Yttrium is a rare earth element whose food-chain evidence here comes from spiked plant experiments, which show it stays mostly in roots, and from short animal studies of oxide nanoparticles.
- Role: A rare earth element; the cited evidence covers oxide nanoparticles and radioactive yttrium-90 used as a medical radiation source.
- Main exposure: Soil contamination near rare earth mining and engineered nanoparticles; no cited study measures yttrium in foods as sold.
- Key distinction: Plants retain yttrium in roots with little movement to shoots, so root data overstate what reaches edible leaves.
This page draws on 6 peer-reviewed studies. The complete citation list is at the bottom of the page.
Overview
Yttrium is grouped with scandium and the lanthanides as a rare earth element 1. The authors of a soil study note that ion-adsorption rare earth ores in southern China are enriched in medium and heavy rare earths such as yttrium, and that decades of leaching extraction have released ammonium salts and rare earths into surrounding ecosystems 1. Yttrium oxide nanoparticles are described as used in several industries, which raises questions about their entry into plants and animals 2 3. The radioactive isotope yttrium-90 is used in medicine as a beta-emitting radiation source 4.
The cited evidence on yttrium is thin and experimental. It contains no measurement of yttrium in any food as eaten, no dietary intake estimate and no regulatory value.
Toxicology
Animal studies
Two companion studies from one research group gave mice oral yttrium oxide nanoparticles at 50 mg/kg body weight three times a week for two weeks, after a single 2,000 mg/kg dose caused no signs of toxicity over 14 days 5 2. In liver, yttrium oxide alone did not change comet assay DNA damage or reactive oxygen species compared with controls 5. In brain, the authors report no remarkable changes, although their own table shows a higher share of DNA in comet tails after yttrium oxide (32.72%) than in controls (18.15%) with a different significance letter 2. Both studies used five mice per group and one dose, and neither measured yttrium in tissues.
In mice injected with radioactive yttrium, the metal bound strongly to bone, and the authors note that unchelated yttrium tends to accumulate in the liver and reticuloendothelial system through colloid or transferrin complexes 4. With the bone-seeking chelator EDTMP, the biological half-life was about 24 hours in liver and kidney and well over 72 hours in bone 4. This describes injected yttrium, not dietary exposure.
Plant effects
Rice seedlings exposed to yttrium oxide nanoparticles at 5 to 100 mg/L for 30 days showed no visible growth changes, but roots showed more lipid peroxidation and suppressed peroxidase and catalase under some conditions 6. Cabbage roots in water with yttrium oxide nanoparticles accumulated particles at the junction of primary and lateral roots, which the authors suggest could block roots 3.
Typical exposure routes
The cited evidence does not measure human exposure to yttrium by any route. It points to two environmental sources. The first is soil contamination around rare earth mining in southern China, as described by the authors of a pot study who spiked soil to 250 mg/kg yttrium to mimic it 1. The second is release of engineered yttrium oxide nanoparticles, which the authors of the mouse studies say could reach people through air, water and food 5.
Food sources
No cited study reports yttrium in a food as sold or harvested. The plant evidence comes from spiked hydroponic or pot experiments on crop seedlings.
In lettuce grown in soil spiked to 250 mg/kg yttrium, a bacterial inoculant lowered root yttrium by 47% and rhizosphere soil-solution yttrium by 56% 1. In cabbage seedlings, imaging detected yttrium oxide nanoparticles in roots but none in shoots 3. Rice seedling roots reached 5,014 to 11,255 mg/kg dry weight under nanoparticle exposure, with limited movement to shoots 6. No rice grain was analyzed.
| Study / location | Material / design | Metal species | Value (units and basis) | n | Interpretation / limitation |
|---|---|---|---|---|---|
| 6 Laboratory, China | Rice seedling roots, hydroponics with 5 to 100 mg/L Y2O3 nanoparticles, 30 days | Total Y | 5,014.12 to 11,255.05 mg/kg dry weight (about 50.6 to 113.5 times control) | 4 bottles per treatment | Spiked exposure; roots only; no grain analyzed |
| 1 Laboratory, China | Lettuce roots, soil spiked to 250 mg/kg Y, with bacterial inoculant | Total Y | 47% lower than uninoculated control | 5 pots per treatment | Percentage change only; absolute values in figures |
| 3 Laboratory, USA | Cabbage seedlings, 0.120 g Y2O3 nanoparticles in 0.38 L water, 22 days | Y2O3 particles | Detected in roots; none detected in shoots | 10 plants per jar | Imaging, not chemical analysis; distilled water stressed all plants |
Regulatory limits
The cited evidence states no regulatory limit, guidance value or tolerable intake for yttrium in food, water or food contact materials. The only reference-type figure is an acute oral LD50 for yttrium oxide nanoparticles in mice taken as above 2,000 mg/kg, from a screening test with no deaths 5.
Testing
Plant studies measured yttrium by ICP-MS after nitric acid and hydrogen peroxide digestion of dried tissue 6 and in digested plant tissue and pore water collected with soil solution samplers 1. Neither paper reports detection limits or reference materials. Synchrotron X-ray micro-tomography with subtraction imaging at the yttrium absorption edge was used to locate nanoparticles inside cabbage roots, but its concentration estimates were reported in inconsistent units 3.
Microbiome effects
The cited evidence does not address yttrium and the human gut microbiome. In soil, microbial consortia isolated from rare earth tailings shifted yttrium behavior in the root zone: a bacterial mix reduced lettuce uptake, while a fungal mix raised soluble yttrium around the hyperaccumulator Solanum nigrum by 89% 1.
Vulnerable populations
The cited evidence does not establish any group with higher exposure or susceptibility to yttrium.
Mitigation
The cited evidence does not establish any food processing method that removes yttrium. In spiked soil, inoculating lettuce with a bacterial consortium lowered root yttrium by 47% while raising shoot dry weight by 33%, which the authors present as a way to protect crops on contaminated land 1. For the hyperaccumulator Solanum nigrum, a fungal consortium raised yttrium availability without a matching rise in plant tissue, so its value for phytoextraction is not yet shown 1.
Open questions
- No cited study measures yttrium in any food as sold or harvested, including crops grown near rare earth mining.
- The cited evidence gives no dietary intake estimate for yttrium.
- No regulatory limit or health-based guidance value appears in the cited evidence.
- Human toxicology and chronic oral animal toxicology are not covered; the only animal data are two-week nanoparticle studies at one dose.
- Toxicity of dissolved yttrium salts, as opposed to oxide nanoparticles, is not addressed.
- Vulnerable populations are not addressed.
- Effects on the human gut microbiome are not addressed.
- Analytical quality control for yttrium in plant tissue (detection limits, reference materials) is not reported.
What remains uncertain
Everything known here about yttrium in crops comes from short, heavily spiked experiments on seedlings. They consistently show retention in roots, but none measured edible parts at harvest, and the experimenters set exposures high (5 to 100 mg/L of nanoparticles, or 250 mg/kg in soil). The lettuce study reports only percentage changes, so it cannot anchor any concentration.
The mammalian data are limited to two small studies of one oxide nanoparticle at one dose, which may share animals, plus older work on injected radioactive yttrium. They are not a basis for judging dietary risk.
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.
- Microbial-Mediated Differential Regulation of Yttrium Behavior in the Rhizosphere: Blocking Uptake in Lactuca sativa L. While Enhancing Bioavailability in Solanum nigrum LPeer-reviewed
- Yttrium oxide nanoparticles ameliorates calcium hydroxide and calcium titanate nanoparticles induced genomic DNA and mitochondrial damage, ROS generation and inflammationPeer-reviewed
- Observation of yttrium oxide nanoparticles in cabbage (Brassica oleracea) through dual energy K-edge subtraction imagingPeer-reviewed
- Yttrium-90-EDTMP: a radiotherapeutic agent in the treatment of leukaemiasPeer-reviewed
- Genotoxicity and oxidative stress induction by calcium hydroxide, calcium titanate or/and yttrium oxide nanoparticles in micePeer-reviewed
- Non-Essential Element-Based Nanoparticles in Rice: Unraveling the Impacts of Yttrium Oxide and Zirconium Oxide Nanoparticles on Root Accumulation and Antioxidant ResponsesPeer-reviewed
Sources
- Microbial inoculants and yttrium uptake by lettuce (2026; peer-reviewed): spiked-soil pot study of microbial effects on yttrium availability and uptake.
- Yttrium oxide nanoparticles in rice seedlings (2026; peer-reviewed): root accumulation and oxidative stress under hydroponic exposure.
- Imaging yttrium oxide nanoparticles in cabbage (2016; peer-reviewed): root retention of nanoparticles shown by synchrotron imaging.
- Oral yttrium oxide nanoparticles and mouse liver DNA (2023; peer-reviewed): genotoxicity screen in liver at one oral dose.
- Oral yttrium oxide nanoparticles and mouse brain DNA (2024; peer-reviewed): genotoxicity and inflammation markers in brain at one oral dose.
- Yttrium-90 bone targeting in mice (1989; peer-reviewed): biodistribution of injected radioactive yttrium.
- Yttrium-90 plaque radiotherapy for iris melanoma (2024; peer-reviewed): off-topic for dietary exposure: medical radiotherapy case series.
- Yttrium adsorbents for arsenate removal (2015; peer-reviewed): off-topic for dietary exposure: water treatment materials.
- Yttrium oxide composite sensor for glyphosate (2025; peer-reviewed): off-topic for dietary exposure: herbicide sensor.
- Yttrium garnet laser and tooth bleaching (2022; peer-reviewed): off-topic for dietary exposure: dental laser study.
Update history
No substantive edit history is available in this build. The full commit record is available in git.