrification process of nitrogen. In the Yangpu site, DO was decreased to less than 3.0 mg/L with BOD higher than 7.5 mg/L in May and July. Low DO concentration will decrease nitrification rate. Nitrification need at higher DO value than other organic substrate oxidation. Consequently, river water contains low NO3(-)-N values with high amounts of TN and NH4+-N there. This will block the self-purification of surface water, by decreasing the rate of nitrification-denitrification transformation process in the water body.

Neurotransmitter level changes in domestic ducks (Shaoxing duck) growing up in typical mercury contaminated area in China.

The neurotransmitter level changes of ducks exposed 8-month in a mercury-polluted site (Wanshan, China) and a reference site (Shanghai, China) were examined. Chemical analyses showed both higher mercury and selenium concentrations in the organ of Wanshan ducks. An increased content of acetylcholine (ACh) in brain and blood and a decreased activity of acetylcholinesterase (AChE) in blood were observed. Moreover, there was an increasing trend for nitric oxide synthase (NOS) activity and nitric oxide(NO) production in duck brain, but a reduction of NOS activity in duck serum. The possible explanations were due to the interactive effect of selenium accumulation and the sublethal exposure level of mercury in Wanshan area. The present study showed that AChE and NOS were sensitive to mercury contamination of real circumstance, suggesting that these two indexes have the potential to be biomarkers in assessment of health effects by mercury contamination.

[Degradation mechanism of acid red B by cathodic oxidation].

Acid red B (ARB) solution with pH = 3 was electrolyzed in a two-chamber cell using Pt/C gas diffusion electrode (GDE) as cathode. The color and COD removal ratio in cathode chamber were 94.2% and 66.8% respectively; and the color and COD removal ratio in anode chamber were 73.3% and 56.6% respectively, which indicated that O2 can be reduced to H2O2 and x OH in the cathode chamber, then ARB was degraded. Through IR and GC-MS analysis for the intermediates of ARB in the cathode chamber, 20 intermediates have been detected, including 14 esters, 3 acids and 3 compounds with -NO2 or N-OH groups and the probable degradation pathway of ARB in the cathode chamber was given.