But the examination board and head teachers say that standards have remained steady.
The standard remains as what a reasonably prudent person would have done in all the circumstances.
But the annual standard, which affects chronic exposure, remains at its original 1997 level.
Despite these problems, the average standard of living in Japan remains amongst the highest in the world.
Given its broad intake, academic standards remain high and examination results good.
For one reason, a double standard may remain.
However, many national standards also remain in force.
And construction rules and standards remain among the city's strictest.
Yet the standard at Gaia remains high (as do the prices), and blueberries are used in unexpected ways.
More recently, this standard for protection of public health was tightened to 0.75 ppm but remains as an 8 hour contact with the air pollutant.