text: And there are also**emerging and new risks**where health data will**not be available until a certain**
  **number of workers are exposed for quite a while**. Some prominent examples are nanotechnologies, 
  the significant increase of new chemically based technologies, vision impairment due to long hours of 
  work under artificial light at the same distance with small digital equipment, 183 more exposure to ‘global’ 
  biological agents due to more interactional tasks, and travel and transport between countries and 
  continents. On that note, the Covid-19 pandemic could also be used as an example. In 2022, the 
  Commission proposed an update of the Recommendation on the ESOD to recognise Covid-19 as an 
  occupational disease for workers particularly concerned: health and social care, home help or where 
  there is a proven risk of infection (during a pandemic) in other sectors 184. 
  
  It adds to these difficulties that workers are often not only exposed to one disease causing exposure but 
  to**several exposures**at the same time (exposure is understood here in a broad sense: ranging from 
  long working hours over postures and movements to harassment and violence and to noise and 
  chemical and biological substances, etc.).**In theory, a single risk**— if below the threshold limit values 
  and in line with legislation and standards —**will not cause harm — given that it is the only exposure**. 
  The impact of this single exposure is not strong enough to generate a disease on the level of severity 
  of a recognised occupational disease. A**combination of several risks**might add several exposures, 
  worsen the impact and cause serious harm. 