Objective:to be competent in the assessment and management of a case which has a significant occupational health component.
APPRECIATE THE RELEVANCE OF CERTAIN SYMPTOMS AND THEIR POTENTIAL LINK TO OCCUPATION
This is considered by looking at each system in turn:
and providing the following information.
1. ABC of Work Related Disorders: Occupational Dermatitis (BMJ 1996; 313:487-489)
Condition: Irritant contact dermatitis (ICD)
This is caused by direct chemical or physical damage to the skin. Everyone is vulnerable to developing an irritant contact dermatitis if exposure is high enough.
The dermatitis may be acute or chronic in nature. The chronic form occurs after repeated exposure. People with atopic eczema are particularly at risk of developing chronic irritant contact dermatitis.
Agents which may cause ICD: Wet cement, vegetable juices, soluble coolants, detergents.
Occupations at risk of ICD: Hairdressers, construction industry, mechanics, cooks.
Condition: Allergic contact dermatitis (ACD)
This form of dermatitis can be due to a type IV hypersensitivity reaction. The dermatitis develops where the allergen comes in to direct contact with the skin. Contact allergens tend to be of low molecular weight. It is not possible as yet to determine an individual’s susceptibility to developing a contact allergy.
Type I immediate hypersensitivity responses may also occur giving ACD. An example is a reaction to proteins present in gloves made from natural rubber (latex). Here a local urticarial reaction may occur at the site of skin contact or it may present as respiratory symptoms e.g.: a wheeze when starched gloves have been used. This is important to consider as sensitisation can lead to anaphylaxis. It is a problem which health care workers need to be aware of although now non powdered or latexfreegloves are now routinely provided. There is an increased incidence of ACD in atopic individuals.
Agents which may cause ACD : latex, hairdressing chemicals, chromate, plant allergens
Occupations at risk of ACD: Hairdressers, health care workers, laboratory workers.
This occurs due to irritation of the hair follicle. It is not a common condition but when seen can look like acne.
Agents which cause folliculitis: Cutting oils used to cool metal
Occupations at risk of folliculitis : Engineers, machine operators.
Wheezing; shortness of breath; haemoptysis; flu-like illnesses; weight loss and cough can all be associated with respiratory pathology.
The potential link to occupation can be divided into the following subgroups.
Pneumoconiosis is a general term for conditions relating to the inhalation of dusts such as coal and silica. Coal miners with X ray changes often showed no symptoms or physical signs of disease. However, some cases go on to develop ‘progressive massive fibrosis, a disabling condition which presents with severe shortness of breath and in some heart failure (cor pulmonale). With the closing of the mines this condition is now uncommon in the UK.
Chronic silicosis still occurs in the UK and is related to inhaling silica dust, usually where working with slate or granite. An acute form of this disease is also seen in which individuals become acutely short of breath following exposure, with death in some cases in months. This type of exposure is associated with sandblasting.
Agents which may cause pneumoconiosis: Coal dust, Silica, Beryllium
Occupations at risk: Mining, sandblasting, iron and slate industry, electronic industry, dental alloy preparation.
Asbestos related disorders:
Asbestos exposure can lead to a number of different disorders broadly categorised as:
Condition: Non Malignant Disorders
The non malignant disorders include asbestosis, pleural plaques, diffuse thickening of the pleura, benign pleural effusions and asbestos corns.
Asbestosis produces a diffuse interstitial pulmonary fibrosis. The diagnosis is obtained from the history and evidence of other pathology related to asbestos exposure. Asbestos corns can present as tender calluses on the hands.
Condition: Malignant Disorders
Malignant disorders related to asbestos exposure are bronchial cancer and mesothelioma of the pleura and peritoneum. It is essential in any individual presenting with a bronchial cancer to exclude exposure to asbestos as these people are eligible to state compensation. Other occupational causes of lung cancer include radiation and chromium exposure.
Most cases of mesothelioma are due to pleural disease. The disease usually occurs 20 – 40 years after exposure. The incidence of death due to this disease in the UK is still rising. The onset of the disease is often insidious with patients complaining of increasing shortness of breath and chest pain. Examination often reveals a pleural effusion. Death usually occurs within a year of diagnosis, so treatment is usually palliative. All cases of mesothelioma related to occupational exposure are eligible for industrial injuries benefits which is compensation obtained from the Department for Work and Pensions.
Agents: there are 2 types of fibrous mineral silicates that cause asbestos disease.
Occupations at risk: Demolition workers, ship yard workers, insulation workers, builders, gas fitters, roofers, carpenters, electricians, asbestos workers.
Condition: Occupational Asthma
Occupational asthma is caused by exposure to specific sensitising substances that are inhaled whilst at work. Such substances are called respiratory sensitisers. This does not include other irritants such as cold or exercise that an individual might encounter in work that can cause bronchoconstriction. There are increasing numbers of sensitisers recognised as likely causes of occupational asthma.
Taking a detailed history of the timing of symptoms along with an occupational history is very important in making the diagnosis of occupational asthma. Here symptoms are initially better whilst on holiday and on rest days. There are often related symptoms of a runny nose. The treatment for occupational asthma is no different to asthma in general, although it is important to avoid further exposure to the sensitiser, as once the lungs become hypersensitive, further exposure to the substance, even at quite low levels, may trigger an attack.
It has been estimated that 1 in 10 people diagnosed with asthma have an occupational origin.
Agents: Isocynates, flour, laboratory animals, enzymes, glutaraldehyde, soldering flux, wood dust, resins
Occupations at risk: Coach and other paint sprayers, laboratory technicians and assistants, baking and milling, joinery, welders, electronic assembly, nursing, manufacturing of plastics.
Condition: Extrinsic Allergic Alveolitis
Extrinsic allergic alveolitis is a granulomatous inflammatory reaction caused by an immunological response to inhaled organic dust or chemicals ‘Farmers Lung’ and ‘Bird Fancier’s lung’ are the most commonly seen of these conditions. Here patients complain of flu like illness and shortness of breath. This usually resolves after 48 hours. More severe disease is associated with weight loss and fatigue. The diagnosis is made from the occupational history, the examination, reduced lung function and antibodies to the causal agent found in the serum.
Agents: Mouldy hay and straw, bird excreta and bloom.
Occupations at risk: Agriculture, horticulture, forestry. caring or handling birds.
Risk factors causing Musculoskeletal disorders (MSD) can be found in virtually every workplace from commerce to agriculture, health service and construction. An estimated 11.6 million working days are lost each year due to work-related MSD’s.
Working practices that are associated with an increased incidence of MSD’s are:
Psychosocial factors (e.g. high job demands, time pressures and lack of control) which impact on a workers general wellbeing are also thought to lead to an increase in incidence of MSD’s.
Symptoms related to MSD can be divided into two major categories
(i) Back pain
(ii) Upper Limb Disorders:
Condition: Back pain
This is the commonest cause of injury and lost time in the workplace, it is seen in nearly every occupation and industry. Approximately 119 million working days are lost annually due to back pain in the UK.
Agents: Multifactorial: occupational and non occupational
Heavy manual handling: repetitive /awkward bending
Occupations at risk: Nursing, construction work, miners.
Condition: Upper Limb Disorder (ULD)
The term upper limb disorders (ULD) is now used instead of ‘repetitive strain injury’ (RSI). ULD is an umbrella term for a range of disorders of the hand, wrist, arm, shoulder and neck. It describes conditions characterised by discomfort and or persistent pain in the soft tissue structures of the neck and upper limb areas. Physical signs may or may not be present, and the condition is caused or aggravated by work factors. It is categorised as follows:
Type 1: Where there is a clear diagnosis e.g. frozen shoulder, carpal tunnel syndrome.
Type 2: Where there is no proven underlying pathology e.g. diffuse non specific forearm pain
Agents: ULD are usually multifactorial conditions: occupational and non occupational factors co exist but work place features include static muscle activity and repeated or forceful dynamic activity.
Occupations at risk: Meat packers and cutters, Assembly line workers.
Also known as ‘Vibration White Finger’. Symptoms can result from almost any vibrating source in contact with the hands (and the feet in some situations) if the vibration is sufficiently intense.
Hand arm vibration syndrome, also known as HAVS consists of
Agents: Pneumatic tools: air compressed and electrical, Sanders, drills, fettling tools, jack hammers, chainsaws, brush saws, hedge trimmers.
Occupations at risk: Forestry workers, Mining and engineering industry, foundry workers
Mental health complaints now form the largest cited cause of long term sickness absences in the UK. This is due mainly to stress, anxiety and depression. However, the prevalence of mental health disorders such as schizophrenia and bipolar disorder has remained overall static. Mental health disorders will be considered under the following headings.
Condition: Major Mental Health Conditions
The incidences of conditions such as schizophrenia and bipolar disorder have remained almost constant over the last ten years.
The impact these disorders have on an individual to manage within the workplace will depend on the severity of the symptoms at any one time. It is possible that someone with a psychosis may function normally in the workplace for many months or years until they develop an exacerbation of their symptoms. Recognising an exacerbation of symptoms and providing the right support will be important in managing the employee and their ability to remain or return to employment. Employment that requires high technical skills or a high degree of responsibility might be more difficult for the individual to return to. There are some forms of employment where a history of psychiatric disease may preclude employment e.g. diving, off shore work (unless fully free of symptoms and off medication for at least one year), public service vehicle drivers, and pilots. Efforts to address maintaining people with severe disease within suitable employment are now being more actively addressed and there are a number of organisations providing support and advice to individuals and their families.
Condition: Common Mental Health Conditions
(i) Depression and anxiety disorders
Common symptoms of anxiety include:
Palpitations, headaches, backache, breathing difficulties
Feeling tense, on edge, worrying about things.
Panic attacks .
Common symptoms of depression include:
Lack of concentration at home and work
Feeling low, bouts of crying.
Poor appetite, lethargy, low motivation
Stress occurs when there is an imbalance between demands made upon an individual and their perceived ability to meet those demands. In particular, an individual’s perception of their control over the demands being made upon them.
Common symptoms of stress include:
Irritability, aggression or obsessive behaviour
Lack of concentration
Increased alcohol consumption
Poor time keeping
Frequent short term absence
Non specific physical symptoms-headaches, sweating, palpitations, nausea
Causes of work-related stress:
Condition: Substance abuse
Drug and alcohol misuse can have a devastating effect on users, and those people who have contact with them: family, friends, and co-workers.
It has been defined as a condition which may cause an individual to experience social, psychological, physical or legal problems related to addiction or one-off use, and is focused on problems rather than types of drugs.
Symptoms and signs of substance abuse are dependent on the drug taken, mode of administration, the quantity and the setting. The most common features can also be signs of a physical or mental health problem, and hence it is important to exclude such causes first.
Common features are:
Condition: Post Traumatic Stress Disorder (PTSD)
The essential features of PTSD are the development of characteristic symptoms following psychologically distressing event outside the range of usual human experience (i.e. outside the range of such common experiences as simple bereavement, chronic illness, business losses and marital conflict. The symptoms need to be present for longer than I month.
Characteristic symptoms include:
Occupations at risk: There is a close inter-relationship between personality, workplace environment and social economic factors. Some occupations have a higher incidence of mental health problems than others. Health care workers have a high incidence of mental health problems. Ambulance personnel have one of the highest rate of stress in healthcare workers. Doctors have high incidence of alcohol abuse and suicide. Other occupations that have high levels of stress and depression include teachers and army personnel.
PTSD is seen particularly in occupations such as the police force, fire fighters and the armed forces.
There are many chemicals that are used in occupation that can be poisonous. These can be broadly separated into conditions that cause peripheral nerve disorders ( Peripheral neuropathies) and central nervous system disorders,
Common symptoms of poisoning include:
Condition: Peripheral neuropathies
Agents: Lead, arsenic, organophosphate pesticides ,
Occupations at risk: Lead battery production, gardeners
Condition: Central nervous system disorders
Agents: Manganese, Benzene, Styrene, Perchloroethylene.
Occupation at risk: Chemical industry, dry cleaning
The term pesticide refers to the way some chemicals are used. There are many differing types of chemicals used as pesticides and therefore a variety of side effects and toxic effects that can occur from their use.
Types of pesticides include:
Most insecticides are readily absorbed through the skin. The rate of absorption is greater in very vascular areas such as the scalp and when the skin is hot. Insects are usually at their height in the summer, when the weather is hot. Therefore the need to be adequately covered when spraying is important to reduce the risk of exposure, even in high temperatures.
The most health relevant insecticide is the cholinesterase group which cause over stimulation and then paralysis of the muscarinic and nicotinic receptors. An example of this group is the organophosphate insecticides eg malathion. Complications include severe bronchorrhea, seizures, weakness, and neuropathy. Respiratory failure is the most common cause of death from severe exposure. Pralidoxime is the specific antidote to acute poisoning and must be given within 4 – 6 hours to be effective. Chronic exposure to organophosphates can lead to neuropsychiatric, extrapyramidal and other neurological symptoms. It has been described as causing a chronic fatigue like syndrome in farm workers exposed to the pesticide following sheep dipping.
ADVERSE EFFECTS OF GASES
Adverse effects of gases either asphyxiate or irritate.
This occurs due to displacement of Oxygen or due to a temporary change of a metabolically active protein e.g. carbon monoxide poisoning.
This occurs when a gas is inhaled that has a pH away from 7.4 such as the aldehydes e.g. formaldehyde
Two irritant gases are generated from the constituents of air itself. Ozone results from the action of ultraviolet light on air; oxides of nitrogen result from the heating of air to flame temperature when oxygen and nitrogen chemically combine. Both ultraviolet and strongly heated air occur during arc welding.
1. ABC Work Related Disorders: Hearing Loss BMJ 1996; 313:223-226
Condition: Noise Induced Hearing Loss
Prolonged repeated exposure to noise can lead to hearing loss, which is often permanent. This is due to destruction of hair cells in the cochlea and is typified by hearing loss at 4000 Hz. This hearing loss is ‘sensorineural’ and is called ‘Noise Induced Hearing Loss’ (NIHL).
Other symptoms related to prolonged noise exposure include:
Agents: Exposure to noisy environments e.g. Armed Forces, construction sites, airfields.
Hobbies: motor cycling, playing drums, rock concerts, shooting
Occupations at risk: Air traffic controllers, construction, printing
ABC Work Related Disorders: Occupational Cancer BMJ 1996; 313:615-619
Other work-related causes of cancer
Apart from asbestos dust, some well-recognised occupational carcinogens include fine hardwood dust which causes nasopharyngeal carcinoma, benzene which causes myeloid leukaemia, and vinyl chloride which causes Angiosarcoma of the liver. Importantly, the major constituent of quartz and sand, silica (SiO2), has been classified as a human carcinogen by the International Agency for Research on Cancer. This applies to fine particles that are likely to be liberated in high energy industrial processes and not, of course, to child’s play in a sand pit or on a beach.
What to ask a worker when you suspect work-related cancer
In regard to particular cancers, enquiries about the following jobs/substances/exposures would be appropriate:
Apart from dermatitis and cancer, there are two other groups of conditions that should be mentioned in the context of ‘could it be my work, doc?’. The first group, pneumoconioses, is of declining incidence; the second group, ‘syndromes’ ascribed to causes and medically under-defined illnesses, are becoming more prominent in the compensation area.
There are many known or suspected carcinogens. The most widely accepted list is that of the International Agency for Research on Cancer (IARC).
Examples of such cancers are:
Angiosarcoma of liver
Bladder cancer transitional cell tumours
Bone marrow cancer
Occupations at risk
Agriculture, fishing, forestry
Vinyl chloride monomer
Angiosarcoma of liver
Chemical Industry (plastic manufacture)
Arsenic, chromium compounds
Metal Industry e.g. chromium plating
Dye manufacturing, rubber product manufacturing
Ionising radiation, cytotoxic drugs
Radiographers, pharmaceutical industry