Ecological risk assessment of heavy metal-contaminated soil using the triad approach

Journal of Soils and Sediments - Heavy metal soil-pollution is of concern due to its adverse effects on the ecosystem and human health. However, conventional ecological risk assessments considering...     

锌与磷肥混合方式对土壤中磷、锌有效性的影响

[目的]研究了锌与磷肥分别以物理混合和反应混合的方式结合后施用对土壤中锌、磷有效性的影响,为磷肥与锌肥的科学配施及高效利用提供科学依据.[方法]将锌肥(ZnSO4·7H2O)分别按0.5％和5％的质量比与磷酸氢二钾进行物理混合(P+Zn)和反应混合(PZn)后,制备含锌磷肥分别为P+Zn0.5、P+Zn5、PZn0.5...     

利用整体分析法研究华北地区奶牛产业温室气体排放

为了研究奶牛产业生产效率对温室气体排放的影响,对单位牛奶产量所产生的温室气体(甲烷、氧化亚氮和二氧化碳)进行科学的评估是非常重要的。在该研究中,利用整体分析方法评估了2012年华北地区奶牛产业的总温室气体排放以及单位牛奶的温室气体排放。估算的排放源包括奶牛胃肠道发酵以及粪便管理系统产生的温室气体(greenhouse gas,GHG)排放、奶牛饲养过程中耗能所带来的GHG排放、饲养奶牛所需作物种植管理过程中以及所需农业机械设备制造所产生的GHG排放、化学肥料生产和施用所来的GHG排放。估算方法采用政府间气候变化专门委员会(IPCC,Intergovernmental Panel on Climate Change)评估报告中的方法学以及相关文献的研究成果。研究结果表明:在华北地区奶牛产业系统中总温室气体排放量为22437.85×103t。甲烷(CH4)是主要的排放源,为8516.53×103 t,其中奶牛胃肠道排放占84%,粪便管理系统占16%;氧化亚氮(N2O)排放为6240.27×103 t,二氧化碳(CO2)排放为7681.05×103 t。基于排放强度,得出单位牛奶的平均温室气体排放量为1.3 kg/kg。     

Proposed assessment of the vulnerability of European soils to pollution using a soter shell approach

After recent unanticipated occurrences of environmental pollution caused by the time-delayed and sudden release of contaminants previously believed to be held firmly in soils, awareness has increased that the vulnerability of soils to chemical degradation needs to be assessed and mapped. Although some soils appear to be capable of receiving and holding chemical compounds while at the same time retaining their ecological functions, others are readily damaged. Procedures for identifying areas where vulnerable soils occur are presented, with special reference to the minimum soil data sets that would be required in a small scale study at the European level using geographical information systems. These data can readily be compiled, stored and processed with the relational database management system developed for SOTER, The 1:1 million world soil and terrain digital database project of the International Society of Soil Science, which is co-ordinated by the International Soil Reference and Information Centre. the proposed initial soil vulnerability programme would essentially serve to increase awareness about areas prone to chemical soil degradation, and will form the basis for implementing soil pollution assessment programmes at larger scales (1:1 M to 1:250 000). the latter national or regional programmes would include the identification of the major sources of soil pollution, and measurement of the accumulated load and the rate of loading according to uniform and standardized procedures, providing the conceptual basis for developing process based models to assess where particular types of soil degradation are likely to occur.     

基于多作物中吡唑醚菌酯的环境行为评估长期膳食风险

农药环境行为及其风险评估是农产品质量安全与生态健康领域重点关注问题,为明确典型农用化合物吡唑醚菌酯在农作物中的行为特征及其暴露风险差异,该研究结合中国农作物主产区分布,运用确定性和概率性双风险模型评估吡唑醚菌酯长期膳食风险,结果表明,吡唑醚菌酯在小麦、花生、黄瓜和西瓜上的原始沉积量高达0.209 mg/kg,半衰期为1.9～9.9 d。作物秸秆中的残留浓度（0.187～75.291 mg/kg）远大于籽粒（≤0.096 mg/kg）。通过膳食途径造成的吡唑醚菌酯暴露会对消费人群造成不可接受的慢性风险,风险商值为123.959%～406.415%。城镇人群的风险显著大于乡村人群（P<0.05）,且风险商值随年龄的递增而降低。概率性模型被进一步引入以量化风险评估的不确定性。该研究根据多作物中吡唑醚菌酯残留水平的概率分布,预警其存在高潜在的长期膳食暴露风险。乡村儿童群体的摄入风险明显高于其他群体,需重点关注。     

辣椒中氟吗啉残留消解动态及膳食风险评估

为研究氟吗啉在辣椒中的残留消解情况及对居民的膳食摄入风险,本文采用高效液相色谱-串联质谱法测定氟吗啉在辣椒上的残留量,分析其消解动态规律。结果显示,氟吗啉在辣椒中的消解动态符合一级反应动力学方程,在浙江和湖南2个试验点的半衰期分别为3.4、 4.1 d。氟吗啉在辣椒中的长期膳食摄入风险商为0.013 8%;在所有登记作物中的总膳食摄入风险商为4.721 9%。膳食风险评估结果表明,氟吗啉在辣椒中的残留对人群膳食风险在可接受范围内,按照推荐使用剂量、喷药次数及安全间隔期在辣椒上施用50%锰锌-氟吗啉可湿性粉剂,辣椒中的氟吗啉残留不会影响我国居民身体健康。     

戊唑醇在猕猴桃中的残留行为及膳食摄入风险评估

采用超高效液相色谱-串联质谱方法研究了戊唑醇在猕猴桃中的消解动态及最终残留水平,并对我国不同人群的长期膳食摄入风险进行了评估。在0.01、 0.10、 1.00和2.00 mg/kg添加水平下,戊唑醇在猕猴桃中的平均回收率为89%～114%,相对标准偏差范围为0.6%～8.2%,定量限为0.01 mg/kg。消解动态结果表明,戊唑醇在猕猴桃上的消解速率符合一级反应动力学方程,半衰期为2.6～6.3 d。在安全间隔期14 d时,猕猴桃中戊唑醇残留中值为0.510 mg/kg,结合我国戊唑醇登记情况和居民膳食结构,计算得到一般人群戊唑醇的估算日摄入量是0.387 48 mg,占ADI的20.5%。不同年龄段人群中长期膳食摄入风险随年龄的升高呈下降趋势。25%戊唑醇可湿性粉剂按有效成分62.5～100 mg/kg剂量,施药2次,安全间隔期为14 d时,戊唑醇在猕猴桃中的残留不会对我国不同年龄段人群健康产生不可接受的风险。     

Evaluation of soil fertility under different Cupressus chengiana forests using multivariate approach

The distribution and growing conditions of Cupressus chengiana forests along with the physical and chemical properties of soils in Northwest Sichuan were studied in 2002 to investigate the conditions and characteristics of soil fertility of C. chengiana and to compare and investigate differences of soil fertility for six C. chengiana populations and their relationships with vegetation, climate and disturbance. The results of the study at 0-20 cm soil depth showed that 1） significant differences （P〈0.05） existed among populations for soil bulk density, soil total porosity, capillary porosity, maximum water-holding capacity, capillary water-holding capacity and topsoil natural water content; 2） chemical characteristics of soil organic matter, total N, total P, alkali-hydrolyzable N, available P, available K and cation exchange capacity were significantly different among the populations; and 3） based on the significant effect of soil fertility factors on forest growth, soil physical and chemical characteristics could be selected as an integrated fertility index （IFI） for evaluation of different C. chengiana populations. Principal component and cluster analyses showed significant differences probably due to the difference of vegetation conditions, management measurements, human-induced disturbances and environmental factors. In order to protect the soil ecological functions in fragile ecological regions, C. chengiana could be used in programs enclosing the hill for natural afforestation, natural forest protection programs, and programs replacing agriculture with afforestation measures.     

Li-cor仪器太阳辐射测量单位定量变换的应用研究

因研究的角度不同,辐射研究结果有能量、亮度、量子数等方面的量纲,实践中不同单位之间换算很有必要。该文研究了太阳辐射测定中几个单位的定量变换方法,得出了相应的变换系数;并实测了植物冠层上和冠层内太阳辐射,并对单位变换系数进行了检验,结果表明：在冠层上,单位变换差异晴天仅为7%,阴天为2%,处在仪器测定辐射的相对误差范围内;在植物冠层内,线状辐射仪和辐照度仪同时采样,以线状辐射仪测得结果为基准,相同时刻辐照度仪测得结果经换算成辐射量子流密度单位后,与线状辐射仪对比差异全天平均达25%,远大于冠层上;光斑作用使LI－200辐照度仪在群体内测光产生较大误差。除中午辐射最大值,光斑最多时段以外,线状传感器能消除光斑的影响。     

A comparison of four dietary assessment methods in materially deprived households in England

OBJECTIVES: Low-income households in the UK concentrate factors associated with poor record-keeping such as lower literacy, numeracy and English language skills. The present study aimed to (1) compare the validity and acceptability of three dietary survey methods against appropriate reference measures and (2) identify a method which was both valid and acceptable in low-income households. DESIGN: Cross-sectional design comparing three 4-day dietary survey methods (multiple-pass 24-hour recall, food checklist and semi-weighed method) against a 4-day weighed inventory and other reference measures within subjects. SETTING: London, UK, 2001. SUBJECTS: Low-income households were selected using a doorstep screening questionnaire in 18 of the 60 most deprived neighbourhoods in London. Results are based on 384 respondents (159 males, 225 females) aged 2-90 years in 240 households. Respondents were mainly White (48%), Black or Black British (31%) or Asian or Asian British (9%). RESULTS: The dietary survey method preferred by interviewers was the 24-hour recall. Most respondents preferred the food checklist. Compared with the weighed inventory, repeat 24-hour recalls and the food checklist yielded higher estimates of energy and nutrient intakes. The semi-weighed method was least liked and yielded the lowest estimates of intake. CONCLUSIONS: Based partly on evidence presented here and partly on evidence to be presented in later publications, four multiple-pass 24-hour recalls were recommended as the most appropriate method for a national study of diet and nutrition in low-income households in the UK.     

An assessment of inter-rater agreement of the literature filtering process in the development of evidence-based dietary guidelines

OBJECTIVE: To determine whether the literature filtering process, a vital initial component of a systematic literature review, could be successfully completed by nutrition professionals or non-professionals. DESIGN: Using a diet-disease relationship as the guideline topic, inter-rater agreement for the title and abstract filtering processes between and among professionals and non-professionals was assessed and compared with an expert reference standard. Predetermined eligibility criteria were applied by all raters to 185 titles and 90 abstracts. Filtering decisions were initially made independently and then revised after a within-pair consensus meeting. SUBJECTS: The raters were six dietitians (RD) and six nutrition graduate students (Grad). To assess inter-rater agreement (reliability), each group was divided into three pairs. RESULTS: Weighted and unweighted kappa statistics and percentage agreement were calculated to determine the inter-rater agreement within pairs. Sensitivity and specificity estimates were determined by comparing responses with those of an expert reference standard. Overall, Grad pairs demonstrated greater inter-rater agreement than RD pairs for title filtering (P<0.05); no differences were observed for abstract filtering. Compared with the expert reference standard, every rater and pair had false-negative responses for both title and abstract filtering. CONCLUSIONS: After consensus meetings, both RDs and Grads were comparable in their agreement on title and abstract filtering, although important differences remained compared with the expert reference standard. This study provides preliminary findings on the value of utilising a non-expert pair in developing guidelines, and suggests that the literature filtering process is complex and quite subjective.     

A coherent geostatistical approach for combining choropleth map and field data in the spatial interpolation of soil properties

Information available for mapping continuous soil attributes often includes point field data and choropleth maps (e.g. soil or geological maps) that model the spatial distribution of soil attributes as the juxtaposition of polygons (areas) with constant values. This paper presents two approaches to incorporate both point and areal data in the spatial interpolation of continuous soil attributes. In the first instance, area-to-point kriging is used to map the variability within soil units while ensuring the coherence of the prediction so that the average of disaggregated estimates is equal to the original areal datum. The resulting estimates are then used as local means in residual kriging. The second approach proceeds in one step and capitalizes on: 1) a general formulation of kriging that allows the combination of both point and areal data through the use of area-to-area, area-to-point, and point-to-point covariances in the kriging system, 2) the availability of GIS to discretize polygons of irregular shape and size, and 3) knowledge of the point-support variogram model that can be inferred directly from point measurements, thereby eliminating the need for deconvolution procedures. The two approaches are illustrated using the geological map and heavy metal concentrations recorded in the topsoil of the Swiss Jura. Sensitivity analysis indicates that the new procedures improve prediction over ordinary kriging and traditional residual kriging based on the assumption that the local mean is constant within each mapping unit.     

Multivariate approach to evaluate the penetrometer resistance in different tillage systems

At present, the penetrometer is the most widely used instrument for assessing in situ soil strength, one of the extrinsic factors affecting plant growth and crop productivity. In this paper we propose a method that discriminates penetrometer resistance due to different soil treatments, by means of Principal Component (PC) analysis. We hypothesized and demonstrated that penetrometer resistance values measured at different soil depths are correlated among themselves (multicollinearity). Considering measurements at each depth as different variables, PC analysis restructured data sets containing these correlated variables into a smaller number of components, whose scores were utilized in univariate analysis of variance (ANOVA) to test differences among imposed soil treatments. We applied the procedure to penetrometer resistance values measured by means of a hand-held cone penetrometer in two long-term experiments conducted in southern Italy, on durum wheat (Triticum durum Desf.) under continuous cropping. In the first trial, four different soil tillage treatments were compared; in the second, two different tillages and two residue management systems were examined. In both trials, PC analysis reduced the original 14 depths of measurements into only 4 PC's, based on correlations of their resistance values, explaining more than 80% of the total variation. Furthermore, ANOVA applied to the scores of each PC, clearly indicated treatment effects on soil strength.

The proposed method has thus allowed assemblage a posteriori of penetration resistance data into only a few significative intervals, using correlations among the measurements made at the different depths. This way, the possible resistance differences due to tillage and/or management treatments have been more easily and more unambiguously showed.     

An assessment of the reference watershed approach for TMDLs with biological impairments

The Reference Watershed Approach (RWA) is used in TMDL development for biological and other impairments with narrative water quality criteria. The questions addressed in this research include: (1) With the RWA, how do land use classifications from different data sources (Digital Ortho-Quarter Quads (DOQQ) and National Land Cover Dataset (NLCD)) impact simulated pollutant loadings? (2) With the RWA, what is the impact of alternative water quality models (GWLF and SWAT) on pollutant loadings? (3) With the RWA, how sensitive are simulated pollutant loadings to the use of different reference watersheds? Various combinations of land use, water quality model, and reference watershed resulted in pollutant reductions that ranged from ?13 to 88%. In a comparison of the use of NLCD versus DOQQ-based land use data with the GWLF model, differences in required reductions ranged from 13 to 74% for three different reference watersheds. Use of alternative water quality models with DOQQ land use data resulted in differences in required sediment reductions from ?43 to 8% for the three reference watersheds. Differences in load reduction requirements were also seen when different reference watersheds were used, regardless of the water quality model or the land use source used. With DOQQ land use, required sediment reductions ranged from 18 to 88% and 37 to 82%, for the SWAT and GWLF models, respectively. These results suggest that explicit margins of safety used to account for modeling uncertainties during TMDL development may need to be substantially greater than 20% when using the reference watershed approach.