8. Conclusions

Hitherto there are no genetic tests available which are capable of distinguishing accurately between employees with greater susceptibility to certain serious occupational risks and those who are less susceptible. It is totally impossible to predict accurately future health problems which may result from the work.

There are various reasons for this state of affairs.

• The genes already studied represent only part of the inherited factors and not more than a fraction of the other (acquired) susceptibility factors which, in an extremely complicated manner, all combine to determine the susceptibility to an occupational illness.
• There are many variants of the genes already known. In addition to the 'wild type' there is an amalgam of different mutations, some of which are not yet known and cannot therefore be tested. Nor is the significance of each of these variants for the susceptibility to occupational diseases known as yet.
• The tests for known genes are not always 100% accurate. In other words some tests do not correctly identify all carriers of a certain gene, and only them.
• The effect of genetic susceptibility factors can change considerably depending on the level of exposure. This effect may even be directly inversely proportional with the exposure (the greater the exposure, the smaller the difference in risk). Our knowledge of this relationship between exposure and genetic susceptibility is however still very limited, and further epidemiological research into a relationship of this kind will not be easy.

Moreover for a long time now occupational medicine in Belgium has not been based on employee selection but on social protection. The task of occupational healthcare provision is to ensure that work is adapted to man and not the other way round. In other words it will opt for other methods of risk control, such as improving working conditions together with health surveillance through periodic medical examinations, instead of excluding people from work.

This tradition of simultaneous protection of the right to work and right to health protection threatens to come under pressure in the current socio-economic context however. On the one hand risk-related work is being turned down by large companies and is being out-sourced to smaller companies with a high staff turnover. On the other hand, just as elsewhere in Europe, the protection of employee health and safety is increasingly leading to a number of generalised norms or standards to comply with. This development can create serious problems for the organisation and efficiency of health surveillance and can reduce social protection. Furthermore the existing regulations on recruitment examinations are insufficiently enforceable because of gaps in the current legislation.

If in spite of these shortcomings genetic tests were to come onto the market unregulated in this context and be used for recruitment, there is a risk that a situation may arise which from the point of view of health protection at work is paradoxical, for the following reasons among others:

1. The idea, and it is often an illusion, that the susceptible individuals are selected out, can lead to a more lax attitude regarding attention to prevention in the workplace, with the result that the risk becomes greater for everyone.
2. Excluding applicants on the basis of genetic susceptibility can lead to social marginalisation, with all the negative consequences of this for the health and well-being of the people concerned. It cannot be emphasised strongly enough that the health of an individual cannot simply be based on the presence or absence of one or other inherited risk factor for a certain occupational disease. That would be a 'reductionist' and all too simplistic or limited approach. This misconception will in practice generally lead to applicants being classified incorrectly as to their fitness for the job and the protection of their health.

3. If a very relevant genetic susceptibility test were to be developed for a certain exposure-related risk, it is highly improbable that those who would benefit most from it would be tested the most rapidly.
   One of the main reasons for this may be that, as soon as there is a shortage of labour, it will be a fact that applicants will no longer be excluded on the basis of the test, whereas the pace of work, exposure and the risk to health in this case may possibly even increase.
   Another reason may be that the most flexible jobs, which are concentrated in smaller companies, often involve more risk and are more likely to escape organised health supervision: there is less competence present in smaller companies and medical examinations are carried out less frequently.

In view of the current development of genetic research, it is not inconceivable that in the future tests will be available which are relevant for the prevention of occupational diseases. These should then be used exclusively in the interest of the people concerned. Provided that the use of tests can lead to decisions which are in line with a basic law, namely the right to work, defining a policy on this will ultimately fall to Parliament and not to social partners or to the market.

In the societal debate about the acceptability of genetic tests, a clear distinction must be drawn between genetic tests which are intended to detect inherited characteristics, which may point to greater susceptibility to certain conditions (genetic screening) and genetic tests which aim to find changes in the hereditary material, which are the result of exposure to harmful substances (genetic biomonitoring). Genetic biomonitoring can form part of the periodic medical examination carried out on employees and is specially designed to establish the effects of exposure to agents in the workplace. The results of genetic monitoring can lead to the unearthing of unknown, but hazardous types of exposure.

Better knowledge of genetic susceptibility to occupational diseases can contribute significantly to more effective medical surveillance of workers exposed to risks. Such knowledge will lead to better interpretation of the results of traditional biomonitoring tests.

Sufficient impartial scientific research capacity on genetic susceptibility should provide the scientific foundations for a policy steered towards social protection and which would prevent the abuse or misuse of genetic susceptibility tests based on prejudice or commercial interests.

The most important cause of misclassification is misconception