The environment has both constructive as well as destructive effects on human life. We can categorize the various types of pollution as air pollution, water pollution and noise pollution.

Pollution is an undesirable change in the physical, chemical or biological characteristics of air, land and water that may harmfully affect life. It is an unfavourable alteration of the environment largely as a result of human activities. It is caused by various pollutants which are substances foreign to the medium such as air or water in which they are present. It causes problems to the animal and human world. The various types of pollution are:

  1. Air Pollution
  2. Water Pollution
  3. Noise Pollution
  4. Crowding
  5. Green House Effect

1. Air Pollution

Air pollution is defined as an imbalance in the quality of air so as to cause adverse effects on the living organisms. It is caused by the excessive presence of certain gases and suspended material particulates (SPM). The air is the carrier of oxygen for all life forms. Gases like carbon di-oxide (CO2), Nitrous Oxide (NO2), Sulphur dioxide (SO2) and suspended particulates including lead are the major pollutants.

These not only cause irritation but also result in diseases like respiratory problems, cardio-vascular problems, hypertension, asthma, eye-related and neurological problems and result in early deaths too. Human behaviour is linked to air pollution both as a causal factor and also as an effect.

The major sources of air pollution are increase in power consumption, industrialization, vehicular traffic and burning of refuse, garbage, smoking and cutting trees for building construction.

2. Water Pollution

Pollution of water refers to addition of excess undesirable substance to water that makes it harmful to human, animal and aquatic life. The poor quality of water causes various diseases like diarrhoea, intestinal worms and hepatitis.

How does the water quality gets affected

It is largely due to following factors:

  • domestic and human waste water
  • industrial waste water
  • agricultural run off

The domestic and human waste water is often times used without proper treatment as irrigation water. Some vegetables which are eaten raw are also washed in this dirty water. This water and the industrial waste water are dumped into the rivers which contaminate the river water too. The chemically treated water of the industries pollutes the river water in such a way that it becomes polluted beyond treatment.

This further affects the quality of our ground and surface water. The decreasing life of our rivers can be seen in the case of Yamuna in Delhi and Ganga in Kanpur.

Water is a basic necessity for life. If water pollution is not checked, then that day is not very far when we will have to buy water even for taking bath and cooking.

3. Noise Pollution

Noise pollution can be defined as the intensity, loudness, timbre or pitch of sound which causes us physical discomfort or it may be unwanted because of the situation. The intensity is an important dimension yet the degree of annoyance is not necessarily related to intensity only. Factors like familiarity and attitude often influence the degree of annoyance. People become habituated to noise and experience lesser degree of discomfort.

There are various ill effects of noise pollution:

  1. Health hazards: It has been observed that traffic noise is related to certain symptoms such as nervousness, sleeplessness, undue irritability, depression and asthma. Some studies have also revealed that noise pollution triggers aggressive behaviour and reduces altruism and helping behaviour. It has also been observed that noise disrupts the harmony of interpersonal relations.

  2. Problems in Communication: One of the easily observed effects of high level of noise is the disruption of communication. Another effect of noise appears to be reduction in performance and low job satisfaction. This has also been inferred that noisy classroom reduces students’ clarity regarding tasks, attention, motivation and reduces academic performance.

  3. Accidents: Apart from various other things, noise has been identified as one of the major factors causing accident.

4. Crowding

Psychologists distinguish between density and crowding. Density is the number of persons per square kilometer. This is an objective measure of the number of persons present at a given place. Suppose there are two situations one in an overcrowded bus and another at a marriage party. Though the density may remain the same in both situations the behaviour and experience would be different.

Therefore, behaviour and experience of crowding depend upon our relationship with the people involved, the duration of the experience, the physical context and the meaning assigned to it. We are likely to feel less crowded in a group of friends than in a group of strangers.

Effects of crowding:

  1. Crime: A link between crime and crowding has been noted. The most known crimes such as pick-pocketing and snatching tend to occur in crowded settings. We are all familiar with increase in this sort of crime during busy rush hour on local trains and buses, peak hours in market places, etc.

  2. Crowding in Corrective Institutions (Prisons) and Psychiatric Institutions: In recent past various cases of riots and clashes among inmates and stress among prison officers have been reported in the different parts of India. Both these cases seem to be related to over crowding because violent criminals require greater personal space than non-violent individuals.

  3. Effects on emotion and behaviour: Crowding leads to increased physiological arousal and stress. Because of this it is not surprising to find increased incidence of high blood pressure and faster heart rate in crowded situations and increased levels of physical illness. So anger and aggression seem to be the most likely emotional responses. Some times crowding also leads to apathy, social withdrawal and learned helplessness.

5. Green House Effect

Human beings, for quite some time now, have been indulging in anti-environmental behaviours on a large scale. Because of this abuse of the environment, like producing waste, burning of fossil fuel (petrol, diesel etc.) deforestation, burning of coal, forest fires, the use of chlorofluorocarbons (CFC) for refrigeration, etc. global warming is taking place.

The gradual increase in temperature of earth’s atmosphere and oceans is being brought about partly as a result of various human activities. It has far reaching consequences on the ecology and environment. These include increase in storms and other weather extremes, melting of ice caps at the North and South Poles that has resulted in raising the sea levels. These effects have been observed in several parts of the world. The oceans are rising about one inch every five years. It has been observed that three of the islands of the Republic of Maldives are now under water.

The change in climate (global warming) is closely related to ‘greenhouse effect’. The effect is called ‘green house effect’ because in cold regions where sunlight is needed for developing plants, a glass house is made which they call - Greenhouse. The Greenhouse has a glass roof that lets in warming sunlight but prevents escape of warm air. In the same manner the four gases released into the atmosphere (carbon dioxide, methane, and CFC) trap the sun’s heat, that turns the earth into a vast "green house" i.e. not letting the heat to be released.

This increases the temperature of the atmosphere. The increase in the levels of the three gases began about the middle of the 18th century. If this trend continues, it is estimated that it will result in an average warming of the earth’s surface air temperature by about 3.5 degrees Fahrenheit by the year 2100.