Styrol is a liquid mainly used to produce plastics. Until now it was thought that the substance was not harmful to humans because studies with rats had shown that it did not cause lung tumours as happened with mice.
The reason why the liquid was not dangerous for rats is that these animals are missing two enzymes of the cytochrom P450(cYp)-„family“. These enzymes are responsible for changing styrol into styrol oxide in lung tissue which in turn may cause tumours. That may be the reason why mice did develop tumours after inhaling styrol - they do possess the enzymes.
The Federal Institute for Risk Assessment in Germany (Bundesinstitut für Risikobewertung - BfR) has undertaken experimental research which implies that styrol may also be dangerous for humans. In experiments the researchers discovered that the styrol-altering enzymes are also present in human lung tissue with an activity comparable to that in mice. That way the tunour causing styrol oxide could also be produced in human lungs. "The results are very important for the current re-evaluation of the sanitary impacts of styrol and also for those using the substance in industrial processing", says Professor Dr. Dr. Andreas Hensel from BfR.
The data collected so far is not enough though in order to determine if the enzymes are present in a concentration sufficient to cause tumours.
COMPAMED.de; Source: Bundesinstitut für Risikobewertung