DEPLETION OF STRATOSPHERIC OZONE

ABSTRACT

Depletion of stratospheric ozone emerged as a political concern in the early 1970s in the United States in the debate over the devel­opment of a commercial fleet of supersonic transports. In the mid- 1970s it became a major political issue with regard to the use of CFCs in aerosol spray cans, and in 1978 the United States banned the nonessential use of CFCs as aerosol propellants. Efforts at ne­gotiating an international agreement controlling CFC use began in the 1980s and culminated in the 1987 Montreal Protocol. This paper traces the evolution of policy responses to stratospheric ozone de­pletion. The evolution of stratospheric ozone depletion policy can best be understood as a two-stage process. The first stage involves the emergence of stratospheric ozone depletion as a domestic issue in the United States and several other countries in the 1970s, while the second stage focuses on its transformation to an international issue in the 1980s. In addition to the emergence of stratospheric ozone depletion as an international political issue, three other factors are important in understanding the sources of the Montreal Protocol: (/) the evolving scientific understanding of the problem, (2) increas­ing public concern over the problem based on the threat of skin cancer and the discovery of the Antarctic ozone hole, and (3) the availability of acceptable substitutes for CFCs.

You May Also Like

HEMATOLOGY AND PLASMA CHEMISTRY REFERENCE OF Oreochromis HYBRID AND Clarias gariepinus.

Tilapia and catfish are a commonly aquaculture fish yet little is known about their normal physiology and response to disease. The present study was carried out to determine the result of complete hematologic and plasma chemistry profile of cat fish Clarias gariepinus (n = 15), and tilapia Oreochromis hybrid (n = 15) obtained from a commercial pond in Gwagwalada and a lake source in jabi respectively. The catfishes were acclimatized for a period of one month and two weeks. Blood from both species of fish were obtained and analyzed so as to obtain the hematologic parameters and plasma chemistry analytes. The result obtained from catfish was compared to those of the tilapia fish. Slight Difference was noted in the values of both specie. Protein values in tilapia fish were noted to be slightly higher than those of the catfish. Values of chloride were much higher in tilapia than the catfish; these were concluded to be as a result of the effect of the water quality since they were both obtained from different water source.
Read More