HCH and lindane contaminated sites: European and global need for a permanent solution for a long-time neglected issue.

During the last 70 years 1, 2, 3, 4, 5, 6-Hexachlorocyclohexane (HCH) has been one of the most extensively used pesticides. Only the gamma-isomer has insecticidal properties. For the marketing of gamma-HCH (lindane) the other 85% HCH isomers which are formed as by-products during HCH production had to be separated and became finally hazardous waste. For each tonne of lindane 8-12 tonnes of waste HCH isomers were produced and production of the approximately 600,000 t of lindane has therefore generated 4.8 to 7.2 million tonnes of HCH/POPs waste. These waste isomers were mostly buried in uncontrolled dumps at many sites around the world. The stockpiles and the large contaminated sites can be categorized as "mega-sites". Countries with HCH legacy problems include Albania, Argentina, Austria, Azerbaijan, Brazil, China, Croatia, Czech Republic, France, Germany, Hungary, India, Italy, Japan, Macedonia, Nigeria, Poland, Romania, Russia, Slovakia, South Africa, Spain, Switzerland, Turkey, The Netherlands, UK, Ukraine and the USA. As lindane and alpha- and beta-HCH have been listed as POPs in the Stockholm Convention since August 2010, the problem of stockpiles of HCH waste is now documented and globally acknowledged. This article describes briefly the legacy of HCH and lindane that has been created. Three of the mega-sites are being discussed and demonstrate the increase in pollution footprint over time. Recent developments in the EU (including the Sabinanigo project in Aragon/Spain) and on a global level are presented. A short overview is given on lack of activities and on actions of countries within their obligations as Parties of the Stockholm Convention. Furthermore, current country activities supported by the Global Environment Facility (GEF), the "financing mechanism" of the convention, are listed. Finally, conclusions and recommendations are formulated that will contribute to the solution of this problem over the next 25 years.

Review Article: Persistent organic pollutants and landfills - a review of past experiences and future challenges.

The landfilling and dumping of persistent organic pollutants (POPs) and other persistent hazardous compounds, such as polychlorinated biphenyls (PCBs), hexachlorocyclohaxane (HCH), polybrominated diphenylether (PBDEs) or perfluorooctane sulfonic acid (PFOS) can have significant adverse environmental consequences. This paper reviews past experiences with such disposal practices and highlights their unsustainability due to the risks of contamination of ecosystems, the food chain, together with ground and drinking water supplies. The use and associated disposal of POPs have been occurring for over 50 years. Concurrent with the phase-out of some of the most hazardous chemicals, the production of new POPs, such as brominated and fluorinated compounds has increased since the 1990s. These latter compounds are commonly used in a wide range of consumer goods, and as consumer products reach the end of their useful lives, ultimately enter waste recycling and disposal systems, in particular at municipal landfills. Because of their very slow, or lack of degradability, POPs will persist in landfills for many decades and possibly centuries. Over these extended time periods engineered landfill systems and their liners are likely to degrade, thus posing a contemporary and future risk of releasing large contaminant loads to the environment. This review highlights the necessity for alternative disposal methods for POP wastes, including destruction or complete removal from potential environmental release. In addition to such end of pipe solutions a policy change in the use pattern of persistent toxic chemicals is inevitable. In addition, inventories for the location and quantity of POPs in landfills, together with an assessment of their threat to ecosystems, drinking water and food resources are identified as key measures to facilitate appropriate management of risks. Finally the challenges of POP wastes in transition/developing countries, the risk of increased leaching of POPs from landfills due to climate change, and the possible negative impact of natural attenuation processes are considered.

Hexachlorocyclohexane (HCH) as new Stockholm Convention POPs--a global perspective on the management of Lindane and its waste isomers.

PURPOSE: Hexachlorocyclohexane (HCH) isomers (α-, ß- and γ- (Lindane)) were recently included as new persistent organic pollutants (POPs) in the Stockholm Convention, and therefore, the legacy of HCH and Lindane production became a contemporary topic of global relevance. This article wants to briefly summarise the outcomes of the Stockholm Convention process and make an estimation of the amount of HCH waste generated and dumped in the former Lindane/HCH-producing countries. RESULTS: In a preliminary assessment, the countries and the respective amount of HCH residues stored and deposited from Lindane production are estimated. Between 4 and 7 million tones of wastes of toxic, persistent and bioaccumulative residues (largely consisting of alpha- (approx. 80%) and beta-HCH) are estimated to have been produced and discarded around the globe during 60 years of Lindane production. For approximately 1.9 million tones, information is available regarding deposition. Countries are: Austria, Brazil, China, Czech Republic, France, Germany, Hungary, India, Italy, Japan, Macedonia, Nigeria, Poland, Romania, Slovakia, South Africa, Spain, Switzerland, Turkey, The Netherlands, UK, USA, and former USSR. The paper highlights the environmental relevance of deposited HCH wastes and the related POPs' contaminated sites and provides suggestions for further steps to address the challenge of the legacy of HCH/Lindane production. CONCLUSION: It can be expected that most locations where HCH waste was discarded/stockpiled are not secured and that critical environmental impacts are resulting from leaching and volatilization. As parties to the Stockholm Convention are legally required to take action to stop further POPs pollution, identification and evaluation of such sites are necessary.

Dioxin- and POP-contaminated sites--contemporary and future relevance and challenges: overview on background, aims and scope of the series.

BACKGROUND, AIM AND SCOPE: Once they have been generated, polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) and other persistent organic pollutants (POPs) can persist in soils and sediments and in waste repositories for periods extending from decades to centuries. In 1994, the US EPA concluded that contaminated sites and other reservoirs are likely to become the major source of contemporary pollution problems with these substances. With this in mind, this article is the first in a new series in ESPR under the title 'Case Studies on Dioxin and POP Contaminated Sites--Contemporary and Future Relevance and Challenges', which will address this important issue. The series will document various experiences from sites contaminated with PCDD/F and other POPs. This article provides an overview of the content of the articles comprising the series. In addition, it provides a review of the subject in its own right and identifies the key issues arising from dioxin/POP-contaminated sites. Additionally, it highlights the important conclusions that can be drawn from these examples. The key aim of this article and of the series as a whole is to provide a comprehensive overview of the types of PCDD/F contaminated sites that exist as a result of historical activities. It details the various processes whereby these sites became contaminated and attempts to evaluate their contemporary relevance as sources of PCDD/Fs and other POPs. It also details the various strategies used to assess these historical legacies of contamination and the concepts developed, or which are under development, to effect their remediation. MAIN FEATURES: Special sessions on 'Contaminated sites--Cases, remediation, risk and policy' were held at the DIOXIN conferences in 2006 and 2007, and this theme will be continued at DIOXIN 2008 to be held in Birmingham. Selected cases from the approximately 70 contributions made to these sessions, together with some additional invited case studies are outlined together with the key issues they raise. By evaluating these cases and adding details of experiences published in the current literature, an overview will be given of the different features and challenges of dioxin and POP-contaminated sites. RESULTS: This article provides a systematic categorisation of types of PCDD/F and POP-contaminated sites. These are categorised according to the chemical or manufacturing process, which generated the PCDD/Fs or POPs and also includes the use and disposal aspects of the product life cycle in question. The highest historical PCDD/F and dioxin-like polychlorinated biphenyl (PCB) contamination burdens have arisen as a result of the production of chlorine and of chlorinated organic chemicals. In particular, the production of chlorinated pesticides, PCBs and the related contaminated waste streams are identified being responsible for historical releases of toxic equivalents (TEQs) at a scale of many tonnes. Along with such releases, major PCDD/F contaminated sites have been created through the application or improper disposal of contaminated pesticides, PCBs and other organochlorine chemicals, as well through the recycling of wastes and their attempted destruction. In some extreme examples, PCDD/F contaminated sites have also resulted from thermal processes such as waste incinerators, secondary metal industries or from the recycling or deposition of specific waste (e.g. electronic waste or car shredder wastes), which often contain chlorinated or brominated organic chemicals. The examples of PCDD/F and dioxin-like PCB contamination of fish in European rivers or the impact of contaminated sites upon fishing grounds and upon other food resources demonstrate the relevance of these historical problems to current and future human generations. Many of the recent food contamination problems that have emerged in Europe and elsewhere demonstrate how PCDD/F and dioxin like PCBs from historical sources can directly contaminate human and animal feedstuffs and indeed highlight their considerable contemporary relevance in this respect. Accordingly, some key experiences and lessons learnt regarding the production, use, disposal and remediation of POPs from the contaminated sites are summarised. DISCUSSION: An important criterion for evaluating the significance and risks of PCDD/Fs and other POPs at contaminated sites is their present or future potential for mobility. This, in turn, determines to a large degree their propensity for off-site transport and environmental accessibility. The detailed evaluation of contaminated site cases reveals different site-specific factors, which influence the varied pathways through which poor water-soluble POPs can be mobilised. Co-contaminants with greater water solubility are also typically present at such sites. Hence, pumping of groundwater (pump and treat) is often required in addition to attempting to physically secure a site. At an increasing number of contaminated sites, securing measures are failing after relatively short time spans compared to the time horizon, which applies to persistent organic pollutant contamination. Due to the immense costs and challenges associated with remediation of contaminated sites 'monitored natural attenuation' is increasingly gaining purchase as a conceptual remediation approach. However, these concepts may well prove limited in their practical application to contaminated sites containing persistent organic pollutants and other key pollutants like heavy metals. CONCLUSIONS: It is inevitable, therefore, that dioxin/POP-contaminated sites will remain of contemporary and future relevance. They will continue to represent an environmental issue for future generations to address. The securing and/or remediation of dioxin/POP-contaminated sites is very costly, generally in the order of tens or hundreds of millions of dollars. Secured landfills and secured production sites need to be considered as constructions not made for 'eternity' but built for a finite time scale. Accordingly, they will need to be controlled, supervised and potentially repaired/renewed. Furthermore, the leachates and groundwater impacted by these sites will require ongoing monitoring and potential further remediation. These activities result in high maintenance costs, which are accrued for decades or centuries and should, therefore, be compared to the fully sustainable option of complete remediation. The contaminated site case studies highlight that, while extensive policies and established funds for remediation exist in most of the industrialised western countries, even these relatively well-regulated and wealthy countries face significant challenges in the implementation of a remediation strategy. This highlights the fact that ultimately only the prevention of contaminated sites represents a sustainable solution for the future and that the Polluter Pays Principle needs to be applied in a comprehensive way to current problems and those which may emerge in the future. RECOMMENDATIONS AND PERSPECTIVES: With the continuing shift of industrial activities in developing and transition economies, which often have poor regulation (and weak self-regulation of industries), additional global challenges regarding POPs and other contaminated sites may be expected. In this respect, a comprehensive application of the "polluter pays principle" in these countries will also be a key to facilitate the clean-up of contaminated areas and the prevention of future contaminated sites. The threats and challenges of contaminated sites and the high costs of securing/remediating the problems highlight the need for a comprehensive approach based upon integrated pollution prevention and control. If applied to all polluting (and potentially polluting) industrial sectors around the globe, such an approach will prove to be both the cheapest and most sustainable way to underpin the development of industries in developing and transition economies.