A engages in a polluting activity. Following exposure to the polluting effects, the community where A's site is situated suffers an increase in the leukaemia rate of more than 50 per cent.
Is A liable for the damage if medical studies attest that the pollutants emitted from A's site can lead to leukaemia? What is the plaintiffs' burden of proof on the issue of causation? Who is entitled to damages and to what extent?
Who has legal standing and who can be awarded damages, given the fact that the cost of therapeutic treatment is borne by social insurance, or by public authority?
Statistical evidence alone is usually not sufficient to establish causation. It would be sufficient only if the degree of probability shown by the evidence meets the level of certainty required by the relevant jurisdiction, be it a high probability burden close to certainty, as in Austria, Germany and Spain, or preponderance of evidence, as in the Scandinavian and the common law countries. Another problem of statistical evidence is that, in tort law, the causal link between the individual tortfeasors and the plaintiffs must always be established. Statistical evidence that shows only the relationship between one possible tortfeasor and a group of harmed persons fails to meet this requirement, if the harm can also be attributed to a natural cause.