Hello, Chuck! With all this discussion of radiation leaks from Japan’s nuclear power plant, it made my family and me wonder: Where else is radiation seeping into our homes and lives? – “Calm but Concerned,” Tacoma, Wash.
I’m going to answer this question in a two-part series. I’m calling this week’s column “Know Your Radiation” and next week’s column “Calculate Your Radiation.”
This week, Japanese authorities discovered radioactive material above the legal limit in milk, water from a Tokyo purifying station and 11 types of vegetables, including spinach, broccoli, turnips, cabbage and parsley.
The radiation, of course, is coming from the damaged Fukushima Dai-ichi nuclear facility, which was crippled by the colossal double hit of a magnitude-9.0 earthquake and a tsunami two weeks ago. The amount detected is twice what is considered safe for infants, prompting the greater Tokyo area’s 39 million residents to be understandably fearful and U.S. officials to announce a ban on items from regions close to the facility.
Japanese officials reported this past week that the water from the Tokyo purifying station showed elevated radiation levels: 210 becquerels of iodine-131 per liter of water, more than twice the recommended limit of 100 becquerels per liter for infants. Another measurement taken later at a different site showed the level was 190 becquerels per liter. (The recommended limit for adults is 300 becquerels.)
On March 21, the British Columbia Centre for Disease Control reported that traces of radiation from the reactor leaks in Japan had been picked up by monitors in British Columbia.
On March 22, the Environmental Protection Agency released a report that “preliminary monitor results in Hawaii detected minuscule levels of an isotope that is consistent with the Japanese nuclear incident.”
On March 23, the Colorado Department of Public Health and Environment announced that minuscule levels of radiation from the Dai-ichi nuclear power plant had been detected in Colorado.
The EPA, however, spoke a common word from all the detection agencies when it explained the harmless nature of the radiation levels abroad: “In a typical day, Americans receive doses of radiation from natural sources like rocks, bricks and the sun that are about 100,000 times higher than what we have detected coming from Japan. For example, the levels we’re seeing coming from Japan are 100,000 times lower than what you get from taking a roundtrip international flight.”
The truth is that we are exposed every day to radiation, by natural and synthetic means, so we should be cautious and educated about radiation’s forms, nature and effects, especially when it comes to overexposure. We must take responsibility for our own health.
In its simplest definition, radiation is basically energy traveling through space. There are two basic types: nonionizing and ionizing. Nonionizing (i.e., not having sufficient energy to ionize an atom) is electromagnetic radiation ranging from extremely low frequency to ultraviolet. And there are two types of ionizing radiation (i.e., having sufficient energy to ionize an atom): particulate (alpha particles, beta particles, neutrons) and electromagnetic (X-rays, gamma rays).
The most familiar form of electromagnetic radiation is sunshine, which provides light and heat. Lower-frequency waves of EM radiation – such as ultraviolet waves, infrared waves, radio waves and microwaves – are types of nonionizing radiation. Higher-frequency waves of EM radiation, such as X-rays and gamma rays, are ionizing radiation.
Nonionizing radiation – e.g., what is found in sunshine – is essential to life, but excessive exposure can cause tissue damage. For example, small doses of sunshine are a great source of vitamin D. But we know that excessive doses can lead to skin cancer.
On the other hand, all forms of ionizing radiation can lead to tissue damage. Nuclear reactors produce tremendous quantities of ionizing radiation as a byproduct of nuclear fission, giving us nuclear energy.
Next week, I’ll actually demonstrate how much radiation exposure you get from items you use daily and then teach you how to calculate your radiation exposure.