When he won the 100-meter dash in the second-fastest time in history Sunday night, Usain Bolt sent the 80,000 who witnessed his feat in person and the millions more who watched it on television into a state of delirium. Bolt’s feat raised the old grade-school axiom “Wanna race?” to athletic nirvana.

But even before his gold medal ceremony here Monday night, that state of euphoria was pierced with variations of the same cynical question: “Is he clean?”

When I called home Monday to talk about one of the most surreal events I’ve ever covered, everyone wanted to know whether the fastest human alive was someone they could truly believe in? Is he free of any illegal performance-enhancer that might make a man capable of posting 9.95 seconds suddenly able to go, oh, 9.63 seconds — Bolt’s Olympic-record winning time?

So Monday night at Olympic Stadium, I asked a dozen current and three former Olympians what they thought. Several were bothered I asked, saying it was unfair to Bolt, who has never tested positive for anything illegal and has welcomed any and all testing procedures since the lead-up to the Beijing Games in 2008. But most of the current Olympians, who have had to defend themselves and teammates against drug allegations, understand it’s now part of the landscape.

“At the end of the day, if he didn’t get caught yet, it means he’s not on anything,” said T’erea Brown, the U.S. hurdler who qualified for the 400 final Monday night. “What he did last night was just amazing. If he would have lost, they would have said, ‘He’s probably not what he was on [in Beijing].’ I don’t think that’s the case. I think he’s supersonic.”

Said Billy Mills, the U.S. gold medalist at 10,000 meters in 1964: “I don’t think he’s on any kind of performance-enhancing drugs. I just think he’s borderline inhuman. He’s just an incredible athlete.”

Mills acknowledged his famous victory in Tokyo, in which an unheralded amateur overtook the world and Olympic champions over the last 100 meters, would have raised eyebrows today.

This skeptical environment is a byproduct of busted world-class sprinters Ben Johnson, Marion Jones and Tim Montgomery. This is the can’t-believe-what-we-see world Bay Area Laboratory Co-Operative chemist Victor Conte has given us. There are no Billy Millses anymore; we’d want to see the results of his urine test first.

Chinese swimmer Ye Shiwen dealt with unfair accusations when the 15-year-old broke world records and won gold medals, actually putting up a faster time in the last 50 meters of one of her races than Ryan Lochte did at the end of one of his. Bethesda’s own Katie Ledecky, 15, just missed the 800-meter freestyle world record when she surprisingly won gold last week, prompting another one of those beat-around-the-bush inquiries.

Why not just ask, “So, did you use?” At least then the questioner wouldn’t feign compassion for having trashed a kid’s genuine Olympic moment.

If it wasn’t before, skepticism is now required at the Games when any athlete in any discipline puts up a time or a performance that is so off the charts it hints of something other than a good coach and a grueling training regimen. Italy’s race-walking champion and three Nigerian women track stars were thrown out before the London Games began because of positive doping tests.

Part of the suspicions around Bolt result from different drug-testing standards in the Caribbean. While Jamaica’s team doctor is a member of track’s governing body’s anti-doping commission, Jamaica and other Caribbean islands don’t have an independent anti-doping federation like the United States Anti-Doping Association.

Bolt has said that he had been tested four times prior to the Beijing Olympics, and all had tested negative for banned substances. Glen Mills, his coach, is more adamant than anyone the world’s fastest man is clean. “We will test any time, any day, any part of the body . . . [Usain] doesn’t even like to take vitamins.”

Bolt’s drug-test samples from Sunday night were presumably driven to a mammoth, 15,000-foot laboratory 45 minutes north of London, where a $30 million facility partly run and staffed by the drug-company conglomerate GlaxoSmithKline (Olympic organizers actually sold sponsorship to a drug lab for the first time in history) have began running an estimated 5,000 blood and urine tests for the athletes of the London Games.

As nervous as Bolt’s fans were before the gun went off Sunday night, the negative-test results from that lab ultimately confirm the final result: that the great Jamaican sprinter, who rescued many of our imaginations after the sport’s greatest sprinters were found to have cheated their peers and their public, was the real, chemical-free deal.

For what it’s worth, I believe Bolt is clean. Not because of his sinewy body type compared to the bulked-up hulk that Ben Johnson was. No, I just don’t think it’s in his nature to put syringes and pills in his body to win. If he hasn’t cheated, I hope he remains drug-free for the rest of his career. For track, the Games and beyond, he needs to be clean.

Only the validity of true Olympic athletic achievement, encompassing every sport and every athlete, is at stake.

For Mike Wise’s previous columns, visit washingtonpost.com/wise.