man made

lots of steel, back-blip from a film I shot and only scanned now. However, there is an issues with this b/w film that I dont understand: there are kind of micro-clouds all over the sky and the left large building. Anyone in the know what might have gone wrong ? I can see its on all negatives of that particular film.

The extra shows the building on the left at 100%, lots of fluffy small clouds that were not there when I shot it.