会议发言noisepollution噪音污染.pptVIP

PRESENTED BY: ZhangTing ; catalog;THE PROBLEM;In this type of contamination the humans are the main guilty because is due to them who exist noise harmful to health or welfare. Transportation vehicles are the worst offenders, with aircraft, railroad stock, trucks, buses, automobiles, and motorcycles all producing excessive noise. ;;In the narrowest sense, sounds are considered noise pollution if they adversely affect wildlife, human activity, or are capable of damaging physical structures on a regular, repeating basis.;Noise pollution can cause annoyance and aggression, hypertension, high stress levels, tinnitus, hearing loss, sleep disturbances, and other harmful effects. ;An impact of noise on animal life is the reduction of usable habitat that noisy areas may cause, which in the case of endangered species may be part of the path to extinction. ;Train, airplane automobile, motorcycle, and even entertainment noise can disturb wildlife habits, sleep disruption in humans and animals, hearing loss, heart disease and in severe cases even mental instability. ;How is noise measured? Noise or sound is measured in decibels (dB). The typical sound levels measured in the surrounding are as follows:* library - 35 dB * office - 60- 65 * normal traffic noise 70 - 80 dB * Airport (plane take off) - 120 dB ;There are a variety of strategies for mitigating roadway noise including: use of noise barriers, limitation of vehicle speeds, alteration of roadway surface texture, limitation of heavy vehicles, use of traffic controls that smooth vehicle flow to reduce braking and acceleration, and tire design. ;Aircraft noise can be reduced to some extent by design of quieter jet engines, which was pursued vigorously in the 1970s and 1980s. ;Another solution to this problem is to use electric, or hybrid-electric, automobile. Hybrid vehicles are so quite, in fact, that legislation is pending to actually make them louder. ;CONCLUSIONS;Noise pollution often persists beca