Occupational epidemiology

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Occupational epidemiology is a subdiscipline of epidemiology that focuses on investigations of workers and the workplace. [1] [2] Occupational epidemiologic studies examine health outcomes among workers, and their potential association with conditions in the workplace including noise, chemicals, heat, or radiation, or work organization such as schedules.

Contents

The need for evidence to inform occupational safety regulations, workers' compensation programs, and safety legislation motivated the development of public health policy, occupational epidemiology methods, and surveillance mechanisms. [3] Occupational epidemiological research can inform risk assessments; development of standards and other risk management activities; and estimates of the co-benefits and co-harms of policies designed to reduce risk factors or conditions that can affect human health. Occupational epidemiology methods are common to methods used in environmental epidemiology. [4]

History

Occupational hazards have long been recognized. For Hippocrates recommended other physicians consider patients' vocational backgrounds when diagnosing and treating disease, and Bernardino Ramazzini in 1700 outlined many occupational ses in his book De Morbis Artificum. There are several examples from the 19th century onwards of hazard recognition proceeding to systematic epidemiology studies. In one example, premature mortality was reported among gold and silver miners in the Erz Mountains in Germany as early as the 16th century. [5] It was initially thought to be the result of consumption, but it was subsequently determined to be silicosis, and studies from 1879 through the 1930s uncovered the association of miners' deaths with lung cancer and nonmalignant respiratory diseases. Other examples include cancer among chimney sweeps, asbestos-related diseases, and the variety of occupational diseases found among factory workers in the early 1900s. [5]

Occupational health risks were initially observed by case series reports of apparent disease excesses or clusters. Although the case series approach provided a good indicator of occupational hazards, they are not adequate on their own to assess a wide spectrum of health outcomes that may not be closely related to workplace exposure. The development of retrospective, cohort design allowed for a more comprehensive study of the cases. Desire to improve the cost-efficiency of studies led to the use of case-control studies. Other methods later used in occupational epidemiology include cross-sectional and longitudinal studies. [5]

Types of studies

Case series

Typically occupational epidemiological investigations begin with the observation of an unusual number of cases of disease among a group of workers. When the investigation does not go further than what is referred to as identifying a disease cluster, the study is referred to as a case series report. [5]

Cohort studies

In a cohort design study, a population, or cohort, of workers is compared to a control group that was not exposed to the workplace hazards being investigated. This type of study is the most accepted in the scientific community because it most closely follows experimental strategy and observes the entire population rather than a sample. In a prospective cohort study, the group examined at the time of the study is compared to a follow-up with the same group in the future. The historical cohort study design begins with defining a cohort at a time in the past and following the cohort over historical time. [5] [6]

Case-control studies

Case-control studies compare the past exposure of cases with the disease to the past exposure of cases that did not have the disease. Because cohort studies require the entire population, case-control studies are a more cost-effective approach, using only the sample of workers with the disease to compare to a control. [5] [6]

Cross-sectional studies

A typical cross-sectional study involves the comparison of varying degrees of exposure and the prevalence of disease, symptoms, or physiological status. The main advantage of cross-sectional studies is that they allow collection of data on conditions which would not be recorded normally because other study designs focus on severe states of disease. This is also the biggest shortcoming of this study type because by using prevalence rather than incidence it cannot be used to make a causal inference. [5] [6]

Application

By contributing to reduction in exposure, occupational epidemiology helps reduce health risks among workers. Using occupational epidemiological methods can also have benefits for society at large. For example, recommendations for exposure limits to benzene developed by the Expert Panel on Air Quality Standards were based on occupational epidemiology. [6]

Using meta-analysis, many occupational epidemiology studies can be synthesized in order to help set occupational exposure limits and make other kinds of policy decisions. This can also can be applied in health risk assessments, which is a method of predicting health risk based on hypothetical exposure conditions. [5]

See also

Related Research Articles

<span class="mw-page-title-main">Epidemiology</span> Study of health and disease within a population

Epidemiology is the study and analysis of the distribution, patterns and determinants of health and disease conditions in a defined population.

A cohort study is a particular form of longitudinal study that samples a cohort, performing a cross-section at intervals through time. It is a type of panel study where the individuals in the panel share a common characteristic.

<span class="mw-page-title-main">Occupational injury</span> Bodily damage resulting from working

An occupational injury is bodily damage resulting from working. The most common organs involved are the spine, hands, the head, lungs, eyes, skeleton, and skin. Occupational injuries can result from exposure to occupational hazards, such as temperature, noise, insect or animal bites, blood-borne pathogens, aerosols, hazardous chemicals, radiation, and occupational burnout.

A case–control study is a type of observational study in which two existing groups differing in outcome are identified and compared on the basis of some supposed causal attribute. Case–control studies are often used to identify factors that may contribute to a medical condition by comparing subjects who have the condition with patients who do not have the condition but are otherwise similar. They require fewer resources but provide less evidence for causal inference than a randomized controlled trial. A case–control study is often used to produce an odds ratio. Some statistical methods make it possible to use a case–control study to also estimate relative risk, risk differences, and other quantities.

<span class="mw-page-title-main">Occupational hygiene</span> Management of workplace health hazards

Occupational hygiene is the anticipation, recognition, evaluation, control, and confirmation (ARECC) of protection from risks associated with exposures to hazards in, or arising from, the workplace that may result in injury, illness, impairment, or affect the well-being of workers and members of the community. These hazards or stressors are typically divided into the categories biological, chemical, physical, ergonomic and psychosocial. The risk of a health effect from a given stressor is a function of the hazard multiplied by the exposure to the individual or group. For chemicals, the hazard can be understood by the dose response profile most often based on toxicological studies or models. Occupational hygienists work closely with toxicologists for understanding chemical hazards, physicists for physical hazards, and physicians and microbiologists for biological hazards. Environmental and occupational hygienists are considered experts in exposure science and exposure risk management. Depending on an individual's type of job, a hygienist will apply their exposure science expertise for the protection of workers, consumers and/or communities.

<span class="mw-page-title-main">Chemical hazard</span> Non-biological hazards of hazardous materials

Chemical hazards are typical of hazardous chemicals and hazardous materials in general. Exposure to certain chemicals can cause acute or long-term adverse health effects. Chemical hazards are usually classified separately from biological hazards (biohazards). Main classifications of chemical hazards include asphyxiants, corrosives, irritants, sensitizers, carcinogens, mutagens, teratogens, reactants, and flammables. In the workplace, exposure to chemical hazards is a type of occupational hazard. The use of protective personal equipment (PPE) may substantially reduce the risk of damage from contact with hazardous materials.

Clinical study design is the formulation of trials and experiments, as well as observational studies in medical, clinical and other types of research involving human beings. The goal of a clinical study is to assess the safety, efficacy, and / or the mechanism of action of an investigational medicinal product (IMP) or procedure, or new drug or device that is in development, but potentially not yet approved by a health authority. It can also be to investigate a drug, device or procedure that has already been approved but is still in need of further investigation, typically with respect to long-term effects or cost-effectiveness.

<span class="mw-page-title-main">Occupational hazard</span> Hazard experienced in the workplace

An occupational hazard is a hazard experienced in the workplace. This encompasses many types of hazards, including chemical hazards, biological hazards (biohazards), psychosocial hazards, and physical hazards. In the United States, the National Institute for Occupational Safety and Health (NIOSH) conduct workplace investigations and research addressing workplace health and safety hazards resulting in guidelines. The Occupational Safety and Health Administration (OSHA) establishes enforceable standards to prevent workplace injuries and illnesses. In the EU, a similar role is taken by EU-OSHA.

Environmental epidemiology is a branch of epidemiology concerned with determining how environmental exposures impact human health. This field seeks to understand how various external risk factors may predispose to or protect against disease, illness, injury, developmental abnormalities, or death. These factors may be naturally occurring or may be introduced into environments where people live, work, and play.

<span class="mw-page-title-main">Retrospective cohort study</span> Historic cohort study

A retrospective cohort study, also called a historic cohort study, is a longitudinal cohort study used in medical and psychological research. A cohort of individuals that share a common exposure factor is compared with another group of equivalent individuals not exposed to that factor, to determine the factor's influence on the incidence of a condition such as disease or death. Retrospective cohort studies have existed for approximately as long as prospective cohort studies.

Workplace health surveillance or occupational health surveillance (U.S.) is the ongoing systematic collection, analysis, and dissemination of exposure and health data on groups of workers. The Joint ILO/WHO Committee on Occupational Health at its 12th Session in 1995 defined an occupational health surveillance system as "a system which includes a functional capacity for data collection, analysis and dissemination linked to occupational health programmes".

Occupational health psychology (OHP) is an interdisciplinary area of psychology that is concerned with the health and safety of workers. OHP addresses a number of major topic areas including the impact of occupational stressors on physical and mental health, the impact of involuntary unemployment on physical and mental health, work-family balance, workplace violence and other forms of mistreatment, psychosocial workplace factors that affect accident risk and safety, and interventions designed to improve and/or protect worker health. Although OHP emerged from two distinct disciplines within applied psychology, namely, health psychology and industrial and organizational psychology, for a long time the psychology establishment, including leaders of industrial/organizational psychology, rarely dealt with occupational stress and employee health, creating a need for the emergence of OHP. OHP has also been informed by other disciplines, including occupational medicine, sociology, industrial engineering, and economics, as well as preventive medicine and public health. OHP is thus concerned with the relationship of psychosocial workplace factors to the development, maintenance, and promotion of workers' health and that of their families. The World Health Organization and the International Labour Organization estimate that exposure to long working hours causes an estimated 745,000 workers to die from ischemic heart disease and stroke in 2016, mediated by occupational stress.

<span class="mw-page-title-main">Physical hazard</span> Hazard due to a physical agent

A physical hazard is an agent, factor or circumstance that can cause harm with contact. They can be classified as type of occupational hazard or environmental hazard. Physical hazards include ergonomic hazards, radiation, heat and cold stress, vibration hazards, and noise hazards. Engineering controls are often used to mitigate physical hazards.

<span class="mw-page-title-main">Nutritional epidemiology</span> Field of medical research on disease and diet

Nutritional epidemiology examines dietary and nutritional factors in relation to disease occurrence at a population level. Nutritional epidemiology is a relatively new field of medical research that studies the relationship between nutrition and health. It is a young discipline in epidemiology that is continuing to grow in relevance to present-day health concerns. Diet and physical activity are difficult to measure accurately, which may partly explain why nutrition has received less attention than other risk factors for disease in epidemiology. Nutritional epidemiology uses knowledge from nutritional science to aid in the understanding of human nutrition and the explanation of basic underlying mechanisms. Nutritional science information is also used in the development of nutritional epidemiological studies and interventions including clinical, case-control and cohort studies. Nutritional epidemiological methods have been developed to study the relationship between diet and disease. Findings from these studies impact public health as they guide the development of dietary recommendations including those tailored specifically for the prevention of certain diseases, conditions and cancers. It is argued by western researchers that nutritional epidemiology should be a core component in the training of all health and social service professions because of its increasing relevance and past successes in improving the health of the public worldwide. However, it is also argued that nutritional epidemiological studies yield unreliable findings as they rely on the role of diet in health and disease, which is known as an exposure that is susceptible to considerable measurement error.

<span class="mw-page-title-main">Occupational safety and health</span> Field concerned with the safety, health and welfare of people at work

Occupational safety and health (OSH) or occupational health and safety (OHS) is a multidisciplinary field concerned with the safety, health, and welfare of people at work. OSH is related to the fields of occupational medicine and occupational hygiene and aligns with workplace health promotion initiatives. OSH also protects all the general public who may be affected by the occupational environment.

<span class="mw-page-title-main">Occupational hearing loss</span> Form of hearing loss

Occupational hearing loss (OHL) is hearing loss that occurs as a result of occupational hazards, such as excessive noise and ototoxic chemicals. Noise is a common workplace hazard, and recognized as the risk factor for noise-induced hearing loss and tinnitus but it is not the only risk factor that can result in a work-related hearing loss. Also, noise-induced hearing loss can result from exposures that are not restricted to the occupational setting.

A psychosocial hazard or work stressor is any occupational hazard related to the way work is designed, organized and managed, as well as the economic and social contexts of work. Unlike the other three categories of occupational hazard, they do not arise from a physical substance, object, or hazardous energy.

Occupational toxicology is the application of toxicology to chemical hazards in the workplace. It focuses on substances and conditions that people may be exposed to in workplaces, including inhalation and dermal exposures, which are most prevalent when discussing occupational toxicology. These environmental and individual exposures can impact health, and there is a focus on identifying early adverse affects that are more subtle than those presented in clinical medicine.

The health and safety hazards of nanomaterials include the potential toxicity of various types of nanomaterials, as well as fire and dust explosion hazards. Because nanotechnology is a recent development, the health and safety effects of exposures to nanomaterials, and what levels of exposure may be acceptable, are subjects of ongoing research. Of the possible hazards, inhalation exposure appears to present the most concern, with animal studies showing pulmonary effects such as inflammation, fibrosis, and carcinogenicity for some nanomaterials. Skin contact and ingestion exposure, and dust explosion hazards, are also a concern.

<span class="mw-page-title-main">Workplace hazard controls for COVID-19</span> Prevention measures for COVID-19

Hazard controls for COVID-19 in workplaces are the application of occupational safety and health methodologies for hazard controls to the prevention of COVID-19. Vaccination is the most effective way to protect against severe illness or death from COVID-19. Multiple layers of controls are recommended, including measures such as remote work and flextime, increased ventilation, personal protective equipment (PPE) and face coverings, social distancing, and enhanced cleaning programs.

References

  1. "Occupational Epidemiology". U.S. Occupational Safety and Health Administration . Retrieved 2016-06-13.
  2. Checkoway, Harvey; Pearce, Neil; Kriebel, David (2004). Research Methods in Occupational Epidemiology. New York, NY: Oxford University Press. ISBN   0-19-509242-2.
  3. Halperin, William; Howard, John (2011-10-07). "Occupational Epidemiology and the National Institute for Occupational Safety and Health". Morbidity and Mortality Weekly Report . U.S. Centers for Disease Control and Prevention. 60 (4): 97–103. PMID   21976172.
  4. Pell, S. (May 1993). "Epidemiologists in industry. Past achievements, unexplored opportunities, and future needs". Journal of Occupational Medicine. 35 (5): 485–492. ISSN   0096-1736. PMID   8515320.
  5. 1 2 3 4 5 6 7 8 Checkoway, Harvey; Pearce, Neil; Crawford-Brown, Douglas J. (1989). Research methods in occupational epidemiology . New York: Oxford University Press. pp.  5–8, 59, 61, 66, 72, 331. ISBN   9780195092424. OCLC   610965808.
  6. 1 2 3 4 Agius, Raymond. "Occupational Epidemiology" . Retrieved 2017-07-30.