Stratospheric ozone depletion by chlorofluorocarbons.

Chlorofluorocarbons (CFCs) are considered to contribute to depletion of stratospheric ozone and the amount of CFCs production/consumption will be reduced according to Montreal Protocol this year.Here, the following current scientific knowledges concerning this global air pollution problem are reviewed.1) Formation of stratospheric ozone layer, especially some key chemical reactions in the stratosphere2) Chemical reactions of CFCs in the stratosphere3) Behavior of CFCs in the troposphere4) Trend of total ozone concentration, deduced from observed data for ca. 30 years5) Model calculations on the future ozone trend6) Countermeasures for reduction of CFCs