(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.

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

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

1. Use of noise barriers
2. Newer roadway for surface transport
3. Traffic control
4. Regulating times for heavy vehicles
5. Installations of noise barriers in the work place
6. Regulation of Loudspeakers

China, USA, India, Russia, Japan.

i. Atmospheric Noise:
Atmospheric noise or static is caused by lightning discharges in thunderstorms and other natural electrical disturbances occurring in the atmosphere.
ii. Industrial Noise:
Industrial noise refers to noise that is created in the factories. Sound becomes noise it becomes unwanted. Heavy industries like shipbuilding, iron, and steel have long been associated with Noise-Induced Hearing Loss (NIHL).
iii. Man-made Noise:
The main sources of man-made noise pollution are ships, aircraft, seismic exploration, marine construction, drilling, and motor boats.

i. Solid waste:
It includes all kinds of rubbish like paper, plastic containers, bottles, cans, food, used cars, broken electronic goods, municipal waste, and hospital waste.
ii. Pesticides and Fertilizers:
Many farming activities engage in the application of fertilizers, pesticides and insecticides for higher crop yield which pollute land.
iii. Deforestation:
Humans depend on trees for many things including life. Trees absorb carbon dioxide from the air and release Oxygen, which is needed for life. Forest helps replenish soils and help retain nutrients being washed away. Deforestation is led to land pollution.

(i) Electronic waste is the new by product of the Info Tech society.
(ii) It includes a growing range of electronic devices from household appliances, such as refrigerators, air conditioners, cell phones, computers.
(iii) e-waste can be defined as the result when consumer, business and household devices are sent for re-cycling (e.g., television, computers, audio-equipments, VCR, DVD, telephone, Fax, Xerox machines, wireless devices, video games).

Discharge of sewage and waste water:
(i) Sewage, garbage and liquid waste of households, agricultural runoff and effluents from factories are discharged into lakes and rivers.
(ii) These wastes contain harmful chemicals and toxins which make the water poisonous for aquatic animals and plants.
Dumping of solid wastes:
(i) The dumping of solid wastes and litters in water bodies cause huge problems.
Discharge of industrial wastes:
(i) Industrial waste contains asbestos, lead, mercury, grease oil and petrochemicals.
Oil Spill:
(i) Sea water gets polluted due to oil spilled from ships and tankers.
Acid Rain:
(i) When the acidic particles caused by air pollution mix with water vapour, it results in acid rain.
Global warming:
(i) The increase in water temperature affects aquatic plants and animals.
Eutrophication:
(i) The increased level of nutrients in water depletes oxygen in water and this negatively affects fish and other aquatic animal population.

Causes of Land Pollution:
(i) Deforestation and soil erosion: Deforestation carried out to create drylands is one of the major concerns.
(ii) Agricultural activities: With growing human and pet animal population, demand for food has increased considerably; Farmers often use highly toxic fertilizers and pesticides to get rid off insects, fungi and bacteria from their crops. However the overuse of these chemicals, results in contamination and poisoning of land.
(iii) Mining activities: During extraction and mining activities, several land spaces are created beneath the surface.
(iv) Landfills: Each household produces tones of garbage each year due to changing economic lifestyle of the people. Garbage like plastic, paper, cloth, wood and hospital waste get accumulated.
(v) Industrialization: Due to increasing consumerism more industries were developed which led to deforestation.
(vi) Construction activities: Due to urbanization, large amount of construction activities are taking place. This has resulted in large waste articles like wood, metal, bricks, plastic. These are dumped at the outskirts of urban areas that lead to land pollution.
(vii) Nuclear waste: The leftover radioactive materials, harmful and toxic chemicals affect human health. They are dumped beneath the earth to avoid any casualty.
Remedial measures to control Land Pollution
1. Making people aware about the concept of a Reduce, Recycle and Reuse
2. Buying biodegradable products
3. Minimizing the usage of pesticides
4. Shifting cultivation
5. Disposing unwanted garbage properly either by burning or by burying under the soil.
6. Minimizing the usage of plastics.

Introduction:
1. Externality refers to external effects or spillover effects resulting from production or consumption on the third parties.
Definition:
1. It may be defined as "the cost or benefit imposed by the consumption and production activities of the individuals on the rest of the society not directly involved in these activity and towards which no payment is made".
Types:
1. Beneficial externalities are called "positive externalities".
2. Adverse externalities are called "negative externalities".
Positive Consumption Externality
1. When some residents of a locality hire a private security agency to patrol their area, the other residents of the area also benefit from better security without bearing cost.
Negative Consumption Externality
1. A person smoking cigarette gets satisfaction but this act causes dissatisfaction to the non-smokers who are driven to passive smoking.
Positive Production Externality
1. The ideal location for beehives is orchards.
2. While bees make honey, they also help in the pollination of apple blossoms.
3. The benefits. accrue to both producers (honey and apple).
4. This is called reciprocal untraded interdependency.
Negative Production Externality
1. They include pollution generated by a factory that imposes costs on others.
2. The emissions and effluents of a factory cause air and water pollution.
3. Water becomes contaminated and unfit for drinking (e.g.) Tanneries.
4. The innocent community bears the external cost for which it is not compensated.