CIEE Environmental Factors & Human Performance 2

Question 1

Which metric best quantifies the combined effect of air temperature, radiant heat, humidity, and air movement on worker heat stress?

Accepted Answer

Wet Bulb Globe Temperature (WBGT)

Answer

WBGT integrates all four environmental heat factors and is the standard metric used by ACGIH and NIOSH for assessing occupational heat stress exposure limits.

Question 2

A worker performs repetitive assembly in a room where air temperature is 75°F but relative humidity is 90%. What is the primary ergonomic concern?

Accepted Answer

Elevated perceived exertion and reduced heat dissipation through sweat evaporation

Answer

High humidity impairs sweat evaporation, the primary heat-dissipation mechanism, raising core temperature and perceived exertion even at moderate air temperatures.

Question 3

Under NIOSH recommendations, which vibration frequency range poses the greatest risk of whole-body vibration (WBV) injury to the lumbar spine?

Accepted Answer

4–8 Hz

Answer

The lumbar spine resonates at 4–8 Hz, meaning whole-body vibration in this range is most efficiently transmitted to and absorbed by spinal structures.

Question 4

Which lighting parameter most directly affects a worker's ability to distinguish fine surface defects during visual inspection tasks?

Accepted Answer

Luminance contrast

Answer

Luminance contrast between a defect and its background is the primary determinant of visual detection performance for fine surface anomalies.

Question 5

A forklift operator complains of fatigue and lower back pain after 6-hour shifts. Which combination of environmental factors should be assessed first?

Accepted Answer

Seat vibration frequency spectrum and seat suspension effectiveness

Answer

Forklift operators are a primary WBV risk population; characterizing vibration frequency and evaluating whether seat suspension mitigates the 4–8 Hz resonance range is the priority assessment.

(CIEE) Certified Industrial Ergonomic Evaluator Practice Test

(CIEE) Certified Industrial Ergonomic Evaluator Practice Test

CIEE Environmental Factors & Human Performance 2