Comparison of Soil Clean-up Standards for Trace Elements Between Countries: Why do they differ? (9 pages)

Goal, Scope and Background

In the nineteen nineties most European countries issued legislation on soil protection, including soil contamination. In the case of a presumed contamination, soil investigation mostly follows a stepwise approach starting with a preliminary investigation, then an in-depth investigation and, finally, remediation. Soil clean-up standards are often foreseen as trigger criteria to determine the need for an in-depth soil investigation or for remediation. There are however large differences in soil clean-up standards. This is partly because of the different roles of soil clean-up standards in each legislative framework and partly because of differences in the soil clean-up standard (SCS) derivation procedures. Despites these differences there are large similarities in the concepts of the derivation procedures for clean-up standards. A better understanding of the differences in clean-up standards is needed. In order to clarify the variation, the background of the clean-up standards for a selected number of countries was investigated. The objective of this paper is to investigate the underlying reason why country-wide generic soil and groundwater clean-up standards of eight trace elements (cadmium, chromium (III), copper, mercury, lead, nickel, zinc and arsenic) differ between the selected countries.

Main Features

To avoid misinterpretation of the differences in application of the clean-up standards, a short overview of the legislative role of clean-up standards is given first. Differences in model concepts and parameter values are discussed, followed by a comparison of the generic soil and groundwater clean-up standards for trace elements and a discussion on the sources of variation. The influence of the use of ecotoxicological criteria and data for the derivation of soil clean-up standards will be discussed in more detail. Selected countries were Canada, the Flemish Region (Belgium), France, Germany, Great-Britain, the Netherlands, Norway, Sweden, Switzerland and United States of America (USA).

Results and Discussion

When soil clean-up standards for eight trace elements (cadmium, chromium (III), copper, mercury, lead, nickel, zinc and arsenic) were compared between the selected countries differences of more than a factor 1000 arose. Notwithstanding the use of similar derivation procedures, differences were caused by the use of different software models with their specific input data, boundary conditions and applied protection criteria for humans and the ecology. Ecotoxicological criteria tend to lower the soil clean-up standard for the selected trace elements.

Conclusions

In the countries that are included in this study, clean-up standards are used is different ways, this is for the determination of the necessity for remediation or for the need for further soil investigation. This paper shows a wide variation in the clean-up standards, which has further implication on the decision for remediation or further investigation and, hence, the financial costs of soil management. All the clean-up standards have as primary goal the protection of human health. A number of countries also include the protection of the ecological function of the soil. Differences in selected software model, (standard) parameters values, selected human toxicological and ecotoxicological criteria, are reason for a substantial variation in the clean-up standards for trace elements.

Recommendations and Perspective

. Is this variation justified? The derivation of soil clean-up standards involves - besides scientific elements - political elements, like differentiation in landuse types (agricultural, residential, recreational, industrial), receptor at risk or protection level. It is obvious that harmonization of these elements will be complicated. However, a European action programme, like the thematic strategy for soil protection, could initiate this process of harmonization. Nevertheless, soil-clean-up standards could never be uniform over the whole of Europe because they include country specific elements (geographical, ethnological) and political decisions.     

畜禽舍粪污自动处理装置的设计研究

笔者通过试验自主设计了一套畜禽舍粪污自动处理装置,该粪污自动处理装置能够实现自动清理畜禽粪便,并使粪便和秸秆及时进行发酵处理,实现农业废弃物资源化利用,有效解决了农业废弃物资源化浪费等问题。     

浅谈清理取缔土小企业面临的问题和对策

分析了土小企业的定义、危害、现状,探讨了土小企业在清理取缔方面面临的问题,从政策法规、环保意识、监察执法等方面提出了对策。     

应用高效液相色谱法同时测定烟草中6种多酚类化合物

应用高压液相色谱法同时测定了烟草中6种多酚类化合物,该方法采用二极阵列管检测器的3个通道同时采集数据,保证了测试结果的可靠性.使用弱酸性的溶液作流动相,梯度洗脱条件下,6种化合物得到了很好的分离.采用加速溶剂萃取(ASE)仪,在40℃下以含0.5%抗坏血酸的无水甲醇为萃取剂,既避免了多酚的分解,又保证了它们被提取的效率.提取液经过实验室自制净化柱的净化,有效地去除了干扰物对分析测试的影响及提取的亲脂性化合物对分离柱的影响.本试验所述的系列方法回收率高于84%,相对标准偏差低于5%,适于烟草中多酚化合物的测定.     

基于Pro／E局部铣削实现工件清根加工方法的研究

利用Pro／E制造模块中NC功能实现工件的清根加工。分别介绍了按前一步骤、前一刀具、拐角选项实现清根加工的加工工艺，通过加工轨迹可显示各功能的特点。     

食品与环境样本中有机氯农药残留的净化技术研究进展

在查阅大量相关文献并结合作者自身研究工作经验的基础上,根据介质中干扰物的种类和特点,按照不同介质进行分类,重点介绍了填充柱、固相萃取、凝胶色谱、磺化和基质固相分散等净化技术在检测分析水、土壤、沉积物、茶叶、中药以及脂肪性样本中有机氯农药残留中的应用。认为将净化技术与提取技术或分析技术有效结合,提高样品净化效率及整体分析速度将是未来净化技术的主要发展趋势。     

农药残留分析中含油脂及硫化物样品的净化方法

本文通过查阅文献及结合作者的工作实践, 对农药残留分析中含油脂及含硫化物样品的净化方法进行了概述。     

Rehabilitation of Former US Military Lands Bordering the Panama Canal

Summary

The Panamanian government is currently negotiating with the United States to determine the extent of the cleanup of US military bases along the Panama Canal. The withdrawal of the US will be completed December 31, 1999. At present, there is no mechanism to ensure that the US will fund, assist with, or assume liability for environmental hazards left on former US Department of Defense lands. Known contamination consists of unexploded munitions on former firing ranges used by the US Army, Navy, and Air Force. Most of these areas are forested with forests of varying age, type, and structure. Complete cleanup could involve complete deforestation of the former bases and firing ranges. The Nature Conservancy has evaluated the ecology of the lands using their “Rapid Ecological Assessment” protocol. The US plans for the lands to become protected areas with warning signs and jersey barriers to protect the public. Panama wants assurance that future cleanup and potential legal damages will be paid for by the US. This paper attempts to summarize the current situation and recommends a potential strategy to both conserve the most biologically diverse forest while maximizing the level of rehabilitation of the areas. It is based on observations and interviews made during a ten-day trip to the Panama Canal Watershed, as well as on news articles, fact sheets from a peace advocacy organization, and primary sources such as correspondence between the US and Panama and minutes from meetings.     

Quality Criteria for Re-Use of Organotin-Containing Sediments on Land (7 pp)

Background, Aim and Scope   The use of organotin compounds as antifouling agents on ships is prohibited at EU level since 1 July 2003. Because of its persistence, the presence of organotin compounds in harbour sediment will however remain a problem for years. Dumping of dredged sediment in sea is subject to very strict quality criteria, stimulating the exploration of re-use alternatives, such as re-use on land. Within the TBT Clean project (EU LIFE Project 02/ENV/B/341) an assessment framework for re-use of organotin containing treated sediment on land as secondary granular building material was developed. Three scenarios were considered: free re-use on land, re-use above groundwater level with cover layer, and re-use under groundwater level (the latter two scenarios are referred to as restricted re-use). Receptors considered were humans, ecosystem and groundwater. Generic upper concentration limits and sediment leaching limits were calculated. Materials and Methods: Upper concentration limits were calculated with the Vlier-Humaan model. This model allows to calculate soil remediation values according to the Flemish legal framework. The focus of the methodology is the protection of human health, although a check for ecotoxicity was included in the project. The soil remediation value for residential land-use was selected within the scenario for free re-use; for restricted re-use (no direct contact possible), the soil remediation value for industrial land-use was selected. Leaching values were calculated with an analytical soil and groundwater transport model. The reference scenario behind the leaching criteria of the European Landfill Directive was modified to fit the project objectives. Default values for application height and length were used. The point-of-compliance was situated at 20 m distance in the groundwater. Physicochemical properties were taken from literature; sorption characteristics were taken from literature and were measured on 6 treated sediment samples during the project. Plant-uptake values were taken from the literature. Toxicological criteria were taken from EFSA. Results: The assessment framework provided an upper limit (SedUL) and an leaching value (SedLV) for each scenario, expressed as mg/kg dm in the sediment. Criteria were calculated for tributyltin (TBT) and dibutyltin (DBT); too few data were available for monobutyltin (MBT). The SedUL equalled 0.51 mg TBT/kg dm and 0.07 mg DBT/kg dm for free re-use and 195 mg TBT/kg dm and 205 mg DBT/kg dm for restricted re-use (two scenarios). For free re-use the SedLV was only limiting for TBT at Kd of < 2000 l/kg in the sediment. Under re-use above groundwater level with coverage SedLV values ranged from 6.9 – 29 mg TBT/kg dm and from 12 – 33.3 mg DBT/kg dm (Kd ranging from 100 – 10000 l/kg); under re-use below groundwater level SedLV values ranged from 0.007 – 0.77 mg TBT or DBT/kg dm (Kd ranging from 100 – 10000 l/kg). Discussion: Results are subject to large uncertainties because of variation in input data; the model output is sensitive to variation in plant uptake (SedUL for free re-use), Koc or Kd (SedUL for restricted re-use, SedLV for re-use with coverage), Henry's law coefficient (SedUL for restricted re-use); all these parameters show orders of magnitude variation. Conclusions: A feasible and consistent framework for evaluation of the re-use of treated organotin containing sediment was developed. However, the resulting quality criteria are still subject to large uncertainties, due to uncertainties in input data. Recommendations and Perspectives: High-quality data on plant uptake and soil sorption of organotin compounds, the influence of soil properties on these processes, and long-term terrestrial toxicity data are needed to refine the calculations. The quality criteria should be reviewed when these data become available.