How Dangerous Is Radiation?

Background radiation is that which is naturally and inevitably present in our environment. It is all around us, all the time. Our bodies are exposed to natural radiation every day -- from soil and underground gases to cosmic radiation from the sun and outer space. But radiation is not always dangerous. It depends on its strength, type and the length of exposure.

Radiation comes in many forms and can be either ionizing or non-ionizing. Ionizing radiation changes the physical state of atoms and causes them to become electrically charged or “ionized”. This means that when ionizing radiation passes through the body, it actually has enough energy to damage DNA and cause various diseases. Ionizing radiation is both natural and man-made. Some of the natural sources of ionizing radiation are naturally-occurring radionuclides in the earth, building materials, air, food and water, and cosmic rays. Medical and dental X-rays, smoke detectors and radionuclides emitted from nuclear power plants are good examples of man-made ionizing radiation. Overexposure to ionizing radiation can cause mutations in genes, which causes birth defects, a high risk of cancer, burns or radiation sickness.

Non-ionizing radiation does not have enough energy to ionize atoms or molecules. It consists of electromagnetic radiation ranging from the extremely low frequency (ELF) to the ultraviolet (UV). Non-ionizing radiation sources include microwaves, radio waves, infrared radiation, visible light and lasers. We are constantly exposed to non-ionizing radiation from our own inventions – power lines, cell phones and microwave ovens. Although considered less dangerous than ionizing radiation, overexposure to non-ionizing radiation can cause health problems.

Living things have evolved in an environment which has significant levels of ionizing radiation. Furthermore, many of us owe our lives and health to such radiation produced artificially. Ionizing radiation is used to diagnose diseases, and some people are treated with radiation to cure diseases. We all benefit from a great number of products and services made possible by the careful use of radiation.

Exercise 1. Translate the following noun groups.

Background radiation, uranium compounds, fluorescence phenomenon, reactor accident, mineral properties, metal sheets, radiation emission, radiation exposure, energy waves, decay process, energy transformation, isotope disintegration, radioactivity level, isotope half-life, gas ionization.

Exercise 2. What do the following abbrevations stand for? Refer to the dictionary or other sources if you do not know the answer.

Дата добавления: 2015-11-14