Toxic Tort Litigation: Diesel Exhaust Lawsuits Are On The Rise

Submitted by the Products Liability PAC

By: Parada K. Ornelas with Wilson Turner Kosmo LLP, in San Diego, California.[1]

Most of us are exposed to gasoline and exhaust every day especially those living in urban areas or near freeways. In an occupational context, those who work on roadways or operate diesel-powered machinery are more likely to be exposed to exhaust than the general population. Today, lawsuits based on occupational exposure to diesel exhaust specifically have become increasingly common as many argue that such exposure can lead to negative health effects.

Diesel Exhaust and Regulations

First, what is diesel exhaust? Diesel-powered engines, such as those in heavy or medium-duty trucks, construction equipment, locomotives, and generators, produce it. Diesel exhaust, a result of complete combustion of diesel leads, primarily consists of nitrogen, as well as carbon dioxide, oxygen, and water vapor. However, “incomplete” combustion of diesel results in a complex mixture of gases and particulates, including unburned hydrocarbons, carbon dioxide, nitrogen oxides, and diesel particulate matter.

The primary concern is that exposure to diesel particulate matter, at sufficient concentrations, may cause respiratory effects, such as reduced lung function, respiratory irritation, and asthma exacerbation. The World Health Organization (WHO) and Environmental Protection Agency (EPA), among others, have linked “traditional” diesel exhaust and cancer. In June 2012, WHO’s International Agency for Research on Cancer (IARC) classified diesel exhaust as a Group 1 “known carcinogen.” IARC found “sufficient” that diesel engine exhaust is linked to lung cancer, and “limited” evidence for an increased risk of bladder cancer. However, diesel exhaust is not the sole associated potential link to lung cancer—smoking, exposure to radon, exposure to high concentrations of certain hazardous chemicals, and family history of lung cancer are all associated with an increased risk of lung cancer.

In addition, there have been increasingly stringent emissions standards, implemented by the EPA, for particulate matter and nitrogen oxides in diesel exhaust. As a result, manufacturers developed and implemented “new technology” diesel beginning in 2007. This “new technology” has shown marked improvements in lowering emissions with multi-component after-treatment systems such as electronic controls, ultra-low sulfur diesel fuel, oxidation catalysts, and wall-flow diesel particulate filters. While the amount of particulates and chemicals are reduced in new diesel technology, it is not yet clear how the quantitative and qualitative changes may translate into health impacts. Moreover, national agencies such as the Occupational Safety and Health Administration (OSHA) and National Institute for Occupational Safety (NIOSH) have instituted exposure limitations applicable to an employer for certain constituents of diesel exhaust such as carbon monoxide, carbon dioxide, and sulfur dioxide.

Diesel Exhaust Litigation

Despite heightened regulations and limitations, we have entered into the age of diesel exhaust litigation. In many of the diesel exhaust cases, liability hinges upon whether experts are able to link general causation to medically or scientifically demonstrate that diesel exposure, not other variables, caused plaintiff’s injury. In one of the earlier diesel exhaust cases, in 2002, the Fourth District of the Court of Appeals of Texas, in Missouri Pacific Railroad Company v. Navarro, 90 S.W.3d 747 (Tex. App. 2002), held that an isolated study finding a statistically significant association between the diesel exhaust and the alleged condition would not be legally sufficient evidence of causation. Plaintiff Manuela Navarro worked for 20 years in various capacities at Union Pacific Railroad Company’s rail yard. Plaintiff was subsequently diagnosed with multiple myeloma (a type of bone marrow cancer) and sued Union Pacific, alleging that her exposure to diesel exhaust while working caused her disease. Plaintiff’s expert estimated her exposure based on a comparison of her job description to a single study that categorized rail yard workers by job classification, and did not take any air samples at any time. The Court, in reversing a judgment in favor of plaintiff, concluded that plaintiff’s expert opinions were not supported by scientific studies and failed to establish a specific level of exposure, thus failed to establish general causation.

About a year after Navarro, the Court of Appeals of Ohio upheld a jury verdict in favor of plaintiff and found that plaintiff’s experts ruled out other potential causes through a proper “differential diagnosis,” eliminating other causes. In Cutlip v. Norfolk S. Corp., 2003 WL 1861015 (Ohio Ct. App. Apr. 11, 2003), plaintiff claimed that he developed asthma from inhaling diesel fumes while working as a locomotive engineer. Plaintiff’s expert physicians arrived at their conclusion that plaintiff’s asthma is related to his exposure to diesel fumes through differential diagnosis, which is essentially a learned process of elimination. In contrast to the Navarro Court, the Ohio Court of Appeals affirmed the trial court’s decision despite the fact that there were no studies showing threshold level for diesel fumes on a railroad.

Since Navarro and Cutlip, other jurisdictions have rejected plaintiff experts’ general causation conclusions as those experts could not exclude other causes or quantify exposure to diesel exhaust. In 2008, the Fifth Circuit found, in Seaman v. Seacor Marine, LLC, 326 F.App’x 721 (5th Cir. 2009), that plaintiff’s expert opinion was unreliable for failure to exclude cigarette smoking as a chief cause of bladder cancer. Similarly, in 2011, the United State District Court for the North District of Indiana and the Court of Appeals of Arkansas found that experts failed to meet Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579 (1993), because they could not quantify plaintiffs’ exposures and did not cite to studies supporting their conclusions that diesel exposure caused plaintiffs’ conditions. (Aurand v. Norfolk Southern Ry. Co., 802 F. Supp.2d 950 (N.D. Ind. 2011) and Richardson v. Union Pacific Railroad Co., 2011 WL 4477791 (Ark. Ct. App. Sept. 28, 2011)).

It remains to be seen whether any trends in expert testimony will emerge between jurisdictions that follow Daubert versus those that follow other standards. As more cases are filed and decided, decisions will help attorneys and experts determine what evidence is required to support expert opinions and conclusions linking diesel exhaust exposure to personal injuries.

Strategies for Defending Diesel Exhaust

Companies defending diesel exhaust cases must develop a game plan at the outset. It is vital that the defense assemble a team of in-house and outside experts that not only understand, but can also explain the nuances associated with the technology at issue. In addition, the defense should consider retaining medical experts that specialize in the effects of diesel exposure and conducting non-traditional tests (e.g., air quality testing) to expose flaws with the plaintiff’s theory of causation. Finally, since plaintiff’s prima facie case hinges on expert testimony, it is crucial for the defense to attack the admissibility of the opinions given by the plaintiff’s experts.

Given the regulatory and legal landscape, it is clear that diesel exhaust litigation is well on its way to becoming the next big thing in the mass toxic tort arena.

Parada K. Ornelas is an associate with Wilson Turner Kosmo LLP in San Diego, California. She is a member of the firm’s Product Liability and Warranty group, representing manufacturers and companies in product liability, personal injury, and wrongful death matters.