lecture 7 (4) - environmental hazard and health impact (radiation)

16/10

what is radiation? a form of _________ that can travel through space in the form of an _______________ wave or as fast moving particles 

energy, electromagnetic 

what is ionizing radiation? radiation _________ sufficient energy to displace an electron from an _______ (alpha and beta radiations, xray and ultraviolet rays)

with, atom 

what is non-ionizing radiation? radiation ___________ sufficient energy to displace an electron from an atom (some ultraviolet rays, visible light, infrared, microwave, radio waves) 

without 

what are the 4 common types of ionizing radiation? 

1. _________ particles 

2. _______ particles

3. _________ rays 

4. _-rays 

alpha, beta, gamma, x

what are alpha particles? ________ charged and made up of two protons and two _________ from the atom’s nucleus

positively, neutrons

what are beta particles? small, ______-moving particles with a __________ electrical charge

fast, negatively

what are gamma rays? ____________ packets of energy called photons, pure energy, no mass

weightless 

what are x-rays? are emitted from processes _________ the nucleus, gamma rays originate inside the nucleus 

inside 

what are some exposures sources of ionizing radiation?
nature: cosmic rays, the earth, radon, the _________ body
man-made: medical, fallout, consumer ________, nuclear power

human, products

what are the health effects of ionizing radiation? generally, biological effects are due to the ionization process that __________ the capacity for cell _________ or division or causes cell mutation. a given total dose will cause more damage if received in a ________ time period

destroys, reproduction, shorter

the ______ of radiation is associated with the amount of bodily tissue _________ that may occur 

dose, damage 

what are the factors that govern the amount of exposure to radiation that a person receives (dose delivered) influence the health effects?

1. the _________ amount of time exposed to the radioactive source

2. __________ from the radioactive source

3. degree of _____________ (rate of energy emission) of a radioactive material

4. ____________ themselves

total, distance, radioactivity, people

what are the high-level exposure of radiation effects? acute effects which are manifested shortly after, a large exposure, ___________ exposures. bone __________ injury, gastrointestinal tract, central __________ system, radiation burns

accidental, marrow, nervous

what are the low-level exposure of radiation effects? described as _________ effects, appearing many years after a “non-lethal” acute dose, or chronic effects after many years of ______ doses, radiation workers. genetic _________ (animals), abnormalities induced in an exposed fetus, cancer

latent, short, mutations

what are the two exposures of radiation? 

occupational and environmental

what are the principles for reducing external exposure? ___________ (reducing the amount of time around a radiation source directly reduces radiation exposure), ______________ (exposure reduces exponentially with increased distance from the source), ____________ (stops alpha and beta particles and greatly reduces x-ray and gamma radiation)

time, distance, shielding

what are some methods to reduce internal intake?

1. vent contaminant and/or exhaust

2. contamination surveys

3. good _________ (washing hands)

4. use of ________ clothing and PPE

5. general protective hazards

   1. knowledge of hazards

   2. area control: signage, records, security

   3. appropriate facilities and equipment for use and control of radioactive materials

hygiene, protective

what are the sources of ultraviolet? ________light (most harmful UV is absorved by atmosphere), fluorescent lamps, electric arc welding 

sun 

what are the health effects of ultraviolet? high dose causes _____ burn and increased risk of skin __________-, ocular effects, weakening of the __________ system, reaction in the skin to produce vitamin D

sun, cancer, immune

what are the protective measures of ultraviolet? ensure that skin and eyes are adequately __________, never look __________ at the source, operate UV lamps in light-tight conditions

protected, directly

what are the health effects of other non-ionizing radiations? 
high level: thermal effects, ocular effects 

low level: does ____ find discenerible short-term health effects

not