A typical chest X ray exposes a patient to an effective dose of 0.02 mSv. How many rem is this, and how many chest X rays would a patient have to receive before biological effects would be observed? (The limit from Table 11.6 is >25 rem.)

Verified step by step guidance

1. Convert the dose from millisieverts (mSv) to rem using the conversion factor: 1 mSv = 0.1 rem.
2. Calculate the dose in rem by multiplying the given dose in mSv (0.02 mSv) by the conversion factor (0.1 rem/mSv).
3. Determine the threshold dose in rem for biological effects from Table 11.6, which is >25 rem.
4. Calculate the number of chest X-rays needed to reach the threshold dose by dividing the threshold dose (25 rem) by the dose per X-ray in rem.
5. Interpret the result to understand how many X-rays are required before biological effects might be observed.

Key Concepts

Effective Dose and Conversion

The effective dose is a measure of the biological effect of radiation on human tissue, expressed in sieverts (Sv) or millisieverts (mSv). To convert mSv to rem, a factor of 0.1 is used, meaning 1 mSv equals 0.1 rem. Therefore, 0.02 mSv corresponds to 0.002 rem, which is crucial for understanding radiation exposure levels.

Biological Effects of Radiation

Biological effects of radiation refer to the potential damage that ionizing radiation can cause to living tissues, which can lead to health issues such as cancer. The threshold for observable biological effects is often set at 25 rem, indicating that doses below this level are generally considered safe for most individuals, while higher doses increase the risk of adverse effects.

Radiation Exposure Limits

Radiation exposure limits are established guidelines that define the maximum allowable doses of radiation for individuals, particularly in medical settings. These limits are based on research and statistical data regarding the risks associated with radiation exposure, helping to protect patients and healthcare workers from potential harm while ensuring necessary diagnostic procedures can be performed.