(i) A pure public good is one for which consumption is non-revival and from which it is impossible to exclude a consumer.
(ii) Pure public goods pose a free-rider problem. As a result, resources are depleted

(i) Environmental quality is a set of properties and characteristics of the environment either generalized or local, as they impinge on human beings and other organisms.
(ii) It is a measure of the condition of an environment relative to the requirements of one or more species and to any human need.

The interdependence of economics and environment is given in the figure

(i) The key objective of EE is to identify those particular tools or policy alternatives that will move the market towards the most efficient allocation of natural resources.
(ii) EE takes into consideration issues such as the conservation and valuation of natural resources, pollution control, waste management, and recycling.

(i) Environmental economics (EE) is the study of interactions between human economic activity and the natural environment.
(ii) EE is the subset of economics that is concerned with the efficient allocation of environmental resources

Sustainable development is concerned with the welfare, of present and future generation.

(i) Atmospheric noise.
(ii) Industrial Noise.
(iii) Man made noise.

(i) Death of aquatic animals.
(ii) Disruption of food - chains.
(iii) Diseases.
(iv) Destruction of ecosystems.

(i) Air Pollution.
(ii) Water pollution.
(iii) Noise pollution.
(iv) Land pollution.

Organic farming is a system of agricultural production which relies on animal manure, organic waste, crop rotation, legumes and biological pest control.

(i) Soil pollution.
(ii) Health Impact
(iii) Cause for air pollution.
(iv) Effect on wildlife.

(i) Mining activities: During extraction and mining activates, several land spaces are created beneath the surface.
(ii) Land fills: Each house hold produces tones of garbage each year due to changing economics life style of the people. Garbage like plastic, paper cloth, wood and hospital waste get accumulated.

(i) Surface water pollution.
(ii) Ground water pollution.
(iii) Micro biological pollution.
(iv) Oxygen depletion pollution.

Pollution is the introduction of contaminants into the natural environment that causes and and verse change, in the form of killing of life, toxicity of environment, damage to ecosystem and aesthetics of our surroundings.

Externality may be defined as "the cost or benefit imposed by the consumption and production activities of the individual on the rest of the society not directly involved in these activity and towards which no payment in made".