WASHINGTON — Nearly every apple tested by the Agriculture Department in 1993 showed traces of pesticides, but far below levels considered to pose a health risk, according to a study of popular fruits and vegetables.

Many samples of other fruits and vegetables showed no pesticide traces at all. Three-quarters of the broccoli samples and nearly half the lettuce had no detectable residues.

“These data reinforce the fact that the nation’s food supply is one of the safest in the world,” said Lon Hatamiya, administrator of the Agricultural Marketing Service, the agency that did the study.

Critics, however, say it’s wrong to make safety judgments based on current tolerances — the level of pesticide residues determined by the Environmental Protection Agency to be safe. Also, they say, the government’s approach of regulating each pesticide individually fails to recognize the combined effect of different chemical compounds on one piece of produce.

“The important part is to look at preventing exposure to these things rather than figuring out what is the acceptable poison,” Kert Davies, analyst for the Washington-based Environmental Working Group, said Monday.

Of the 7,328 samples taken, 110 had pesticide levels above the legal limits — 1.5 percent. Imports, though smaller in volume, had a higher violation rate — 2.4 percent — compared with 1.3 percent for U.S. fruits and vegetables.

The EPA uses the Agriculture Department numbers, along with data on food consumption, to help determine the safe level of pesticides to allow in different foods. The Food and Drug Administration is in charge of enforcement.