Expert testimony concerns possible adverse health effects of long-term exposure to carbon monoxide is admissible

Law Reporter, Sep 2002

John's Heating Service v. Lamb, _ P.3d _, Nos. S-9042, S-9052, 2002 WL 959940 (Alaska May 10, 2002).

The Alaska Supreme Court held that a trial court did not abuse its discretion by admitting expert testimony to show that chronic carbon monoxide exposure is harmful.

Here, a married couple sued a heating service provider, alleging that a defective furnace had caused them to be exposed to carbon monoxide. At trial, defendant tried to preclude the testimony of plaintiffs' medical experts on the effects of chronic carbon monoxide exposure, but the court ruled that the question of causation was for the jury, which awarded damages.

Affirming in part, the state high court said trial courts must consider four factors before admitting expert testimony: whether it has been subjected to peer review, whether it has gained general acceptance in the relevant scientific community, whether the proffered theory of technique can be empirically tested, and the error rate of the theory or technique. Addressing these factors, the court said the record reflects the existence of peer-reviewed, published case studies of chronic carbon monoxide exposure and its effects. Moreover, all five of the experts who testified in this case, including two called by defendant, agreed that chronic carbon monoxide exposure can be harmful to humans, the court noted.

The court rejected defendant's argument that because the threshold level at which carbon monoxide becomes harmful is unknown, the theory that chronic carbon monoxide exposure is harmful is unreliable. The fact that shortterm, acute exposure causes neurological harm makes it reasonable to suggest that chronic, low-level exposure can also cause harm, the court found. While precise information concerning the amount of exposure to a given substance that is necessary to cause specific harm to humans is beneficial in this type of case, the court said, such evidence is not always available, or necessary, to demonstrate that a substance is toxic to humans. The fact that such testing on humans simply cannot be ethically undertaken explains and excuses the lack of testing to some extent, it added. Because of this, the absence of an empirical basis for the theory does not render the evidence inadmissible here, the court concluded.

The court also rejected defendant's argument that the differential diagnosis methodology used by some of plaintiffs' experts is scientifically unreliable and therefore the witnesses' testimony is inadmissible. Differential diagnosis is a standard methodology, the court said, and a majority of federal circuit courts allow expert testimony based on it.

Plaintiffs' Counsel

*Sarah J. Tugman, Anchorage, Alaska