有报道证实，稀土虽非生物的必需元素, 但能被生物吸收 ,由于稀土添加剂

It has been reported that although rare earth is not a biologically essential element, it can be bioabsorbed. Because rare earth additives have a certain role in promoting biological growth at low doses, they are used in livestock, poultry and fish breeding High concentration has obvious inhibitory effect, more and more rare earths enter the bio-chain and food chain, causing potential negative impact on the agricultural ecological environment. In all rare earths, lanthanum ions are similar to calcium ions, and have a high affinity for human bones. They may replace calcium ions in bones, which will inevitably have an effect on bone calcium and phosphorus metabolism. Li Rongchang et al. (2004) reported that after feeding rats at a low dose of 2 mg / kg body weight / day lanthanum nitrate for 6 months, the changes in bone structure caused by lanthanum accumulation in the bone were studied. It showed that the trabecular bone became thinner, thinner, fractured and appeared a large number of depressions, and the increase of crystallinity and other changes, suggesting that long-term intake of low-dose lanthanum nitrate in rats can lead to accumulation in bone, causing changes in bone microstructure. After entering the blood, lanthanum can be distributed in multiple tissues and organs throughout the body, mainly accumulating in the liver, accounting for about 50% of the absorption, and can also enter the body through the blood-brain barrier

It has been reported that rare earths, although anonynonic essential elements, but can be biologically absorbed, because rare earth additives in low-dose conditions have a certain role in promoting biological growth and are used in livestock breeding, poultry breeding, fish breeding, but high concentrations have obvious inhibitory effects, more and more rare earths into the biological chain, food chain, the agricultural ecological environment has a potential negative impact. In all rare earths, niobium ions and calcium ions are similar, have a high affinity for human bones, may replace the calcium ions in the bone, is bound to have an impact on bone calcium phosphorus metabolism. Li Rongchang et al. (2004) reported that 6 months after feeding rats with low doses of 2 mg/kg weight/day, the bone structure changes caused by the accumulation of radon in the bone were studied, and the results of the electro-mirror observation showed that the bone girders became thin, thin, fractured and a large number of depressions, and the crystallinity increased, suggesting that long-term intake of low-dose nitric acid could lead to bone build-up. Radon can be distributed throughout the body after entering the blood, mainly in the liver accumulation, about 50% of the absorption, but also through the blood-brain barrier into the body

It has been reported that although rare earth is not an essential element of living things, it can be absorbed by living things. Because rare earth additives can promote the growth of living things under low dose conditions, they are used in livestock and animal feeding, poultry feeding and fish feeding. However, high concentration of rare earth has obvious inhibition effect. More and more rare earth enters the biological chain and food chain, It has a potential negative impact on the agricultural ecological environment. Among all the rare earth elements, lanthanum ion is similar to calcium ion, which has a high affinity for human bone, may replace calcium ion in bone, and will inevitably affect the metabolism of calcium and phosphorus in bone. Li Rongchang et al. (2004) reported that six months after the rats were fed with 2 mg / kg body weight / day low-dose lanthanum nitrate by gavage, the changes of bone structure caused by lanthanum accumulation in the bone were studied, The increase of crystallinity suggests that the long-term intake of low dose lanthanum nitrate may lead to the accumulation of lanthanum in bone and the change of bone microstructure. After entering the blood, lanthanum can be distributed in many tissues and organs of the whole body, mainly accumulating in the liver, accounting for about 50% of the absorption, and can also enter the body through the blood-brain barrier<br>