Human being experiences both nourishing and destructive effect of environment. It is clear from the human history that people have been threatened by flood, earthquake and other natural calamities. There are new threats for us from the environment due to technological growth and development. These threats are man-made. We have to find ways to cope up with these stressors. The environmental stressors that affect the human behaviour are mentioned below :
(1) Noise Pollution : There is considerable noise pollution due to industrial and technological advances. Noise means the sounds which are unnecessary, unwanted and having negative effect on people. It's effect is not pleasant. It creates disruption which is psychological in nature. The disruption created by noise has emotional aspect. If the noise is very disruptive, we may get excited. Thus, any sound which is unpleasant to the person is considered noise. For example - pop music or rock music could be noisy for many people.
Sound pollution has negative physiological and psychological effect on human being. Noise may cause high level of arousal, stress, disturbance in concentration,reduction in reading ability and performance. People living in the highly noisy atmosphere have to utilize extra physical and psychological energy. So they get tired soon. Sadness or unpredictability of sound is reason for unfavourable negative reactions. We should adopt more easily, regular, mild and predictable sound,like chirping of the birds in the morning which can reduce the negative effect of noise. We notice that people staying around airport or railway station sufferfrom memory loss, hearing loss, high blood pressure etc. due to disturbing heavy noise.
(2) Air Pollution : Pure air is more important for living beings. When the air is polluted, it is harmful for our health. Air pollution occurs due to smoke from factories and vehicles, smoke of burning coal and burning tobacco. Due to this, the poisonous gases like carbon monoxide, nitrous oxide, and sulphur dioxide enter our body through breathing and causes diseases of respiratory system, burning of skin, cancer etc.
(3) Pollution of Crowding : When a large number of people live in a limited space, it causes crowding. Studies indicate that due to crowding, there were incidents of sickness among animals. Studies conducted on human being regarding density affects the quality of individual behaviour as well as social behaviour. For example : When 7 to 8 people live in a 10' x 10' room, it affects on their interpersonal relations. They become more aggressive, less altruistic, less helping and regressive.
Crowding is a big problem. According to some researchers, the term crowding is used in reference to the feeling of crampedness. Some people do not consider crowding in terms of physical density. Therefore, it is necessary to use two different terms, when a large number of people are present in one place, that is density and due to very close contact the feeling of pushing and pummeling one another is known as crowding. Density refers to actual number of people per square foot, while crowding is the subjective feeling of being too close to one - another. In density, there is a feeling of common belongingness while in crowding, the feeling is too less.
Studies regarding crowding show that it has negative effect on task performance, personality and interpersonal relationship and physical and mental health of the person. The common effects of crowding are obstructions in goal achievement, undesirable interference.