Engulfed by the scorching heat of this arid city and the disgrace of a widening drug scandal, the track and field world championships get underway Saturday with athletes eager to create new headlines with their performances but also concerned about the recent spate of positive drug tests.

Another track and field veteran, the Netherlands' 36-year-old sprinter Troy Douglas, tested positive for the anabolic steroid Nandrolone, the world governing body of track and field (IAAF) confirmed today.

The latest drug case--and particularly the higher-profile cases of Jamaica's Merlene Ottey, Cuba's Javier Sotomayor and Britain's Linford Christie--has threatened to overshadow an otherwise impressive summer for track and field in which three world records were set.

This week, the International Amateur Athletic Federation ratified the 100-meter dash record (9.79 seconds) set by U.S. sprinter Maurice Greene in June; the mile record (3:43.13) achieved by Morocco's Hicham El Guerrouj in July; and the decathlon mark (8,994 points) set by the Czech Republic's Tomas Dvorak in July.

Yet with Wednesday's withdrawal of 39-year-old Ottey from the championships after a positive test for Nandrolone--the same drug that turned up in a urine sample from 39-year-old Christie--talk of world records has taken a backseat to discussions about drug use in track and field.

"This gives the sport a really negative image," 800-meter runner Meredith Rainey-Valmon, who lives in Bethesda, said today. "With so many [positives] coming on the heels of one another, it's starting to give the sport the look of cycling. It's like it's just the tip of the iceberg. . . . But something doesn't make sense about the situation. With really veteran athletes, it doesn't seem like they would make that mistake at this point in their careers.

"I don't think any of the athletes are 100 percent confident in the testing system. Even though I'm not taking anything, when I get a sample sent off, I never feel 100 percent comfortable that the result will come out the truth."

Several athletes have called for blood tests to bolster the current system of urine testing, a step the International Olympic Committee executive board announced today it will take for the 2000 Games in Sydney on a voluntary if not mandatory basis [see story, Page D1].

Despite the dark cloud of controversy created by the surge of positive drug tests in recent weeks, the world championships could offer positives of another kind.

Perhaps the most touching moments will involve Swedish hurdler Ludmila Engquist, who is competing here despite having breast cancer diagnosed last year. Engquist has scheduled her chemotherapy treatments around this event.

U.S. sprinter Marion Jones will seek to reach her goal of four world gold medals--in the 100, 200, long jump and 4x100 relay. The favorite in the two sprint events, Jones historically has struggled in the long jump.

During the national championships this summer, she finished seven inches behind Dawn Burrell, the younger sister of former 100-meter world record holder Leroy. However, Jones lost one of her principal rivals in the event today when former world champion Heike Drechsler of Germany pulled out with a leg injury.

Lake Braddock High's Allen Johnson wants his third straight world title in the 110-meter hurdles. Meanwhile, U.S. sprinter Michael Johnson chases his ninth world championship gold--while seeking to deflect criticism that he has dodged his top competitors in races this season.

Greene, the defending gold medalist in the 100, said he intends to win three gold medals here--in the 100, 200 and 4x100 meters.

Of course, for that to happen, the United States' men would have to overcome a ignominious history in 4x100-meter relay. At the 1997 and 1995 world championships and the 1988 Olympics, the U.S. men were disqualified because of dropped batons.

This year's team was set about two weeks ago and the team members trained together in Monaco. Running for the U.S. team will be Jon Drummond, Tim Montgomery, Brian Lewis and Greene. Lewis and Montgomery, the first two runners at the '97 worlds, muffed the exchange in that event.

"The relay is going to be great," Lewis said today. "We have everything down. . . . We have a lot of confidence."

One of the most exciting races could be the men's 1,500, as young Kenyan Noah Ngeny seeks to unseat El Guerrouj, whom Ngeny trailed by just a step when El Guerrouj broke the mile record in July. Denmark's Wilson Kipketer, the world record holder in the 800 meters, will seek a repeat world championship gold after having overcome malaria contracted during a trip last year to his native Kenya.

Ethiopia's Haile Gebrselassie is seeking his fourth world title in the 10,000 meters--even though he has not run a single race at that distance this season. In the men's marathon, Spaniards Abel Anton, Martin Fiz and Fabian Roncero hope to sweep the medals in their home country.

"In the last few weeks our beautiful sport has been marred," Jones said Thursday. "We hope that our wonderful performances in a couple of days will overshadow what has happened."