A engages in a polluting activity. B, who has been substantially exposed to its negative effects, develops cancer. B wants to sue A for damages.
Who bears the burden of proof on the issue of causation?
How certain must it be that A's activity caused B's illness so that B is entitled to damages? Which rules of evidence (preponderance rule, free evaluation of evidence) apply?
Burden of proof
All the jurisdictions analysed have the general rule that the burden of proof on causation lies with the plaintiff. In some European countries, this is explicitly provided for by legal provisions, such as in Belgium (Article 1315 Burgerlijk Wetboek and Article 870 of the Code of Civil Procedure), Finland (§ 3 Environmental Damages Act 1994), France (Article 1315 Code Civil), Greece (Article 338 of the Code of Civil Procedure), Italy (Article 2697 Codice Civile), the Netherlands (Article 150 Wetboek van Burgerlijke Rechtsvordering), Portugal (Article 563 Código Civil), Spain (Article 217 Civil Procedure Act) and Sweden (Procedural Code, Chapter 35). In other countries this principle derives from case law (England, Ireland, Scotland), or judicial interpretation (Austria, Germany).
Level of certainty
Causation is established if the plaintiff can link the defendant to the harm to the satisfaction of the court. There are, however, considerable differences with regard to the level of probability that is necessary to establish causation. Austrian, German, Greek and Spanish law require a very high level of probability, close to certainty.