Medical Imaging Contrast Media Contribute to Environmental Pollution

THURSDAY, Dec. 18, 2025 (HealthDay News) — Contrast media from medical imaging may be contributing to environmental pollution, according to a research letter published online Dec. 5 in JAMA Network Open.

Florence X. Doo, M.D., from the University of Maryland in Baltimore, and colleagues quantified contrast use patterns as a contributor to the triple planetary health crisis. Analysis included U.S. Medicare Part B fee-for-service limited public claims data (2011 to 2024 Physician/Supplier Procedure Summary) to estimate national-level aggregated counts of billed procedures that used contrast (computed tomography [CT] and angiography [CTA], and magnetic resonance imaging [MRI] and angiography [MRA]).

The researchers found that over the study period, Medicare beneficiaries underwent an estimated 169.3 million contrast-enhanced examinations across 82 Current Procedural Terminology (CPT) codes (iodinated [50 percent]: CT [68 percent] and CTA [32 percent]; gadolinium [50 percent]: MRI [71 percent] and MRA [29 percent]), requiring approximately 13.5 billion mL of contrast media. Iodinated agents accounted for the majority of the total combined contrast volume (95.6 percent), with CT abdomen or pelvis representing the largest single contributor at 4.4 of 12.9 billion mL. Brain MRI led gadolinium agent usage at 221 million mL. Overall, annual contrast volume increased, with mean year-over-year growth from 2014 to 2019 of 5.2 percent for iodinated agents and 3.5 percent for gadolinium agents. Following COVID-19 pandemic–related declines in 2020, there was normalization from 2022 through 2024.

“Contrast agents are necessary for effective imaging, but they don’t disappear after use. Iodine and gadolinium are non-renewable resources that can enter wastewater and accumulate in rivers, oceans, and even drinking water,” Doo said in a statement. “Quantifying which imaging exams use the most contrast helps us innovate thoughtful, practical contrast stewardship strategies to ensure patients continue to receive safe and high-quality imaging care.”

Abstract/Full Text