Environmental Engineering Expert Witness’ Testimony on Toxic Chemical Exposure Admitted
Posted on October 24, 2024 by Expert Witness Profiler
Over sixty Plaintiffs alleged that Defendant Lockheed Martin Corporation’s weapons manufacturing facility in Orlando released toxic chemicals that contaminated the air, soil, and groundwater, leading to various injuries among the Plaintiffs. The instant case formed a part of a group of related toxic tort cases.
Following a complex history during the dispositive motion stage, the Court resolved the general causation issues. It then shifted focus to specific causation for the limited number of remaining Plaintiffs.
All remaining Plaintiffs relied on environmental engineering expert witness, Ranajit Sahu’s testimony, which was central to their specific causation theory. He used air modeling data to demonstrate that Lockheed’s facility emitted five toxic chemicals and the Plaintiffs were exposed to these chemicals while in a nearby building.
In response, Lockheed sought to exclude Sahu’s testimony, arguing that his methodology was unreliable. The Plaintiffs opposed this motion, asserting the validity of Sahu’s methods.
Environmental Engineering Expert Witness
Ranajit Sahu has over twenty-three years of experience in the fields of environmental, mechanical, and chemical engineering. His expertise includes program and project management services, design and specification of pollution control equipment, soil and groundwater remediation, and combustion engineering evaluations. He conducted energy studies and addressed multimedia environmental regulatory compliance, working with statutes and regulations such as the Federal Clean Air Act and its amendments, the Clean Water Act, TSCA, RCRA, CERCLA, SARA, OSHA, and NEPA, along with various related state statutes.
Sahu is also skilled in transportation air quality impact analysis, multimedia compliance audits, and multimedia permitting, which includes air quality NSR/PSD permitting, Title V permitting, and NPDES permitting for industrial and stormwater discharges. He has conducted multimedia/multi-pathway human health risk assessments for toxic substances, air dispersion modeling, and regulatory strategy development and support, including the negotiation of consent agreements and orders.
Discussion by the Court
Sahu’s Methodology
Sahu relies on AERMOD, a recognized model for estimating air concentrations based on emission rates provided by the modeler. He modeled concentrations using the “actual emission rates” for each chemical, sourced from Lockheed’s chemical management system (CMS) reports. Subsequently, he compared these results to the expected background levels of each chemical in Florida. He used EPA data to assess the relative exposures of individuals in the Plaintiffs’ building against the general state population. Sahu concluded that the Plaintiffs’ exposures significantly exceeded the highest background levels.
Lockheed’s Concerns
Lockheed raised several objections to Sahu’s methodology. They claimed that the “actual emission rates” he used were inflated estimates, aimed at ensuring regulatory compliance rather than reflecting true emissions. To maintain its federal permit, Lockheed adopted the high-end percentages of chemicals from each product’s safety data sheet (SDS). For instance, if an SDS indicated a product contained 20-25% arsenic, Lockheed assumed 25%. This resulted in inflated CMS numbers that Sahu input as “actual emission rates.” Lockheed contended that these overestimates compromised the model’s accuracy.
Lockheed also criticized Sahu’s reliance on the CMS data. They argued that the data did not factor in capture, control, and transfer efficiencies. Consequently, this led to an overestimation of actual emissions. However, Sahu defended his approach, noting that the CMS data represented what Lockheed reported to regulators.
Analysis
Sahu’s reliance on Lockheed’s reported data did not undermine his methodology’s reliability. The validity of Sahu’s methods remained intact, despite Lockheed’s claims. The Court emphasized that questions regarding the accuracy of Sahu’s data were appropriate for cross-examination rather than discrediting the overall scientific validity of his methods.
Lockheed’s additional critiques included Sahu’s focus on outdoor air concentrations and the use of EPA data. Sahu clarified that typical building filters would not capture the chemicals in question. He also explained that he used statewide EPA data to establish conservative background exposure levels. Furthermore, Sahu noted that both parties lacked knowledge of alternative local sources for emissions.
Ultimately, the Court recognized that the Eleventh Circuit allows modeling to estimate emissions. The AERMOD model, which Sahu used, has received widespread approval. Sahu articulated his rationale for the model inputs and their applications, adhering to accepted scientific standards. The Court decided that Lockheed’s objections called into question the weight of the evidence instead of its admissibility. Thus, Sahu’s methodology was sufficiently reliable to warrant presentation to the jury.
Held
The Court denied Defendant Lockheed’s motion to exclude Plaintiffs’ environmental engineering expert witness, Ranajit Sahu.
Key Takeaways:
The Court allowed the testimony of environmental engineering expert Ranajit Sahu, emphasizing the reliability of his methodology despite Lockheed’s objections. Sahu used the AERMOD model to estimate air concentrations based on emission rates from Lockheed’s chemical management system, demonstrating that Plaintiffs were exposed to toxic chemicals exceeding background levels.
The Court noted that Lockheed’s concerns regarding data accuracy and methodology did not discredit Sahu’s scientific validity. Instead, these issues were appropriate for cross-examination, reinforcing the notion that the jury, not the Court, should weigh the evidence. Thus, Sahu’s testimony was deemed reliable and relevant for the jury’s consideration.
Please refer to the blog previously published about this case:
Pathology Expert Witness’ Testimony Excluded Due to Rampant Plagiarism
Case Details:
| Case caption: | Henderson Et Al V. Lockheed Martin Corporation Et Al |
| Docket Number: | 6:21cv1363 |
| Court: | United States District Court for the Middle District of Florida, Orlando Division |
| Dated: | October 23, 2024 |
