What percentage of the lead exposed to the body is directed to the bones?

The correct choice indicates that a significant percentage of lead exposed to the body—specifically 90%—is directed to the bones. This is crucial for understanding how lead interacts with the human body, especially considering its toxic effects. When lead is absorbed through the gastrointestinal tract or lungs, it travels through the bloodstream and can accumulate in various tissues.

Bones are particularly susceptible to lead accumulation due to their structure and the body’s natural processes, where lead can replace calcium in the bone matrix. This absorption into the bones can lead to long-term health effects because lead stored in the bones can be released back into the bloodstream over time, especially during periods of high bone turnover, such as pregnancy or illness.

Understanding this process is vital for professionals working in environments where lead exposure is a risk, as it underscores the importance of monitoring and mitigating lead levels to protect overall health.