I remember reading a novel, probably a short one, in the library, probably between 1984 and 1987 (but may have been published as much as 20 years older than that). The plot was very rambling; at the moment, the only two features I am sure I remember are:
- "plastic cancer" -- a syndrome where the tissues of an animal or human gradually turned to a solid plastic compound, keeping their shape and coloring but, of course, no longer being alive
- A ring singularity wormhole that was being used to communicate with the past. No physical objects travelled, only messages.
It may have had alternate chapters taking place in the future and past (relative to each other).
At one point, a bunny had succumbed to plastic cancer. A man then sawed it in half with a hacksaw. Later in the book, perhaps due to changing the past or something, there was no more plastic cancer, and he found a bloody bunny corpse that had been sawed in half.
EDIT: Google Books has turned up a snippet from a review; unfortunately no title. The review seems to be from Foundation: The review of science fiction, Number 15, January 1979. So that probably pins the book publication to 1978-1979.
... reviewed by Pauline Jones
In this book the schizophrenic hero, Neil Prentice, passes into a 1984 future with the help of a drug called TNA. His route lies through a black hole. His mission is to save humanity from this future and its concomitant horrors of plastic cancer and premature ageing. In the course of the narrative, marketable preoccupations such as pollution, laser power...