Environmental Health
Lecture -
Noise & Radiation
8
EFFECTS ON
HEALTH
Dr.Shahid Mahmood
Assistant Professor
Department of Community Medicine
FJMC Lahore

Acknowledgement
 Park K. Textbook of Preventive and
Social Medicine
 Maxcy- Rosenau-Last. Public health
and Preventive Medicine
o World Health Organization (WHO)
 Iliyas-Shah-Ansari . Public health
and Community Medicine
 www.google.com/images

Learning Objectives
At the end of this session, Students will
be able to :
1. Define Noise and sources of Noise in
our surroundings.
2. Describe the sources of radiation, its
types and associated health hazards.
3. Explain the methods to prevent and
control the unhealthy effect from Noise
and Radiation

Sound is the sequence of pressure waves produced
by oscillations, propagated through Medium (Solids,
gas, liquids)
Wavelength

20th Century = CENTURY OF NOISE Noise ‘Definition’ Stress factor
Wrong Sound
In Wrong Place
At Wrong Time
Unwanted Sound??
Subjective ??

Noise – Properties
Loudness / Intensity Frequency
 Depends on Amplitude of  Frequency is no. of
vibrations waves passing a point
per unit time
 Measured in decibels
Higher f= High sound
(dB)
 50 dB means that sound Measured in Hertz(Hz)
is 50 times more intense 1 Hz = 1 wave per
than lowest second
distinguishable (reference) Human ear can hear:
sound 20 Hz – 20,000 Hz
< 20 = Infra –audible
Upper tolerable limit isterm joining 20,000 and frequency =
Noise expressed in Psycho-acoustic
> loudness = ultrasonic

Sources of Noise in
Environment
 Automobile (Pressure Horns)
 Factories (Machines/ Vibrating
tools)
 Air crafts & trains
 Musical instruments
 Human voices (class room…?)
 Mega Phones use , Mobile
tones
 TV , radio , Loud speakers

Noisy spots (Noise Polluted
areas)
 Bus terminals
 Traffic congested
area
 Air ports
 Railway lines
 Area of festivity
 Music shows

Measuring Sound / Noise levels
Sound level meter measure the sound/noise on a
weighted curve called Curve A - Expressed as dB [A]
Sound level meters

Octave band Analyzer with computer program
High
Low pitch
pitch
Audiometer and its tracing

Usual Sound levels at various
places

Acceptable Noise level
(Standard)
Area Spot Sound Level (dBA)
25
Residential Bed room
Living room 40
35-45
Commercial Office
Conference 40-45
Restaurant 40-60
40-60
Industrial Workshop
Laboratory 40-50
35-40
Educational Class room
Library 30-40
20-35
Hospitals Wards

Noise Pollution
Auditory Effect
Auditory fatigue – 90 dB ; 4000 Hz (buzzing &
whistling in ears )
Deafness (hearing loss)
Temporary [ Sudden exposure; 24 hours; 4000-6000Hz ]
Permanent [ Chronic exposure >100dB; affect
internal ear, organ of corti; rupture of tympanic
membrane (160dB); usually Occupational;
Non-Auditory
1. Speech disturbance (traffic, stations) – SIL 12dB
2. Annoyance : Irritation , Short temperedness, impatience
3. Reduction in work efficiency – economic loss
4. Physiological changes : Sleeplessness, increase
pulse, BP, Breathing , sweating , nausea,

Principles of Noise Control
Sound abatement methods
(reducing sound generation and
transmission)
1. Sound Insulation : reducing
transmission by introducing barrier
– Thick glass , concrete material
2. Sound Absorption – tiles , forms
and fiber-glass
3. Vibration dumping - Application of
material of surface- wooden plateform

Noisy spots (Noise Polluted
areas)
 Bus terminals
 Traffic congested
area
 Air ports
 Railway lines
 Area of festivity
 Music shows

Prevention and Control
(Noise pollution)
1. Proper Town Planning :
 Separate industrial, residential and traffic zones
 Wide green belts between main roads and
residences
 Wide roads to accommodate traffic

2. Control of vehicles and
Pressure horns
 Heavy vehicles – Not
allowed on narrow
street –traffic jam
 Pressure horns
prohibited , drivers
educated
3. Using insulation
material in buildings
4. Reducing sound
generation at various
industrial activity
spots

Noise control Measures
3. Periodic monitoring- sound
levels both in industrial and
residential areas for
surveillance
4. Periodic examination of
workers in noisy working
conditions , rotating their jobs,
proving them protective
gadgets
5. Health education (community)

Radiation is a process in which energetic particles
or energetic waves travel through a medium or

Radiation types
Ionizing • Electromagnetic radiations
radiation • X-rays (15-20cm) ; gamma rays
(ability to (50cm)
penetrate • Corpuscular radiations
tissues & • Alpha particles (0.05mm) – more
deposit its harmful
energy ) • Beta Particles (0.06-4mm)
• Proton
Electromagnetic
Non-Ionizing  Ultraviolet radiations (UV)
radiation  Visible light
( longer Infrared radiation
wavelength and  microwave radiation
low energy)  radio-frequency radiation

Measuring radiation
Radioactivity Unit
No. of nuclear disintegration per unit time
of radioactive material
Unit of radioactive activity = Becquerel
(Bq)
1 Bq = 1 disintegration per second
Radiation Potency (strength of radiation)
1. Roentgen – unit of exposure
2. Rad – Unit of absorbed dose
3. Rem – Unit measuring Potential to health
A new International system(SI) of unit have now
replaced Roentgen= Coulomb ; Rad = Gray ;
Rem = Sievert
Dose equivalent (Sievert ) ‘ Sv’ = D (absorbed dose- Gy) x Q (quality factor)
[ Value of Q factor for X-rays = 1 & Particles = 20 ]

Natural background radiation

Sources of Radiation
exposure
Natural Man- Made
Sources
Cosmic rays Medical & dental
X-rays , Radio-isotopes
Environmental Occupational Exposure
Atmospheric (Radium / uranium )
Terrestrial
Internal Nuclear accidents
Potssium -40 (Chernobyl)
Carbon-14 Exposure for many years
Total natural radiation per TV , computer, Mobile,
year exposure = 0.1 Luminous markers,
radioactive dial watches

Biological Effects of ionizing
radiation
Radiation
sickness
Immediate
Acute radiation
syndrome
Somatic
( Affect the Leukemia
individual
exposed)
Carcinogenesis
Biological effects Delayed
Fetal
development
abnormalities
Genetic
Chromosomes Shortening of
( Affect next mutations life
generation)

E Radiation Protection- Radiation
d Hygiene
u 1. Natural radiation of 0.1 rad pose no hazard
c 2. Permissible dose for man-made is 5 rad per
a X-ray department hygiene
year.
t
1. Unnecessary x-rays should be avoided (one
i
short = 4 rad), especially children /pregnant
o
women
n
2. Proper surveillance of X-rays plant ,
measurement of radiation in that area and
surrounding
3. Protection of workers using lead shield,
apron
4. Workers should wear film badge or
dosimeter showing accumulated exposure

International agencies working for
Radiation Protection
 International Commission on
Radiological Protection (ICRP)
 International Atomic energy
Agency(IAEA)
 World health Organization (WHO )
Peaceful use of Atomic energy
Develop standards and code of
practice
Periodic inspection of nuclear sites
Agreement on reducing nuclear
weapons