Radiation

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Cataracts

Some studies show effects of teratoginicity and carcinogenicity.

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RADIATION CONTROLS

A. Basic Control Methods for External Radiation

Decrease Time

Increase Distance

Increase Shielding

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Time: Minimize time of exposure to minimize total dose. Rotate employees to restrict individual dose.

Distance: Maximize distance to source to maximize attenuation in air. The effect of distance can be estimated from equations.

Shielding: Minimize exposure by placing absorbing shield between worker and source.

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B. Monitoring

Personal Dosimeters: Normally they do not prevent exposures (no alarm), just record it. They can provide a record of accumulated exposure for an individual worker over extended periods of time (hours, days or weeks), and are small enough for measuring localized exposures Common types: Film badges; Thermoluminescence detectors (TLD); and pocket dosimeters.

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Direct Reading Survey Meters and Counters: Useful in identifying source of exposures recorded by personal dosimeters, and in evaluating potential sources, such as surface or sample contamination, source leakage, inadequate decontamination procedures, background radiation.

Common types:

Alpha  Proportional or Scintillation counters Beta, gamma  Geiger-Mueller or Proportional counters X-ray, Gamma  Ionization chambers Neutrons  Proportional counters

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Continuous Monitors: Continuous direct reading ionization detectors (same detectors as above) can provide read-out and/or alarm to monitor hazardous locations and alert workers to leakage, thereby preventing exposures.

Long-Term Samplers: Used to measure average exposures over a longer time period. For example, charcoal canisters or electrets are set out for days to months to measure radon in basements (should be <4 pCi/L).

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Elements of Radiation Protection Program