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Non-Ionizing Radiation

Non-Ionizing Radiation. I o n i z i n g. N o n – I o n i z i n g.

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Non-Ionizing Radiation

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  1. Non-Ionizing Radiation I o n i z i ng N o n – I o n i z i n g includes all kinds of electromagnetic radiations with frequencies < 1015 Hz and wavelengths λ = 10-8 - 104 m. i.e. ultraviolet radiation UV- light,Visible light, Infrared radiation IR-light, Microwaves, Long ,Medium, Short, and Ultra-short radiowaves). These elmg. radiations never create electrically charged IONS (cations+ and anions-) when targeting atoms or molecules. γ-Rays X-raysUV VL IR MW R a d i o

  2. 1. Ultraviolet Radiation (UV-Light) UV Lightis invisible radiation with λ = 100- 400 nm, Sources: natural (Sun), artificial (mercury lamps ) Classification: UVA- long wave,“black-tanning light“ λ = 315 - 400 nm UVB- medium wave,“inflamatory“λ = 280 - 315 nm UVC- short wave,“killing germs“λ = 100 - 280 nm (comes only from artificial sources) Earth is targeted from Sun by UVA (90%) and UVB (10%)lights. 90% of UVB is absorbed by O3 and O2 Ozone O3 andO2 lower the intensity of UVA and UVB lights and totally absorb UVC light Ozone holes- increase alevel of UV radiation!

  3. Effects of UV Radiation on Human Body Skin:Erythema- „early red coloured skin inflammation“(appears after 2-3 hours) Tanning(delayed pigmentation, because production of melanine.( it starts approx. 24- 48 hours after expo- sure) Vitamine Dproduction Skin Aging(Wrinkles, Dry skin, Skin cancer-melanoma) Eye: Inflammation- Conjunctivitis, Pain, Cataract IMUNITY: increases.Overexposure- decreases

  4. UV-light: Penetration Through Skin

  5. Protection against UV- light overexposure • Avoid tanning newborns and small children • Avoid tanning between 10 a.m.- 2 p.m, when intensity of Sun light is the highest • Always take sunscreens- wear glasses with UVA and UVB factors, cover head by wide hats, protect body with summer dress, and use grease without perfums • SUNNSCREENS must contain both UV-A and UV B protecting factors (at least No 20 for level of Sun radiation) • Do not tan when taking remedies (e.g. antibiotics, sulfonamids, etc.) • Avoid visit solaria frequently - mainly persons with blond hair and light colored skin - do it with care! • Skin has its own „memory“ and re-members its burning by UV-light overexposure! • Burning of skin in childhood is very dangerous, leading to cancer in adult age, as well ! • Take into account the Solar index

  6. 2. Mobile Communication- Ultra High Frequency (UHF) radiowaves It is an electromagnetic (elmg.)radiation with frequencies btw. 300-3000 MHz, and λ = 1 - 0.1m Is kind of non-ionizing radiation Is used at TV and Mobile Transmissions Mobile Phones work mostly under frequency 900 and 1800 MHz. Mobile phone is smalltransceiver,periodically connecting by radiowaves with Basic Mobile Station (BMS are placed on the top of hills, on the roofs, etc.) The intensity of electromagnetic radiation in a vicinity of BMS is very high and danger for body

  7. Effects of Mobile Radiowaves During callingEM radiation from mobile spre-ads to an environment as a radiosignal. The weaker is a received signal ( e.g. in car, train, or in buildings of steel and concrete)the higher is an intensity of emitted EM radiation. This radiation affects the head, ear, neck also the digits and hand of calling person on the side where a phone is taken by hand.

  8. Absorbtion of Mobile Radiowaves by Body The depht of penetration of mobile radiation to tiss-ues is 1-2 cm (affecting mostly the brain structu-res). The index for Specific Rate of Absorbtion (SAR)for brain tissue was established. N= 1.6- 2.0 (W.kg-1) For a particular value of SAR in different types of phones see the box where the mobileis stored. The intensity of mobile radiation is low (2 W), however in brain,theintensity maybe add together (summated) above normal value of SAR.Thus,the effectsdepend both on an intensity of mobile EM radiation and a time of calling (exposure)

  9. Biological Effects of Mobile Radiowaves 1. ThermalEffects-passingthetissueradiowavescreateheat - temperaturewithinthebrainrisesup ( approx. 0.10 C during 12 min. timeofphonecall), and this, in turnmaydamagetheneurons. Disordersoftheoptic and cochlearnerveswerealsopublishedlately. Also a lowerproductionofhormonmelatoninewasfound. Subjectivelly, persons are complainted on : burning and itchingof skin witherythema, somefeelingofheat in theear, badconcentration, sleepingdisorders, etc. 2.Non ThermalEffects-to-datemechanismsare obscure, howeverscientistspresumepossibilityforappearanceofbraincancere.g. astrocytoma(withlocationatthesideofhead, thatisdirectlytouched by phone)

  10. How to use mobiles safely? • Buy only phones with SAR <1.6(W.kg-1):look for SAR number being placed on the box • Do not call when driving or travelling by train (i.e. avoid do make calls at all places with low signal !) • Do not call over 2 minutes, as well. Rather use „hands free“ set. • Do not touch the head with an antena • Do not allow children ( at least till 6 years of age) to use and make calls from mobiles • In patients with cardiostimulator (pacemaker) store the mobile in pocket at least 20 cmfrom pacemaker and heart (usually on an opposite side of body)

  11. Ionizing Radiation Alpha particles Beta particles Gamma rays (or photons) X-Rays (or photons) Neutrons

  12. :Alpha Particles Ionizing Radiation Alpha Particles: 2 neutrons and 2 protons They travel short distances, have large mass Only a hazard when inhaled

  13. Ionizing Radiation:Beta Particles Beta Particles: Electrons or positrons having small mass and variable energy. Electrons form when a neutron transforms into a proton and an electron or:

  14. Ionizing Radiation:Gamma Rays Gamma Rays (or photons): Result when the nucleus releases Energy, usually after an alpha, beta or positron transition

  15. Ionizing Radiation:X-Rays X-Rays: Occur whenever an inner shell orbital electron is removed and rearrangement of the atomic electrons results with the release of the elements characteristic X-Ray energy

  16. Ionizing Radiation:Neutrons Neutrons: Have the same mass as protons but are uncharged They behave like bowling balls

  17. Radioactivity: Elements & Atoms • Atoms are composed of smaller particles referred to as: • Protons • Neutrons • Electrons

  18. Ionization Ionizing radiation is produced by unstable atoms. Unstable atoms differ from stable atoms because they have an excess of energy or mass or both. Unstable atoms are said to be radioactive. In order to reach stability, these atoms give off, or emit, the excess energy or mass. These emissions are called radiation.

  19. Types or Products of Ionizing Radiation   or X-ray neutron

  20. Ionizing Radiation alpha particle beta particle Radioactive Atom X-ray gamma ray

  21. Direct Ionization Caused By: Protons Alpha Particles Beta Particles Positron Particles

  22. Indirect Ionization Caused By: Neutrons Gamma Rays X-Rays

  23. Ionizing Radiation at the Cellular Level • Causes breaks in one or both DNA strands or; • Causes Free Radical formation

  24. Commonly Transported Radioisotopes Americium-241= Diagnose thyroid disorders, smoke detectors. Cesium-137= Cancer treatment. Iodine-125,131= Diagnosis & treatment liver, kidney,heart, lung and brain. Technetium-99m=Bone and brain imaging; thyroid and liver studies; localization of brain tumors.

  25. Radiation Measurement • Terminology: • Exposure rate = amount radiation possible to receive per unit time. • Dose = total amount of radiation received.

  26. Background Early risk associated with use of ionizing radiation skin erythema dose - 25yrs 1928 - ROENTGEN introduced by ICRP

  27. Roentgen • Named after Wilhelm C. Roentgen • (thus the abbr... is capital “R”) • Pronounced rent’gen with a hard “g” • Limitations • only applies to photons • only applies in air • only applies to energies less than 3 MeV

  28. rad 1 rad = 1 Roentgen

  29. rem • Roentgen Equivalent Man The unit of dose equivalent for any type of ionizing radiation absorbed by body tissue in terms of estimated biological effect - Unit of dose equivalent Dose in health record is in units of rem 1 rem = 1 Roentgen

  30. Quality Factor (Q) The specific value that accounts for the ability of different types of ionizing radiation to cause varying degrees of biological damage • X-rays, gamma rays, & beta particles 1 • Neutrons & High energy protons 10 • Alpha Particles 20

  31. Curie (Ci) • Named in honor of Pierre Curie Radiation hazard does not solely depend on the activity. It also depends on the type of decay (alpha, beta, photon, etc.)

  32. New Terms sort of International Units have replaced the RAD and REM GRAY (Gy) = 100 RAD SIEVERT (Sv) = 100 REM Same Quality Factors apply to the Sv

  33. Units of Radioactivity Curie (Ci) = 2.22 E12 dpm or 3.7E10 dps Becquerel (Bq) = 1 dps Maximum Dose/year = 5 REM or 50 mSv Maximum Dose/year for Declared Pregnant Woman & Minors= 0.5 REM or 5 mSv

  34. Half Life Calculation

  35. Dose Response Relationships 0-150 rem—No or minimal symptoms 150-400 rem—Moderate to severe illness 400-800 rem—Severe illness deaths start above 500 rem Above 800 rem—Fatal ***Acute whole body doses

  36. Activity Typical Dose Smoking 280 millirem/year Radioactive materials use in a UM lab <10 millirem/year Dental x-ray 10 millirem per x-ray Chest x-ray  8 millirem per x-ray Drinking water  5 millirem/year Cross country round trip by air  5 millirem per trip  Coal Burning power plant 0.165 millirem/year  Your Annual Exposure

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