Radiation and Food Safety

Introduction

The definition of radiation in science refers to the energy carried by waves or particles. In common conversations, radiation refers to the harmful ionising radiation, which are particles with enough energy to break chemical bonds, cause mutations to DNA and increase your risk of cancer.

Radioactive materials are high energy, unstable materials that spontaneously decay to more stable forms with emission of radiation. Humans are constantly exposed to radiation from outer space (cosmic radiation), the environment, medical imaging scans, and food. For example, in the environment, radon – a radioactive gas – is naturally found in the air we inhale. Some gemstones, such as zircon, are also naturally radioactive. Other radioactive elements such as uranium, thorium, and actinium are naturally present in the Earth’s minerals.

This article provides more information on the occurrence and safety of radioactive materials found in food.

What is natural radiation in food?

Did you know we are exposed to natural radiation in food all the time? All food naturally contains radioactive materials. Potassium – an essential nutrient for health – has a small percentage in the radioactive form (potassium-40). Radium – another radioactive element – is also commonly found in food containing potassium. Hence, all food, particularly food high in potassium like bananas, carrots, potatoes, leafy vegetables, salt, peanuts and red meat, are "radioactive".

Although radiation can damage our DNA, our bodies can repair the damage. The natural radiation from our food and environment, together with the cosmic radiation from outer space is well within the levels that the human body can tolerate. Chart 1 illustrates the levels of radiation that a typical human is exposed to.

As part of SFA's food safety monitoring regime, SFA's National Centre for Food Science (NCFS) regularly monitors the background radioactivity levels for common food items such as eggs, vegetables, milk and fish. The radiation levels in the surveyed food were found to be consistent with naturally occurring levels.