Medical specialty focusing on detection and prevention of diseases that arise from the work environment
Defined as those health outcomes that are ‘“…caused or influenced by exposure to general conditions or specific hazards encountered in the work environment.’”
Origin of Occupational Health
Recognition of occupational risks from mining occurred during Greek and Roman times.
Noteworthy Figures in History
Rhazes (ca. 850-923) used occupational classifications in medical case descriptions.
Paracelsus (1493-1541) wrote a book on occupational diseases.
Bernardino Ramazzini (1633-1714) Considered the “father of occupational medicine”
His book De Morbis Artificum Diatriba (Diseases of Workers) detailing the manifestations of occupational diseases was published in 1700.
Some Occupational Diseases Found in Historical Literature
Mad hatter’s disease
Mule spinners’ cancer
Historically Significant Occupational Accidents
Triangle Shirtwaist Company fire
Gauley Bridge disaster
Triangle Shirtwaist Company Fire
Occurred on March 25, 1911 in New York City
146 women died in 15 minutes
Doors were locked and fire escapes were missing.
Gauley Bridge Disaster
Covered a time span that began about 1931
Caused exposure of unprotected workers to high levels of silica dust
Resulted in about 1,500 cases of silicosis and 1,000 deaths
The Occupational Environment and Health
During 2001, approximately 5.2 million nonfatal, work-related illnesses and injuries were reported in private industry.
During 2002, there were 5,542 work-related injury deaths.
The Costs of Occupational Injuries, Illnesses and Fatalities
Direct costs of injuries in 2002 were estimated at $45.8 billion for private sector.
Indirect costs in 2002 were estimated to be up to $229 billion for private industry.
Leading Causes of Disabling Conditions
Sprains and strains, Bruises and contusions, Cuts, lacerations, and punctures
Agents of Occupational Disease
Noise, Dusts,Toxic heavy metals and their fumes, Carbon monoxide, Chemicals, Ionizing radiation, Microbial agent, Lifting heavy weights, Repetitive motion, Workplace accidents,Work-related stress, Noise
The term ototoxic refers to agents that can produce hearing loss.
Ototoxic agents include very loud sounds and several classes of drugs and chemicals used in the work environment.
Toxic Heavy Metals and Their Fumes
Toxic heavy metals:
(arsenic, lead, mercury, cadmium, chromium and nickel) are potential hazards to human health. Processing and milling of heavy metals put workers at risk of breathing fumes and dusts that contain toxic levels of these metals.
An odorless, hazardous, toxic gas Found in many work settings Causes the formation of carboxyhemoglobin, which reduces the oxygen-carrying capacity of blood
Are a source of health risks for workers in many occupational categories
For example, health care workers, workers exposed to sewage, and agricultural workers may be exposed to bacteria, viruses, and disease-carrying insects.
Chronic stress has been implicated in a range of somatic conditions (e.g., coronary heart disease) and mental disorders including depression.
Workplace violence has been noted as a serious outcome of job-related stress.
Occupationally Associated Diseases and Conditions
Allergic and irritant dermatitis
Chronic obstructive pulmonary disease and asthma
Fertility and pregnancy abnormalities
Hearing loss caused by noise
Traumatic injuries and fatalities
Allergic and Irritant Dermatitis
The skin is one of the most common sites of contact with chemicals in the workplace. Manufacturing, construction, food production, and activities such as metal plating and engine service put workers at highest risk for skin problems.
Many of the work-related respiratory diseases are chronic conditions that have long latency periods. Asbestosis, coal workers’ pneumoconiosis, silicosis, byssinosis, mesothelioma, and lung cancer are examples of work-related respiratory diseases.
Chronic Obstructive Pulmonary Disease (COPD) and Asthma
About 30% of cases of COPD and asthma can be linked to occupational exposures.
COPD is related to workplace exposure to dusts. Asthma has become the most frequently diagnosed occupational respiratory disease in the U.S.
Fertility and Pregnancy Abnormalities
Examples are birth defects, prematurity, low birth weight, spontaneous abortions, and developmental disabilities. A total of 4 million chemicals in use commercially use have not been tested for their reproductive effects. Most of the 1,000 chemicals used in the work environment that have been demonstrated to cause adverse reproductive effects among animals have not been tested with humans.
Hearing Loss Caused by Noise
The second most-commonly self-reported occupational injury or illness As many as 10 million workers in U.S. suffer from noise-induced hearing loss. Prolonged exposure may result in psychological reactions that adversely impact the immune system and physical well-being.
Nature of Sound and Hearing
Sound is produced by oscillating waves of various frequencies.
The term Hertz (Hz) denotes the number of cycles per second associated with the oscillation of a given sound wave.
Sound Pressure Level (SPL) and Decibels (dBs)
The sound pressure level (SPL) is a measure of the intensity of sound.
The SPL is reported on a logarithmic scale that uses decibels (dBs).
An increase of 10dB represents a 10-fold increase in sound intensity.
dBs are advantageous for characterizing the large variability in the range of sounds that the human ear can perceive.
Two Employment Categories Affected Greatly by Noise
Health care industry
Permissible Noise Levels in the Workplace
The NIOSH recommended exposure limit (REL) for noise exposure in the workplace during an 8-hour shift is 85 dBA.
dBA refers to A-weighting, meaning that exposure is an 8-hour time-weighted average.
Infectious Diseases (Examples of Workers at Risk)
Health care workers
Public utility workers
Social service workers and corrections personnel
Clinical laboratory specialists
Adult film industry workers
Musculoskeletal Disorder (MSD)
Refers to “…an injury or disorder of the muscles, nerves, tendons, joints, cartilage, or spinal disks.”
Common MSD in the Workplace*
Sprains, strains, tears
Back pain, hurt back
Carpal tunnel syndrome
Soreness, pain, hurt, except the back
MSD system and connective tissue diseases and disorders, except tendonitis
Traumatic Injuries and Fatalities
Acute trauma is one of the major sources of work-related death and disability.
There was a 42% decrease in the average annual rate of occupational fatalities in the U.S. between 1980 and 1995.
In 2002, a total of 5,524 fatal occupational injuries were reported in the U.S.
Industries Accounting for the Largest Frequencies of Death
Transportation and public utilities
Agriculture, forestry, fishing, and hunting
The term job stress is “. . . defined as the harmful physical and emotional responses that occur when the requirements of the job do not match the capabilities, resources, or needs of the worker.”
Conditions Associated with Job Stress
Anxiety, stress, and neurotic disorders
Critical incident stress
Note: Of six job categories, the classification of technical, sales, and administrative support had the highest percentage of cases of anxiety, stress, and neurotic disorders in 2001.
Preventing Occupational Disease
Primary Prevention Engineering controls Quieter machinery, improved building ventilation Optimal work practices and administrative controls Use of safety education programs, reorganizing work schedules to reduce exposure to hazards
Personal Protective Equipment (PPE)
Apparatuses “…designed to protect employees from serious workplace injuries or illnesses resulting from contact with chemical, radiological, physical, electrical, mechanical, or other workplace hazards.”
Primary Prevention Versus Use of PPE
The three methods of primary prevention are preferred over other methods for protecting workers such as the use of PPE.
Examples of PPE:
Respirators, Various types are used to filter airborne particles, remove airborne chemicals and gases, or supply clean air.
Devices to Protect Hearing
Ear muffs and ear plugs
Goggles, face shields, safety glasses, and full-face respirators
Public Health Surveillance
Surveillance systems include the collection of information about occupational injuries and illnesses and maintenance of databases on exposures to occupational hazards.
U.S. Agencies That Conduct Surveillance
National Institute for Occupational Safety and Health (NIOSH)
National Center for Health Statistics (NCHS)
Bureau of Labor Statistics (BLS)
Occupational Safety and Health Administration (OSHA)
Mine Safety and Health Administration (MSHA)
Surveillance Programs Operated by NIOSH
National Surveillance System of Pneumoconiosis Mortality (NSSPM)
National Traumatic Occupational Fatalities (NTOF) Surveillance System
State-based Sentinel Event Notification System for Occupational Risks (SENSOR)
Guidelines and regulations for limitation of workplace exposures to hazardous agents
The threshold limit value (TLV) “Refers to airborne concentrations of substances and represents conditions under which it is believed that nearly all workers may be unaffected.”