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4.2 Exposure to Radiation
Exposure to Radiation Human dose to radiation is typically measured in rem, or
in one-thousandths of a rem, called millirem (mrem), 1 rem = 1000 mrem. Another
unit of dose is the Sievert (Sv), 1 Sv = 100 rem. The allowable limit for occupational
exposure in the U.S (and many countries internationally) is 5,000 mrem/year (50
mSv/year) for deep (penetrating) dose and 50,000 mrem/year (500 mSv/year) for
shallow (i.e., skin) dose or dose to extremities. Deep, shallow, and extremity exposure
from a properly used the Beethor X3G Series analyzer should be less than 200 mrem
per year, (2.0 mSv per year) even if the analyzer is used as much as 2,000 hours per
year, with the shutter open continuously. The only anticipated exceptions to the 200
mrem maximum annual dose are: 1) routine and frequent analysis of plastic samples
without use of a test stand, backscatter shield, or similar additional protective
measures, or 2) improper use where a part of the body is in the primary beam path.
NEVER OPERATE THE DEVICE WITH A PART OF YOUR BODY IN THE
PRIMARY BEAM PATH OR WITH THE PRIMARY BEAM PATH DIRECTED
AT ANYONE ELSE. Also, consider the use of protective accessories such as a
shielded test stand or backscatter shield (or equivalent) when performing routine
and/or frequent analysis of any of the following:
• Plastic (or similarly low density) samples,
• Thin samples (such as foils, circuit boards, and wires)
• Samples that is smaller than the analysis window.
4.3 Monitoring your radiation exposure
Individuals can be monitored for the radiation dose they receive by use of
radiation dosimetry devices (dosimeters). Monitoring dose using a dosimeter can be a
way of identifying improper use and at the same time demonstrating proper use. In
some locations, dosimetry is required by regulations and in others it is optional. It is
normally required when the user could reasonably be expected to receive in excess of
10% of the annual dose limit. Beethor recommends that you determine and obey the
local regulatory requirements concerning radiation monitoring of occupational
workers.
4.4 Pregnancy and Radiation Exposure
International guidance documents (e.g., ICRP Publication 60 and NCRP
Publication 116*) recommend that the radiation dose to the embryo/fetus of a
pregnant woman should not exceed a total of 500 mrem (10% of normal radiation
worker limit) during the gestation period. While this dose limit exceeds the dose limit
to a trained operator, pregnant workers may want to take special precautions to reduce
their exposure to radiation. For more information see the U.S. NRC Regulatory Guide
8.13 "Instruction Concerning Prenatal Radiation Exposure" which can be found on the
