[Chemical accident in Schönbeck--an assessment of the risk to health and environment].

Travelling from Belgium to the BUNA works in Schkopau, ten of eighteen tank wagons filled with vinyl chloride (VC) derailed on the Magdeburg-Halle railway line just outside Schönebeck station. One wagon exploded and four others went up in flames. Buildings and trees in gardens located in the immediate vicinity of the track caught fire and burned. Four owners of garden plots suffered burns. A total of 28 people received inpatient treatment in a nearby hospital, another 268 people were treated as outpatients. The typical symptoms of fume poisoning such as headache, nausea, irritations of respiratory tract and eyes were the primarily diagnosed problems. The vegetation was damaged by flue gases and developing HCl causing fire and caustic burns. Fire brigades and special task forces succeeded to control the looming danger of health and environmental hazards by cooling the burning wagons and pumping the liquid gases from the tank wagons. Vinyl chloride which was released over several days was measured in residential areas to be 0.06-8 ml/m3 air. Vinyl chloride is a gas which is heavier than air. When exposed to light it will be degraded within a few days. A technical guide concentration of 3 ml/m3 air has been adopted for its cancerogenic 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 fire only. With the water used for fire fighting vinyl chloride penetrated into the groundwater revealing values of up to 73 mg/litre. A total of 292 urine samples taken from patients and members of the rescue forces, residents and a control group were tested for their contents of the VC metabolite thiodiacetic acid. However, this number does not allow to draw any conclusions 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 indicated 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 integrated in civil forums. When the project "Extension of the vinyl chloride plant" for PVC production at Buna Sow Leuna Olefinverbund GmbH will be completed, deliveries of vinyl chloride by rail and road will be unnecessary in future. However, the problem of transporting dangerous goods and a complex training of task forces will continue to be of topical importance.