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

2. 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.

3. 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

4. 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.

5. 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

6. 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.

7. 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

8. 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

9. THANK YOU