Is Agent Orange (Dioxin) associated with pulmonary fibrosis?

From the Research

Yes, Agent Orange has been linked to scarring in the lungs, as evidenced by a significant association with idiopathic pulmonary fibrosis (IPF) in a large cohort of U.S. veterans. The most recent and highest quality study, published in 2022 in the American Journal of Respiratory and Critical Care Medicine 1, found that presumptive Agent Orange exposure was associated with a greater risk of IPF, with an odds ratio of 1.14 (95% CI, 1.12-1.16; P < 0.001). This study suggests that Agent Orange exposure may contribute to the development of lung scarring, which can lead to thickened, stiff lung tissue and impaired oxygen exchange.

Key findings from this study include:

• Among 3.6 million male Vietnam veterans, 26% had presumptive Agent Orange exposure
• IPF occurred in 2.2% of veterans with Agent Orange exposure versus 1.9% without exposure
• The relationship between Agent Orange exposure and IPF persisted after adjusting for known IPF risk factors
• The attributable risk among exposed veterans was 7% (95% CI, 5.3-8.7%; P < 0.001)

While other studies have investigated the relationship between Agent Orange exposure and various health outcomes, including lung cancer 2, peripheral neuropathy 3, and head and neck cancer 4, the study by 1 provides the most direct evidence of a link between Agent Orange exposure and lung scarring. Additionally, a study on the efficacy of antifibrotic medications in interstitial lung diseases other than IPF found that nintedanib may be effective in slowing disease progression in patients with interstitial lung diseases other than IPF 5. However, this study does not directly address the relationship between Agent Orange exposure and lung scarring.

In clinical practice, it is essential to consider the potential link between Agent Orange exposure and lung scarring when evaluating veterans with respiratory symptoms, particularly those with a history of exposure to Agent Orange. Early intervention and monitoring may help mitigate the effects of lung scarring and improve outcomes for affected individuals.