text: The situation is complex, because only few and mostly the recognised**occupational diseases**have a 
  unique cause-effect relationship, that is, a**very strong relation between one specific exposure at**
  **work and one (or more) well-defined disease(s)**as a result of this exposure. 
  In 1987, a joint ILO/WHO expert committee on occupational health offered the suggestion that**the term**
  ***work-related diseases***may be appropriate to describe not only recognised occupational diseases but 
  other disorders to which the work environment and performance of work contribute significantly as one 
  of the several causative factors (Joint ILO/WHO Committee on Occupational Health 1989): 
  *‘Nevertheless, it is not always that easy to designate a disease as being work-related. In fact, there is a*
  *wide range of diseases that could be related in one way or another to occupation or working conditions.*
  *On the one hand, there are the classical diseases that are occupational in nature, generally related to*