The Brazil nut is the most radioactive food, as it naturally contains 0.5 millirem of radium, or a level of radiation is approximately 1,000 times greater than most foods. To put it into perspective, the average person receives approximately 300 to 620 millirem of radiation in total each year, mainly from natural sources. Radium is a radioactive metal that occurs naturally in the environment, such as in soil. However, high levels can significantly damage human cells. Brazil nuts have such high levels of radium because of the deep roots of the trees that grow them. Only minimal amounts of radiation actually stay in the body after eating Brazil nuts. Therefore, no negative health effects tend to occur as a result.
More about sources of radioactivity:
- Smoking is one of the biggest sources of radiation in the body, at over 16,000 millirem a year, because tobacco actually absorbs and retains radioactivity materials in harmful, concentrated amounts.
- People who use low sodium salt tend to absorb 10 millirem of radiation each year in the form of potassium chloride.
- The US Capitol Building is radioactive because it is constructed of granite, which emits uranium—the government building is estimated to give off 85 millirem of radiation annually.