Causation Requirements in Toxic Torts
The Michigan Court of Appeals has offered much needed guidance to those considering pursuing toxic tort claims. That guidance, found in the case of Powell-Murphy v Revitalizing Auto Communities Environmental Response Trust, 2020 WL 4722070 (2020), sets forth what a plaintiff must show to overcome the sometimes difficult causation requirement required in these type of claims.
Powell-Murphy involved workers at the United States Postal Service Metroplex Processing and Distribution Center in Pontiac, Michigan (the “Metroplex” facility). Plaintiffs claimed the Metroplex facility was built on land containing pools of contaminants. Decomposition of those contaminants resulted in the generation of methane and other toxic gasses. Plaintiffs alleged they were exposed to hazardous levels of those gases while working at the Metroplex facility and as a result, suffered a variety of physical ailments.
Toxic torts are a type of negligence action. In any negligence action, the plaintiff must show that but for the defendant’s actions, the plaintiff’s injury would not have occurred. In a toxic tort action, that requires the plaintiff to show that the complained of substance is capable of causing an injury AND the substance caused that injury. That can be a difficult hurdle to meet. The causes of many illnesses like cancer are not fully understood. In addition to the toxicity of a particular substance, exposure (concentration and duration) also plays a role. With these factors in mind, what is a plaintiff required to show to allow a jury to make a reasonable inference based on the facts.
The Powell-Murphy court stated the mere existence of a toxin in the environment is not enough to establish causation without proof that the particular level of exposure could cause the plaintiff’s symptoms. Quoting Justice Markman’s concurring opinion in Lowery v Enbridge, 500 Mich 1034, 1043 (2017), the court stated “causation requires not simply proof of exposure to the substance, but proof of enough exposure to cause the plaintiff’s specific illness.”
The court acknowledged plaintiffs had presented testing evidence to show the presence of methane in parts of the Metroplex facility had increased over pre-construction levels. However, the court noted the absence of any evidence of the specific levels of methane (or other potentially harmful toxins) in or around the Metroplex facility to which Plaintiffs were exposed. Without that information, the court concluded a fact-finder could not determine whether the alleged exposure could have caused plaintiffs’ injuries.
The lesson to be learned from Powell-Murphy is that all plaintiffs asserting a toxic tort claim must show the estimated amount and duration of exposure at issue before the fact-finder can reasonably conclude that exposure to the defendant’s toxin in the amount and duration alleged is capable of causing the alleged injury.