A series of questions and answers about ionising radiation and its presence in consumer products including food.
What is natural background radiation?
Ionising radiation is a type of energy released by atoms that travels in the form of electromagnetic waves (e.g. gamma, X-rays) or particles (e.g. neutrons, beta or alpha). Unstable elements, or radioniclides like uranium-238, spontaneously disintegrate and emit ionising radiation. Ionising radiation has enough energy to cause chemical changes by breaking chemical bonds. This effect can cause damage to living tissue.
Ionising radiation has many beneficial applications, including uses in medicine, industry, agriculture and research. As the use of ionising radiation increases, so does the potential for health risks if not properly used or contained. The risk from exposure to high radiation levels is relatively well quantified. At these levels acute health effects such as skin burns or acute radiation syndrome can occur. Although the scientific evidence for increased health risk is more limited at low doses of ionising radiation, there may be risk of longer term health effects such as cancer.
Are all consumer products we use in every day life radioactive?
Yes. Everything we encounter in our daily lives contains radioactive material. This includes the air we breathe, the water we drink, the food we eat and the ground we walk upon. Radioactive material can also be found in the consumer products we purchase and use.
This is because sources of natural radiation have existed since the Earth was formed and are found in rocks and soil such as the radioactive isotope uranium. Other radiation sources result from human activities. These include radiation from medical procedures (e.g. X-rays), radioactive fallout from nuclear weapon detontations and radioactive waste from nuclear power stations. They can also include radiation from building materials, mining wastes, fertiliser and other materials made from minerals containing naturally occurring radionuclides.
For further information refer to our fact sheet Ionising Radiation and Health
I have granite benchtops and tiles in my home. Should I be concerned for my family's health?
No. Granite and many other stone based materials found in homes will contain small levels of naturally occurring radioactive isotopes such as uranium and thorium, and their radioactive decay products. The levels can vary considerably, depending on the source of the stone. Measurable levels of these elements are also found in almost all ordinary rocks, soil and building material. Radiation doses are small and are not a concern to health.
For further information refer to our fact sheet Ionising Radiation and Health.
Could the building products in my home contain harmful levels of radioactivity?
No. Many building products are manufactured from materials which contain naturally occurring radioactive isotopes such as uranium, radium and thorium. The radiation levels within buildings made of masonry material, including bricks, cement or concrete, are higher than buildings made of wood. Radiation from building products will result in small radiation doses and is not a concern to health.
ARPANSA has assessed radiation levels in homes. For further information on this research refer to our fact sheet Radon Exposure and Health.
Should I be concerned about the fertiliser I use to grow edibles in my garden?
Some fertilisers are manufactured from rocks that contain naturally occurring radioactive minerals. The radioactive content of these fertilisers varies considerably and depends both on their levels in the original mineral and the production process. Whilst protection against inhalation of fertiliser is recommended for non-radiological reasons, the level of radioactive isotopes within a typical fertiliser is low and is further diluted when added to soil. This means that only trace amounts of radioactive isotopes will be uptaken in food grown in these fertiliser types. Consumption of food containing only trace amounts of radioactive isotopes is not a concern to health.
Does mineral jewellery contain radioactivity that could be a health concern?
Some jewellery may contain elevated levels of radioactive isotopes. In some cases, particularly where 'scalar energy' or 'quantum energy' is mentioned to advertise health benefits in pendants, the beta and gamma radiation levels observed may be high enough to deliver a radiation dose to the skin and underlying tissue which exceeds the public dose limit if worn next to the skin for prolonged periods.
If you have any concerns you should contact us for specific advice.
I have antique uranium glassware in my house. Should I be concerned about the radiation levels?
No. Glassware, especially antique glassware with a yellow or greenish colour, contains small amounts of uranium compounds to create this colour. This glass was often used in the past for tableware and has now become very collectable. Even in large collections, the levels of uranium remains very low and will result in small radiation doses that are not a concern to health. In recent years uranium glass is used in beads and marbles for decorative novelties.
Should I be concerned that my camera lens contains harmful levels of radioactive material?
No. Thorium dioxide is radioactive and was historically added to optical glasses and camera lenses to increase the refractive index to produce high-quality lenses and glasses. This use of thorium ended in the late 1980s. Lanthanum oxide has replaced thorium dioxide in almost all modern high-index glasses. Exposure to thorium dioxide found in camera lenses is very small and is not a concern to health.
Should I be concerned about smoke detectors that contain radioactive material?
No. Some smoke detectors do contain small amounts of radioactive material. Smoke detectors and alarms are important home safety devices. The radiation dose to the occupants of a house from a domestic smoke alarm is negligible. Due to the small amount of radioactive material used and the secure means of its enclosure, these smoke alarms will not cause any risk to human health from radiation exposure under all normal conditions, including during a fire.
For further information refer to our fact sheet Smoke Detectors and Health.
Do gas mantles used in my camping lanterns contain harmful levels of radioactive material?
No. Only small quantities of the radioactive isotope thorium were used in gas mantles or lanterns to produce very bright, white light. Using mantles that contain thorium may result in very small radiation doses and is not a concern to health. Although extremely unlikely, there is a small increase in risk if powder from the burnt mantle is broken and inhaled or ingested. In recent years thorium has been replaced by non-radioactive yttrium, which produces the same intense white light.
If you have any concerns you should contact us for specific advice.
Do cigarettes contain harmful levels of radioactivity?
The tobacco leaves used in making cigarettes contain small amounts of naturally radioactive isotopes, particularly lead-210 and polonium-210. The radioactive content of tobacco leaves depends heavily on soil conditions and fertiliser use. Research indicates that lead-210 and polonium-210 are present in tobacco smoke as it passes into the lung. International studies indicate that smoking 20 cigarettes a day for a year would result in radiation doses of less than the public dose limit.
However, there is scientific evidence that a smoker who is also exposed to radioactive radon gas has a much higher risk of lung cancer. For further information on radon refer to our fact sheet Radon Exposure and Health.
Do televisions emit harmful radiation?
No. Older televisions and monitors that contained a cathode ray tube can emit a small amount of radiation during operation. The very small amount of radiation escaping the front of these monitors is not of a concern to health. There is no measurable ionising radiation from plasma, LCD or OLED flat screen TVs, though like most electronic devices they do produce a wide spectrum of electromagnetic radiation.
For further information on electromagnetic radiation refer to our fact sheet Measuring Magnetic Fields.
I work with thoriated tungsten welding rods. Should I be concerned about my health?
No. The small amounts of the radioactive isotope thorium in thoriated tungsten welding rods will not cause any risk to human health from radiation exposure when good workplace safety procedures, such as the use of face masks and the provision of good ventilation, are undertaken. Recently thorium has been replaced by non-radioactive lanthanum by some manufacturers.
I have dentures or fillings made of porcelain. Should I be concerned if they are radioactive?
Modern porcelain used in dentures and fillings contain only small amounts of the radionuclide potassium-40 which is found naturally in porcelain. At these levels radiation doses are very low and are not a health concern.
Up until the 1980s uranium compounds were added to some porcelain mixes to improve the natural white colour. International studies indicate that radiation levels are low and are not a concern to human health.
If you have any concerns you should contact us for specific advice.
Does contamination occur when radiation is used to sterilise food or household products?
No. The purpose of irradiating (the process where an object is exposed to radiation – gamma rays are used in this case) food is to kill harmful bacteria and to extend the shelf-life of the food. No radioactivity is introduced into the food by the sterilisation treatment. In Australia, herbs and spices, herbal infusions, and some fruits and vegetables can be irradiated. Foods that are treated must be labelled with a statement that the food, ingredients or components have been treated with ionising radiation.
For further information refer to the Food Standards Australia New Zealand link below:
Food irradiation | Food Standards Australia New Zealand
Should I be concerned about my health from radioactivity in gemstones?
No. The small amounts of radioactive material found in gemstones result in very low radiation doses and are not a health concern. Most gemstones contain naturally occurring radionuclides. Some gemstones are irradiated (the process where an object is exposed to radiation – electron or neutron bombardment or gamma rays are used in this case) in order to enhance or alter their colours. These stones are stored until the radioactivity is below the concentration necessary to reach the exemption criteria for supply to the public (and thus will not cause any risk to human health from radiation exposure). The most commonly irradiated stone is topaz, which becomes blue as a result of the exposure to ionising radiation. Tourmaline, zircon, beryl, quartz, or coloured diamonds are examples of irradiated gemstones encountered in the marketplace. Some gemstones containing natural radionuclides are purely collectors' items and are not used in jewellery.
Does food contain radiation?
Radiation is energy travelling as waves or particles. Ionising radiation, which has enough energy to remove electrons from cells, is produced from natural and artificial radioactive materials. It is present in the environment because naturally occurring radioactive materials such as uranium, thorium and potassium exist in rocks and soil where plants grow. Natural radioactivity is present in the air we breathe, food we eat, water we drink and even in our bodies.
How much radiation is in Brazil nuts?
Recent scientific reviews have confirmed that while Brazil nuts naturally contain small amounts of radium, the radiation dose from eating them remains very low. 30 grams of Brazil nuts contains 0.001 mSv. By comparison, a typical dental x-ray exposes you to 0.01 mSv or about the equivalent of 300g of Brazil nuts.
How much radiation you are exposed to each year from Brazil nuts depends on how often, and how much of them you eat. We estimate that the Because radium content varies between Brazil nuts, annual doses can range from 220 µSv per year if you eat two Brazil nuts every day, which is 22% of the annual limit, or 88 µSv per year if you eat them occasionally. Daily consumption remains well below the public exposure limit.
Precautionary guidance advises avoiding Brazil nuts during pregnancy and breastfeeding, due to radium’s ability to accumulate in developing bone tissue. Even if a pregnant person has eaten Brazil nuts daily, the associated radiation dose remains very small and far below levels known to cause harm. The guidance to avoid them is precautionary, not a response to evidence of risk. We recommend speaking with your doctor if you have questions or are concerned.
How much radiation is in a banana?
Bananas are a common example of a natural radiation source. They contain high levels of potassium, and a small amount of this is radioactive. The amount of radiation is extremely small, and far less than the total natural ‘background radiation’ we are exposed to each year. Bananas are estimated to have about 0.0001 mSv of radiation per serve. By comparison, a flight from Australia to Europe gives people a dose of 0.1 mSv or the equivalent of eating 1000 bananas.
How does ARPANSA measure radiation in food?
ARPANSA analyses a wide range of foods that are found in our diet. These foods are tested in our specialised radiochemistry laboratory using sensitive equipment that can measure very small amounts of radioactive substances. The amount of radioactivity in food is almost undetectable so we need highly sensitive equipment that can measure tiny amounts of radioactivity.
What types of radiation are found in food?
Food, like everything, is made up of atoms. Atoms are extremely small particles that are the basic building blocks of ordinary matter – a bit like ingredients you could say! Elements are made up of different types of atoms. Versions of these elements can be radioactive. That is, they release radiation. Radiation in our diet comes from foods and drinks that contain radioactive isotopes. Some naturally occurring elements in food, such as potassium, have radioactive isotopes. Other elements like radium, thorium and uranium may also be present at trace levels. While not essential for health, the amounts present in food are extremely small and pose no health risk. The benefits of a healthy diet that includes food containing them far outweigh the very low, sometimes undetectable radiation exposure.
How are imported foods monitored?
We work with Food Standards Australia New Zealand (FSANZ) to ensure that Australia maintains strict radiation monitoring protocols. Following global events like Chernobyl and Fukushima, Australia did enhance screening of imported foods, particularly from affected regions. But these actions were precautionary and did not result in major domestic recalls. Based on assessments provided by leading international authorities such as the United Nations Scientific Committee on the Effects of Atomic Radiation, we know how much radiation is contained from dietary sources around the world.
Has radiation from nuclear accidents affected food in Australia?
Artificial or human-made radionuclides are present in the environment in some locations because of fallout due to atmospheric nuclear weapons testing conducted between 1945 and 1980, from nuclear power plant reactor accidents such as the Chernobyl accident in 1986 and from the Fukushima Dai-ichi accident in 2011.
Our technical report on radiation in food from 2019 found that the artificial radionuclides, 60Co, 134Cs and 241Am were not detectable in any of the food samples analysed.
Caesium-137 was detected at very low activity concentrations in 2.4 per cent of the samples in that study. Cs-137 is a radioactive isotope produced during nuclear fission. It enters the environment as a fallout product from nuclear detonations, where it is dispersed into the atmosphere and deposited onto land and water through rainfall and dust settling. Health impacts of consuming food containing Cs-137 at levels below regulatory limits are negligible. Cs-137 can be found in very small quantities in some meats and vegetables like beef, fish, milk, peanut butter and carrots.
How do radiation levels in food compare to other everyday exposures?
We have a fact sheet on our website that explains how much radiation you receive in an average year from different natural and human sources: https://www.arpansa.gov.au/understanding-radiation/radiation-sources/more-radiation-sources/ionising-radiation-and-health
Our scientists estimate that people receive less than 1 mSv of their radiation dose each year from ingesting food and drink. This is part of the 1.7 mSv of background radiation that scientists estimate we are exposed to each year in Australia. 30 grams of Brazil nuts contains 0.001 mSv. By comparison, a typical dental x-ray exposes you to 0.01 mSv or the equivalent of 300g of Brazil nuts.
