How to reduce radiation exposure around humans
Posted by LiLeah on
Radiation Sources and Doses
Sources of are all around us all the time. Some are natural and some are man-made. The amount of radiation absorbed by a person is measured in dose. A dose is the amount of radiation energy absorbed by the body.
Background Radiation
is present on Earth at all times. The majority of background radiation occurs naturally from minerals and a small fraction comes from man-made elements. Naturally occurring radioactive minerals in the ground, soil, and water produce background radiation. The human body even contains some of these naturally-occurring radioactive minerals. Cosmic radiation from space also contributes to the background radiation around us. There can be large variances in natural background radiation levels from place to place, as well as changes in the same location over time.
Cosmic Radiation
Cosmic radiation comes from extremely energetic particles from the sun and stars that enter Earth’s atmosphere. Some particles make it to the ground, while others interact with the atmosphere to create different types of radiation. Radiation levels increase as you get closer to the source, so the amount of cosmic radiation generally increases with elevation. The higher the altitude, the higher the dose. That is why those living in Denver, Colorado (altitude of 5,280 feet) receive a higher annual radiation dose from cosmic radiation than someone living at sea level (altitude of 0 feet).
Radioactive Materials in the Earth and in Our Bodies
Uranium and thorium naturally found in the earth are called and are the source of terrestrial radiation. Trace amounts of uranium, thorium and their decay products can be found everywhere. Terrestrial radiation levels vary by location, but areas with higher concentrations of uranium and thorium in surface soils generally have higher dose levels.
Traces of radioactive materials can be found in the body, mainly naturally occurring potassium-40. Potassium-40 is found in the food, soil, and water we ingest. Our bodies contain small amounts of radiation because the body metabolizes the non-radioactive and radioactive forms of potassium and other elements in the same way.
Man-made Sources
A small fraction of background radiation comes from human activities. Trace amounts of radioactive elements have dispersed in the environment from nuclear weapons tests and accidents like the one at the Chernobyl nuclear power plant in Ukraine. Nuclear reactors emit small amounts of radioactive elements. Radioactive materials used in industry and even in some consumer products are also a source of small amounts of background radiation.
Average U.S. Doses and Sources
All of us are exposed to radiation every day, from natural sources such as minerals in the ground, and man-made sources such as medical x-rays. According to the National Council on Radiation Protection and Measurements (NCRP), the average annual radiation dose per person in the U.S. is 6.2 millisieverts (620 . The pie chart below shows the sources of this average dose.
Most of our average annual dose comes from natural sources:
- The radioactive gases radon and thoron, which are created when other naturally occurring elements undergo radioactive decay.
- Space (cosmic radiation).
- Naturally occurring radioactive minerals:
- Internal (in your body).
- Terrestrial (in the ground).
Another 48 percent of the average American’s dose comes from medical procedures. This total does not include the dose from radiation therapy used in the treatment of cancer, which is typically many times larger.
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How to reduce radiation exposure around humans？
1. Basic principles of physical protection
Time: Reduce exposure time (such as shortening the length of mobile phone calls).
Distance: Increase the distance from the radiation source (such as staying away from microwave ovens and Wi-Fi routers).
Shielding: Use radiation protection materials to block or absorb radiation.
2. Physical protection methods for different radiation sources
Electromagnetic radiation (non-ionizing radiation) protection
Sources: mobile phones, Wi-Fi, Bluetooth, microwave ovens, computers, high-voltage wires, etc.
(1) Radiation protection products
Mobile phone radiation protection stickers/mobile phone cases
Some mobile phone cases with metal coatings can reduce SAR (specific absorption rate), but the effect is limited.
A more effective method is to use hands-free headphones or AirTube headphones (to reduce head radiation).
Radiation protection clothing (pregnant women/daily use)
Silver fiber/metal fiber fabrics: can shield some low-frequency radiation from Wi-Fi, mobile phones, etc. (shielding effect is better above 30dB).
Applicable scenarios: pregnant women, people who have long-term contact with electronic devices (such as IT workers).
Wi-Fi router shield
Metal mesh shields can reduce signal radiation (but will reduce Wi-Fi coverage).
Alternative solution: turn off the router at night or use an Ethernet wired connection.
Computer/monitor radiation protection screen
Some metal-coated blue light protection screens can reduce electromagnetic radiation (but their main function is to protect the eyes).
(2) Home optimization
Keep distance:
Do not place mobile phones at the bedside (≥1 meter).
Keep more than 1 meter away when the microwave oven is running.
Reduce use:
Replace Wi-Fi with wired networks (especially when sleeping).
Use low-radiation home appliances (such as induction cookers instead of microwave ovens).