NEBOSH Workplace Hazards 2 ā Questions and Answers
Question 1: What is 'noise-induced hearing loss' (NIHL) and at what exposure level must employers act?
- NIHL is permanent irreversible hearing damage from excessive noise; the action level requiring controls is 80 dB(A) for daily exposure (lower action value) (Correct answer)
- NIHL is temporary and fully reversible
- Only sudden loud noises cause hearing damage
- The action level is 100 dB(A)
Correct answer: NIHL is permanent irreversible hearing damage from excessive noise; the action level requiring controls is 80 dB(A) for daily exposure (lower action value)
NIHL results from sustained exposure to high sound levels (>80ā85 dB(A)), causing progressive, permanent, and irreversible destruction of cochlear hair cells. Under Control of Noise at Work Regulations (UK/Gulf equivalent): lower action value 80 dB(A) triggers information/training; upper action value 85 dB(A) requires engineering controls and hearing protection.
Question 2: What are the main effects of whole-body vibration (WBV) on workers?
- Lower back pain, spinal damage, and musculoskeletal disorders ā common in workers operating heavy vehicles and plant (Correct answer)
- Only affects workers' hands and arms
- Causes hearing loss
- Vibration has no health effects below visible shaking
Correct answer: Lower back pain, spinal damage, and musculoskeletal disorders ā common in workers operating heavy vehicles and plant
WBV from driving heavy vehicles, construction plant, and industrial machinery transmits energy through the seat and body to the spine. Chronic exposure causes lower back pain, intervertebral disc degeneration, and increased risk of musculoskeletal disorders. Exposure action value is 0.5 m/sĀ² (8-hour average) under EU/UK regulations.
Question 3: What is hand-arm vibration syndrome (HAVS)?
- A permanent, irreversible condition from prolonged use of vibrating hand tools, causing vascular damage (vibration white finger), sensory loss, and musculoskeletal injury (Correct answer)
- A temporary condition that resolves when tool use stops
- Only causes skin irritation
- HAVS only affects workers over 60
Correct answer: A permanent, irreversible condition from prolonged use of vibrating hand tools, causing vascular damage (vibration white finger), sensory loss, and musculoskeletal injury
HAVS results from chronic exposure to vibrating hand tools (grinders, drills, jackhammers, chippers). Vascular component (vibration white finger): blanching of fingers in cold. Neurological: tingling, numbness, reduced grip. Musculoskeletal: damage to joints. HAVS is progressive, permanent, and disabling.
Question 4: What is the correct approach for managing workers in extreme heat environments in the Gulf?
- Engineering controls (cooling, shade), acclimatisation programs, hydration, scheduling work to avoid peak heat, heat illness recognition training, and pre-employment health screening (Correct answer)
- Provide extra PPE only
- Restrict water to prevent frequent toilet breaks
- Heat is unavoidable in the Gulf ā no specific management is needed
Correct answer: Engineering controls (cooling, shade), acclimatisation programs, hydration, scheduling work to avoid peak heat, heat illness recognition training, and pre-employment health screening
Gulf construction workers face extreme heat stress risk. Management requires: engineering controls (shade, cooling), acclimatisation (gradual heat exposure over 7ā14 days for new/returning workers), scheduled hydration (200ā250 mL water every 15ā20 min), work-rest ratios, heat illness recognition, and the UAE's mandated outdoor work ban.
Question 5: What is 'sick building syndrome' (SBS)?
- A collection of non-specific symptoms (headaches, eye irritation, fatigue, respiratory symptoms) experienced by occupants of a specific building, relieved when leaving, without identifiable cause (Correct answer)
- Actual infectious disease spread within a building
- A formal medical diagnosis requiring hospitalization
- Only affects workers in hospitals
Correct answer: A collection of non-specific symptoms (headaches, eye irritation, fatigue, respiratory symptoms) experienced by occupants of a specific building, relieved when leaving, without identifiable cause
SBS is characterized by occupants experiencing symptoms (headaches, fatigue, dry eyes, nasal irritation) that improve on leaving the building. Contributing factors include poor ventilation (inadequate fresh air), chemical off-gassing from furnishings, biological contamination (mold, Legionella risk), and poor temperature/humidity control.
Question 6: What is the primary risk from working with ionizing radiation in healthcare or industrial settings?
- DNA damage leading to cancer (stochastic effect) and tissue damage at high doses (deterministic effect) (Correct answer)
- Only superficial skin burns
- Radiation causes no long-term health effects at occupational levels
- Radiation effects are immediately apparent in all cases
Correct answer: DNA damage leading to cancer (stochastic effect) and tissue damage at high doses (deterministic effect)
Ionizing radiation (X-rays, gamma, alpha, beta, neutron) damages DNA directly. Stochastic effects (cancer, genetic mutations) have no safe threshold ā probability increases with dose. Deterministic effects (tissue damage, radiation sickness) occur above specific thresholds. The ALARA principle (As Low As Reasonably Achievable) governs occupational radiation protection.
NEBOSH Workplace Hazards 2
What is 'noise-induced hearing loss' (NIHL) and at what exposure level must employers act?