Chemical odor from the exterior wall

If there is a Vielstinker drilling, then knock out the stone and replace it.
Who knows what was disposed of in the open stone

I also consider that the most likely. Someone disposed of something in the hollow stones.

Which toxins were measured?

Hello,

these substances were rated as conspicuous:

1,3,5-Trimethylbenzene
Cyclohexanone
1,2,4-Trimethylbenzene
n-Decane
o-Ethyltoluene
1,2,3-Trimethylbenzene

Best regards

Mark

If you are looking for enius pollutants, you come across a page where many substances are listed. When I look at yours, it is most likely a solvent or additive in paints... n-Decane is, for example, not included, but Decanal is. No idea if it has the same function...

Perhaps the agent used to weld [Bitumenbahnen] or dilute [Bitumenkleber].