The evidence reviewed here covers only the radioisotope indium-111 as a medical imaging tracer; it gives no food, water, exposure, toxicity or limit data for indium.
- Role: In the cited papers, indium appears only as indium-111, a radioactive tracer used to label white blood cells or tumor-targeting agents for imaging.
- Main exposure: The only route described is deliberate medical administration of a radiotracer; no dietary or environmental route is covered.
- Key distinction: A diagnostic radioisotope given in a clinic is a different question from indium as a food or environmental contaminant, which the cited papers do not address.
This page draws on 2 peer-reviewed studies. The complete citation list is at the bottom of the page.
Overview
This page is very thin because the evidence reviewed for it is narrow. Both papers concern indium-111, a radioactive isotope used as a tracer in medical imaging, and neither measures indium in food, water, soil or people as a contaminant. One is a surgical imaging study of how well gamma signal from an indium-111 labeled tracer can be detected through tissue 1. The other is a case report in which an indium-111 labeled white blood cell scan supported a diagnosis of endocarditis 2.
Toxicology
The cited evidence does not establish anything about indium toxicity. Neither paper reports adverse effects of indium or of the radiotracer.
Typical exposure routes
The cited evidence does not establish dietary, drinking water, occupational or environmental exposure to indium. The only route in the papers is clinical administration of indium-111 labeled material for imaging: labeled white blood cells in one patient 2 and a dual-labeled tracer in mouse tumor models 1. Neither paper reports the administered activity or radiation dose.
Food sources
The cited evidence does not establish indium concentrations in any food. No food was analyzed for indium.
Regulatory limits
The cited evidence does not establish any regulatory limit or guideline value for indium. The case report notes that indium-111 white blood cell scintigraphy for suspected endocarditis receives a rating of 3, meaning rarely appropriate, under American College of Radiology appropriateness criteria 2. That rating concerns the choice of imaging test, not exposure.
Testing
The cited evidence does not describe any method for measuring indium in food, water or biological samples. The imaging study measured gamma counts from indium-111 with a handheld surgical probe and found that at least 5% of the maximum signal was still detectable through up to 5 cm of tissue or gelatin, compared with about 0.5 cm for a near-infrared fluorescent dye 1. This is radiation detection for surgery, not trace element analysis.
Microbiome effects
The cited evidence does not establish any effect of indium on microbiomes.
Vulnerable populations
The cited evidence does not identify any population at higher risk from indium.
Mitigation
The cited evidence does not establish any removal, processing or remediation method for indium.
Open questions
- Toxicology: no data on indium toxicity in any species.
- Typical exposure routes: no dietary, water, occupational or environmental exposure data.
- Food sources: no measurements of indium in any food.
- Regulatory limits: no limit or guideline value for indium.
- Testing: no analytical method for indium as a trace element.
- Microbiome effects: not studied.
- Vulnerable populations: not identified.
- Mitigation: not studied.
- Radiation dose and administered activity of indium-111 in the clinical uses described.
What remains uncertain
Almost everything about indium as a food or environmental contaminant remains uncertain on this evidence. The two papers treat indium only as a short-lived radioactive label in medicine, so they cannot inform questions about indium in diets, drinking water or consumer products. A useful page on indium will need occurrence, biomonitoring and toxicity studies that are not part of the evidence reviewed here.
References
Works cited in this page’s text, in first-appearance order. See Sources for this page’s source inventory. Each title links to a source record with bibliographic details, reported findings, and document provenance.
- Detection properties of indium-111 and IRDye800CW for intraoperative molecular imaging use across tissue phantom modelsPeer-reviewed
- Edwardsiella tarda Endocarditis Confirmed by Indium-111 White Blood Cell Scan: An Unusual Pathogen and Diagnostic ModalityPeer-reviewed
Sources
- Indium-111 and IRDye800CW detection through tissue phantoms (2025; peer-reviewed): off-topic for dietary exposure: surgical imaging tracer detection study.
- Indium-111 white blood cell scan in endocarditis (2016; peer-reviewed): off-topic for dietary exposure: single clinical case using a diagnostic radiotracer.
Update history
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