Water pollution:
- The introduction of any type of foreign materials into natural water to reduce the biodiversity of aquatic life may be regarded as water pollution.
- Water pollution is caused due to run off of wastes from kitchen, industries, and mines; agricultural wastes and pesticides; radioactive substances, and sewage.
Factors that contribute to water pollution can be categorized into two different groups
a) Point sources
b) Non-point sources
Point sources are the easiest to identify and control whereas non point sources are ambiguously defined and harder to control. Some point sources of water pollution include
a) Waste products from factories
b) Waste from sewage system
c) Waste from power plants
d) Waste from underground coalmines
e) Waste from oil wells
The term non-point source encompasses a large range of sources such as:
- when rain or snow moves through the ground and picks up pollutants as it move towards a major body of water
- the runoff of fertilizers from farm animals and crop land
- air pollutants getting washed or deposited to earth
- storm water drainage from lawns, parking lots, and streets .
- Radiation pollution:
- This type of pollution is caused by radioactive substances (uranium, Beryllium, Tellurium) released in explosions of nuclear weapons, nuclear reaction leakage and leads to the pollution of seas, oceans, vegetation, including human beings.
- Malformation of body at birth, abnormality in organ development are some of the effects observed in the laboratory animals.
- Thermal pollution:
- Thermal pollution is caused by heat produced from various industries and atomic reactors.
- Waste heat not only cause pollution to air or water by changing the climate of the area, but also can cause damage to aquatic and terrestrial life.
- As the temperature of water increases into viscosity decreases, the vapor pressure increases, and solubility of gases in water decreases. These changes have important effects on aquatic life.
- Noise pollution:
- Noise is unwanted sound that also pollute the environment.
- The sources of noise pollution are industrial machines, factories, mills, aircrafts, automobiles, electronic horns, and loudspeakers.
- Noise pollution causes hearing loss, produces annoyance, and psychological effects in human beings.
- Noise pollution also cause physiological effects including dilation of the pupil, puling of skin, tensing voluntary muscles, diminishing of gastric secretions, etc.