Occupational Health and Safety

• Occupational health is a public health area focused on promoting and maintaining the physical, mental, and social well-being of workers across all occupations.

Objectives of Occupational Health

• Maintenance and promotion of workers' health and working capacity

• Improvement of working conditions and the environment to ensure safety and health

• Development of work organization and cultures that reflect essential values, effective management, personnel policies, participation, and quality-related practices to improve safety and health

• Occupational risks like injuries, noise, carcinogenic agents, airborne particles, and ergonomic risks are major contributors to chronic diseases.

• About 70% of workers lack insurance to cover occupational diseases and injuries.

Hazard vs. Risk

• A hazard is any source of potential damage, harm, or adverse health effects under work conditions.
• Risk is the probability of a person experiencing harm or adverse health effects when exposed to a hazard.

Types of Occupational Hazards

• Physical
• Chemical
• Biological
• Ergonomic

Physical Hazards

• Workplace agents, factors, or circumstances that can cause tissue damage through energy transfer
• Examples include noise, vibration, heat, illumination, and radiation.

Noise

• Loud workplace noise can damage hearing and is a risk in all industries.
• NIOSH set a recommended exposure limit (REL) of 85 A-weighted decibels (dBA) over an 8-hour workday.
• Employers, health and safety professionals, and workers can prevent hazardous noise exposure.
• Noise hazards are dose-related, with higher doses increasing the risk to workers' hearing.

Noise Dose Factors

• Intensity/Loudness is measured by a noise level meter in decibels (dB).
• Frequency; 3000-4000 Hz frequencies are most likely to damage hearing, accounted for in sound level meters.
• Duration is the length of time of noise exposure.

The sound level to raise your voice

• Raising your voice to be heard 3 feet away often indicates noise levels of 85 dBA, produced by equipment like printing presses, lawn mowers, vacuums, and power tools.

• Shouting is likely necessary at 95 dBA or higher, from sources like bulldozers, ambulance sirens, chain saws, bars/nightclubs, and large sporting events.

• As noise levels increase, the allowable exposure time decreases, showing an inverse relationship.

• The allowable exposure limit decreases by half for every 3 dBA increase in loudness.

Hierarchy of Hearing Loss Control

• Elimination: Design processes to be quiet and remove hearing hazards
• Substitution: Use non-ototoxic chemicals and replace noisy equipment with quieter options
• Engineering Controls: Modify noise sources or transmission paths and install ventilation
• Administrative Controls: Adjust operation schedules to limit exposure, perform maintenance regularly
• PPE: Use earplugs, earmuffs or respirators, provide training, and fit testing

Vibration

• NIOSH states vibrating hand tools can cause vibration syndrome, also known as vibration white finger or Raynaud's phenomenon.
• Vibration exposure has adverse circulatory and neural effects on the fingers.
• Symptoms include numbness, pain, and blanching (turning pale and ashen).

Hand-Arm Vibrations

• Also known as localized vibration exposure.

• Affects those who use vibrating hand tools regularly in construction, manufacturing, automotive, landscaping, and gardening.

• Early stages are characterized by tingling or numbness.

• Temporary tingling or numbness after using a vibrating tool is not vibration syndrome.

• Diagnosis requires persistent neurological symptoms that occur without immediate exposure to vibration.

• Carpal tunnel syndrome can result from damage to the median nerve caused by hand-arm vibrations

Stages of Vibration Syndrome

• 00: No tingling, numbness, or blanching of fingers, with no complaints
• OT: Intermittent tingling with no interference with activities
• ON: Intermittent numbness with no interference with activities
• TN: Intermittent tingling and numbness with no interference with activities
• 01: Blanching of fingertip with or without tingling and/or numbness, with no complaints
• 02: Blanching of one or more fingers beyond tips, usually during winter, with possible interference with nonwork activities and no interference at work
• 03: Extensive blanching of fingers during summer and winter causing definite interference at work and home
• 04: Extensive blanching of most fingers during summer and winter, which leads to changing of occupation

Workers exposed to hand-arm vibrations

• Construction (hand tools)
• Farming (gasoline chain saws)
• Metal working (hand tools)
• Steel (furnace cleaning using powered hand tools)
• Lumber and wood (gasoline chain saws)
• Furniture manufacturing (hand tools)
• Mining (pneumatic drills)
• Truck and auto manufacturing (hand tools)
• Foundries (hand tools)

Preventing Vibration Injuries

• Maintain and inspect machinery regularly to decrease vibration levels

• Design workstations and equipment ergonomically

• Use low-vibration tools with anti-vibration handles and grips.

• Rotate workers and provide breaks to minimize vibration exposure.

• Monitor vibration levels, training on vibration risks

• Protective gear for preventing vibration injuries include anti-vibration gloves, seats, and suspension systems

• Health Monitoring; Perform periodic medical assessments to to identify, and treat vibration-related injuries.

Whole-Body Vibrations

• Also known as Head-to-toe vibrations.
• Can lead to injuries in construction, mining, agriculture, transportation, manufacturing, and aviation.
• May lead to musculoskeletal disorders, circulatory issues, and digestive problems.
• NIOSH recommends engineering controls, medical surveillance, work practices, and PPEs to control whole body vibration

Heat

• Total heat stress is the sum of metabolic heat generated in the body, plus heat gained from the environment (environmental heat), minus heat lost from the body.
• Environmental and/or metabolic heat stress results in physiological responses (heat strain) to promote heat transfer from the body back to the environment to maintain core body temperature.

Modes of Heat Exchange

• Convection
• Radiation
• Evaporation

Clothing effects on heat exchange

• Clothing acts as a barrier against heat, cold, moisture, and abrasion.

Heat related illness risk factors

• High temperature & humidity
• Direct sun exposure
• Indoor radiant heat sources
• Limited air movement
• Not enough fluids
• Physical exertion
• PPE & clothing
• Physical condition & health problems
• Medications
• Pregnancy
• Lack of recent exposure
• Advanced age
• Previous heat-related illness

Age-related Factors

• The aging process results in a more sluggish activity of sweat glands, which makes body temperature control less effective
• Aging results in decreased skin blood flow when exposed to heat, which impairs thermoregulation.

Sex related Factors

• Average-sized women have lower aerobic capacity than average-sized men.
• Men have higher sweat concentrations of sodium and chloride
• Women have a lower sweat response during exercise which increases body temperature

Pregnancy Related Factors

• Pregnancy naturally elevates body temperature, increasing heat exhaustion risk during extreme temperatures.

Body Fat factors

• The need to carry additional weight which increases energy use
• Obesity, resulting in a less favorable body surface area to body weight ratio
• More subcutaneous fat that provides an insulation barrier

Alcohol and caffeine factors

• Ingesting alcohol reduces heat tolerance, thus increasing the risk of heat-related illnesses
• Coffee has a mild diuretic effect and should not be used for fluid replacement
• Hot temperatures in beverages can exacerbate heat stroke

Acute Heat Disorders

• Heat Stroke
• Rhabdomyolysis
• Heat Exhaustion
• Heat Syncope
• Heat Cramps
• Heat rash

Heat Stroke

• Classic heat stroke includes major disruption of CNS function, lack of sweating, and a rectal temperature exceeding 41°C
• Exertional heat stroke occurs in physically active individuals who continue sweating and leading to Rhabdomyolysis and renal failure (25%).

Rhabdomyolysis

• It is associated with heat stress and prolonged physical exertion. It causes breakdown of muscle and rupture/necrosis.
• Released Electrolytes; Potassium is main electrolyte released into the blood. Irregular heart rhythms and seizures can occur from high levels in body.
• Kidneys Filter; The large muscle proteins damage filtration system of the kidneys

Heat Exhaustion

• Considered a precursor the more serious condition of heat stroke
• Accompanied by a slightly elevated core body temperature (38-39°C)
• Symptoms include headache, nausea, vertigo, weakness, thirst, heavy sweating, irritability, and decreased urine output.
• Failure to replace water predisposes the individual to heat disorders.
• Data suggests heat exhaustion occurs 10x more frequently, than heat stroke

Heat Cramps

• Attributed to continued salt loss in sweat, with a high intake of water but inappropriate salt replacement
• Other electrolytes, such as magnesium, calcium, and potassium, may also be involved.

Heat Syncope

• Occurs with prolonged standing or sudden rising and temporary circulatory failure or the pooling of blood and/or a decrease in of the diastolic filling of the heart.
• Symptoms include light-headedness, dizziness, and fainting.

Heat Rashes

• Miliaria rubra (prickly heat) is the most common heat rash, with red papules in areas of restricted clothing and causes prickling sensations with sweating.
• If untreated, papules may become infected and develop secondary staphylococcal infections

More heat rashes

• Miliaria crystallina occurs after skin injury due to sweating, which causes small/large watery vesicles
• Miliaria profunda occurs when sweat ducts are blocked below the surface, after sunburn injury.
• Discrete, pale elevations of the skin are present resembling gooseflesh

Tips for preventing heat-related illness

• Drink plenty of fluids and stay cool indoors
• Wear light clothing and sunscreen
• Reschedule outdoor activities and pace yourself
• Use a buddy system.

Chemical Hazards

• Cause a wide range of health hazards such as irritation, sensitization, and carcinogenicity
• OSHA's Hazard Communication Standard (HCS) ensures workers know workplace chemical hazards and have protective measures.

Hazards and Unsafe Practices

• Absent or inadequate engineering controls
• Inadequate, illegible, or absent labeling
• Improper Storage
• PPE unavailable, inadequate size/fit, or training
• Local ventilation is not installed, improperly positioned, maintained, or used properly

Entry routes of Chemical hazards

• Inhalation
• Ingestion
• Skin contact
• Mucous membranes

Local toxicity

• Occurs at the site of chemical contact.

Systemic toxicity

• Occurs distant from the point of contact, and involving many organ systems.

Acute toxicity

• Occurs almost immediately (hours/days) after an exposure.

Chronic toxicity

• Represents cumulative damage to specific organ systems after months/years and may have recognized clinical disease

Toxic Disorders Associated with Chemical Hazards

• Asthma and Liver Damage
• Bladder Cancer and Reproductive System
• Blood Systems and Skin Disease
• Kidney Damage and Occupational Health Hazards
• Ammonia and Benzene
• Asphyxiation and Carbon Monoxide
• Asbestos and Diesel Exhaust
• Aspiration and Hydrogen Sulfide
• Isocyanates and Methanol
• Lead and Ototoxins
• Liquid Petroleum Gas and Propane
• Mercury and Silica
• Welding Fumes and UV Radiation
• Wildfire Smoke Exposure

TLVs & BEIs

• TLVs are airborne concentrations of chemical substances where almost all workers can be repeatedly exposed without adverse effects.
• BEIs are guidance values for assessing biological monitoring results and represent levels of likely observed chemicals in specimens.

Biological Hazards

• Those, that threaten the health of living organisms
• Often shortened to "biohazards"
• Hazards concerned with the human health and safety

Biological Agent

• Typically refers to an organism that can directly cause human disease
• Examples: Bacteria, Viruses, Parasites, and Fungi
  • → Medical or clinical staff at risk of bloodborne pathogens like HIV
  • → Workers at risk of environmental pathogens like mold or Legionnaires' Disease
  • → First responders or researchers at risk of weaponized biological agents like anthrax
  • → Anyone who may be exposed to people with infectious diseases like COVID-19

Biotoxin

• A toxic or poisonous substance with a biological origin
• Plants, bacteria, insects, or animals can produce them and persist in the environment even after the living thing that created them has died
  • Snake venom, botulism (produced by botulinum bacteria) or ricin (produced by plants)

Human Blood Hazards

• Even if blood inherently not dangerous, it can contain a dangerous biological agent
• Needles and other sharps are potential blood-to-blood transmission vectors

Bodily Matter Hazards

• Blood is not the only bodily material or fluid that can transmit disease
• Saliva, urine, mucus, vomit, and feces are also hazardous to human health
• Medical, janitorial, cleaning and childcare personnel are all at risk

Animal waste or waste product hazards

• Animal products that can also transfer disease
• Some animal diseases are also transmissible to humans
• Farm workers or slaughterhouse employees are at rick of Avian Flu
• Raw milk and soiled straw bedding are potential biohazards

Organic Matter

• That which is a substance that used to be a living thing or was created by a living thing
• Materials Such As: Garbage, wastewater, sewage, plant material, and organic dust; and soil or pond water

How to prevent Biological Hazards:

• There are many different types of biohazards with various methods for prevention and mitigation. The will often include a plan with:
• Engineering controls such as regular cleaning, pest prevention, waste disposal, or PPE requirements, administrative hand washing facilities, sick leave, vaccine requirements, and training

Ergonomics

• NIOSH recommends, that the design of a work environment fit the employees physical capabilities and limitations which can include:
  • Tools
  • Lighting
  • Equipment

Musculoskeletal Disorders (MSDS)

• Disorders of the muscles, nerves, tendons, ligaments, joints, cartilage, or spinal discs
  • Causes by sudden or sustained force, vibration, repetitive motion, or awkward postures. -.Not a result of any instantaneous non-exertion event
  • Can range for mild to intense, with cause of occasional to chronic pain
  • Can indicate a risk of disability

MSDS Examples:

• Carpal tunnel syndrome
• Tendinitis
• Rotator cuff injuries (affects the shoulder)
• Epicondylitis (affects the elbow)
• Trigger finger
• Muscle strains and low back injuries

Specific MSDS and Risk Factors

• Neck WMSD
• Shoulder WMSD (shoulder tendinitis)
• Elbow WMSD (Epicondylitis)
• Carpal Tunnel Syndrome (CTS)
• Hand/Wrist Tendinitis
• Hand-arm Vibration Syndrome
• Low-Back MSD

NECK and Shoulder WMSD

• Repetitive work involving awkward neck posture and forceful arm and hand movements that stress neck muscles. Static awkward posture and contact stress
• Also applies to Shoulder WMSD

ELBOW WMSD (EPICONDYLITIS)

Includes, forceful work or with wrist generates that stresses the elbow, combined risk factors such as force, repetition and force/posture

Carpel Tunnel Syndrome and Hand/Wrist Tendinitis

• Includes, repetitive work that emphasizes awkward postitures stressing Elbows & wrists
• Includes combined risk associated with high repetition hand/wrist exertion and forceful work

Hand and Arm vibration syndrome

• This specific condition can occur, due to duration and Intesity when using vibrational tools.

Work Risks and Work Place MSDS

• MSD's can be attributed the work performed and environment they're performed in
• Workplace risks: can include MSD's caused by work conditions
• Include risks ranging from biohazards such as saliva, urine mucus, vomit,
• To more physicals ones from cold/heat and extreme vibrations, resulting in unnatural postures
• Can also endure with psychosocial stressors

ERGOnomics PROGRAM

• A systematic process of identifying, analyzing, controlling workplace risk factors. In order to reduce chance of MSDs Employers Responsibility's to protect Workers

Process for protecting work

• Employers are responsibly for a safety and healthy work envirounemnt that includes the application of ergonomic principles
  • Provide Management Support, that is strong can be critical to process

Actions for Safety

• Is critical to overall success. Management needs designate specific goals and task by staff member, and keep communication with workforce
• Workers also need be involved in the participation assessment with solution development.
• Identification with hazard in high priority in the workplace
• Assistance and voice from employees need to be heard for a collaborative enviroouenmt
• Training provide need emphasize to all members, how to understand, recognize.and the benefit of implementing it properly
• Must provide, early system report to address potential ergonomic risk and problems
• Action that, emphasizes hazard is also required, for safety and progress. Safety.