A chemical tracking agent that threatened to rupture U.S.-Soviet relations is harmless and was only sparsely used, the American Embassy announced Friday.
Tests of ”spy dust” samples collected in Leningrad and Moscow determined that exposure to the substance, earlier feared to be carcinogenic, ”does not pose a health hazard,” officials said.
However, U.S. Ambassador Arthur Hartman denounced the use of tracking powders and demanded that the Soviet government halt application of the chemicals.
”No special substances should be used against the American community,”
he said. ”We want to make clear to the Soviet authorities that active measures against Americans in Moscow are not acceptable.”
U.S. officials announced last August the discovery that Soviet security forces were dusting American residents` doorknobs, steering wheels and the like with nitro phenyl pentadiene (NPPD).
Once the Americans were contaminated, their movements could be confirmed by following the NPPD trail, visible with the use of special equipment, embassy spokesmen said.
The Soviet Union launched a sharp counterattack, saying the accusations were absurd and aimed at poisoning U.S.-Soviet affairs.
Despite initial alarm, tests concluded that the chemical is not a mutagen and does not cause cancer. No birth defects were discovered in pregnant laboratory animals exposed to NPPD.
”NPPD is not readily absorbed through the skin,” said a report released by the U.S. Embassy. ”If it does enter the bloodstream, it is rapidly metabolized and excreted from the body.”
In the first survey of the American community here after disclosure of the spy dust threat, 436 samples were taken from apartments, offices and autos of 20 percent of the U.S. residents. No NPPD contamination was discovered, officials said.
A follow-up sampling was conducted last month of a special set of embassy employees thought to be of particular interest to state security forces.
Five automobiles, said by Hartman to be private cars and not official embassy vehicles, were found to have been contaminated. He said the cars apparently were sprayed when parked overnight at residences away from the embassy.
During the investigation, the State Department report said, the use of a second tracking chemical, luminol, was discovered. The report said that luminol is a widely used, commercially produced laboratory chemical that poses no health hazard.
The report concludes that ”the use of NPPD and other tracking agents was confined to a small percentage of American personnel specifically targeted by Soviet authorities.”
Hartman declined to elaborate on who those people are or their job responsibilities, except to say that they are among a group of U.S. government employees ”that tends to have contact with Soviet citizens.”
The health investigation was led by the National Institute for Environmental Health Sciences and included representatives of the
Environmental Protection Agency and Centers for Disease Control.
Hartman said government researchers now have developed a simple test that can be administered by embassy employees to detect future contaminations.
When reports surfaced last summer that a possibly carcinogenic tracking powder may have been used against Americans in Moscow, the response ranged from anguish to satire.
Some American residents in Moscow met guests arriving at the airport with gag gifts of rubber gloves, while others angrily pleaded for more information about possible side effects.
After the findings were reported Friday, the response among Americans again varied.
”I thought it was a canard from the beginning,” said an American businessman accredited to work in Moscow. ”Now I know for sure.”
Another American resident in Moscow, the father of two, said he was satisfied with actions to issue a warning–even if all the facts were not yet known.