What is Radiation?
When people say “radiation”, they typically mean “ionizing radiation”. Ionizing radiation is the emission of particles from matter with enough energy to ionize other matter. In simple terms, a radioactive object emits radiation, high energy particles (like gamma rays) which can change the structure of other matter. While many atoms we interact with are stable, some are not. Unstable atoms eventually come apart, changing into a more stable atom. They loose energy doing this. That excess energy is emitted as a particle (e.g. gamma ray, beta, or alpha). These emitted particles can sometimes have enough energy to pass through out skin and slice open our DNA at the atomic level. This is how radiation can cause cancer.
- Radiation comes from radioactive materials.
- Not everything is radioactive.
- Radiation is all around us, all of the time.
Is Radiation Harmful?
Strickly speaking, any dose of radiation can cause damage. All doses of radiation result in some risk. There is no totally “safe” dose.
however, that risk is proportionate to the dose. The affects of radiation are random and their likelihood increases with exposure. For example, of the people exposed to the Hiroshima bomb, some never developed any cancer and some died quickly from it. Over all, their likelihood of cancer was greater.
Think of this like drinking alcohol:
Every sip of alcohol carries a tiny chance of cancer or liver issues. Limited consumption (what most people drink) carries a low risk, whereas high levels of consumption have been linked to elevated risks. Both long term consumption and short term large doses of alcohol can be of trouble.
The same is roughly true of radiation. Long term low dose exposure from our natural background and common medical procedures (e.g. dental x-ray) do carry a risk, but the risk is low. Adding additional exposure, such as living in a contaminated area, having high dose procedures performed (e.g. CAT scan), do raise your risks.
- We are all exposed to radiation from birth until death.
- There is no safe dose.
- A dose of radiation does not mean you will get cancer, but that your chances are raised (*below 1 Sv, a rate only seen at meltdowns and nuclear bombings)
Can a Geiger counter be used to test food for radiation?
While a Geiger counter can tell you if your food is grossly radioactive. If you were caught in a nuclear attack or accident and fallout may have contaminated your food, a Geiger counter could tell you if the food was radioactive enough to cause immediate harm. The problem is that most people are not in such a situation. Most people are really looking to find trace radiation. The Geiger counter cannot be reasonably used to detect the low levels of radiation with fallout outside of the immediate incident area. There are two reasons why this is the case: 1. Geiger counters are not sensitive enough to detect trace radiation*. 2. Geiger counters cannot differentiate between the radiation sources. In effect, a Geiger counter can tell you something is radioactive, but not why.
The proper tool for testing food is a spectrometer (such as a Gamma Spectrometer).
*A Geiger counter can detect very low trace levels, but this requires careful testing and significant statistical skills. Therefore it is unreasonable for the average person.
- Many foods are naturally radioactive.
- A dose which is above the safe limits set by your country may still be too low to detect on a Geiger counter
Video showing natural radioactivity in food
Why is my rain radioactive?
Most of the radiation detected by Geiger counters from rain is from Radon Washout, a processes whereby radon in the air (decays from natural uranium around the world) is “washed” out and falls to the ground in the rain. After a few hours, the samples taken will typically return to the normal background readings of your Geiger counter (if they do not, you might have something else). Readings can be as high as several thousand counts per minute on a Geiger counter. This is a natural process and not man made or linked to Chernobyl or Fukushima.
- Radon washout has existed since rain first fell on our planet.
- Radon is the second leading cause of lung cancer and should be taken seriously.
How can I test for Radiation?
You can buy a detector and look at your radioactive world! various detectors detect various things and are used for different tasks:
- Food testing – Gamma Spectrometer
- Finding uranium/thorium – Scintillator
- Finding radioactive objects around the house – Large “pancake” style Geiger counter
- Area monitoring – Gamma/Beta Geiger counter
- Extremely high dose rates – Ionization Chamber
- Radon – Ion chamber radon detector
- The greater the sensitivity, the greater the cost.
- With detectors, it is the size that counts.