NOISE POLLUTION & THERMAL POLLUTION SNS COLLEGE OF ENGINEERING NOISE POLLUTION & THERMAL POLLUTION

NOISE POLLUTION Defined as unwanted sounds that unreasonably (a kind of harsh, loud and confused sound), intruding into our daily activities The most significant attributes of noise are: Its loudness Duration The unit of noise is decibel. Human ear can tolerate noise up to 120 decibels.

Sources of NOISE POLLUTION Road Traffic: Most prevalent and most damaging source Impact of road traffic noise depends on factors like: road location & design, and land use planning measures, building design, vehicle standards & driving behavior (ii) Air Traffic Noise from supersonic crafts are dangerous because of its intensity (iii) Railways: The level of noise associated with rail traffic is related to type of engine or rolling stock used, speed of the train, track type & condition, warning signals at crossings, whistles & horns, freight classification yards, & railroad construction & maintenance. (iv) Industry Product fabrication Product assembly Power generation Processing. (v) Construction: construction equipments. (vi) Consumer products: recreational, hobbies/workshop, household, music. (vii) Other sources: sirens, agricultural noise, noise from animals, humans & military

Measurement of Noise Noise intensity is measured in decibel (Db) units Decibel scale is logarithmic, Each 10 Db increase represents a 10 fold increase in noise intensity distance diminishes the effective decibel level reaching the ear. e.g. Moderate auto traffic at a distance of 30 m rates about 50 decibels, but for the same, for a driver with a car window open or a pedestrian on the sidewalk, same traffic rates about 70 decibels.

Effects of Noise At 45 decibels of noise, average person cannot sleep, At 85 decibels hearing damage, & at 120 decibels ear experiences pain. Lack of sleep, irritability, heartburn, indigestion, ulcers, high blood pressure, & possibly heart disease Hearing loss Non-auditory physiological effects Annoyance Communication interference

Noise Pollution Control Source path receiver concept: Can be controlled either by reducing the noise at the source or by preventing its transmission or by protecting the receiver At the source: lubrication of machines, tightening the loose units, reducing the eccentricity In the path: keeping the noisy machine covered, construction of noise barriers, sound-proofing of the building Receiver: No use of horns other than in emergency, vehicle engines and appliances in good Condition, purchase the least noisy air conditioner or vacuum cleaner/quieter appliances, rest areas away from noise, turn down volume of Stereos.

Thermal Pollution Thermal pollution is the process of heating up of water bodies through run off or discharge Decreases the solubility of oxygen, resulting in suffocation of plants and animals Human activities introducing thermal pollution: Industries and power plants Trees and tall vegetation providing shades are cut down Soil erosion by construction, removal of stream side vegetation, farming practices, overgrazing & recreation increases – reduction in green Thermal pollution can also occur through Earthquakes

Effects of Thermal Pollution Thermal shock Thermal enrichment: Heated water from power plant may be used to extend plant growing season, speed up growth of fish and other aquatic animal for commercial purpose

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