OHS lecture 7
Physical Risk Factors
Key Reminder: Safeguard your hearing.
Importance: Use proper Personal Protective Equipment (PPE).
The main physical risk factors include:
Noise
Vibration
Thermal Comfort
Lighting
Pressure
Radiation
Noise
Definition: Noise is defined as unwanted, unpleasant, or disturbing sounds.
Industrial Noise: Refers to sounds in workplaces affecting workers physiologically and psychologically, which can reduce work efficiency.
Sound Phenomenon: Sound is produced by the compression and expansion of molecules in matter and travels through it.
Sound Pressure and Frequency
Important Measurements: Assessments of pressure and frequency in noise are essential.
Measurement Unit: The unit of pressure used in regulations is Pascal (Pa).
Equivalences: 1 atm corresponds to 760 mmHg, 1.01325 bar, and 101,325 Pa.
Characteristics of Sound Waves
Key Characteristics:
Wavelength (λ): Distance traveled by the wave in one period.
Amplitude (A): The height of sound waves, determining loudness.
Period (T): Time for two successive identical wave positions.
Velocity (Vs): Speed of sound is approximately 340 m/s.
Sound Properties
Frequency (f): Number of cycles per second, measured in Hertz (Hz).
Analysis of Pitch: Pitch increases as frequency doubles.
Sound Emission and Immission
Definitions:
Emission: The sound emitted by the source itself.
Immission: The sound that reaches the listener's ear.
Pure Sound: Produced by harmonic sound pressure.
Amplitude’s Role: High amplitude correlates with loud sounds; low amplitude indicates softer sounds.
Sound Frequency Classification
Categories:
Infrasound: < 20 Hz (below human hearing)
Audible Sound: 20 Hz to 20,000 Hz (within human hearing range)
Ultrasound: > 20,000 Hz (beyond human hearing)
Noise Spectrum Classification
Types of Noise:
Broadband Noise: Wide frequency range (e.g., traffic noise).
Narrowband Noise: Limited frequency range, centered around specific frequency (e.g., a whistle).
Page 11: Human Hearing Thresholds
Key Measurements:
20 µPa (2.10^-5 Pa): Human Hearing Threshold
Range: 20 Hz to 20,000 Hz.
Sound Intensity Measurement: Intensity is expressed in decibels (dB).
Reference for Sound Pressure: 2.10^-5 Pa is the threshold at 1000 Hz.
Noise Level Classification
Noise Levels (dB):
0 dB: Threshold of Hearing
20-30 dB: Whisper
60-70 dB: Normal Conversation
70-85 dB: Busy Traffic
85-90 dB: Lawn Mower/Vacuum Cleaner
90-100 dB: Heavy Traffic/Subway
110-120 dB: Jet Engine/Rock Concert
130 dB: Threshold of Pain
Prolonged exposure above 85 dB can incur hearing damage.
Noise Level Graph
Supplementary visuals indicating various noise levels affecting human hearing.
Total Noise Level Computation
Formula: To compute total noise: L_total = 10 log10 (Σ 10^(L_i/10))
Additively represents contributions from each source in a logarithmic scale, reflecting real-world noise environments.
Noise Level Bonification Example
Example calculation and demonstration for cumulative noise levels when multiple sources are present.
Noise Level Differences
Differences between two levels provide additional insights for analysis in sound levels, facilitating easier understanding of cumulative effects.
Effects of Noise on Humans
Categories of Effects:
Physical Effects
Physiological Effects
Psychological Effects
Performance Effects
Physical Effects of Noise
Impacts include:
Hearing Loss
Tinnitus (ringing in ears)
Statistics show approximately 10% of occupational diseases relate to hearing loss.
Types of Hearing Loss
Categories:
Conductive Hearing Loss: Damage in eardrum and middle ear.
Sensorineural Hearing Loss: Damage in auditory cells of the inner ear; can be temporary or permanent.
Hearing Loss Prolonged Exposure Chart
Chart illustrating hearing loss percentages over exposure periods (5, 10, and 20 years) for different noise levels.
Page 21: Physiological Effects of Noise
Consequences include:
Increased blood pressure and heart rate.
Muscle contractions and respiratory changes.
Psychological Effects of Noise
Behavioral disorders, excessive irritability, and stress are linked to exposure to high noise levels.
Performance Effects of Noise
Decreased work efficiency, difficulty in focusing, and slower movement due to high noise levels.
Noise Measurement Devices
Types of noise measuring devices:
Types 0-3 and Personal Dosimeters for workplace environments.
Sound Levels and Indicators
Measurement terms include:
Equivalent Continuous Sound Pressure Level (LAeq)
Day/Night/Evening Noise Indicators (L_day, L_night, L_evening).
Specific Noise Measurement Terms
Peak Sound Level (Lmax) and Sound Exposure Level (SEL) explained for understanding noise that occurs suddenly and then decreases.
Noise Protection Methods - Source Control
Proposed measures:
Use quieter machines
Regular maintenance of machinery
Insulate noise sources.
Noise Protection Methods - Organizational Measures
Suggested strategies:
Separate noisy tasks
Implement noise barriers
Increase distance from noise sources.
Noise Protection Methods - Environmental Adjustments
Recommendations for work environment changes:
Use sound-absorbing materials
Employ acoustic screens or partitions.
PPE for Noise Protection
Types and Noise Reduction Levels of PPE:
Ear plugs, earmuffs, and other sound-diminishing equipment with specific dB levels noted.
Noise Regulation Overview
Purpose: Protect workers from noise-related health risks.
Release Date: July 28, 2013; Official Gazette Number: 28721.
Weekly Noise Exposure Levels
Weekly exposure levels must not exceed 87 dB(A).
Defined terms of time-weighted average of noise exposure.
Noise Regulation Measures
Suggested improvements:
Alternative methods with reduced noise
Proper training for equipment handling.
Additional Regulatory Measures
Technical methods proposed to decrease noise through insulation and dampening.
Noise Level Standards
Standard noise levels outlined:
ILO suggests 85 dB(A) the Turkish regulation sets at 87 dB(A).
Preventive Measures against Noise Hazards
Precaution suggestions to avoid noise hazards ranked by effectiveness.
Introduction to Vibration
Overview of vibration as a risk factor.
Definition of Vibration
Vibration described as the alternate displacement of an object in relation to a specific point, affecting work environments.
Key Concepts in Vibration
Concepts:
Resonance, Natural Frequency, Critical Speed; examples included.
Types of Vibration
Classification:
Periodic vs. Random Vibration.
Vibration Based on Applied Area
Types:
Hand-Arm Vibration vs. Whole Body Vibration.
Sources of Hand-Arm and Whole Body Vibration
Identifiable sources contributing to vibrations in different settings.
Vibration Threshold Values
Daily exposure limits provided for hand-arm and whole-body vibration.
Effects of Vibration on Humans
Critical factored considerations impacting humans associated with vibration exposure.
Hand-Arm Vibration Effects
Impacts of hand-arm vibrations leading to pain and specific disorders.
Whole Body Vibration Effects
Physical implications of whole body vibrations, including musculoskeletal effects.
Other Frequency Ranges Effects
Discusses effects correlating with various frequency ranges of vibration exposure.
Vibration Prevention: Source Control
Recommendations focusing on machinery choice and maintenance practices.
Vibration Prevention: Organizational Measures
Strategies for workplaces to control vibration exposure through shift rotations and breaks.
Vibration Prevention: Personal Measures
PPE recommendations to reduce exposure to vibrations. Medical check-ups emphasized.
Vibration Regulation Overview
Overview of regulation enacted to protect from vibration-related risks.
Vibration Regulation Measures
Suggested design alternatives and ergonomics to mitigate exposure.
Further Regulatory Suggestions
Additional workplace arrangements and protections for employees.
Exploration of Thermal Comfort
Explanation of thermal comfort concerning worker performance and environmental factors.
Factors Affecting Thermal Comfort
Temperature, humidity, air movement, radiant heat discussed.
Temperature Measurement
Outline of temperature's measurement standards and units (Celsius, Fahrenheit, Kelvin).
Heat Transfer Principles
Types of heat transfer explained: conduction, convection, radiation.
Body Temperature Regulation
Mechanisms explained for body temperature maintenance during work.
Radiant Heat
Description of radiant heat and methods of measurement using specific tools such as globe thermometers.
Humidity Measurement
Definitions of absolute and relative humidity, along with their implications
Workplace Humidity Standards
Standards for maintaining relative humidity in workplaces for optimal worker comfort.
Thermal Comfort Airflow Requirements
Describes airflow rates, measurements, and minimum air volume per person in work settings.
Effective Temperature Measurement
Parameters needed for calculating effective temperature.
Factors Affecting Thermal Comfort
Detailed list of contributing factors affecting thermal comfort in the workplace.
Negative Effects of Cold on Workers
Symptoms and discomfort caused by cold environments highlighted.
Negative Effects of Heat on Workers
Distinct conditions due to heat exposure, including heat stroke and exhaustion.
Negative Health Reactions to Heat
Additional heat-related conditions. Specific warnings against high temperatures outlined.
Safety Measures for Cold Environments
Protective measures for working in cold environments specified.
Technical Protection Against Heat
Measures include protective barriers and ventilation practices.
Organizational Protection Against Heat
Organizational strategies to manage worker exposure to heat.
Personal Protective Measures for Heat
Recommendations for clothing and physiological considerations during heat exposure.
Radiant Heat Protection Steps
Summary of actions and resources for mitigating radiant heat risks outlined.
Importance of Quality Lighting
General effects of proper lighting on work performance and safety.
Factors Affecting Lighting Quality
Discuss light intensity, distribution, temperature, and glare control as essential factors.
Lighting Considerations
The importance of lighting source choice and their implications for work efficiency.
Illuminance Measurement Definitions
Key terms and units related to lighting and their relevance to workplace standards.
Required Illuminance Levels
Standards set for various tasks in workplaces to ensure proper visibility and safety.
Light Reflection and Glare Prevention
Discussion of luminescence and reflection properties.
Light Management Strategies
Suggestions regarding window placement, color choices, and lighting object placement to enhance work environments.
Illuminance and Reflection
Detailed analysis of reflection events and mitigation strategies.
Types of Workplace Lighting
Differences between direct and indirect lighting and their practical implications.
‘Workplace Environment Lighting Considerations
Key parameters governing adequate lighting provided.
Summary Suggestions for Lighting Improvement
Comprehensive measures for improving workplace lighting conditions outlined.
Pressure Overview
Definition and units of pressure discussed.
Pressure's Role in Work Environments
The importance of pressure at varying altitudes and its implications for workers in corresponding fields.
Effects of Pressure Changes
Explanation of pressure-related health risks and the associated conditions.
Pressure Exposure in Workers
Specifics around the acceptable pressure changes workers face without severe health implications.
Occupational Diseases Due to Pressure
Information on how abnormal pressure experiences are classified as occupational diseases.
Protection from Pressure Effects
Methodologies to protect workers from hazardous pressure effects.
Health Precautions for Workers
Emphasis on education and restrictions during exposure to high-pressure work environments.
Regulation Measures for Worker Protection
Overview of regulations designed to protect workers from pressure-related health risks.
Introduction to Radiation
General overview of radiation as a risk factor in occupational health.
Nature of Radiation Energy
Insight into the speed of radiation and its penetration capabilities.
Types of Radiation
Classification of radiation forms and their mechanisms.
Effects of Radiation Exposure
Health implications of both external and internal radiation exposure detailed.
Alpha Radiation Characteristics
Characteristics, source, and health implications of exposure to alpha radiation.
Beta Radiation Characteristics
Overview of beta radiation and protection guidelines suggested for exposure.
Neutron Radiation Hazards
Discussion around neutron radiation and its serious risks outlined.
Continued Neutron Radiation Details
Further elaboration on the depth of penetration and potential cellular damage from neutron radiation.
Proton Radiation Explained
Overview of proton radiation characteristics and their danger in occupational settings.
Gamma Rays and Their Uses
Properties and applications of gamma rays, particularly in medical uses and safety concerns.
X-Ray Details
Health considerations and the uses of X-rays within medical contexts discussed.
Non-Ionizing Radiation Overview
Types of non-ionizing radiation and their sources.
UV Rays and Effects
Overview of UV radiation, its effects on human health, and exposure notes.
Infrared Radiation Properties
Infrared radiation fold, and common uses in technology along with its effects on health.
Communication and Heating Radiation
Short-wave radiation and microwaves explained with their significance.
Occupational Disease Monitoring
Importance of monitoring workers exposed to radiation for health assessment and disease prevention.
Summary Overview of Radiation
Concluding observations on the impact and management of radiation in occupational settings..