Human Health and the Environment 6 - EESA10 Lecture 6...

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EESA10 Lecture 6 Radiation and Human Health Slide 1 – Radiation and Human Health Radiation is everywhere, all around us. We cannot escape radiation. But the question is what type and how much radiation is there. Even if we are walking outside in the woods, we are still exposed to some radiation, because of Background Radiation: Something that is produced and emitted from outer space. Natural radioactivity in the earth and by cosmic rays from outer space. This type of radiation cannot be controlled. We are always exposed to it. It has existed for hundreds of thousands of years. Something that we can control is man made radiation (Electronic devices, appliances, etc.). (Note: Nowadays, engineers have found technologies to protect us from most of this radiation). Examples of some man-made devices that emit different types of radiation include: - X-ray machines (different kind of equipment used in labs for analysis, for example, CCA can also be detected using X-ray) - X-ray Diagnostic (X-ray used for diagnostic of different body parts) - Television sets - Microwave ovens - Lasers Slide 2 – Ionizing radiation exposure to the public Natural radiation sources consists of 82% of total measurable radiation Man-made radiation is just 18%. Medical x-rays, nuclear medicine can treat some illnesses and some other types of radiation. What is surprising is that Radon (gas in indoor air) makes up 55% of total radiation. Slide 3 – Radiation and Human Health We have two big groups of radiation: 1) Ionized Radiation (Cosmic, Gamma, X-rays): This is radiation that has so much energy that can change atoms on some other chemicals. They can push electrons out of their atoms and produce ionized form of that element. They are very strong as they have so much energy. (Note: On electric spectrum, elements that are very high in energy have short wavelength, elements with low energy (non-ionized) have long wavelength.) 2) Non-Ionized Radiation (Radio waves, TV waves, Microwaves): This type does not have enough energy (low in energy) and they cannot remove electrons from atoms. Slide 4 – Ionized Radiation
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Affect of this radiation is obvious. All scientists agree that this radiation is really harmful. How does it affect human health? First, the radioactive material (like Uranium), decays naturally and spontaneously, and produces ionizing radiation. This ion radiation, strips away electrons from atoms (create two charged ions) It can also break some chemical bonds. This is important for human body as it consists of water and chemicals. Examples: alpha, beta particles, gamma and x- rays. These examples differ based on the amounts of energy they have. Slide 5 - Health effects from exposure to radionuclides
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This note was uploaded on 04/09/2011 for the course ENVIRONMEN EESA10 taught by Professor Silvajastovenovij during the Spring '11 term at University of Toronto- Toronto.

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Human Health and the Environment 6 - EESA10 Lecture 6...

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