Pentagon officials warned that the test had increased the threat to American satellites.
Both agencies said the number of students, particularly members of minority groups, who took the tests also increased.
These tests increased the quantity of carbon-14 in the atmosphere and hence in all photosynthetic material.
They expect a national test would only increase that tension by pitting one school against another.
These tests showed that the tests had increased the concentration of Strontium-90 dramatically.
Another test involving a space-borne hydrogen maser increased the accuracy of the measurement to about 10 (0.01%).
The best studies for assessing whether a screening test will increase a population's health are rigorous randomized controlled trials.
This test is increasing in popularity due to its reliability and accuracy.
When jobs are more scarce, he said, more people take the test to increase the chances of getting a job.
This test could increase the number of lives saved that are affected with these diseases.