This was the 1940s in Europe.
Tell me, do you have any concept of what large stockyards combined with large slaughtering yards and rendering plants smells like? Oh, such locations are pretty much gone in the modern era, but I am old enough to remember such smells. Passing through entire valleys in Japan where the only thing you can smell is the stink from tens of thousands of pigs, as well as the slaughterhouses and rendering yards.
Or similar smells in many US cities even into the 1970s and early 1980s. Even 50 years ago, much of the US was quite fragrant due to things like stockyards, butchering plants, rendering plants, even from the process of preparing timber for use.
One thing I often shake my head about is how things that I grew up knowing are now completely foreign to those younger than I am. Like Timber Kilns.
Now to a great many over 60, kilns like that were a common sight, especially in California, Oregon, and Washington. And many can still be seen to this day, abandoned as they have not been used for over half a century. But that was a timber kiln, where they would roast lumber in order to help dry it out quickly before it was sent off to the lumberyard.
And good god almighty, when they were in operation they absolutely smelled to high heavens! And it was a smell that all of us that lived in "Timber Country" were more than familiar with. There are a great many areas in California, Oregon, and Idaho that for me have a childhood memory of the stinks associated with them.
And the stink of Chicago was legendary at that time. Dozens of square miles of stockyards, slaughterhouses, butcher shops, meat processing plants, and rendering plants.