Wednesday September 5, 2007 (Foodconsumer.org) -- Radiation such as x-ray is a risk factor for a variety of cancer.   Experts representing their respective interests have been debating over the risk of exposure to low-dose radiation. A new study confirmed that even tiny amounts of radiation raise risk of solid cancers, a notion that has been rejected by the medical industry for decades.

Among a population near the Techa River where the Soviet nuclear weapons program was executed, Russian epidemiologists found radiation exposure is responsible for 3 percent of the cancer cases.  The results were published in the Sep 3, 2007  issue of the International Journal of Epidemiology.

In the study, Krestinina LY from Urals Research Center for Radiation Medicine in Chelyabinsk, Russia and colleagues followed about 9500 people for 47 years.   1836 solid cancer cases were recorded during the follow-up.

The researchers said the cancer-causing effect fitted a linear dose-response model and the elevated risk did not vary with gender, ethnicity, attainted age or age at first exposure.

They concluded that “low-dose, low-dose-rate exposures lead to significant increases in solid cancer risk that appear to be linear in dose.”

The observation was consistent with prior evidence that suggests the effect of low-dose radiation exposure such as the exposure to the radiation in the environment does exist and is likely to have a linear relationship with the dosage.

John Gofman, Ph.D. M.D., a distinguished nuclear physician and participant of the Manhattan Project who passed away a couple of weeks ago had been insisting for decades that the cancer-causing effect of low-dose radiation is harmful and urged the medical industry to reduce use of x-ray.

Dr. Gofman believed that 75 percent of breast cancer cases involved exposure to x-ray, a type of radiation that has been recognized by the U.S. government to be a cancer-causing agent.

X-ray is widely used in diagnostic tools and radiotherapy, yet many patients are not well informed of the risk of x-ray radiation, which can cause not only cancer, but also damage arteries, leading to heart disease, according to Dr. Gofman.

Radiation can be released from the earth and the sky.   This often constitutes the basis for doctors to down-play the cancer causing effect of radiation.   When you ask a doctor how detrimental a chest x-ray can be, you would be told that the dose is minimal or equivalent to the amount you are exposed to during a round trip flight from New York to Los Angeles.

The comparison is not adequate, according to Dr. Gofman.   Medical x-ray is more powerful than that you receive from the environment.   Also the dose-rate makes some difference.

X-ray is particularly harmful to children.   According to the U.S. Environmental Protection Agency, children under age 2 would have 7 times higher risk of cancer if they receive a chest x-ray compared to those who do not receive any.   Those who receive the exposure after 2 would still have 2 to 3 times higher risk.

In addition to medical and environmental radiation, one major application of radiation is found in smoke detectors, which can release constantly radioactive particles, which may be more harmful than x-ray.

The radiation effect accumulates.   You may not get cancer right off the bat, but when you accumulate the harm to certain degree, you get it.