CIH Physical Agents: Noise and Radiation 3

Question 1

Which audiometric finding is considered a 'standard threshold shift' (STS) under OSHA's Hearing Conservation Amendment?

Accepted Answer

An average shift of 10 dB or more at 2000, 3000, and 4000 Hz

Answer

OSHA defines STS as an average shift of 10 dB or more at 2000, 3000, and 4000 Hz compared to the baseline audiogram.

Question 2

What is the primary purpose of a baseline audiogram in a hearing conservation program?

Accepted Answer

To serve as a reference for detecting future threshold shifts

Answer

The baseline audiogram establishes the worker's initial hearing threshold levels so that future audiograms can be compared to detect noise-induced changes.

Question 3

Ultraviolet radiation in occupational settings is most commonly associated with which health effect?

Accepted Answer

Erythema (sunburn) and increased skin cancer risk

Answer

Occupational UV radiation exposure primarily causes erythema, photokeratitis, and increases the risk of skin cancer, particularly from UVB wavelengths.

Question 4

A survey meter reads 25 mR/hr at 1 meter from an unshielded gamma source. Using the inverse square law, what is the dose rate at 5 meters?

Accepted Answer

1 mR/hr

Answer

By the inverse square law: 25 × (1/5)² = 25 × 0.04 = 1 mR/hr at 5 meters.

Question 5

Which non-ionizing radiation type is regulated by OSHA in welding operations primarily because of risk to the eyes?

Accepted Answer

Ultraviolet radiation

Answer

UV radiation from welding arcs causes photokeratitis ('arc eye' or 'welder's flash'), making eye protection mandatory in welding operations.

CIH - Certified Industrial Hygienist Exam Practice Test

CIH - Certified Industrial Hygienist Exam Practice Test

CIH Physical Agents: Noise and Radiation 3