Occupational risks from biological agents: Facing up the challenges
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In the last decade, media coverage of biological hazards, such as the anthrax threat to mail workers due to bioterrorist activities, the outbreak of severe acute respiratory syndrome (SARS) affecting health care workers or the threat of avian flu for poultry workers has sensitised the public awareness of risks caused by biological agents. These few selected examples of biological risks aroused considerable public attention also because they illustrated how we ourselves contribute to spreading diseases caused by such microorganisms as a result of today’s lifestyle and working life. Global travelling, global trade and worldwide migration for employment may function as “shuttles” for the spread of dangerous biological agents around the world in a very short time, and communicable diseases may quickly reach a pandemic dimension. It is even assumed that a severe flu caused by a new, highly pathogenic strain of human influenza virus could spread worldwide in less than three months.
The diseases mentioned above represent only a few examples of the many diseases caused by biological agents that can be contracted in the workplace, and the infectious microorganisms involved only a small part of the large number of existing biological agents. According to Directive 2000/54/EC, biological agents are defined as bacteria, viruses, fungi, cell cultures and human endoparasites. They are classified into four risk groups according to their level of risk of infection. Beside infections, some biological agents have a sensitising and/or toxic potential, which also have to be considered in the workplace risk assessment.
Workers potentially in close contact with infectious agents, such as in animal breeding, slaughterhouses, veterinary medicine, laboratories or health care are the highest risk group but are not the only ones at risk. Biological agents are ubiquitous. In many workplaces workers are daily exposed to biological agents that do not cause infectious diseases but bear a considerable risk potential of allergies or toxicity. Hazardous bioaerosols are associated with a wide range of health effects. They are present in many working areas, especially in industries using organic materials (e.g. natural fibre textile processing, food processing, paper industry), water or other liquids which are recycled for the production process (e.g. cooling lubricants in metalworking industries), up to agriculture, wastewater or waste treatment activities, and even in offices located in wet buildings or in premises where air-conditioning systems are poorly maintained. These hazards are often less known than the more spectacular infectious diseases, such as HIV or tuberculosis, although many more workers may be concerned.
For most biological agents, safe exposure levels - i.e. below which no negative health effect is observed - could not yet be established, making it impossible to set Occupational Exposure Limits (OELs). For several reasons, setting OELs is unlikely to be feasible in the foreseeable future. Nevertheless, employers have the duty to assess biological risks in the workplace and, on the basis of the risk assessment, to implement the appropriate prevention measures to protect workers from biological risks at work. Performing a risk assessment without OELs as reference point is possible e.g. by comparing the actual concentration level with the usual environmental level or with the concentrations in different workplace settings. In contrast to chemical hazards, biological agents are living organisms that are able to grow and to multiply in the workplace if the living conditions they need are present. Assessing properly the risk of exposure to biological agents therefore demands some knowledge of microbial ecology. The necessary information to do so must be made available and understandable to those who have to conduct the risk assessment.
Renowned experts were invited to present the current knowledge and challenges on the key issues identified in the forecast:
- OSH risks linked to pandemics; - Endotoxins in the workplace; - Poor indoor air quality; - The recognition of work-related origin of diseases caused by biological agents; - The difficulty of assessing biological risks in the workplace;
- The need for Occupational Exposure Limits (OELs) and feasibility of OEL setting;
in order to stimulate debate about the
- Needs for resarch and actions.Click here to hide the full text
Some years after the implementation of the EU-Directive 2000/54/EC on the protection of workers from risks related to exposure to biological agents at work, there is still a lack of understanding and awareness of the health risks caused by those agents at work. Information about such risks has to be transported to employers and workers, especially to those who are exposed to biological agents which are not necessary and intentional elements of the work process - e.g. in agriculture, waste treatment - as they show a low level of awareness of biological risks. Indeed, while the Directive is in general well applied in working environments where infections by biological agents are the main and obvious occupational risk factors – e.g. in laboratories and in the health care sector - many difficulties remain in many working areas, especially where the risks are linked to the sensitising or toxic potential of biological agents, and hinder the proper risk assessment according to the Directive requirements.
The extension of the scope of the Directive to microbiological products, allergenic and toxic materials could be considered, as well as the opportunity to include genetically-modified organisms into the risk group classification.
During the workshop, it was obvious that researchers as well as government representatives have the same concerns and objectives. However, increased communication and cooperation between the two groups is needed in particular with a view to develop simple and practical tools for employers to help them to do a proper risk assessment and to take appropriate measures to protect workers. In the frame of the next European Campaign 2008-2009 dedicated to risks assessment, the EU-OSHA is preparing two “E-Facts” – short practical publications for the EU-OSHA’s website – “Risk assessment for biological agents” including a checklist, and “Checklist for the prevention of accidents in laboratories”. EU-wide good practice examples will also be made available on the website. In addition, a Power-Point presentation with practical information for the risk assessment of dangerous substances in general (chemical substances and biological agents) will be made available as a tool ready-to-use e.g. in the scope of training.
In order to provide an overview of research activities in the EU and encourage cooperation, it would be useful to develop a common database of EU-wide information on e.g. research activities on occupational risks of biological agents, on their concentrations in different work environments, on the allergic and toxic properties of the biological agents themselves and of their products.
A further conclusion of the group is that the setting of occupational exposure limits (OELs) for biological agents is seen as not feasible yet.
One of the main results of the expert forecast carried out by the EU-OSHA and its Topic Centre Risk Observatory, as well as of the workshop discussion, is that multidisciplinary cooperation and coordination between OSH and other disciplines concerned by the biological risks such as public health, environmental protection, food safety or animal health is essential to manage these risks globally. The workshop participants felt that the outbreaks of Bovine Spongiform Encephalopathy (BSE), Severe Acute Respiratory Syndrome and avian influenza in the last decade illustrate very convincingly this need. As a step in this direction, the EU-OSHA invited representatives of these disciplines at the workshop. However, mainly OSH specialists and one representative of the Directorate General “Environment” responded positively. Concerted efforts should be made to include representatives of these disciplines, and especially public health, in future activities.This workshop was the first of the series and will be followed by two similar workshops to consolidate with EU policy makers, EU social partners, stakeholders and experts the results of the expert forecasts on emerging psychosocial risks and emerging chemical risks in 2008.Click here to hide the full text
Based on the presentations and the discussions, the participants were invited to propose priorities for research and for actions, concrete suggestions on how to improve the prevention of occupational biological risks, and their views on how the EU-OSHA could help in this matter.
Priorities for research and actions
The participants distinguished between two types of research needs:
1) the need to develop more knowledge of the risk; and
2) the need to develop tools for employers to perform the risk assessment of biological agents.
Research priorities related to knowledge development:
- There is a need for more research into dose-effects relationships.
Closing the gap between results from measurements of concentrations of biological agents and data of medical significance on the subsequent health effects would help the determination of dose-effect relationships. A better understanding of the dose-effects relationships would also enable the setting of health-based occupational exposure limits (OELs) for biological agents. However, there were some discussions among the workshop participants on the usefulness of the establishment of such OELs. On the one hand, OELs may constitute a tool and guidance for the exposure assessment and risk control. On the other hand, it is important to keep in mind that the first measure in the hierarchy of prevention measures stipulated in Directive 2000/54/EC is to “avoid the use of a harmful biological agents if the nature of the activity so permits, by replacing it with a biological agent which, under its conditions of use, is not dangerous or is less dangerous to workers' health […].” Therefore, even in the absence of OELs, biological risks have to be assessed and controlled. Even when OELs are available, the risk assessment and risk control should not be blindly based on OELs but take into consideration the priority principle of avoidance of the risk if the nature of activity permits.
The participants again emphasised that OELs can be and should be set only if the link between exposure level and observed health problems can be clearly established.
In any case, the level of workplace exposure versus public exposure has to be considered as different exposure levels may be regarded as acceptable depending on the situation.
Last but not least, OELs are only relevant for airborne biological agents, which represent a part only of biological risk factors. For bloodborne occupational agents and biological agents transmitted by skin contact, other means should be used for quantitative risk assessment.
- Data sets on exposure levels in various occupational environments should be collated from all European sources, coordinated and shared in order to identify knowledge gaps and avoid duplication of efforts.
This knowledge may be helpful to derive “baselines” for various occupational environments and to establish benchmarking which is seen as an effective system to propose adequate exposure limits. Exposure data may be collected by biological agents or by sectors/industries. Some participants commented that probably the combination of both data breakdowns is necessary in order to avoid that certain industries are branded as high-risk sectors.
There is also a need to determine background information on natural levels of biological agents for certain working environments (e.g. schools, offices, non-industrial indoor atmosphere in general, farms) in the EU, and to develop a database to make this information available at EU level. This would also be helpful to derive the above mentioned “baselines”.
- More research is needed on the combined effects of biological and chemical agents, e.g. on the sensitising effects of exposure to chemicals which may precondition the development of diseases caused by biological agents, or vice-versa the infection with biological agents which may make an individual more reactive to some chemicals.
- More research on endotoxins, more particularly into their effects on health and on dose effect-relationships, would - among other - enable the formulation of recommendations for the activities and sectors concerned adapted to their specific exposure patterns.
Priorities related to the development of practical tools for the risk assessment:
According to the workshop participants, more efforts should be dedicated to the development of practical help to perform the assessment of biological risks – an item which they say is absent from national and EU agenda but requires up-stream research. It was pointed out that it is the responsibility of the research community and not of employers to develop appropriate methods for the measurement of biological agents in the workplace and to give advice on suitable measures to minimise the risk of exposure to hazardous biological agents at work. The employers, on the other hand, have the duty to carry out the risk assessment and to take the appropriate prevention measures as stipulated in the legislation in order to protect the workers from the risks caused by biological agents.
Some guidance and subsidiary literature is already available but the persons who have to do the risk assessment are not aware of this. Efforts should therefore concentrate on disseminating this information to managers, OSH professionals, engineers, workers´ representatives, local government authorities, occupational doctors and nurses, etc..More particularly, the need for practical guidance has been identified for the assessment of the following risks:
- risks linked to the occurrence of biological agents in indoor air;
- risks of genetically modified organisms, which are not taken into consideration in the list of classified agents in Directive 2000/54/EC.
Recommendations on how to achieve a better workplace prevention of biological risks.
Communications and awareness raising:
There is a need to improve the general workforce’s awareness and understanding of biological agents and the risks they pose. In order to achieve this, general information on the potential risks of biological agents, good practice examples and practical guidance should be better communicated.
Mainstreaming OSH into the conception stage of working environments:
Workplaces should be designed in such a way that workers’ exposure to biological agents is minimised. However, the discussion pointed out that this may be feasible in workplaces where the use of biological agents is intentional and needed for the work process - e.g. in microbiology laboratories - but more difficult in workplaces where the presence of biological agents is unintentional.
Need to improve multidisciplinary cooperation:
Coordination of research and cooperation at EU level of national OSH bodies is regarded as a necessary step towards a consistent risk prevention of biological risks in all EU Member States. Furthermore, not only the need for a better cooperation within the OSH community but also for multidisciplinary cooperation between OSH and other disciplines was emphasised. Especially the collaboration between OSH and public health authorities was seen as a high priority. With regards to the prevention of pandemics for example, the participants acknowledged that there is an overlap between public health and OSH concerns and that improvement of the cooperation between these two disciplines is necessary including, but not only, in emergency situations. Nevertheless, it was underlined that public health prevention is not the remit of employers. However, the existing OSH knowledge and expertise may be useful for public health purposes as it was shown on the example of appropriate PPE against biological agents e.g. in the cases of SARS or avian influenza.
The participants also underlined the importance of the collaboration with environmental protection actors. For example, in relation to the development of antimicrobial resistance, there is a need for cooperation between OSH services and both:
- public health services more particularly as far as the protection of the high-risk group of health care workers is concerned; and
- environmental services - for example OSH concerns should be taken into consideration in the context of the evaluation and authorisation by environmental authorities of biocides as they contribute to the appearance antimicrobial resistance and raise an increasing concern for the treatment of infectious diseases that may be acquired at work.
The workshop attendees pointed out that such a holistic approach is very expensive and funding opportunities are limited. A supranational coordination of research activities in this field could therefore help to avoid duplication of work and to save money.At the workplace level, better communication and cooperation between OSH and public health professionals would help the risk assessment and prevention, as well as contribute to infection control.
Ad-hoc discussion on Directive 2000/54/EC
Some years after the transposition of Directive 2000/54/EC into national legislation, the EU Commission is now analysing how the directive is implemented in the Member States. First, the evaluation confirmed that there is a need for the development of practical and simple tools facilitating the risk assessment of biological agents at the workplace. More generally, it showed that guidance for the management of biological risks should be provided to employers. The evaluation of the Directive also looked at the relevance of the given classification of biological agents. With this regard, the workshop participants noted that the classification is exclusively based on the infection potential of biological agents and encouraged the inclusion of allergenic, toxic and carcinogenic biological materials currently not classified in the Directive, including substances which may be the products of biological agents, such as endotoxins, mycotoxins and enzymes. Indeed, although endotoxins for example are not biological agents but products thereof, they may be the actual cause of their sensitising or toxic effects and should therefore be included into the Directive and considered in the risk assessment just as well as infectious agents. The participants recommended the development of a database containing information on allergenic, toxic and carcinogenic biological materials. In their views, this is necessary to avoid the under-rating of the allergic or toxic potential of exposure to such biological substances, especially in activities where their presence is unintentional. The inclusion of genetically-modified organisms into the risk-group classification should also be considered. DG-EMPL clarified that article 19 of the Directive foresees that, if necessary, purely technical adjustments to the Annexes in the light of technical progress can be adopted in accordance with the specific procedure established in the article 17 of the "Framework" Directive 89/391/EEC.
Role suggested for the EU-OSHA
The participants identified the following supporting activities that the EU-OSHA could undertake in order to help tackling the challenges raised by biological agents in the workplace:
- To help disseminate available information such as national initiatives, good practice examples, practical guidance, general information on the health risks of biological agents in working environments, etc.
- To establish and maintain a network of experts and stakeholders from the EU Member States involved in the field of biological agents, and to facilitate information sharing and debate, by means of e.g. meetings, seminars, a newsletter or discussion forums.
- To set-up a European database - with information on e.g. research activities on occupational risks of biological agents, characteristic levels of biological agents in different work environments, allergic and toxic properties of biological agents/products of microbial origin - and to promote its existence with the aim to invite e.g. researchers to submit further data and to support research cooperation on the field of biological agents at European level.
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