The effect of work on human health, and the impact on a person's work on their health. It includes identifying, treating and preventing work-related illness caused by chemical, biological, physical and psychosocial factors, and the promotion of a healthy and productive workforce.
Occupational health includes both mental and physical health. It also deals with compliance with health-and-safety-at-work legislation, common-law duties and best practice in providing work environments that reduce risks as much as possible. It involves workers’ fitness to work; how to design the workplace to accommodate people with disabilities; and procedures to assist the return to work of those absent with long-term illness. Occupational health is multidisciplinary, involving physicians, nurses, physiotherapists, hygienists, ergonomists, disability managers, workplace counsellors and health-and-safety practitioners.
The branch of medicine that deals with the control, prevention, diagnosis, treatment and management of ill-health and injuries caused or made worse by work, and with ensuring that workers are fit to carry out their duties.
It includes statutory surveillance of workers’ exposure to hazardous agents; advice to employers and employees on eliminating or reducing risks to health and safety at work; diagnosis and treatment/management of occupational illness; advice on adapting the working environment to suit the worker, particularly those with disabilities or long-term health problems; and advice on the return to work and, if necessary, rehabilitation of workers absent through illness. Occupational physicians may play a wider role in monitoring the health of workplace populations and in advising employers on controlling health hazards where ill-health trends are observed. They may also conduct epidemiological research (see EPIDEMIOLOGY) on workplace diseases.
Because of occupational physicians’ dual role as advisers to both employer and employee, they must be particularly careful with regards to the individual worker's medical CONFIDENTIALITY.
are physical and/or mental illnesses that are caused or made worse by work. There are no precise figures for the number of people who die prematurely because of work-related ill-health, and it would be impossible to gauge the exact contribution that work has on, for example, cardiovascular disease and cancers where their causes are multifactorial. The toll would, however, dwarf the number of deaths caused by accidents at work.
Some conditions – certain skin conditions, for example – may show a close relationship to work, with symptoms appearing only after exposure to particular agents or possibly disappearing at weekends or with time away from work. Others, however, may be chronic and can have serious long-term implications for a person's future health and employment.
The ten most frequently reported disease categories are:
stress and mental ill-health (see MENTAL ILLNESS):.
back injuries (see BACKACHE);
upper-limb and neck disorders;
lower respiratory disease;
deafness, TINNITUS or other ear conditions;
lower-limb musculoskeletal conditions;
skin disease (see SKIN, DISEASES OF);
HEADACHE or ‘eyestrain’;
traumatic injury (includes wounds and fractures from accidents at work);
vibration white finger (hand-arm vibration syndrome).
In the UK, more than 60 diseases are prescribed under the Industrial Injuries Scheme and a person will automatically be entitled to state compensation for disability connected to one of these conditions, provided that he or she works in one of the occupations for which such compensation is prescribed. Examples are:
CARPAL TUNNEL SYNDROME connected to the use of hand-held vibrating tools;
hearing loss from use of pneumatic percussive tools and chainsaws, working with textile manufacturing or woodworking machines, and in ships’ engine rooms;
LEPTOSPIROSIS – infection with Leptospira (various listed occupations such as sewage workers);
viral HEPATITIS from contact with human blood, blood products or other similar sources;
LEAD POISONING, from any occupation causing exposure to fumes, dust and vapour from lead or lead products;
ASTHMA caused by exposure to, amongst others, isocyanates, curing agents, solder flux fumes and insects reared for research;
MESOTHELIOMA from exposure to asbestos.
Other occupational diseases include the following.
A group of diseases which cause fibrotic lung disease following the inhalation of dust, most commonly coal dust with or without silica contamination. SILICOSIS is the most severe disease. Asbestos fibres cause a restrictive lung disease but are also responsible for certain malignant conditions such as pleural and peritoneal MESOTHELIOMA and lung cancer. The lung-cancer risk is increased by cigarette-smoking.
Even though the use of asbestos is virtually banned in the UK, many workers remain at risk of exposure because of the vast quantities still present in buildings (much of which is not listed in building plans). Carpenters, electricians, plumbers, builders and demolition workers are all liable to exposure from any work that disturbs existing asbestos.
accounts for about 10 per cent of all adult-onset asthma and is most frequently linked to: isocyanates (e.g. spray painters, electrical processors); flour and grain (bakers and farmers); wood dust (wood workers); glutaraldehyde (nurses, darkroom technicians); solder/colophony (welders, electronic assembly workers); laboratory animals (technicians, scientists); resins and glues (metal and electrical workers, construction, chemical processors); and latex (nurses, auxiliaries, laboratory technicians).
About three-quarters of cases are irritant contact dermatitis due to acids, alkalis and solvents. Allergic contact dermatitis is a more specific response by susceptible individuals to a range of allergens (see ALLERGEN). The main ones include chromates, nickel, epoxy resins, rubber additives, germicidal agents, dyes, topical anaesthetics and antibiotics as well as certain plants and woods. Latex gloves are a particular cause of occupational dermatitis among health-care and laboratory staff and have resulted in workers being forced to leave their profession through ill-health. (See also SKIN, DISEASES OF.)
account for over a third of all disabilities among working-age people. Back pain (all causes – see BACKACHE) has been estimated to cause a loss of more than 50 million days every year in the UK due to sickness absence. It is a particular problem in the health-care sector because of the risk of injury from lifting and moving patients.
Some conditions, such as carpal tunnel syndrome, are prescribed diseases in certain occupations but are not always caused by work, while other conditions may be revealed or made worse by work – such as OSTEOARTHRITIS in the hand. Much attention has focused on injuries caused by repeated movement, excessive force, and awkward postures such as tenosynovitis (inflammation of a tendon) and epicondylitis (inflammation of a bone surface). The greatest controversy surrounds upper-limb disorders that do not present obvious tissue or nerve damage but cause significant pain and discomfort. These are sometimes referred to as ‘repetitive strain injury’ or ‘diffuse RSI’. Psychosocial factors, such as high demands of the job, lack of control and poor social support at work, have been implicated in the development of many upper-limb disorders, and in prevention and management it is important to deal with the psychological as well as the physical risk factors. Occupations known to be at particular risk of work-related upper-limb disorders include poultry processors, packers, electronic assembly workers, data processors, supermarket check-out operators and telephonists. (See UPPER LIMB DISORDERS.)
The most important of these is occupational deafness. Workplace noise exposures in excess of 85 decibels for a working day are likely to cause damage to hearing which is initially restricted to the vital frequencies associated with speech – around 3–4 kHz. Protection from such noise is imperative.
Hand-arm vibration syndrome is a disorder of the vascular and/or neural endings in the hands leading to episodic blanching (‘white finger’) and numbness which is exacerbated by low temperature.
Decompression sickness is caused by a rapid change in ambient pressure and is a disease associated with deep-sea divers, tunnel workers and high-flying aviators. Apart from the direct effects of pressure change such as ruptured tympanic membrane or sinus pain, the more serious damage is indirectly due to nitrogen bubbles appearing in the blood and blocking small vessels. Central and peripheral nervous-system damage and bone necrosis are the most dangerous sequelae.
Non-ionising radiation from lasers or microwaves can cause severe localised heating leading to tissue damage, for example cataracts (see under EYE, DISORDERS OF). Ionising radiation from radioactive sources can cause similar acute tissue damage to the eyes as well as damage to rapidly dividing cells in the gut and bone marrow. Longer-term effects include genetic damage and various malignant disorders of which LEUKAEMIA and aplastic ANAEMIA are notable. Particular radioactive isotopes may destroy or induce malignant change in target organs, for example, 131I (thyroid), 90Sr (bone).
Important occupational carcinogens include asbestos (mesothelioma, lung cancer); polynuclear aromatic hydrocarbons such as mineral oils, soots, tars (skin and lung cancer); the aromatic amines in dyestuffs (bladder cancer); certain hexavalent chromates, arsenic and nickel refining (lung cancer); wood and leather dust (nasal sinus cancer); benzene (leukaemia); and vinyl chloride monomer (angiosarcoma of the liver). It has been estimated that elimination of all known occupational carcinogens, if it were possible, would lead to an annual saving of 5,000 premature deaths in Britain.
Two broad categories of job carry an occupational risk. These are workers in contact with animals (farmers, veterinary surgeons and slaughtermen) and those in contact with human sources of infection (health-care staff and sewage workers).
Occupational infections include various zoonoses (pathogens transmissible from animals to humans), such as ANTHRAX, Borrelia burgdorferi (LYME DISEASE), bovine TUBERCULOSIS, BRUCELLOSIS, Chlamydia psittaci, leptospirosis, ORF virus, Q fever, RINGWORM and Streptococcus suis. Human pathogens that may be transmissible at work include tuberculosis, and blood-borne pathogens such as viral hepatitis (B and C) and HIV (see AIDS/HIV). Health-care workers at risk of exposure to infected blood and body fluids should be immunised against hepatitis B.
Workers involved in the application of pesticides are particularly at risk if safe procedures are not followed or if equipment is faulty. Exposure to organophosphate pesticides, for example, can lead to breathing difficulties, vomiting, diarrhoea and abdominal cramps, and to other neurological effects including confusion and dizziness; severe poisonings can lead to death. Exposure can be through ingestion, inhalation and skin contact.
Stress at work is an adverse reaction to excessive pressures or demands. The causes include the nature of the job (e.g. long or unsocial working hours, high work demands, imbalance between effort and reward, poorly managed organisational change, lack of control over work, poor social support at work, fear of redundancy and bullying), as well as individual factors (such as personality type, personal circumstances, coping strategies, and availability of psychosocial support outside work). Stress may influence behaviours such as smoking, alcohol consumption, drug use or abuse, sleep and diet, which may in turn affect people's health. It may also alter the course and response to treatment of conditions such as cardiovascular disease. As well as these general effects of stress, specific types of disorder may be observed.
Exposure to extremely traumatic incidents at work, such as dealing with a major accident involving loss of life or serious injury (e.g. paramedics at the scene of an explosion or rail disaster), may result in POST-TRAUMATIC STRESS DISORDER (PTSD), an abnormal psychological reaction to a traumatic event, characterised by extreme psychological discomfort. This may result in severe anxiety or panic when reminded of the causative event; sufferers may be plagued with uncontrollable memories (‘flash-backs’) and feel as if they are going through the trauma again.
are medical practitioners with a post-registration qualification in occupational medicine. In the UK, they will have completed a period of supervised in-post training to a curriculum set by the Faculty of Occupational Medicine of the Royal College of Physicians.