The chemical accident in Schonebeck - An assessment of health and environmental risks

Travelling from Belgium to the BUNA works in Schkopau, ten of eighteen tank wagons filled with vinyl chloride (VC) derailed on the Magdeburg Halle rai lway line just outside Schonebeck station. One wagon exploded and four othe rs went up in flames. Buildings and trees in gardens located in the immedia te vicinity of the track caught fire and burned, Four owners of garden plot s suffered burns. A total of 28 people received inpatient treatment in a ne arby hospital, another 268 people were treated as outpatients. The typical symptoms of fume poisening such as headache, nausea, irritations of respira tory tract and eyes were the primarily diagnosed problems. The vegetation w as damaged by flue gases and developing HCl causing fire and caustic burns. Fire brigades and special task forces succeeded to control the looming dan ger of health and environmental hazards by cooling the burning wagons and p umping the liquid gases from the tank wagons. Vinyl chloride which was released over several days was measured in residen tial areas to be 0.06-8 ml/m(3) air. Vinyl chloride is a gas which is heavi er than air. When exposed to light it will be degraded within a few days. A technical guide concentration of 3 ml/m(3) air has been adopted for its ca ncerogenic potential. Dioxin values measured in soils and plants were in the natural range of 20 ng I-TE/kg DS. These values increased to 8300 ng at the very seat of the fi re only. With the water used for fire fighting vinyl chloride penetrated in to the groundwater revealing values of up to 73 mg/litre. A total of 292 ur ine samples taken from patients and members of the rescue forces, residents a nd a control group were tested for their contents of the VC metabolite t hiodiacetic acid. However, this number does not allow to draw any conclusio ns with regard to a potential increase in the risk of cancer. With 0.27, 0. 43 and 0.37 mg/litre of urine, the mean values are in the normal range for unexposed people. Only three cases showing values of up to 3.1 mg/litre ind icated that a real exposure had taken place. The environmental and health authorities have evaluated the results of the measurements at site. They had set up a consultancy service and were integr ated in civil forums. When the project "Extension of the vinyl chloride pla nt" for PVC production at Buna Sow Leuna Olefinverbund GmbH will be complet ed, deliveries of vinyl chloride by rail and road will be unnecessary in fu ture. However, the problem of transporting dangerous goods and a complex tr aining of task forces will continue to be of topical importance.