No. Ultra-processed foods predate these increased cancer rates by decades, it started after World War Two. Pollution was far worse in the past, coal was nasty. Meaningful healthcare implies modern healthcare, it detects cancers it doesn't prevent them.
It's almost certainly plastics and other chemicals that we are exposed to on a routine basis. Prior to the 90's most things were still glass, metal and wood. Now even our clothes are plastic and everything is stored in some chemical blended storage.