ENVIRONMENTAL RISKS

NOISE POLLUTION:
How can noise harm you?

Noise-induced hearing loss may occur through occupational noise exposure or through
exposurre to moderm urban noise. It is a gradual process progressing over a period of years, 
withyou any external signs at the outset. It causes comulative and finally irreversible damage in 
the middle and inner ear. After exposing the ear to sound above 110 dB or so for a few 
minutes, audiometry will show a temporary hearing loss, and after sufficient exposure time this 
becomes permanent.

WATER POLLUTION:

Water pollution is the contamination of water bodies (e.g. lakes, rivers, oceans, aquifers and groundwater). Water pollution occurs when pollutants are discharged directly or indirectly into water bodies without adequate treatment to remove harmful compounds.

Water pollution affects plants and organisms living in these bodies of water. In almost all cases the effect is damaging not only to individual species and populations, but also to the natural biological communities.Water pollution is a major global problem which requires ongoing evaluation and revision of water resource policy at all levels (international down to individual aquifers and wells).

Water is typically referred to as polluted when it is impaired by anthropogenic contaminants and either does not support a human use, such as drinking water, and/or undergoes a marked shift in its ability to support its constituent biotic communities, such as fish. Natural phenomena such as volcanoes, algae blooms, storms, and earthquakes also cause major changes in water quality and the ecological status of water.

AIR POLLUTION 

• Acid rain :Acid rain comes from industrial countries. But the wind carries it and a lot of it falls on their neighbours. 
• The greenhouse effect: industrial countries also cause the 'greenhouse effect'. This gas works like the glass walls of a greenhouse. It lets in the sun, but it doesn't let out the heat. So the Earth gets hotter and hotter. 
• Pesticides The pesticide chemicals get into the 'food chain'. Insects eat the pesticide. Birds eat the insects. Big birds eat little birds. At the top of the food chain you find birds like the Peregrine Falcon. Fifty years ago they were common. But more and more of the pesticide DDT got into their blood. Their eggs became weak, and broke. Now the Peregrine Falcon is quite rare.