WASHINGTON (AP) -- The Environmental Protection Agency has signed off on the safety of all but two of 30 pesticides it studied to see whether they are unreasonably dangerous to human health when combined.

EPA Assistant Administrator Stephen L. Johnson said reviewing the cumulative risks of organophosphorus pesticides gave the agency general confidence in the safety of the nation's food supply.

But Johnson, who oversees the Office of Prevention, Pesticides and Toxic Substances, said dichlorvos, or DDVP, which is used in pest strips in homes, and dimethoate, which is sprayed on dozens of fruits and vegetables, could cause headaches, nausea, weakness, even death.

"If it turns out that our concerns are valid, we will need to take action," Johnson said of the two chemicals. "Banning them certainly is one of the options."

The findings were issued late Monday, just hours after a federal appeals court in Washington turned back the third pesticide industry attempt to bar them from being made public. Industry officials did not immediately return phone calls for comment.

Natural Resources Defense Council, the New York-based environmental group whose lawsuit prompted the review, said the EPA had ignored some of the biggest health risks from the chemicals and failed to adequately consider all of the threats to children.

Over the past several years, EPA has reviewed all but five of 49 organophosphorus pesticides. Fourteen have been or will be taken off the market. EPA contends the five for which it didn't consider the cumulative risks posed little threat to human health.

But NRDC disagrees, saying EPA didn't study for any of the pesticides other non-dietary routes of exposure like airborne drifts from spraying and the more frequent contact that about 1 million farm kids have with the chemicals.

"When all the facts come in, it will become clear that EPA must take much more aggressive action against these poisons," said Erik D. Olson, an NRDC senior attorney in Washington. "Kids are exposed more, and are more vulnerable to the toxic effects of organophosphates."

Johnson said, however, EPA believes almost all the uses of the organophosphates that are remaining "pose virtually no risk to anyone, particularly to children."

The EPA's review resulted from a settlement in a 1999 case brought by NRDC, environmentalists and farm workers, who challenged a missed deadline for reviewing the most dangerous pesticides, including those used in foods most eaten by children.

Industry groups had hoped the Bush administration would withdraw from the settlement, which was reached on President Clinton's last full day in the White House but since upheld twice, by federal district and appeals courts in San Francisco.

EPA Administrator Christie Whitman also looked over the settlement, decided it was fair, defended it in court and went ahead with the review.

It is the first time federal regulators have studied how an entire class of chemicals might react with each other and be hazardous in the human body. The review excluded data from controversial human testing by industry, since EPA is temporarily banning its consideration pending a National Academy of Sciences' analysis of the subject due a year from now.

Copyright 2002 The Associated Press. All rights reserved.