They pickle in old age quite well.
There is a tomb near Wuhan of a fairly well off Chinese man who died about a thousand years ago. The tomb, a small wooden cabin, had leaked silt that had preserved his body to an amazing degree. He was still complete, externally, internally and still flexible.
The carried an autopsy and found the cause of death was a stomach problem. His lungs, despite being covered with lamp black were in good condition and did not contribute to his death.
The old ones have spent half their life in small, unventilated sheds with a coal or wood fire keeping them warm.
Pollution? Child's play.