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Overview of Occupational and Environmental Medicine


Michael I. Greenberg

, MD, Drexel University College of Medicine;

David Vearrier

, MD, MPH, University of Mississippi Medical Center

Reviewed/Revised Aug 2022 | Modified Sep 2022

Occupational and environmental medicine (OEM) is the prevention, diagnosis, and treatment of injuries, illnesses, and disabilities that are related to the job and workplace of workers or to the environment of the community. Promoting the overall health and safety of workers in the workplace, at home, and in the community also helps workers be more productive. Doctors who practice OEM may also care for people exposed to environmental contaminants that are not related to work (such as lead poisoning Lead Poisoning Lead poisoning affects many parts of the body, including the brain, nerves, kidneys, liver, and blood. Children are particularly susceptible because their nervous system is still developing... read more in children).

OEM doctors promote the physical and mental health and safety of workers by

  • Implementing preventive measures and education (such as health and wellness programs)

  • Screening job applicants to determine their ability to meet core job requirements

  • Determining whether an injury or illness is work-related

  • Diagnosing and treating occupational and environmental injury and illness promptly, preferably in the workplace

  • Making sure that workers who have been injured or ill are returning to work safely and usefully

  • Determining the extent of a worker's disability and ability to work after a long-term injury or illness

  • Evaluating the safety of the workplace in terms of exposures to hazards and ergonomics

  • Designing and arranging a work space to help people interact with things as efficiently and safely as possible

  • Recommending measures to protect workers' health (such as guidelines for when personal protective equipment is required)

Thus, OEM benefits both workers and employers.

The most common illnesses and injuries treated by OEM doctors in the workplace are

Sometimes an injury (such as a repetitive motion injury) is caused by a combination of activities at work and outside of work.

Sometimes illnesses resulting from substances in the environment cause symptoms common in many diseases. For example, exposure to carbon monoxide may cause symptoms that resemble those of a viral infection, such as headache, nausea, and vomiting.

The purpose of the Occupational Safety and Health Administration (OSHA), a federal agency, is to make sure workers have safe and healthful working conditions. To do so, OSHA has set up standards and provides training, education, and help. Employers are required to comply with all applicable OSHA standards, including removing all serious recognized hazards from the workplace. All employers are also required to report work-related deaths, hospitalizations, amputations, and loss of an eye to OSHA.

Evaluation of the Worker

When a worker is injured or becomes ill, OEM doctors try to determine whether the injury or illness is work-related or related to something in the environment. So doctors ask the worker questions designed to determine what led to the problem, such as:

  • Where the injury or possible exposure occurred

  • What the worker was doing when injured or became ill

Doctors may suspect a work-related cause, for example, if a person suddenly develops an unexpected illness that has no other clear non–work-related cause. Doctors may also suspect a work-related cause if a group of workers develop similar problems. In that case, doctors also ask managers whether other workers have similar symptoms. For example, if several workers from the same building report headache, nausea, and vomiting, they may have been exposed to carbon monoxide. Doctors may ask workers who have similar symptoms or who do not have symptoms but work in the same area as the worker being evaluated and may ask members of the community about any symptoms they have. This information can help doctors determine what chemicals or other exposures are causing symptoms among workers and others that have or may have had similar exposures. This information can help doctors determine whether the illness is work-related or not.

Safety Evaluation of the Workplace

If the injury or illness is work-related, OEM doctors evaluate the conditions that led to the injury or illness. They evaluate workplace safety and ergonomics. They can then recommend ways to prevent future injury or illness.

Doctors check for one or more of these types of hazards:

  • Air contaminants (such as dusts and fumes)

  • Chemical hazards (such as asbestos, emissions from diesel or gasoline engines, formaldehyde, and lead)

  • Biologic hazards (such as bacteria or viruses)

  • Physical hazards (such as radiation, temperature extremes, noise, and vibration)

  • Ergonomic hazards (such as lifting, reaching, and repetitive movements)

Doctors then talk to the employer about ways to reduce potential risks for workers. The most effective way to reduce risk is to remove the hazard from the workplace entirely. If removal is not possible, the hazard may be replaced with a less dangerous substitute. For example, a newer machine with additional safeguards may be substituted. Other less effective strategies are isolating a process or machine from the worker and changing the way workers interact with the hazard, either by improving training and procedures or by limiting the total time a worker is exposed to the hazard. Use of personal protective equipment (PPE) is the least effective way to reduce risk, partly because it requires that PPE fit or seal tightly and that workers use it consistently.

Assessment of Disability

OEM doctors are frequently asked to assess disability in a worker. In the United States, various organizations (such as the Social Security Disability System, Civil Service Retirement, state worker's compensation programs, and state and Railroad Retirement Board) have regulations that establish whether a worker is disabled and whether the disabled worker should receive disability benefits.

During these assessments, OEM doctors determine

  • Which organs are impaired

  • How severe and long-lasting the impairment is

  • Whether function in a body part has been lost

  • Whether the worker is disabled (unable to do activities, including activities necessary for employment) because of an impairment


If the injury may have resulted from exposure to a substance in the workplace, tests are done to measure how much of the substance workers are exposed to regularly and/or after an incident (such as an unintended release of a substance). Workers may be tested to determine whether an exposure in the workplace has damaged an organ (such as the lungs).

Governmental agencies (such as the Occupational Safety and Health Administration [OSHA] or the National Institute for Occupational Safety & Health [NIOSH]) may inspect the workplace when workers report dangerous conditions or injuries or illnesses.

Testing may also be done to determine how much of a substance people in the community are exposed to after an unintended release of that substance.

Treatment and Return to Work

Treatment for illnesses and injuries that occurred at the workplace is the same as that outside the workplace.

An important goal of OEM doctors is to return workers to the workplace as soon as it is safe. An early return to work can reduce the number of missed work days and the extent of disability over the long term. When workers with an injury or illness cannot return to their typical work routine, they may be assigned transitional duty (sometimes called light or modified duty). For example, OEM doctors may recommend limitations on pushing, pulling, lifting, sitting, and standing.

Preemployment Screening

OEM doctors screen job applicants to determine whether they can safely fulfill the duties of the position they are applying for. OEM doctors evaluate such factors as an applicant's preexisting chronic illnesses or conditions, use of drugs that may cause impairment, and substance abuse (often with drug tests) and the results of a physical examination.

Screening and Surveillance of Workers

OEM doctors provide medical screening and surveillance of workers in workplaces with potential exposures to hazardous substances. In the United States, the Occupational Safety and Health Administration (OSHA) issues standards for such screening and surveillance.

Medical screening is a one-time evaluation, typically before the worker is hired. Screening is done to detect illness or dysfunction before a person seeks medical care. For example, doctors may screen people who may be at high risk of certain conditions.

Medical surveillance involves periodic evaluations of one or more workers over time to monitor their risks when they are exposed to potential workplace hazards that require specific preventive measures.

Depending on the substance involved, screening, surveillance, or both may be done.

More Information

The following English-language resources may be useful. Please note that THE MANUAL is not responsible for the content of these resources.

  • An Employee's Guide on Reporting a Work-Related Injury or Disease: Provides detailed information about reporting a work-related injury or illness, including links to the forms needed.

  • Occupational Health and Safety Administration: Sets and enforces standards to ensure safe and healthful working conditions for workers; also provides information about workers' rights, hazard recognition, COVID-19, fall prevention, suicide prevention, personal protective equipment, and documentation requirements.

  • Pediatric Environmental Health Specialty Units: Provides information about how environmental factors (such as hurricanes, floods, lead, and wildfires) affect the health of children and adults of reproductive age; also provides contact information to experts in various areas of the United States.

  • National Institute for Occupational Safety and Health (NIOSH): Seeks new information about occupational safety and health, based on its own scientific research, and provides guidance and authoritative recommendations for improving safety and health in the workplace; also provides information about such topics as nail gun safety and about the health implications and applications of nanotechnology (eg, nanotechnology laboratory safety).

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