Medical Imaging Contrast Agents Linked to Growing Environmental Concerns
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Medical imaging procedures utilizing contrast media may be contributing to significant environmental pollution, according to new research published online December 5 in JAMA network Open. A study quantifying the use of these agents reveals a significant and increasing volume entering wastewater systems, possibly impacting rivers, oceans, and even drinking water supplies.
Researchers, led by Florence X.Doo, M.D., from the university of Maryland in Baltimore, sought to understand the scale of contrast agent usage as it relates to the broader “triple planetary health crisis”-the interconnectedness of human health, environmental sustainability, and social justice. Their analysis leveraged U.S. Medicare part B claims data from 2011 to 2024 to estimate national trends in procedures utilizing contrast for both computed tomography (CT) and magnetic resonance imaging (MRI) scans.
Millions of Contrast-Enhanced Exams Annually
The study found that Medicare beneficiaries underwent an estimated 169.3 million contrast-enhanced examinations over the study period, encompassing 82 different medical codes. These procedures required approximately 13.5 billion mL of contrast media. The vast majority – 50 percent – utilized iodinated agents, primarily in CT and angiography (CTA) scans, while the remaining 50 percent employed gadolinium-based agents for MRI and magnetic resonance angiography (MRA).
Specifically, iodinated agents accounted for 95.6 percent of the total contrast volume.Within this category, CT scans of the abdomen or pelvis were the largest single contributor, accounting for 4.4 billion mL out of a total 12.9 billion mL used for iodinated contrast. Gadolinium usage was most prominent in brain MRI scans, totaling 221 million mL.
Rising Usage, Post-Pandemic Rebound
the annual volume of contrast agents used increased steadily between 2014 and 2019.Researchers observed a mean year-over-year growth rate of 5.2 percent for iodinated agents and 3.5 percent for gadolinium agents. While the COVID-19 pandemic caused a temporary decline in usage in 2020, data indicates a return to pre-pandemic levels and normalization from 2022 through 2024.
“Contrast agents are necessary for effective imaging, but they don’t disappear after use,” a senior researcher stated. “Iodine and gadolinium are non-renewable resources that can enter wastewater and accumulate in rivers, oceans, and even drinking water.”
The research underscores the need for responsible use and potential mitigation strategies. as the study’s authors emphasize, quantifying contrast usage is a crucial first step toward developing “thoughtful, practical contrast stewardship strategies” that ensure patients continue to recieve high-quality care while minimizing environmental impact.
This research highlights a growing awareness of the environmental footprint of modern medicine and the importance of balancing patient needs with planetary health.
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Why was this study conducted? This study was conducted to quantify the use of medical imaging contrast agents and understand their potential impact on the environment, specifically as it relates to the interconnectedness of human health, environmental sustainability, and social justice – the “triple planetary health crisis.”
