Substantial factor?  I know it when I see it.

Many of us have struggled for quite some time in reaching a consensus on what level of exposure does, and does not, constitute a “substantial factor” when assessing causation of an asbestos-related disease.  In a recent order on a motion for summary judgment, Judge Eduardo Robreno of the asbestos MDL, applying maritime law, weighed in on the issue.  His decision gives additional guidance, if it does not end the discussion.

The case involved a former U.S. Navy sailor who testified to exposure to original asbestos-containing gaskets and packing used with two pumps found on the virtually new USS Downes.  Even while accepting that evidence as accurate, Judge Robreno granted the MSJ by determining this was a “mere minimal exposure” as described in Lindstrom v. A-C Prod. Liab. Trust, 424 F. 3d 488 at 492. Judge Robreno stated:

Although there is evidence that Plaintiff was exposed to respirable dust from the original gasket and packing used with a single Buffalo electric fire pump, and the original gasket used with a single Buffalo evaporator pump —-, maritime law requires more than a “mere minimal exposure” to support a finding of causation. (Citation omitted.)  As such, no reasonable jury could conclude from the evidence that Decedent was exposed to asbestos from a product manufactured and/or supplied by Defendant such that it was a substantial factor in the development of his illness.

Other courts have likewise relied upon Lindstrom to reject claims that minimal exposures constituted a substantial factor.  The Sixth Circuit expressed the sentiment memorably in Moeller v. Garlock Sealing Technologies, 660 F.3d 950 at 955 (6th Cir. 2011):

On the basis of the record, saying that exposure to Garlock gaskets was a substantial cause of [plaintiff’s] mesothelioma would be akin to saying that one who pours a bucket of water into the ocean has substantially contributed to the ocean’s volume.

From a defense prospective, this order from Judge Robreno compares favorably with other attempts to define a substantial factor.  In California, for example, we must deal with the language of Jones v. John Crane, Inc., 35 Cal. Rptr. 3d 144 (2005).  In Jones, John Crane argued that the exposures attributable to its products were comparable to ambient levels of asbestos in the community at large, and paled in comparison to the plaintiffs’ other exposures (10 fiber hours, or .005 fiber years, compared to an estimated 200 fiber years of exposure to asbestos-containing insulation and 2.8 fiber years from ambient exposures). Plaintiff experts challenged the defense calculations and offered expert testimony that every exposure contributed to the risk.  The court ruled against the defense: “[A] level of exposure that is the equivalent of that to which one might be exposed in the ambient air over a lifetime is not necessarily insignificant.”

While the order from Judge Robreno gives us at least one example of what does not constitute a substantial factor, it provides scant guidance as to how to assess future cases.  Nevertheless, at least when maritime law is applied, it is reassuring to know that there are some acknowledged exposure scenarios that do not qualify as substantial factors.