Tag: environment and conservation

Greenhouse gases trap heat and make the planet warmer causes global warming. Human activities are responsible for almost all of the increase in greenhouse gases in the atmosphere over the last 150 years and USA is responsible for releasing largest amount of greenhouse gases. The primary sources of greenhouse gases in USA are electricity production (31%), transportation (27%), industry (21%), commercial and residential (12%) etc.

There are five major types of pollution:
1. Air pollution

Geochemical cycle refers to the chemical interactions in surface reservoirs such as the atmosphere, hydrosphere, lithosphere, and biosphere. Pollution is any undesirable change in physical, chemical or biological characteristics of air, land, water or soil. Agents that bring about such an undesirable change are called as pollutants. Local flora and fauna is also affected by the pollutant. Balance of nature also gets disturbed as pollutant affects the living organism and composition of gases in the atmosphere.

Pollutant is a substance which when introduced into the environment has undesired effects. Pollutant causes long- or short-term damage by changing the environmental factors. Some pollutants are biodegradable and therefore do not persist in the environment in the long term. However, the degradation products of some pollutants are themselves polluting such as the products DDE and DDD produced from degradation of DDT.

• Pollution is the introduction of contaminants into the natural environment that causes adverse change. 
• Pollution can take the form of chemical substances or energy, such as noise, heat or light. Pollutants, the components of pollution, can be either foreign substances/energies or naturally occurring contaminants. 
• Hence, Introduction of contaminants into an environment that causes instability, disorder, harm or discomfort to the ecosystem i.e, physical systems or living organisms, is called Pollution.
• So, the correct answer is 'Pollution'.

Non- biodegradable compounds such as DDT and mercury accumulate in the tissues of organisms that consume them since they do not break down easily. As a result, when they, in turn, are consumed by secondary organisms their amount magnifies. This is known as biomagnification. Hence, such non-biodegradable compounds affect the organisms of higher trophic level more. So, the correct option is 'heavy metal salts and non-biodegradable phenolic compounds'.