CIH Physical Agents: Noise and Radiation 4

Question 1

Which radioactive decay process results in the emission of a helium-4 nucleus?

Accepted Answer

Alpha decay

Answer

Alpha decay emits an alpha particle, which consists of 2 protons and 2 neutrons — identical to a helium-4 nucleus.

Question 2

What is the occupational annual effective dose limit for radiation workers in the United States under NRC regulations (10 CFR 20)?

Accepted Answer

50 mSv (5 rem)

Answer

NRC regulations set the annual occupational whole-body effective dose limit at 50 mSv (5 rem) per year for radiation workers.

Question 3

In noise control engineering, which approach is generally considered the most effective and preferred by the hierarchy of controls?

Accepted Answer

Substitution of quieter equipment

Answer

Substituting a noisy process or equipment with a quieter alternative eliminates the hazard at the source and is preferred over controls that merely reduce exposure.

Question 4

Radon-222 is a significant occupational hazard primarily in which of the following work environments?

Accepted Answer

Underground mines and poorly ventilated basements

Answer

Radon-222, a naturally occurring radioactive gas, accumulates in underground mines and poorly ventilated enclosed spaces, posing a significant lung cancer risk.

Question 5

What does the Noise Reduction Rating (NRR) on a hearing protector label represent?

Accepted Answer

The laboratory-measured attenuation under ideal fitting conditions

Answer

The NRR is determined under ideal laboratory conditions using trained subjects, so real-world attenuation is typically significantly lower.

CIH - Certified Industrial Hygienist Exam Practice Test

CIH - Certified Industrial Hygienist Exam Practice Test

CIH Physical Agents: Noise and Radiation 4