Since the shocking episode of Rissho High
School on July 18, 1970, the authorities in
protecting against photochemical smog have
advocated that those who suffered from respiratory
symptoms, eye irritation, headache and
others are requested to report. They have announced
a photochemical smog warning whenever
oxidant level exceeds 0.15 ppm.
Accordingly, human health disturbances by
photochemical smog must establish themselves
on their criteria, causes and effects.