My magazines go back a fair way so I had a flick through the period. Winning Jan/Feb 1991 (so would have been written end-1990) has an editorial by Rich Carlson. I won’t type out the whole thing, but here is the first section. From this I guess it can be confirmed that EPO and the deaths were being seen, at least by some, as potentially linked pretty early on in the piece; and that at that time, for at least some, the link was seen as no more than potential. The story headline is ‘Fatal Attraction’:
“I went to a symposium on drug-use in sports recently. It was called ‘EPO and Athletics: playing a dangerous game’ and it was sponsored by Amgen, Inc., the company that manufactures Erythropoietin. The Amgen folks are concerned these days because it appears that the miracle drug they thought they’d developed for the good of mankind has also become the latest turbo-charger-in-a-bottle for some athletes, apparently with deadly consequences. EPO’s ability to increase red blood cell production is supposed to alleviate some of the suffering experienced by kidney-failure patients. And it does. But when misused, EPO can dangerously thicken the blood, leading to heart attack or stroke; and Amgen and a lot of other people, including the Dutch government, are alarmed because during the past three years more than a dozen Dutch cyclists have dropped dead, and there have been rumors that EPO may have been involved in at least some instances. Amgen is quick to point out there’s no proof to link any of these deaths with the use of EPO, but they obviously have their suspicions.” (Winning Bicycling Illustrated, No 87)