This controlled feeding study switched rats and guinea pigs onto pelleted diets of known strontium content and isotope ratio and followed how bone and continuously growing incisors took on the new signal. A strontium-rich mineral water measurably shifted the rats’ tissue isotope ratios, showing that drinking water can be a meaningful strontium source when its strontium content is high.
Key numbers
- Pellet strontium (bulk): rat supplier pellet 4.8 µg/g; insect pellet 11.7 µg/g; plant pellet 19.6 µg/g; meat pellet 26.4 µg/g; standard pellet 20.0 µg/g; standard pellet with 4 percent loess 31.1 µg/g; with 4 percent kaolin 21.2 µg/g (Table 2, p. 7).
- Weak-acid leachates of pellets held only a small part of bulk strontium, for example 0.54 to 1.2 µg/g for the insect pellet (Table 2, p. 7).
- Zurich tap water 0.29 µg/g (about 0.29 mg/L, n = 14); strontium-rich mineral water 8.6 µg/g, reported in the text as 8.6 mg/L, about 30 times the tap water (Table 2, p. 7; p. 7 text; Discussion, p. 19).
- Rats given the plant diet with the strontium-rich water had significantly different bone and incisor isotope ratios from rats on the same diet with tap water (p below 0.01 for bone) (Discussion, p. 19).
- Rat incisors fully turned over to the new diet signal within 54 days, while guinea pig incisors still carried part of the earlier signal (Discussion, p. 19).
Methods (brief)
Animals were switched from supplier diets to experimental pellets; diets, pellet leachates (pH 1 and 3) and waters were analyzed for strontium concentration and isotope ratio; bone and incisor enamel were analyzed by solution and laser ablation multi-collector ICP-MS. Mixing models combined water and food end members.
Evidence fitness
Supports measured strontium concentrations in laboratory animal feeds and two drinking waters, and the point that high-strontium water contributes to skeletal strontium. It does not support statements about human intake or toxicity.
Limitations
Animal feeds are formulated laboratory pellets, not human foods. Water values are single brand and single city measurements. Bioavailability was approximated by acid leachates rather than measured absorption.
Related evidence
- Strontium
- Water
- ICP-MS — Inductively coupled plasma mass spectrometry
- ICP-OES — optical emission spectrometry
Update history
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