Based on recommendations made by theKurokawaTeam, in 1965 companies began to raise the fluegas stack height in order to reduce the concentration of soot and smokeby dispersing them into the atmosphere. As a result, while the concentration of atmospheric pollutants fell drastically in Isozu and other locations, the areas affected by air pollution became more widespread.
Buoyed by rapid economic growth, companies in the petrochemical complexes enhanced their production capacities, resulting in increasing consumption of heavy oils and discharge of sulfur oxides (SOx). This called for radical measures to reduce air pollution.