Miranda v. Bomel Construction Co., Inc

In Miranda v. Bomel Construction Co., Inc. (2010) 187 Cal.App.4th 1326, the Court of Appeal affirmed the trial court's grant of summary judgment in favor of the defendants in a personal injury action. (Id. at p. 1328.) The plaintiff was infected with Valley Fever, a fungal infection contracted from spores commonly found in dirt in California's Central San Joaquin Valley. The plaintiff's office was located next to a vacant lot, used for stockpiling excess dirt from a large construction project. He sued the general contractor and subcontractor on the theory that they negligently allowed the excavated dirt to be in a dangerous condition so as to cause him to be injured upon breathing particles from the dirt. (Id. at pp. 1328-1329.) The defendants' expert declared that persons can become infected by the fungus by inhaling spores that become airborne after disturbance of contaminated soil by humans or natural disasters, that strong winds during a storm can carry spores for hundreds of kilometers, and that the fungus was "hyperendemic" in certain areas of the San Joaquin Valley, where almost one third of the population tests positive for exposure. (Id. at pp. 1329-1330.) The expert also opined that the exact source of exposure cannot be determined absent scientific data confirming the existence of the fungus in the soil at issue at the time of exposure. (Id. at p. 1330.) The appellate court explained that, unlike ordinary negligence, " 'in a personal injury action causation must be proven within a reasonable medical probability based upon competent expert testimony. Mere possibility alone is insufficient to establish a prima facie case. That there is a distinction between a reasonable medical "probability" and a medical "possibility" needs little discussion. There can be many possible "causes," indeed, an infinite number of circumstances which can produce an injury or disease. A possible cause only becomes "probable" when, in the absence of other reasonable causal explanations, it becomes more likely than not that the injury was a result of its action. This is the outer limit of inference upon which an issue may be submitted to the jury. ' " (Id. at p. 1336.) The appellate court concluded that, although medical and scientific data supported the plaintiff's claim that exposure to dust was a critical factor in his injury, "neither expert accounted for the undisputed facts showing there were other reasonable and likely sources of the fungus spore causing Miranda's injury. Neither of the plaintiff's experts offered an opinion on whether there was a way to medically or scientifically determine the origins of the infecting fungal spore. Nor did they dispute the fungus grows all over California . . . ." (Miranda v. Bomel Construction Co., Inc., supra, 187 Cal.App.4th at p. 1337.) In light of that undisputed evidence, that the plaintiff was infected, standing by itself, did not create a reasonable inference that the dust from defendants' excavation, as opposed to another location, was the source of the disease. (Ibid.) The court analogized to other naturally occurring illnesses, stating, "You can have your suspicions, but without scientific data tracing the source, you cannot be sure who infected you with their head cold or stomach flu. We do not wish to downplay the seriousness of Valley Fever, but its source is just as elusive as most other invisible bacteria or virus." (Id. at p. 1340.) The court concluded, "because there are other explanations for the cause of Miranda's injury, and it could have occurred even in the absence of negligence, proof of causation requires more than speculation, conjecture, and inferences as to who to blame." (Id. at p. 1342.)