When Congress passed the Promise to Address Comprehensive Toxics (PACT) Act in 2022, it brought long-overdue relief to veterans denied benefits because there wasn’t enough scientific evidence tying burn pit exposure to their illnesses.
What few know is that Rutgers researchers helped lay the scientific groundwork that made it possible to link certain illnesses to military service in the Middle East.
In December 2024, the U.S. Department of Veterans Affairs (VA) officially adopted rules to implement PACT that included a new method for conclusively determining whether specific respiratory illnesses are service-related. That method was developed in part by J. Scott Parrott , a professor with the Rutgers School of Health Professions, and his team through a VA-funded grant.
That work by Parrott, a statistics and methodology expert, and other researchers with the School of Health Professions now has been published in Evidence-Based Technology , a peer-reviewed science journal.
“Usually, you publish the research, and it changes policy,” Parrott said. “This time, policy changed – and then the paper came out.”
The unusual timeline – policy preceding publication – reflects the urgency of the issue.
Concerns about airborne hazards began during the 1990 Gulf War and intensified after conflicts in Iraq and Afghanistan following 9/11. While environmental monitoring documented widespread dust and pollution, one exposure drew particular alarm: open-air burn pits, according to the published paper.
Used at up to 86% of military bases – especially between 2005 and 2012 – burn pits served as a primary waste-disposal method. Medical waste, plastics, batteries, vehicles, insecticide containers and human waste were ignited with jet fuel. The smoke from the burns released a complex mix of toxins which enter the body through inhalation.
Veterans began reporting chronic respiratory conditions, rare lung diseases and other serious health problems. Yet, establishing a direct causation proved difficult.
In 2020, the National Academies of Sciences, Engineering, and Medicine reviewed VA’s presumptive-injury policies and concluded that evidence connecting deployment in Southwest Asia to respiratory diseases, cancers and autoimmune disorders was inconclusive.
Parrott received a VA grant the following year to reexamine the evidence and build a comprehensive exposure-disease database. The problem, he said, wasn’t a lack of research, but that conventional frameworks demanded a level of proof – akin to a randomized clinical trial – that is impossible in war-zone conditions.
“We were asked to develop a different and innovative methodology,” Parrott said. “These events occurred decades ago, when exposures weren’t being measured because people are firing bullets and lobbing bombs at you. You can’t go back and gather more data.”
So, his team reframed the question: If definitive experimental proof is unattainable, can the totality of preclinical, clinical, environmental and epidemiological evidence point to the most plausible explanation?
They examined whether clinical patterns, biological findings and deployment histories aligned in ways consistent with inhalational injury.
“You can’t prove it in the strictest sense,” Parrott said. “But you can determine whether there is any other plausible explanation. And if there isn’t, that’s strong enough to guide policy.”
The conclusion in the paper is fairly direct.
“The sum total of the evidence indicates that deployment to the Southwest Asia theater of operations increases the risk of developing a subset of interstitial lung diseases and constrictive bronchiolitis,” the authors wrote in the article published Feb. 1.
The methodology assigns graded levels of confidence rather than demanding unattainable certainty. That shift gave the VA a new path forward in evaluating service-related illnesses.
The work isn’t abstract for Parrott.
His son-in-law, James Petty, a veteran of multiple tours in Iraq and Afghanistan and later a military contractor in Kuwait, developed a rare lung condition after deployment. He now suffers from chronic respiratory and cardiopulmonary disorders.
Parrott said seeing his work shape federal policy is rewarding. “But it’s also personal.”
For Parrott and his team, the work is ongoing.
Rutgers is hosting the evidence synthesis platform used by the VA, which previously resided with the U.S. Agency for Healthcare Research and Quality. When it was decommissioned in November, Parrott and his team agreed to clone and rebuild it at Rutgers. The result is a continuously updated open-source repository synthesizing research and data on military exposures accessible to policymakers, clinicians, and veterans.
The team also is studying how large-language models – the technology behind artificial intelligence – can assist in analyzing complex epidemiological and preclinical studies, potentially accelerating evidence reviews without sacrificing rigor.
By changing how evidence is evaluated, Parrott’s work reshapes how uncertainty is weighed in public policy – and how veterans can gain recognition and disability benefits for illnesses tied to their service.
For those still waiting for answers, that shift could prove transformative.
Evidence-Based Toxicology
Data/statistical analysis
Not applicable
An abductive inferential system approach to weight of evidence syntheses: the problem and military exposures worked example
4-Feb-2026
No potential conflict of interest was reported by the authors. The contents do not necessarily represent the views of the U.S. Department of Veterans Affairs or the United States Government.