Virginia's highest court is the latest to wrestle with causation in asbestos/mesothelioma cases. Ultimately reversing a judgment in favor of Plaintiff and remanding the case for a new trial, the court in Ford v. Boomer decided that the substantial factor (or here, substantial contribution) test is unreliable and in any event inconsistent with Virginia law. The court embraced the Restatement (Third) of Torts' view of substantial factor causation (that it's incoherent), writing: "If courts cannot be relied upon to consistently construe the language, we cannot expect lay jurors to accomplish the same task." Concerned that the trial court's instruction to the jury, specifically that plaintiff must prove that exposure to defendant's product "was a substantial contributing factor in causing plaintiff's injury" left the jury free to assign liability to any exposure that was more than de minimis (the term was not defined), the court held that defendant's objection to the charge should have been sustained.
Ok, so if substantial factor/contribution cause doesn't cut it in Virginia what does? And if some exposure beyond "de minimis" isn't enough, what is? Sufficient cause, i.e. sufficient exposure! In parsing the Restatement (Third) of Torts section 27 and its comments the court concluded that the logic of permitting a jury to assign liability to either or both defendants in a case in which each negligently started a fire sufficient on its own to have destroyed plaintiff's property would apply with equal force in an asbestos/mesothelioma case. Consequently, "[t]he exposure must have been 'a' sufficient cause..."
So how does a plaintiff show that a putative exposure was "a" sufficient cause? He'll need "medical testimony as to the requisite exposure necessary to cause mesothelioma, to determine whether the exposure attributable to each defendant was more likely than not sufficient to have caused the harm." And how does he show that the attributable exposure was more likely than not causative? That's the $64,000 question.
If all plaintiffs need is the ipse dixit of a high priced testifying expert then they'll just go from saying "any exposure above background was a substantial factor" to "any exposure above background was sufficient" and nothing will change. Presuming that Virginia is serious about requiring plaintiffs to prove that a given exposure (which is to say dose) could have been sufficient, plaintiffs will have to show that the exposure in question more than doubled the risk of the disease. Essentially it means drawing the line at the lowest dose credibly shown to double risk. That's nothing new. It's the rule Judge Davidson has been applying for years in the Texas MDL.
So good news for Virginia defendants, right? Well, in Texas we have a great shares defense and apportionment scheme. Virginia? This sentence from Boomer should answer the question: "Other sufficient causes, whether innocent or arising from negligence, do not provide a defense." The only defense suggested by the court for an exposure determined to be sufficient (other than a warning) would be to show that the exposure occurred after the plaintiff had already developed his cancer. That means Virginia's old school joint and several liability scheme prevents Boomer from being much of a boon to most defendants. Yet, because plaintiffs will have to prove something like a 0.1 f/cc-yr cumulative dose for each putative "sufficient cause", the most marginal of the remaining defendants should get some relief. At least until plaintiffs can show the background risk is say 1:2,000,000, at which time 0.05 f/cc-yr becomes "sufficient". Etc., etc. (Now do you see why we've been saying the Restatement (Third) of Torts is a Trojan horse for the Precautionary Principle?)