The Environmental Protection Agency's own advisory panel of scientists last week wrote a letter to the EPA saying its new smog standard fails to protect people.

The stern letter to Administrator Stephen Johnson called for a further tightening of the standard and complained that the panel's previous recommendation had been ignored. There has been no public response from the agency, which says its decision is supported in scientific research.

Johnson on March 12 lowered the ozone health threshold from 80 parts per billion to 75 parts per billion. More than 340 counties nationally will have dirty air by that standard. The San Joaquin Valley, which has never achieved any ozone standard, probably will need another 20 years to attain the new one.

But the new standard still was not good enough, according to the Clean Air Scientific Advisory Committee, created by Congress to advise the EPA. The committee had urged the EPA to set a standard for ozone of
between 60 parts per billion and 70 parts per billion.

According to the Associated Press, the committee said it remained convinced that the EPA’s concentration level “fails to ... ensure an adequate margin of safety” for the elderly, children and people with respiratory illnesses.