U.S. Officials Accuse Soviets of Cover-Up on Toxic Weapons

WASHINGTON —  The Soviet Union, attempting to avoid mentioning a weapon the Reagan Administration maintains the Soviets use illegally in Afghanistan, changed the definition of toxic weapons in a recent military publication, U.S. officials say.

The Soviet Military Encyclopedia changed the definition to exclude mycotoxins, which had been included in the category of toxic weapons in previous editions of the publications, said the officials, speaking on condition of anonymity.

They said the change is an indication that the Soviets will soon assert that use of mycotoxins is not in violation of a 1972 treaty banning biological and toxin weaponry. Mycotoxins are a type of fungus that can be lethal to humans.

The United States has said the Soviets used weapons based on mycotoxins against rebels fighting the Soviet-backed government of Afghanistan.

Toxins are naturally occurring, non-living poisons, such as snake venom. They differ from chemical weapons that are produced in laboratories and biological weapons, which involve live diseases.