雙倍風險標準的因果關係論

本文以雙倍風險標準作為討論核心，雙倍風險標準內容為侵權法應該要在比例的基礎上容許風險升高的回復，但要件為原告必須證明對有毒物質的接觸，對於導致將來疾病發生的風險達到兩倍以上，即流行病學上所稱的相對風險值或勝算比大於2時，作為認定侵權法中因果關係的最低限度門檻。本文認為該標準於不確定因果關係的侵權案件類型，包括食品安全、藥害、環境汙染等毒物侵權領域，起著重要的指導作用，可以同時符應因果關係要件，以及矯正正義者的要求。以該標準限制潛在風險升高的原告人數，將使其具實務上的可行性，純粹的比例責任制系統將造成數以百萬人可以提出風險升高的侵權訴訟。同樣基於機率式因果關係的認知，相較於純粹的比例責任制，雙倍風險標準更適合作為侵權法的歸責原則。

關鍵字

雙倍風險標準；因果關係；矯正正義；比例責任制；相對風險值；勝算比

並列摘要

The core issue of this article is the doubling of the risk standard. The content of the standard is ＂Tort law should permit enhanced risk recovery on a proportional basis, but only when a plaintiff can prove that the toxic exposure has more than doubled her risk of contracting disease in the future.＂ In epidemiological terms, this minimum causation threshold is the equivalent of saying that the ＂relative risk＂ or ＂odds ratio＂ of disease based on exposure is greater than two. This Article recognize that the standard has guided function in determining uncertainty of causation, including food, drug, environmental, and. toxic tort cases. The standard is correspond to actual causation and corrective justice. By limiting the number of potential enhanced risk plaintiffs, the standard actually may be administrated feasibly. A pure proportional liability system would allow millions of people to bring multiple enhanced risk tort actions. Based on the probability causation ground, the doubling of the risk standard is better than pure proportional liability system in tort cases.