Fear of RadioactivityPrint this page 

Last week, a man walked into the Sky Bridge Medical Center in Denver, Colorado in the United States with a rock on his pocket. The rock was radioactive. The hospital responded by sending an emergency team to test the man and the rock. During this incident, the emergency room in the hospital was closed for over an hour while the team sought to determine the effects the radioactive rock had on the hospital and the medical personnel. The emergency response team later determined that the rock was not harmful and had neither affected the patient nor the hospital staff. The fire authority spokesman noted that there was nothing unique about the rock - as it was a rock that can be found naturally in the outdoors.

What is of interest in the above real life story is how often we come across these radioactive rocks that occur naturally; hence lending credence that radioactivity is a part of our very lives. Radioactivity is natural and is not only man made. Radioactive decay is part of the design of our magnificent universe - without it life would not exist as we know it today.

Although radioactivity occurs naturally, it does not always mean that it is safe. Like toxic materials, a certain amount of radioactivity could severely impact our health. However, unlike toxic materials, radioactive materials decay over time and will eventually become safe. In layman's terms, if you have two barrels with one containing radioactive material and the other barrel with toxic material (picture below), over time the hazard from the radioactive material barrel will reduce and diminish while the hazard from the toxic material barrel will continue to exist at the same dangerous levels. Toxic materials such as batteries and engine oil are produced in our manufacturing factories; and these toxic materials NEVER decay. Hence, toxic materials build-up is more detrimental to human health in comparison to radioactive materials.

Metals like uranium takes about 4.5 billion years to reach its half life. What this means is that after 4.5 billion years, the activity and quantity of uranium reduces by half. Again, in other words, if we have 1 kilogram of uranium today, after 4.5 billion years, about 500g of uranium would be left.

Let us take another look at the impact of this mathematical statement. It takes 4.5 billion years for 500g from 1000g of uranium to change from uranium into another element. This is equivalent to 1.11 micrograms of uranium that will decay in a year. What this means is that per year, or per hour, or per second, there is very little activity happening with uranium. In contrast, elements with very short half lives will have very high activity and radiation because they decay much quicker.

Thus, keep this in mind the next time someone approaches you saying "but radioactivity of uranium can last for millions of years". It is true that radioactivity of uranium is billions of years, but it does not necessarily mean that it is unsafe. There are a lot other factors involved to reflect on before a radioactive material can be classified unsafe.