Monitoring new and emerging risks

Introduction

This article, based on recent literature, will identify, define and discuss new and emerging OSH-risks together with the driving forces behind these risks. Emerging risks will be described as being related to ^[1] physical load and musculoskeletal disorders [MSDs], ^[2] psychosocial risks, and ^[3] dangerous substances [e.g. chemical and biological substances]. In the following paragraphs some of the consequences of these risks for specific worker groups will be identified. In the final paragraph the gaps in knowledge and risk management will be briefly discussed.

Defining ‘emerging OSH risk’

An ‘emerging OSH risk’ is often defined as any occupational risk that is both new and increasing see also ^{[1] [2] [3] [4] [5]}. By new, it means that:

• The risk was previously unknown and is caused by new processes, new technologies, new types of workplaces, or social or organisational change; or,
• A long standing issue is newly considered to be a risk due to changes in social or public perceptions; or,
• New scientific knowledge allows a long standing issue to be identified as a risk.

The risk is increasing if:

• The number of hazards leading to the risk is growing; or,
• The likelihood of exposure to the hazard leading to the risk is increasing, (exposure level and/or the number of people exposed); or,
• The effect of the hazard on the worker’s health is getting worse (seriousness of health effects and/or the number of people affected).

Drivers of the changing world of work

Working environments are constantly changing alongside the introduction of new technologies, substances and work processes, together with changes in the labour market, and with new forms of employment and work organisation. These changes bring new opportunities as well as new risks for workers and employers , which in turn demand political, organisational, technical, and regulatory initiatives to ensure high levels of safety and health at work. The drivers for the changing world of work are generally identified as ^{[1] [2]},^{[3] [4] [5] [6] [7]}:

1. Globalization and growth of the service sector, resulting in more competition, increased economic pressures, more restructuring and downsizing, more precarious work, and an increase in job insecurity, as well as increased intensification and increased time pressures at work. The number of workers who work in temporary employment is increasing. The current crisis in Europe has increased the economic pressures on companies and this in turn intensifies the effects on EU-employees.
2. Work really changes and technical innovation takes place, leading to an employment shift towards services with no clear separation between working time and leisure time. Despite all kinds of opportunities and productivity gains, this possibly results in a poor work-life balance and, in particular a greater complexity of working tasks that requires lifelong learning to secure employability. Additionally, the service economy with its growing number of offices leads to MSDs from inactivity, static postures and repetitive movements. Furthermore the service economy is creating more and newer human interfaces, and this is leading to increased psychosocial pressures such as violence and harassment. Finally, technical innovations can also lead to new risks caused by new environmental agents [chemical or physical] or via new exposure characteristics.
3. Europe is ageing. This demographic change is also a major driver for labour market development in Europe, and this will have a huge impact on occupational safety and health. For governments, enterprises and citizens alike, it will be of crucial importance to be able to prolong working life in a healthy and productive way. For employees this means that they will have to be able and motivated to work until an older age. For companies and enterprises this means that they have to provide opportunities for life long learning and employment opportunities for these ageing workers.

The emerging OSH risk areas affected by these drivers are:

1. Important emerging physical risks are ^[1] physical inactivity and ^[2]the combined exposure to a mixture of environmental stressors that multiplicatively increase the risks of musculoskeletal disorders [MSDs], the leading cause of sickness absence and work disability;
2. Important emerging psychosocial risks are ^[1] job insecurity,^[2]work intensification, high demands at work, and ^[3]emotional demands, including violence, harassments and bullying. Additionally, work-life balance may also be considered a risk;
3. Important emerging dangerous substances due to technological innovation.

Specific attention is paid to an increased exposure to:

• Chemicals, with specific attention to nanomaterials; and
• Biological agents.

New and emerging physical risks

Physical inactivity, lifestyle at work & obesity

The growing use of computers and automated systems, primarily aimed at optimizing productivity, appears to cause an increase in sedentary work or prolonged standing at work, which results in an increase in physical inactivity. In industry the emphasis on lean production leads to less walking [e.g. to fetch supplies]. An increase in the use of computers and in productivity demands leads to more time spent in a fixed body posture. Work commitments and other time demands are also commonly cited as reasons for physical inactivity ^[8];^[9]. An increase in travelling time to work and having an inactive leisure time additionally contribute to the overall increase in this inactivity.

Examples of [typically] sedentary jobs are crane operators, straddle-carrier drivers, truck drivers, workers in semiconductor factories, workers operating automated systems and machines, workers at visual display units and call centre workers ^{[1] [2]}.

Physical inactivity is associated with increased health risks such as coronary heart disease, type II diabetes, and certain types of cancers and psychological disorders [depression and anxiety] ^{[10] [11] [12] [13]}. Another important risk of inactivity is obesity ^[14]. Obesity itself can lead to several adverse health effects, such as back pain ^[15], high blood pressure, cardiovascular disorders, and diabetes ^{[16] [17]}. In addition, sedentary jobs are associated with an increased prevalence of musculoskeletal complaints or disorders, e.g. neck and shoulder disorders [e.g.^{[18] [19] [20]}, and upper and lower back disorders [e.g. ^[21]. Such disorders may lead to sick leave and work disability e.g.^{[22] [23]}. The established health risks associated with sedentary work are: premature death in general, type II diabetes and obesity ^[24]. The World Health Organisation ^[13] estimates that worldwide each year 1.9 million people die a premature death because of an inactive lifestyle.

Recent research shows that long periods of uninterrupted sitting, which are common in office work and driving tasks, entail a health risk that is independent from the amount of physical activity that a person does when not sitting ^[25]. This means that a person with a sedentary job but active lifestyle still has a higher health risk than a person with a non-sedentary job, e.g. construction work, but inactive lifestyle.

Several guidelines have been developed for a healthy amount of activity at work and include existing guidelines and standards for musculoskeletal load. Asidefrom regular physical activity, regular breaks are recommended and have been mentioned in several Council Directives. In the Netherlands, an initiative has been taken to develop recommendations for the amount of physical activity and recovery time of static muscle load at work ^{[26] [27] [28]}.

More information on the physiological effects of [in]activity and on interventions to increase physical activity can be found in musculoskeletal disorders.

Combined exposure to physical and psychosocial risks

It is well established that workers are exposed to a diverse and dynamic mix of environmental stressors as part of their work. Differential exposure to various environmental stressors can contribute to increased health and safety risks. In particular, it is the combination of biomechanical or ergonomic risks and psychosocial risks that has received attention as predictors of MSDs. There is a considerable body of research indicating that psychosocial risks can generate work-related MSDs [^{[1][2] [29] [30]}. Workers exposed to many biomechanical and psychosocial workplace risk factors are more likely to report symptoms of MSD disorders than workers exposed to just one of such factors 31. ^[31]. Psychosocial risk factors at work have a greater effect on the prevalence of musculoskeletal complaints when exposure to physical risk factors at work is high rather than when it is low. In addition, work organisation characteristics such as low job control [^[1],^[2]], high job demands, poor management support or little support from colleagues, as well as restructuring, job redesign, outsourcing and downsizing ^{[32] [33]} have been shown to be causally related to increased risks in MSDs.

New and emerging psychosocial risks

Job insecurity

The proportion of temporary contracts has significantly increased in the past two decades ^{[34] [35]}. Temporary contracts themselves are not synonymous to ‘precarious contracts’, but it is often considered to be part of it, particularly in times of an economic recession. The definition of precarious contracts should include the fact that this is only short-term employment, with little social protection, low levels of income, poor control over work, and high job vulnerability ^[36]. Such precarious work forms include: temporary agency work, short-term contracts, part-time work, home-based work, on-call work, and day hire work. In times of unstable labour markets, these work forms appear to politicians as a way of promising means to avoid unemployment, as they provide for more flexibility in the labour market ^[36].

Workers under these types of flexible employment contracts are more vulnerable than, for instance, employees working under standard contracts ^[37]. They usually carry out hazardous jobs with increased exposure to more dangerous substances in poorer conditions, and often receive less OSH training, which increases the risk of occupational accidents and illness. Only in rare cases can such flexible work forms be beneficial. For instance, it is expected that people who work at home will generally have more freedom to choose their own pace of work, and have more autonomy and flexibility than those office based, however; several national studies contradict this assumption.

Job insecurity and increased work-related stress due to precarious work will have a negative impact on workers’ health . Job insecurity is an important stressor resulting in reduced well-being [psychological distress, anxiety, depression, and burnout], reduced job satisfaction [e.g. withdrawal from the job and the organization] and increased psychosomatic complaints as well as physical strains ^{[38] [39]} 39 40. All these effects are negatively related to personal growth as well as to recognition and participation in social life ^[36]. Additionally, decreased well-being and reduced job satisfaction of employees negatively affects the effectiveness of the organisation.

According to the report on emerging psychosocial OSH risks of EU-OSHA ^{[3] [4]}, only a few attempts have been undertaken thus far to protect workers in precarious contracts. One possible intervention is to implement policies that oblige employers to provide workers under fixed-term contracts and in temporary agency work with training on how to do their work in a safe way before they start working as well as at regular intervals.

Workers appear to be able to deal with job insecurity in a better way if they are informed about planned restructuring as soon as possible. It is recommended that realistic and honest communications during restructuring processes as well as the use of restorative strategies are used ^[40]. In the case of people who already experience high job insecurity, it is very important to provide social support, since this buffers the negative effects of job insecurity on health. An example of this would be providing counselling to employees^[3].

Work intensification and high demands at work

Due to redundancies, restructuring, budgetary constraints, as well as new forms of work organisation and employment contracts, an increase in work intensification was observed in Europe until about 2005. By 2010, these levels of intensification appear to have leveled out ^[41].

The increasing demands workers are exposed to are quantitative [high speed, no time to finish work in regular working hours], qualitative [increased complexity], emotional [emotional load or a need to be friendly due to direct contact with customers i.e. service relationship situations], and often physical loads as well.

The widespread use of Information and Communication Technology (ICT) in almost all EU countries and in most sectors ^[42], may contribute to the phenomenon of work intensification. The development in technology use can be classified as mechanisation, automation or computerisation, and for each one of them human activities are substituted by machines leaving them with monotonous vigilance tasks. On the other hand, the use of computers and smart phones with internet which provides easy access to all kinds of information but also the expectation from colleagues, supervisor and clients that one is always available, always reads e-mail and can always be contacted. Technology has a great impact on workers’ task characteristics and hence on their health and well-being. Some OSH risk factors associated with ICT work and that were discussed in a Commission’s Staff working paper ^[43] are:

• Stress symptoms due to excessive working hours, workload and increasing complexity of tasks or isolation in home worker;
• Information overload;
• Stress of having to constantly upgrade skills;
• Human relationships replaced by virtual contacts; and
• Physical impairments such as repetitive strain injuries and other musculoskeletal disorders due to inadequate or ergonomically unadapted equipment or due to forced postures or due to the combined effects of both.

High job demands and low control are systematically found to be causally linked to cardiovascular heart disease e.g. ^{[44] [45]}, musculoskeletal disorders e.g. ^[32] as well as mental health problems ^{[46] [47]}. In addition, long term absence and disability are causally related to these risks as well ^{[22] [48]} High demands and low control are highly prevalent in education, the service sector, particularly in health care, in the transport sector and in the hotels and restaurant sectors ^{[41] [49] [50]}.

High emotional load and violence and harassment at work

The labour market shift towards the service industry will mean that ‘emotional demands’ at work will increase. Experts are of the opinion that, although these risks are not new, they are a growing concern especially in the healthcare and service sectors, which are growing and where competition is increasing^[3]. Some of the experts identify bullying as a contributing factor to these increased emotional demands. The successive European Working Conditions Surveys [EWCS], together with several national surveys [i.e. Germany, Finland, The Netherlands, Sweden] have highlighted a trend towards the increasing incidence of workplace bullying, harassment and violence as the basis for work related health problems ^[51].

The EWCS 2005 indicates that there has been an increase in the level of physical violence in the period 1995-2005 from 4% to 6% ^[52]. In the EWCS 2010 no trend could be followed due to a change in wording of the questions ^[41]. In 2005, the survey reveals that 2% of all workers are subjected to physical violence from fellow workers, 4% from people outside the workplace, and 6% report being subjected to threats of physical violence. Additionally, 5% of the workers report having been subjected to bullying and harassment in the workplace. Female workers (6%) are more at risk than male workers (4%) and younger women are at greatest risk. The highest exposure rates are found in the services sector (6.6% in education, 8.7% in health and social work, and 8.5% in hotels and restaurants).

The ESENER survey indicates that about 18% of employer representatives report violence or threat of violence as a major concern in their establishment and a comparable percentage indicates bullying or harassment to be of major concern too ^[53].

Those affected by violence and harassment in the workplace tend to report higher levels of work-related ill health. The proportion of workers reporting symptoms of psychosocial risk factors, such as sleeping problems, anxiety and irritability, is nearly four times greater among those who have experienced violence or bullying and harassment than amongst those who have not ^[52]. The negative impacts of violence and harassment are sizeable and not exclusively linked to psychological or mental health.

More information on the prevalence and management of violence and harassment at work can be found in Emotional work, violence and Harassment.

Work-life balance

Poor work-life balance was also identified by the experts as one of the top emerging psychosocial risks. All of the changes in work-organisation mentioned above may lead to higher pressure on workers and can spill over into private life. Additionally, phenomena such as more women at work, single parents and households with ‘dual careers’, with less family support and in some cases with more dependent, older relatives, result in an increase in the number of workers for whom a good work-life balance is especially important.

The way people combine work with their private life depends very much on their personal circumstances, including their family situation. The requirements for work-life balance also differ over the course of a person’s lifetime. In addition, cultural traditions [e.g. mother staying at home to take care of children or other dependants], social infrastructure [accessibility and availability of crèches], working hours and the option of flexible working time arrangements impact how and to what extent men and women can take up work. In that sense, employers can also play an important role in the facilitation of certain working time arrangements. In companies where flexible working time arrangements were introduced both to improve work-life balance and to better adapt to the workload of the company, managers as well as employee representatives report higher job satisfaction and a better adaptation of the working hours to the workload. Work-life balance Household working time arrangements differ across countries.

In 2010 some 18 percent of the workers indicate they have problems with their work-life balance 42. On average, men have more problems than women, particularly in the middle of their working career.

It is clear that the risk groups are those workers with children at the height of their career or workers with parental obligations which both occur later in life. The success of finding support from the employer in managing these issues is highly related to the way this is perceived to be a problem. In addition, European countries highly differ from one-another in the way that they support child care facilities.

New and emerging risks at work as related to dangerous substances

Engineered nanomaterials

Nanotechnology has been defined as the ‘design, characterisation, production and application of structures, devices and systems by controlling shape and size at nanometre scale’ ^[54]. A nanometre is x10 -9 of one metre, and the benefits of nanotechnology arises due to novel properties that engineering materials at this scale can bring. EU-OSHA ^[5] presented literature on the risk perception and risk communication with regard to nano-materials in the workplace. Nanotechnology offers phenomenal opportunities for the development of new materials and products. According to Lux Research ^[55], the global nanomaterials and -intermediates market is increasing rapidly and will touch over US $500,000 million worth in 2015 ^[55]. Due to the small size, engineered nanomaterials (ENMs) have unique properties that improve the performance of many products ^[56]. Nanomaterials have applications in many industrial sectors (currently the main 4 areas are : 1. materials and manufacturing industry including automotive, construction and chemical industry, 2. electronics and IT, 3. health and life sciences, and 4. energy and environment). The direct employment generation impact of nanotechnologies (which includes nanomaterials, -intermediates and –products) is estimated to be around 2.3 million jobs around worldwide by 2015, of which 0.4 million in Europe. Figures on employment in nanotechnology predicted 10 million for 2014 worldwide with almost 6 million in Europe ^[57].

A key issue of ENMs is the unknown human risks of the applied nanomaterials during their life cycle, especially for workers exposed to ENMs at the workplace. Workers in nanotechnology may be exposed to novel properties of materials and products causing health effects that have not yet been fully explored. The risks posed by ‘nanoparticles and ultrafine particles’ are by far the strongest as agreed by experts in the expert forecast by EU-OSHA ^[5].

Many initiatives have been launched to obtain data about the safety of nanomaterials. However, it will take many years to gather and analyse all the data required to perform a comprehensive risk assessment for nanomaterials. Although there is a considerable lack of knowledge ^[58], there are indications that because of their size, ENMs can enter the body via the digestive system, respiratory system or the skin. Once in the body, ENMs can translocate to organs or tissue distant from the portal of entry. Such translocation is facilitated by the propensity of the nanoparticles to enter cells, to cross membranes and to move along the nerves. Factors that can alter the risk if nanoparticles penetrating into the body include: the mass, surface area or number of particles, whether the material is dry powder or in solution, the degree of containment and the duration of the exposure. The ENMs may accumulate in the body –particularly in the lungs, the brain and the liver. The basis for the toxicity appears to be primarily expressed through an ability to cause inflammation and to raise potential for autoimmune deficits, and may induce diseases such as cancer.

A precautionary approach is recommended since an appropriate risk evaluation is impossible due to an incomplete picture of both the hazard of and the exposure to nanoparticles. The huge variety in size, shape and surface chemistry and coating means that, even for one chemical such as Titanium Oxide (one of the most prolifically used nanomaterials already on the market), the number of possible forms of nanoparticles is very large, which greatly complicates the risk assessment required to ensure the health and safety of workers who are handling or using ENMs. A generic approach to mitigate exposure is the control hierarchy. Many (inter)national bodies for standardization, e.g. BSI, ASTM, ISO, and (supra) governmental organizations, e.g. OECD, have addressed issues related to safe production and use of nano-materials. Most of the control measures and recommendations are similar to those for toxic dusts or aerosols, although their performance has not been evaluated for nanomaterials in a structural way. Recently, data on effectiveness of filter[materials], clothing and glove materials against nano-aerosols have been published. ^{[59] [60] [61]}. The results indicate a very good performance of filter materials and non-permeable materials.

In addition to the limited data on effectiveness, the evaluation of the performance of control measures in view of exposure and risk reduction is also hampered by the absence of exposure limits. To bridge this knowledge gap, safe practices for production and use are defined based on state-of-the-art knowledge and expertise ^[62].

Other emerging chemical substances

In the expert forecast by EU-OSHA ^[5] diesel exhaust was highlighted as the second most emerging risk. The CARcinogen EXposure (CAREX) database showed that 3.1 million workers in the EU-15 were exposed for at least 75% of their working time to diesel exhaust in the beginning of the 1990s, making it the fourth most common carcinogen found in the workplace after solar radiation, tobacco smoke and crystalline silica ^[63].

More specifically with regard to lung cancer, a positive association between diesel exhaust emissions and lung cancer is suspected, but is still controversial. In addition, a link between diesel exhaust emissions and non-cancer damage to the lung has also been found. However, more research is needed on the health effects of these emissions.

Hazardous levels of diesel can be found in occupations ranging from mining to driving diesel-fuelled trucks or forklifts.

Man-made mineral fibers are increasingly manufactured for all kind of purposes, and can be classified as being siliceous or non-siliceous. The size of the fibers is acknowledged to be linked to their harmful toxic effects: the longer and thinner the fibers, the more dangerous they are. Fibers with a geometric diameter less than 3 µm may reach the alveolar zone of the lungs ^[5]. Existing standard air sampling methods do not allow precise measurement of the fiber size. Specific fiber dimensions hypothesized to have biological activity have been proposed but need to be evaluated in epidemiologic studies. In general, fibrous structure increases inflammatory, cytotoxic and carcinogenic potential.

Manufacturers strive to reduce the biopersistence of siliceous fibers by modifying their compositions, which in principle is favorable for OSH. However, these compositional changes make it more difficult to obtain comparable data from epidemiological studies. As a consequence very few toxicological data are available for these new products. In addition, the toxicity of non-siliceous man-made fibers has been little investigated, but they seem to be biopersistent. Although some man-made fibers contain up to 25% additives, studies rarely take their presence into account. Workers handling fibre-based products, especially during laying, maintenance or removal operations, may be highly exposed.

Another three chemical risks were identified as emerging in the expert forecast with a view to allergies and sensitizing effects. They are epoxy resins, isocyanates and dermal exposure ^[5]. Epoxy resins are important and widely used polymeric systems. They are used in adhesives, sealants, inks, varnishes and reinforced polymer composite structure with glass fibers. The continuous demand for always newer generations of epoxy resins and derived products with enhanced properties may introduce new, unknown adverse health effects. Epoxy resins have become one of the main causes of occupational allergic contact dermatitis. Skin sensitization of the hands, arms, face, and throat as well as photosensitization has also been reported. Workers in the production of epoxy resins, workers in the manufacture of composite products, in the electrical and electronic industry, and painters may be at risk. Epoxy resins skin sensitization is particularly problematic in the construction industry where a safe and healthy working environment (e.g. clean room) and the use of protective clothing (e.g. gloves) is less common and/or less practical. The identification of the epoxy system involved in the process is essential for the selection of the appropriate prevention measure.

Another emerging chemical risk is the increasing use of isocyanates. Exposure to these chemicals not only occurs at the production stage but also when polyurethane products containing isocyanates are used [e.g. when spraying], are processed (e.g. by grinding or welding), or when they undergo thermal or chemical degradation. Isocyanates are powerful irritants to the mucous membranes of the eyes and of the gastrointestinal and respiratory tracts. Direct skin contact can cause serious inflammation and dermatitis. Isocyanates are also powerful asthmatic sensitizing agents. Early recognition of sensitization, coupled with prompt and strict elimination of the source of exposure, is essential for the reduction of the risk of long-term or permanent respiratory problems in sensitized workers.

Dermal exposure is a major route of occupational exposure to dangerous substances. In the EU member states, skin diseases are the second most common occupational diseases after MSDs; contact dermatitis being the most common. Chemicals are responsible for 80-90% of skin diseases. In the construction industry, chromate is the most important allergen, followed by epoxy resins and cobalt. Particularly in the health care sector, natural rubber protein [latex] is an occupational allergen. Soaps, detergents and solvents can cause dermatitis since they remove the surface lipids and dissolve the skin’s natural protective barrier. The use of protective gloves is controversial due to other influencing factors such as the wet atmosphere inside the glove.

Emerging biological risks related to OSH

Occupational risks related to global epidemics are the biggest ‘biological risk’ issue identified in the EU-OSHA forecast on biological risks related to OSH ^[64]. A global epidemic or pandemic disease is identified as an epidemic outbreak of a severe infectious disease affecting a large number of people and spreading worldwide in a short period of time.Biological agents. Whereas earlier pandemics circled the globe in six to nine months, today new biological agents can reach any continent in less than three months because of air travel ^[6]. Besides the increased speed and volume of international transport of humans, animals, and products, agricultural expansion and intensification, increasing numbers of immune-compromised people as a consequence of an ageing population, ecological factors as well as other factors related to the disease-causing agents contribute to the emergence and spread of disease.

Pathogens such as the severe acute respiratory syndrome [SARS], Ebola, and Marburg viruses are new or newly recognized. In addition, new outbreaks of well-characterized outbreak-prone diseases such as cholera, dengue, measles, meningitis, and yellow fever still emerge ^{[65] [66]}.

Workers are certainly affected by these diseases and pathogens. It is difficult to identify the occupations most at risk, since sources of exposure vary and involve people, animals, plants, as well as goods. In the case of transmissions of zoonoses, workers in contact with live or dead infected animals or with aerosols, dust or surfaces contaminated by animal secretions are at increased risk ^{[67] [68] [69] [70]}. At risk occupations thus include workers in farms, slaughterhouse facilities, workers involved in the disposal of carcasses, the cleaning and disinfection of contaminated areas, as well as veterinary services and research ^{[71] [72] [73]}.

Due to globalization, the risks of importing tropical disease has increased, e.g. with imported goods and particularly those in water. Therefore, workers handling international trade containers are at risk of mosquito-borne Dengue fever ^[73] or other tropical fevers and encephalitis that are attributed to mosquitoes ^{[74] [75]} . Trading in exotic domestic pets such as bats, prairie dogs or reptiles exposes international trade workers to zoo noses ^{[76] [77] [78] [79]}. In the case of human-to-human transmissions, health care workers are most at risk ^{[80] [81] [82]}.

Measures such as border closure and travel restrictions may delay but cannot stop the introduction of a micro-organism into a foreign country. Instead, regularly updated national preparedness plans are necessary to adequately respond to global epidemics. In addition, collective organisational measures for effective forecasting, surveillance, prevention and control of global epidemics should be accompanied by personal protective measures. Global epidemics require a global response, but simple and practical tools for employers to help them do a proper risk assessment and to take appropriate measures to protect workers is important as well.

Combined risks including dangerous substances

When considering simultaneous or sequential exposure to multiple environmental stressors,, there is clear evidence that toxicity can be modified ^{[83] [84]}. For example, exposure to tobacco smoke and asbestos ^[85] or radon ^[86] multiplies the risk of lung cancer. This has a much greater effect than what should be expected from simply adding the effects of the individual stressors. This study concludes that one-third of cancer cases among smokers exposed to asbestos can be attributed to the synergistic behaviour of the two carcinogens ^[87] DS,CMR.

A multiplicative relationship between radon-progeny exposure and current smoking and the risk of lung cancer has consistently been shown ^[83]. Similarly, exposure to aflatoxin-contaminated food and hepatitis B infection greatly increases the risk of hepatocellular carcinoma ^[88]. Exposure to noise and toluene results in a higher risk of hearing loss, than from either stressor alone ^[89].

In spite of the fact that there are usually multiple risks at a job, risk assessment methods are useful but preventive measures that are provided or suggested are often one-dimensional. In most cases, there is a lack of proper tools to adequately evaluate interactions among risk factors ^{[1] [2]}. In addition, effects of long lasting exposure to various work-related risks is particularly difficult to assess since there has been a significant increase in outsourcing and subcontracting within the last two decades, increasing the combined exposure in certain risk groups. The effects of long lasting exposure to work-related risks will be extremely difficult to trace.

More information on the management of dangerous substances is to be found at risk management of dangerous substances.

Conclusions

As a means to pull together the conclusion on the emerging risks discussed above, the risks can be evaluated on four dimensions: ^[1]the number of workers exposed,^[2] exposure duration,^[3] effects of the risks on the worker, and ^[4] the probability that this effect will occur. Physical inactivity, work intensification, and work life [im]balance are very prevalent, often with a long exposure duration, but their effects are estimated by experts to be of medium importance ^[6]. Other less prevalent emerging risks such as violence and harassment and the effects of chemical and biological risks are considered to have a high impact on workers exposed to these risks. The latter types of emerging risks are known to expose workers in specific sectors and occupational groups. The effects of combined risks are often multiplicative, particularly in the case of chemical exposures. This issue is very complex and not only combined chemicals, but all types of combined risks should be taken into account, as well as the different ‘exposure routes’ possible. The management of these combined risks not only demands an open mind but quite often also multidisciplinary professionals to identify these combined risks [at the workplace] as well as to manage these risk and evaluate the risk management.

Overall, it is clear that the need for further knowledge [e.g. chemical risks/nanoparticles], tools for risk assessment [e.g. multiple risks], and assessment and management tools for easy application at company or sector level is high (e.g. inactivity and psychosocial risks). These tools for risk assessment often involve different risks and different risk groups. Differential efforts are needed that contribute to sustainable employment and prolong a productive working life in Europe.