[Effect of Zinc Fertilizer Application on Cadmium Accumulation in Wheat Grain and Its Application Risk].

The interaction of zinc (Zn) and cadmium (Cd) is an important research direction in the prevention and control of Cd pollution of wheat in recent years. In this study, a typical wheat field in North China was selected as the object to explore the control effect and application risk of Zn fertilizer on Cd pollution in a soil-wheat system through field experiments. The results showed that under the treatment of a low dosage of Zn, the Cd concentrations in wheat grains in Jiyuan City and Kaifeng City decreased by 33.4% and 25.3% compared with those in the control, respectively. By contrast, Cd concentrations in wheat grains treated with a high dosage of Zn increased by 22.4% and 34.2% compared with that of the low-dosage Zn treatment. After the application of Zn, the total amount and available Zn concentrations increased significantly, and Cd was partially activated in these two locations. Canonical correlation analysis (CCA) showed that when the Zn concentrations in the soils were less than 200 mg·kg-1, soil Zn was the main factor affecting Cd accumulation in the soil-wheat system, whereas when Zn concentrations in soils were greater than 200 mg·kg-1, the activation of soil Cd was the main factor affecting Cd accumulation in wheat grains. Regression analysis showed that when the soil Cd/Zn ratio decreased to 0.0089 (low dosage of Zn), Zn and Cd showed an antagonistic effect, whereas when the soil Cd/Zn ratio decreased to 0.0078 (high dosage of Zn), Zn and Cd showed a synergistic effect. According to the characteristics of regional Cd pollution, adjusting the amount of Zn fertilizer can improve the efficiency of pollution control and avoid aggravating the harm of Cd pollution.

[Serum Lipid Levels and Their Prognostic Significance in Patients with Multiple Myeloma].

OBJECTIVE: To investigate the serum lipid levels and their prognostic significance in patients with multiple myeloma (MM). METHODS: A total of 87 newly diagnosed MM patients and 87 healthy controls in our hospital from January 2012 to April 2021 were selected. Serum lipid levels were compared between MM patients and healthy controls. The differences of serum lipid levels in patients among two groups of sex, age, hemoglobin (Hb), albumin (ALB), platelet (PLT), ß2-microglobulin (ß2-MG) and bone marrow plasma cell ratio (BMPC), different immune types, different ISS stages, before and after chemotherapy were analyzed. Univariate and COX multivariate regression analysis were used to analyze the influence of clinical parameters such as serum lipid indexes on prognosis of MM. RESULTS: The serum levels of total cholesterol (TC), low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C), apolipoprotein A1 (Apo A1) and apolipoprotein B (Apo B) in MM patients were significantly lower than those in healthy controls (P<0.05). Anemia, low protein and low PLT in patients were related to low cholesterol. The levels of TC, LDL-C, HDL-C, Apo A1 and Apo B in patients with low Hb and ALB were significantly lower than those in patients with high Hb and ALB (P<0.05). The Apo B level of low PLT patients was significantly lower than that of high PLT patients (P<0.05). The levels of TC, LDL-C, HDL-C, Apo A1 and Apo B in patients with different immune types were significantly different, the above indexes of IgA type were significantly lower than IgG type(P<0.05), IgG type were significantly lower than light chain type(P<0.05), double clone type were significantly lower than light chain type (P<0.05). The levels of TC, LDL-C, and Apo B in patients with different ISS stages were significantly different, stage Ⅱ were lower than those of stage Ⅰ (P>0.05), stage Ⅲ were significantly lower than those of stage Ⅱ and stageⅠ(P<0.05). The levels of TC, TG, LDL-C, HDL-C, Apo A1 and Apo B in patients after chemotherapy were significantly higher than those before chemotherapy (P<0.05). Univariate analysis showed that Hb, PLT, ß2-MG, BMPC, LDL-C and Apo B affected the prognosis of MM. Multivariate analysis showed that BMPC and Apo B were independent factors affecting the prognosis of MM. CONCLUSION: The serum cholesterol level is decreased in MM patients, and hypocholesterolemia is related to the classification and staging of the disease. With the improvement of the disease, the serum cholesterol level is increased, and low serum Apo B level predicts a poor prognosis.

[Assessing the Lead Accumulation Risks of Wheat Grain by Developing a Source-Specific Accumulation Risk Assessment Model].

Characterizing the lead (Pb) transfer in the "source-soil-wheat" chain is of great importance for the prevention and control of the Pb accumulation risk in wheat grain harvested from the croplands of China. In this study, we used the Jiyuan City, northern China, as a case study to investigate the influence of contamination sources and soil factors on the accumulation of Pb in wheat grain. A site-specific source risk assessment model (SRAM), coupling the positive matrix factorization model, Freundlich-type function, and the Monte Carlo simulation method, was developed to estimate the risk of Pb accumulation in wheat grain harvested from different scenarios. Based on the results of the spatial analysis, the effectiveness and potential risk of the control measures applied in the study area was also evaluated. Atmospheric deposition and phosphate fertilizer application were identified as major sources contributing to 29.0% of the Pb accumulations in wheat grain. Soil pH and cation-exchange capacity (CEC) were the primary causative factors affecting the Pb accumulation in wheat grain. Cropping wheat in the high Pb continuation risk areas (western and northwestern areas) of Jiyuan City caused a 10.5% likelihood of Pb to accumulate above the China food standard limit of 0.2 mg·kg-1 (DW). This risk was significantly decreased to 2.39% when the CEC levels of affected soils was improved to 20 cmol·kg-1 and above.

[Ecological risk assessment of contaminated soil using improved "Weight of Evidence"approach:A case study of electroplating site in Jingjiang, Jiangsu, China]. / 基于改进的"证据-权重法"评估污染土壤生态风险:以江苏靖江某电镀场地为例.

Ecological risk assessment of soil in contaminated sites provides the scientific basis for accurately developing soil quality standards, confirming remediation targets, and making safe use of contaminated soil. It thus is a critical mean to protect soil health and safety. "Weight-of-Evidence" (WoE) has been widely used in ecological risk assessment due to its systematic, integrated and scientific properties. However, most current WoE approaches are poor in objectivity and comparability because they rely too much on expertise scoring in weighing and the difficulty to collect complete evidence bodies with quantitative and comprehensive information. Focusing on those issues above, we developed an improved framework of WoE approach for ecological risk assessment of contaminated site soil based on the "Four-Step" framework of EPA coupled with the concept of hierarchy. Assessment methods and procedures for each tier were unified. Weights were weighed quantitatively through multiple criteria decision analysis. The relative independence among bodies of evidence was assured by the pre-establishment of hierarchy. The "site specific" was stressed based on matrix trails and field investigation. Finally, a case study in an electroplating site in Jingjiang was conducted to verify the approach. Results of the case study suggested that the approach was practical and that the assessment results were objective, scientific, and accurate.

[Characteristics and influencing factors of microbial function in soils around a typical mining smelter]. / å ¸åž‹çŸ¿å†¶åŒºå‘¨è¾¹åœŸå£¤å¾®ç”Ÿç‰©åŠŸèƒ½ç‰¹å¾åŠå½±å“å› ç´ .

Soil microorganisms were sensitive to heavy metal pollution, whose ecological effect on soil microbial community was impacted by the interaction of contaminated stresses and environmental factors. To explore the dominant factors governing those effects in heavy metal contaminated soil, field investigation was conducted for soil from different land use types in an area surrounding a typical mining smelter in Hunan Province. Soil microbial function parameters including microbial biomass carbon (MBC), basal respiration (BR), substrate-induced respiration (SIR) and nitrification potential (PNR) were used as measure endpoints for ecological effect to reflect soil carbon and nitrogen cycling. The results showed that the effect of land use on MBC, BR, and SIR was insignificant. The dominant impacting factors on microbial functions included CaCl2 extracted Pb (CaCl2-Pb) and soil organic matter (SOM) content. Results of multiple regression analysis showed that soil CaCl2-Pb and SOM together explained 39.8%-58.3% of the total variations of BR, SIR and PNR in soil, when CaCl2-Pb and SOM ranged in 0.004-13.14 mg·kg-1 and 0.24%-4.34%, respectively. Significantly quantitative exposure-effect equations were developed between the responses of soil BR, SIR and PNR and soil CaCl2-Pb and SOM when soil samples with medium contents (namely, SOM 1.70%～2.36% and CaCl2-Pb 0.004-12.98 mg·kg-1), which meant they could be used to quantitatively assess the ecological effect of heavy metals on microbial community function as measure endpoints.

[Security Risk and Influencing Factors of Agro-Products in Farmland Soil Around a Typical Mining Smelter].

The security risks of heavy metal pollution in agro-products are becoming increasingly serious. This paper investigated the heavy metal contamination of farmland soils and agro-products around a typical mining smelter in Hunan province, and explored the influencing factors based on principal component and correlation analyses. The results showed that the soils were significantly contaminated by heavy metals, with a mean concentrations of Cd, Cu, Pb, and Zn of 9.12, 358, 303, and 185 mg·kg-1, respectively, pH range from 4.67 to 7.22. All the sites included were under strict control. With regards to the agro-products, the concentration of heavy metal elements were different, and the order of heavy metal concentrations was Zn>Cu>Pb>Cd, with an order of biological enrichment factor(BCF) of Cd>Zn>Cu>Pb. Over-the-standard elements in agro-products included Pb and Cd at 78% and 41%, respectively, which indicated a higher security risk from these products. The accumulation of the same heavy metals in leaf vegetables were generally higher than sweet potatoes and solanaceous vegetables. The heavy metal concentrations in soils corresponded to the first principal component(P<0.01), with the variance reaching 88.0%, which dominated the sources of Cd, Cu, Pb, and Zn in agro-products. The enrichment characteristics were mainly affected by the type of crops, and was also regulated by the soil pH, cation exchange capacity, and soil organic matter(the correlation coefficients of r were -0.407- -0.641, P<0.05). In conclusion, there was a combined heavy metal pollution and high risk in soils and agro-products. Therefore, the planting of crops in the study area should be avoided, and soil remediation measures should be implemented to reduce security risks.

[Simulation Cadmium (Cd) Accumulation in Typical Paddy Soils in South China].

The simulation analysis of the migration path and soil accumulation trend of Cd in paddy soil systems could contribute to improved scientific and reasonable risk decision-making. In this study, based on a regional survey of environmental media in Youxian County, Hunan Province, a pollutant accumulation model (PAM) was built to predict the cumulative trend of Cd in paddy soils. Combined with Monte Carlo simulation, the PAM model was used to evaluate the effectiveness and sustainability of various remediation measures. Results showed that the probability of Cd accumulation in paddy soils in Youxian County exceeded that of the national soil environmental quality standard by 2-fold and was up to 82.1%, and the average accumulation rate reached 4.28 µg·(kg·a)-1 after 50 years of cultivation under current input pattern. Sensitivity analysis results showed that atmospheric deposition and rice uptake were the key processes affecting Cd accumulation in paddy soils. Results of a multi-scenario simulation showed that the comprehensive measures, such as reducing the straw returning, optimizing the layout of industrial and mining enterprises that reduce the atmospheric deposition of Cd, and cleaning irrigation water, could reduce the Cd accumulation in paddy soils by 43.7% and reduce the probability of light Cd pollution by 80.6% after 50 years, which would be an effective long-term measure to prevent and control Cd pollution risk in paddy soils.

[Advances in ecological risk assessment of soil in contaminated sites]. / æ±¡æŸ“åœºåœ°åœŸå£¤ç”Ÿæ€é£Žé™©è¯„ä¼°ç ”ç©¶è¿›å±•.

With the rapid urbanization and industrial structure adjustment in China, many contaminated sites have been left for remediation. It is essential to develop and implement ecological risk assessment (ERA) before remediating contaminated sites at a large scale as well as sequential management. In this review, we discussed the key problems in ecological risk assessment of soils in contaminated sites focusing on scientific principles, frameworks, techniques, and approaches, including 1) the site-specific framework, 2) uncertainty of conceptual model, 3) toxic mechanisms of combined contamination in soil, 4) screening of assessment endpoints, and 5) development of assessing approaches and frameworks. Then, two perspectives were addressed: the toxicological mechanism of soil combined pollution including bioavailability of contaminants in soil and their joint effect is the scientific problem in ecological risk assessment of soil in contaminated site; and weight of evidence approach based on USEPA four-step approach and EU Tier approach is applicable for ecological risk assessment in field conditions. Future studies should focus on: 1) the coordination of ecological risk assessment (ERA) framework and risk management framework, 2) conceptual mo-del, 3) process-based reactive transport models for exposure evaluation, 4) ecotoxicological mechanism of combined contamination in site soil, and 5) high ecological level endpoints. The aim of this review was to provide theoretical base and framework for the establishment of local guideline of ecological risk assessment in China.

[Application of Antinuclear Antibody and Antinuclear Antibody Spectrum in Lymphoma Treatment].

OBJECTIVE: To investigate the significance of antinuclear antibody and antinuclear antibody spectrum in the stage and prognosis of lymphoma patients. METHODS: 79 cases of lymphoma (lymphoma group) treated in the Second Affiliated Hospital of Fujian Medical University and 50 cases of healthy people (control group) were selected. Antinuclear antibodies (ANA) were detected by indirect innmunofluorescence and ANA spectrums were detected by linear Western blot, the expression level of ANA and ANA spectrum in the two groups were analyzed. The lymphoma group was divided into the positive and the negative group according to ANA level, the levels of lactate dehydrogenase (LDH), white blood cell (WBC), disease type, stage and prognosis of the two groups were compared. RESULTS: In the lymphoma group, the positive rate of ANA was 48.1%, while the positive rate was 8.0% in the health control group, both of them showed statistically significant (χ2=22.42, P＜0.05). ANA fluorescence karyotype in lymphoma group was mainly speckle type. In the Lymphoma group, the positive rate of ANA spectrum was 29.1%, while the positive rate in the control group was 4.0%, both of them showed statistically significant (χ2=12.36, P＜0.05). The target antigen distribution of ANA spectrum in the lymphoma group was relatively complex, mainly RO52 and SSA, while that in the control group was simple. The positive rate of ANA in lymphoma patients showed increased with age, the titer was mainly 1∶100 low titer positive, the positive rate of ANA in female patients was higher than that in male patients; The average count±standard deviation of LDH and WBC in the ANA positive and negative group were (253.67±255.85) U/L, (218.18±208.34) U/L, (6.34±3.31)×109/L and (6.81±3.91)×109/L respectively, which showed no statistical significance between the two groups (t=0.59 P＞0.05; t=0.57 P＞0.05); B-cell lymphoma was the main disease in both groups, which accounted for 81.6% (31/38) and 68.3% (28/41) respectively; while in B-cell lymphoma, diffuse large B-cell lymphoma was the main lymphoma. For the patients with B-cell lymphoma, the patients at stage IV in ANA positive group was 58.1% (18/31), while that in the ANA negative group was 28.6% (8 / 28), and both of them showed statistically significant (χ2=5.19, P＜0.05). Follow-up showed that the survival rate of the patients in ANA negative group was higher than that in ANA positive group, which showed statistically significant difference (P＜0.05). CONCLUSION: The postive rate of antinuclear antibody and antinuclear antibody spectrum are higher in lymphoma patients, which have considerable significance for the stage and prognosis of lymphoma treatment.

[Effect of a Mining and Smelting Plant on the Accumulation of Heavy Metals in Soils in Arid Areas in Xinjiang].

Arid and semi-arid regions in West China are ecologically fragile zones. Increasing attention has been focused on soil pollution triggered by mining and smelting in those areas. Nine heavy metals in the soil around a mining and smelting plant in Xinjiang were investigated using multivariate analysis, the geoaccumulation index, and GIS techniques. The heavy metals Cu and As were identified as the main pollutants in the study area. The accumulation of the heavy metals Cr, Zn, Ni, and Cd is small and weakly disturbed by human activity. Anthropogenic accumulation of Co and Pb was observed at a few sampling sites; its degree was also small. Anthropogenic accumulation of Mn in soil was not apparent. The factor analysis indicates two sources for the nine heavy metals in the soils. Source 1 includes As, Cu, Ni, Cr, Zn, Cd, and Co, while Source 2 includes Mn and Pb. The spatial distribution suggests that the sites with the highest As, Cu, Ni, Cr, Zn, Pb, Cd, and Co concentrations are in areas close to the tailing dump. The sealing tailing dump is the prior way to prevent the spread of heavy metals. The results also reveal that the PCA/APCS receptor model is not applicable for the quantification of the contribution of heavy metals in soils in this case.

[Variation Characteristics of Vegetables Cadmium Uptake Factors and Its Relations to Environmental Factors].

The consumption of vegetables is a probable cause of Cd exposure in several world areas including China.In this study,we selected the prefecture of Youxian,southern China,as a case to analyze the influences of various environmental factors on Cd accumulation in vegetables based on a large scale agricultural and climatologically survey and collection of 585 irrigation water and 625 paired soil-vegetables samples.The results showed the concentration of Cd differed greatly in the irrigation water,soil and vegetables.The average daily dose for the adult populations consumed vegetables cropping in affected areas was slightly above the tolerable daily intake level,suggesting a potential health risk.The vegetables Cd uptake factor followed the natural lognormal distribution,and had a 10 percentile probability of higher than 1.The PUF values exhibited comparable results and appeared to define a reasonable and consistent Cd risk assessment.Many environmental variables (soil pH,soil organic matter,cation-exchange capacity,rainfall,water pH,and nitrogenous fertilizer usage) exhibited significant correlations with the concentrations of Cd in the soil-vegetable system.The canonical corresponding analysis and path model analysis found that soil pH and soil organic matter (SOM) had major direct effects on PUF.The close correlations between rainfall,water pH,nitrogen fertilizer usage and PUF were mainly resuled from the direct effect of soil pH and SOM.The high field-moisture capacity in the study area generated a rapid acidification causing the migration of Cd to weaker bounding sites thus promoting the vegetables uptake.The excessive application of nitrogen fertilizers led to a substantial loss of SOM and worsening of soil acidification ultimately causing increasing Cd accumulation in vegetables.Considering that the soil pH and SOM in the study area were maintained at a low level,the accumulation risk of Cd in soil-vegetable system needs to be addressed.The influence of environmental factors on vegetables accumulating Cd needs to be fully considered for better and safer vegetables production.

[Prediction of Cd in vegetables and soil Cd threshold derivation based on transfer function.] / 基于转移方程的蔬菜镉累积预测和土壤风险阈值推导.

The construction of transfer function of cadmium (Cd) in the soil-vegetable system is important for risk management. This study investigated the Cd concentration in 745 paired soils and vegetable samples, aiming to determine the influences of major soil properties on uptake of Cd by vegetables, and to derive the soil Cd threshold for vegetable cultivation based on China foodstuff regulations. Results of species sensitivity distribution model showed that the Cd accumulation potential of leafy vegetables was greater than that of rootstalk vegetables. Stepwise multiple regression analysis showed soil total Cd, pH, and soil organic matter (SOM) were major factors contributing to Cd accumulation in vegetables. The derived transfer function explained 54.2% and 69.1% of the variance for the accumulation of Cd in leafy and rootstalk vegetables, respectively. The derived soil threshold increased with soil pH and SOM contents. The rootstalk vegetables were potentially hazardous when grown in strong acidic areas. For soils in the southern China with excessive acidic nature and low SOM contents, the soil Cd limits for vegetables cultivation might be over-estimated.

[Impacts of Industrial Zone in Arid Area in Ningxia Province on the Accumulation of Heavy Metals in Agricultural Soils].

With the transferring of the industry from the east coastal regions of China to the mid and west regions, those places once called "Clean Earth" in the arid north-west region are facing the contamination risks by industrial emission. In order to study the impacts of the industrial zone on the accumulation of heavy metals Zn, Cr, Ni, Mn, Co, Cu, Cd, Pb in agricultural soils, we collected the agricultural soil samples in a county in Ningxia province using GIS technology. Samples were collected in a belt way along the yellow river and expanding from the industrial zone as the center according to the main local wind direction. It was suggested that the accumulation of heavy metals in studied agricultural soils was slight. High accumulation of Zn and Cd only occurred in several sites. However, the accumulation of heavy metals in industrial zone was more apparent. Except for Ni, the rest 7 elements had obvious accumulation. One third of the sites had Cd concentration at contamination level. The spatial analysis revealed that the distributions of Cd, Zn, Cu, Mn, and Pb were closely related to the location of industrial zone. Industrial zone had not caused the contamination of heavy metals in agricultural soils yet. Due to the high pH value (average pH value of 8.54), no soil contamination issue was found at present. However, the impacts of industrial zone on the accumulation of heavy metals in agricultural soils were apparent. The input pathway of heavy metals into agricultural soils was mainly dust deposition. The industrial zone also increased the heavy metal concentrations in irrigation water to some extent.

[Comprehensive Risk Evaluation of Cadmium in Soil-rice System Based on Uncertainty Analysis].

Cadmium (Cd) can cause adverse health effects and is a subject of concern in rice consumption. The uncertainty analysis helps improve the accuracy in the risk assessment for Cd in soil-rice system. A regional investigation on Youxian prefecture, southern China, was conducted to analyze the Cd concentration in rice. Based on the species sensitivity distribution model (SSD), health risk assessment model, and Monte Carlo simulation, the accumulation characteristic of Cd in soil-rice system, accumulation risk of Cd in soil, and health risk of Cd concentration in rice were determined. The results showed that the plant uptake factor (PUF) of Cd of rice was well fitted by the SSD model. The mean level of PUF was 1.86, with a significant spatial heterogeneity. The rice produced in WL county tended to accumulate a high level of Cd. There was no significant relationship between concentrations of Cd in soil and rice, suggesting that of rice renders the Cd risk management very difficult. The pollution load index of Cd in soil was 2.4, which belonged to a moderate contamination level. Under current accumulation condition of Cd in soil, there would be a 90.4% probability for soil Cd concentration to be higher than the national soil quality standard after 10 years. Health risk assessment showed that the average daily dose (ADD) was 2.9 µg·(kg·d)-1, 3.5 fold higher than the WHO limit. About 93.9% of the adult populations consuming rice cropping in affected areas had the risk that the daily Cd intake was above the WHO limit. The health risk index (HRI) was around 2.1 to 4.7. The probability for health risk index (HRI) higher than 5 was 21.5%, suggesting a high health risk. When the soil pH was lower than 5.5, the probability for HRI higher than 1 was 95.3%, and when the soil pH was higher than 6, the probability for HRI higher than 1 reduced to 68.1%. An improved management of soil pH values would be needed for a better and safer rice production. The combination of uncertainty analysis, species sensitivity model and health risk assessment model was validated to be feasible and reliable in the risk analysis.

[Effects of Rice Cultivar and Typical Soil Improvement Measures on the Uptake of Cd in Rice Grains].

Cadmium pollution of rice is a big problem in agricultural food safety. The accident "Cd rice" occurred last year in Youxian County, Hunan Province caused serious social panic. In this study, trials on "Cd rice" controlling techniques specific to the Cd pollution in paddy soil in Youxian were investigated. It was suggested that the average Cd contents in rice grains of the rice variety "Zhu Liang You 06" in Datongqiao and Wangling were 0.167 and 0.127 mg x kg(-1), respectively, which were only equal to 20% of the contents of other varieties. The trials for stabilizing agents revealed that treatments of lime and mineral fertilizer decreased Cd contents in rice grains to 20-30% of the control. Plastic film-mulched treatment decreased the rice grain Cd to 50%. And combined treatment of plastic film-mulched and biochar and silicon foliar-fertilizer decreased 80% of rice Cd content. Single treatments of silicon foliar-fertilizer and combined treatment of silicon foliar-fertilizer and topdressing fertilizer decreased more than 90% of Cd content. Results of BCR revealed that the percentage of cationic exchangeable and/or carbonate associated Cd fraction was more than 55% for most of the soil samples. Lime treatment significantly decreased the percentage of cationic exchangeable and/or carbonate and oxides of Fe and Mn associated Cd and increased the crystalline structure of clay minerals associated Cd. The change rate reached about 20%. Our results suggested concentration of soil Cd and pH were the two significant factors impacting the uptake of Cd by rice grains.

[Urban ecological risk assessment: a review].

With the development of urbanization and the degradation of urban living environment, urban ecological risks caused by urbanization have attracted more and more attentions. Based on urban ecology principles and ecological risk assessment frameworks, contents of urban ecological risk assessment were reviewed in terms of driven forces, risk resources, risk receptors, endpoints and integrated approaches for risk assessment. It was suggested that types and degrees of urban economical and social activities were the driven forces for urban ecological risks. Ecological functional components at different levels in urban ecosystems as well as the urban system as a whole were the risk receptors. Assessment endpoints involved in changes of urban ecological structures, processes, functional components and the integrity of characteristic and function. Social-ecological models should be the major approaches for urban ecological risk assessment. Trends for urban ecological risk assessment study should focus on setting a definite protection target and criteria corresponding to assessment endpoints, establishing a multiple-parameter assessment system and integrative assessment approaches.

[Sources and spatial distribution of typical heavy metal pollutants in soils in Xihu Scenic Area].

Due to the importance as a famous scenic area in China and its special geographical position, heavy metal pollution in soils in Xihu Scenic Area has attracted great concerns. Typical heavy metals in surface soils (0- 20 cm) in Xihu Scenic Area was investigated using the grid sampling method and statistical analysis and Aregis approaches. It was suggested that there were anthropogenic accumulations of Cu, Zn and Pb in soils, and they were the main heavy metal pollutants in Xihu Scenic Area. The contents of Cu, Zn, Pb in soils are in the ranges of 4.6-197 mg x kg(-1), 11.1-885 mg x kg(-1) and 11.7-346 mg x kg(-1), respectively. The area with the highest 25% of Cu, Pb and Zn content located in the north-east part of the scenic area, which had lower ratios of green land, dense traffic roads and was characterized with high urbanization. Results of multiple comparison among different land uses and spatial cluster and outlier analysis revealed that those three main heavy metal pollutants Cu, Pb and Zn in Xihu Scenic Area were from traffic emissions. The purpose of this study was to provide basic data and theoretical bases for the ecological risk assessment of heavy metals in urban soils and environmental management of urban soils.

[Correlation between atmospheric PM2.5 concentration and meteorological factors during summer and autumn in Beijing, China].

Based on the monitoring data from 1st July to 31th October, 2008 and 2009 at the Beijing urban ecosystem research station, correlations between PM2.5 concentration and 6 meteorological factors were analyzed, including temperature, relative humidity, wind speed, vapour pressure, atmospheric pressure and wind direction. Main results showed that the dynamics of PM2.5 concentration displayed an obvious fluctuation cycle every 6 weeks, while few changes happened within one week. The highest variation in weekly average of PM2.5 concentration happened during the third 6 weeks, followed by the first 6 weeks, and the lowest variation occurred in the second 6 weeks. Correlation analysis suggested that the weekly average of PM2.5 concentration was significantly correlated with all the 6 meteorological factors, and its correlation with the vapour pressure was the greatest. Results presented in this study confirmed that the weekly average of PM2.5 concentration between Ju- ly and August in Beijing could be estimated by the vapour pressure. The research would benefit the analysis and regulation of the pollution source of PM2.5 in Beijing.

[Effects of reclaimed water recharge on groundwater quality: a review].

Reclaimed water recharge to groundwater is an effective way to relieve water resource crisis. However, reclaimed water contains some pollutants such as nitrate, heavy metals, and new type contaminants, and thus, there exists definite environmental risk in the reclaimed water recharge to groundwater. To promote the development of reclaimed water recharge to groundwater and the safe use of reclaimed water in China, this paper analyzed the relevant literatures and practical experiences around the world, and summarized the effects of different reclaimed water recharge modes on the groundwater quality. Surface recharge makes the salt and nitrate contents in groundwater increased but the risk of heavy metals pollution be smaller, whereas well recharge can induce the arsenic release from sedimentary aquifers, which needs to be paid more attention to. New type contaminants are the hotspots in current researches, and their real risks are unknown. Pathogens have less pollution risks on groundwater, but some virus with strong activity can have the risks. Some suggestions were put forward to reduce the risks associated with the reclaimed water recharge to groundwater in China.

[Accumulation characteristics of arsenic in suburban soils of Beijing].

Various land uses and enormous environmental pressures are characteristics of suburbs. Full understanding of suburban soil pollution is necessary for urban planning and development. In this study, 167 surface soil samples (0-20 cm) located in suburbs of Beijing between the fifth and sixth ring road were collected based on the 3 km x 3 km grids. The purpose of our investigation is to reveal the accumulating characteristics of As in Beijing suburbs. Results showed that arsenic contents in suburban soils of Beijing ranged from 2.89 mg x kg(-1) to 11.38 mg x kg(-1), with mean of 7.11 mg x kg(-1). The means were in the range of the background values reported in late 1990s, but the values of each quantile were lower than the soil background values reported in early 1980s. Factor analysis suggested that As in Beijing suburban soil shared the same group as those elements coming from parent materials such as Co, Mn and Ni. The spatial distribution map using Kriging interpolation showed that As contents in northwestern, eastern and southeastern parts were higher than those in northeastern and southwestern parts. Those plots with contents of the highest 25% were all located near the pollution sources, while most of those with the lowest 25% contents located far from the pollution sources. Comparison of As contents in different land uses showed that human activities had influence on the accumulation of As in soils. Inhabitation areas and agricultural fields had higher As contents than the green lands and vacant lands. Pollution sources significantly affected the accumulation of As in soils of inhabitation areas, green lands and vacant lands. Arsenic contents in soils near factories were significantly higher than those far from factories and traffic corridors. To sum up, the spatial distributions of As contents in soils in Beijing suburban area were generally determined by the distributions of parent materials, while human activities increased the accumulation of As in soils to some degree.