The lindane legacy

A meeting took place recently in Bilbao in the Basque country, Spain, where lindane production plants left 33 severely contaminated sites and over 5,000 tonnes of hexachlorocyclohexane (HCH) to be disposed of. Scientists, engineers and policy makers from 24 countries gathered for the 5th HCH and Pesticides Forum to learn and discuss disposal and management techniques. Mark Davis reports.

Protesters outside the 5th HCH and Pesticides Forum meeting campaigning against lindane

Outside the conference local campaigners wearing skeleton masks and acting out death from chemical releases protested about the authority's choice of methods for dealing with the waste chemicals and contaminated soil.
    HCH is a chemical cocktail of several isomers (variations on the chemical structure) which have been used for many years as insecticides. The most widely used, and the only one still in widespread use, is the gamma-HCH isomer which is also commonly known as lindane. The alpha, beta and delta isomers have largely been banned and are not intentionally manufactured, although in producing gamma-HCH small amounts of the other isomers are always produced.

The safety cell
Bilbao hosted two HCH production companies which operated between 1947-87.  After their closure 77,000 tonnes of contaminated soil and chemicals in 33 uncontrolled dumps, as well as 5,000 tonnes of pure HCH were left for the authorities to deal with.
    The method chosen for the uncontrolled dumps was to construct a sealed 'safety cell' at Bilbao Airport to which their contents would be transferred. The cell consists of several layers of under-seal and over-seal, leachate collection and processing and a landscaped surface. 113,000 m³ of contaminated soil were transferred and have now been sealed in the cell. 
    Local campaign group Herri Batasuna complains that the project has no adequate environmental impact assessment, there has been insufficient public consultation and no public agreement, and that the site is at risk from aircraft crashes and there is no emergency plan in place to deal with such an incident. The organisation is also unhappy about the planned Brakaldo safety cell which will contain additional 300,000 m³ of contaminated soil from 13 uncontrolled dumps.
    Vice Minister of the Environment for the Basque government, Esther Larrañaga said that after years of debate and inaction, decisions had to be taken. Any decision would have its critics, but they believed that the controlled landfill option and the sites chosen were the most appropriate.

HCH recycling
While the safety cells provide a solution for the uncontrolled dumps and contaminated soil, a different and equally controversial solution has been developed for the 5,000 tonnes of pure HCH left by Bilbao Chemical. Rather than burying or destroying the chemicals, the authorities have chosen to commission a plant to recycle it.
    On the site of a former HCH manufacturing plant, close to residential buildings and main roads, a plant is being constructed for the specific purpose of turning 5,000 tonnes of HCH into trichloro-benzene which has a commercial value as an intermediate in the manufacture of other chemical products. Once the reprocessing is complete the plant will be dismantled and sold. The buildings will be demolished, and together with the contaminated soil on which they stand will be landfilled in one of the safety cells.
    The process may be as safe as its enthusiastic implementers claim, or as risky as the protesters declare, but one wonders at the wisdom of locating such a facility in an urban environment, and whether the effort and expense of developing and constructing the plant can be justified.

5th HCH Pesticides Forum
The Basque country has a legacy of highly toxic waste to deal with. And they are not alone, as the HCH and Pesticides Forum heard. Poland has an estimated 60,000 tonnes of obsolete pesticides many of which are leaking into the soil and ground water from corroding concrete storage bunkers. The Netherlands has between  200,000-400,000 contaminated sites which will cost up to US$50 billion to clean up. In fact it is estimated that there is one polluted site for every 30-50 inhabitants in the industrialised countries.
    A large and highly technical industry is evolving rapidly to provide solutions to these problems. The techniques on offer include secure landfill, incineration, bioremediation, chemical and physical soil treatment and some novel experimental techniques.
    The box (below) describes the benefits and drawbacks to these technologies. The materials used to seal landfill sites may deteriorate with time allowing the contaminants to leak into the surrounding soil and water; incineration may create and release highly toxic dioxins and furans or other pollutants; bioremediation is too slow and specific, and soil washing does not completely clean the soil.
    Equally important are the questions of who pays for the clean-up and how can similar problems be prevented in the future? To its credit, the 5th HCH and Pesticides Forum addressed prevention by inviting Chiquita bananas to present their Integrated Production Management system in Costa Rica, Brazil to present its replacement and reduction of pesticide use in disease vector control, and the European Commission to present its Progressive Pest Management strategy developed by the Pesticides Trust [now PAN UK].
    The next Forum meeting will be held in Poland in the year 2000. As problems are being solved in the North will we continue to see similar problems of contamination and toxic waste expanding in the South? The future must look rosy for toxic waste handling and site decontamination contractors. (MD)

 [This article first appeared in Pesticides News No. 41, September 1998, pages 6-7]