Everyone should be concerned - 82% of our high school seniors are not performing at the proficient level in science

Education Secretary, Rod Paige

And he warned that failure to produce scientists could in the future damage national security.

These science scores for the year 2000 found that 47% of school leavers were below the "basic" ability band.

"Everyone should be concerned - 82% of our high school seniors are not performing at the proficient level in science," said Mr Paige.

"If our graduates know less about science than their predecessors four years ago, then our hopes for a strong 21st century workforce are dimming just when we need them most," said Mr Paige.

Compared with the last such survey in 1996, fourth and eight graders had stayed at the same level, but there had been a decline in 12th grade.

"America needs inventors, engineers, doctors, computer designers and scientists," he said. But the education system was not delivering the standards of science education that was needed.

There is something wrong when American schools cannot produce enough good workers for valuable American jobs

Education Secretary Rod Paige

And noting that the achievement gap between white and ethnic minority students had narrowed among 12th graders, he said this was "because white students did worse".

The report concluded that it was "white students with educated parents and economic advantages whose scores declined significantly at the 12th-grade level".

Improvements were needed "not just for our economy, but also for our national security," said Mr Paige.

At present the United States depended on importing thousands of scientists trained elsewhere, he said.

"There is something wrong when American schools cannot produce enough good workers for valuable American jobs," he said.

And he pointed to a recent report produced by senators which had concluded that the "need for the highest quality of human capital in science, mathematics and engineering is not being met".

Mr Paige promised to raise the standard of teaching and said that it would be easier for military staff, leaving the armed forces with science experience, to become teachers.

The assessments are based on a four-yearly sample, which in this study involved 240,000 students.

The test questions were based on three fields of science: Earth, physical, and life sciences.