Limited access

Upgrade to access all content for this subject

A banana equivalent dose (abbreviated BED) is an informal expression of ionizing radiation exposure. It gives the potential dose of naturally occurring radioactive isotopes one is exposed to by eating one average sized banana. Although the amount in a single banana is small in environmental and medical terms, the radioactivity from a truckload of bananas is capable of causing a false alarm when passed through a Radiation Portal Monitor used to detect possible smuggling of nuclear material at U.S. ports.

The radiation exposure from consuming a banana is approximately 1% of the average daily exposure radiation. An average person is exposed to 100 banana equivalent doses (100 BED) per day in daily life. The maximum permitted radiation leakage for a nuclear power plant is equivalent to 2,500 BED, while a chest CT scan delivers 70,000 BED. A lethal dose of radiation treatment is approximately 80,000,000 BED. A person living 10 miles from the Three Mile Island nuclear reactor received 700 BED of exposure to radiation, the equivalent of eating two bananas each day for a year.

Which activities will result in the least and the greatest amount of exposure to radiation? Make only two selections, one in each column.

Least

Greatest

Take a walk near 3 mile island every other day for six months.

Walk by a power plant once a month for two years.

Receive one chest CT scan.

Eat 1 banana every day for 50 years.

Eat 50 bananas every day in a leap year.

Select an assignment template