Context: Most ingested uranium is excreted during digestion. Only 0.5% is absorbed when insoluble forms of uranium, such as its oxide, are ingested, whereas absorption of the more soluble uranyl ion can be up to 5%. However, soluble uranium compounds tend to quickly pass through the body, whereas insoluble uranium compounds, especially when inhaled by way of dust into the lungs, pose a more serious exposure hazard. After entering the bloodstream, the absorbed uranium tends to bioaccumulate and stay for many years in bone tissue because of uranium's affinity for phosphates. Uranium is not absorbed through the skin, and alpha particles released by uranium cannot penetrate the skin.

Question: What happens to a majority of ingested uranium?
Answer: excreted

Question: Up to what percentage of uranyl ion can be absorbed when ingested?
Answer: 5%

Question: About what percentage of uranium oxide is absorbed when ingested?
Answer: 0.5%

Question: What does uranium have an affinity for?
Answer: phosphates

Question: Where does uranium accumulate in the body?
Answer: bone tissue

Question: What happens to a minority of ingested uranium?
Answer: Unanswerable

Question: Up to what percentage of uranyl ion can be absorbed when digested?
Answer: Unanswerable

Question: About what percentage of uranium dioxide is absorbed when ingested?
Answer: Unanswerable

Question: What does uranium not have an affinity for?
Answer: Unanswerable

Question: Where doesn't uranium accumulate in the body?
Answer: Unanswerable