Environmental chemistry deals with the study of the origin , transport , reactions , effects , fates of chemical species in the environment .
ENVIRONMENTAL POLLUTION : - Environmental pollution is the effect of undesirable changes in our surroundings that have harmful effects on plants , animals and human beings . A substance which causes pollution is called a pollutant . they can be solid , liquid or in the gaseous state .
ATMOSPHERIC POLLUTION : - The atmosphere that surrounds the earth is not of the same thickness at different heights . Atmospheric pollution is generally studied as tropospheric and stratospheric pollution . The ozone layer prevents about 99.5 % of the sun ’ s UV rays .
TROPOSPHERIC POLLUTION : - Tropospheric pollution occurs due to the presence of undesirable solid or gaseous particles in the air . The following are the major gaseous and particulate pollutants present in the troposphere ;
� Gaseous air pollutants : These are oxides of sulphur , nitrogen and carbon , hydrogen sulphide , hydrocarbons , ozone and other oxidants . � Particulate pollutants ; these are dust , mist , fumes , smoke , smog etc
GLOBAL WARMING AND GREENHOUSE EFFECT : - About 75 % of the solar energy reaching the earth is absorbed by the earth ’ s surface , which increases it ’ s temperature . The rest of the heat radiates back to the atmosphere . Some of the heat is trapped by the gases such as carbon dioxide , methane , ozone , CFCS and Water vapour . they add to the heating of the atmosphere causing Global warming
In a greenhouse , visible light passes through the transparent glass and heats up the soil and the plants . The warm soil and plants emit infrared rays , it partly reflects and partly absorbs these radiations , this mechanism keeps the energy of the sun trapped in the greenhouse .