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The Poisonous Breath
Dr. Dhiraj Nanda
Everybody
be prepared for a wonderful but oxygen-less 22nd century
when sky will not look blue; atmosphere will be hazy to
gaze through; the beautiful and innocent faces in
streets, markets, parks will be covered with pollution
masks. The children of 21st century will colour the sky
in grey colour in their drawing books because the clear
blue sky of today will visible in grey colour to them.
They will hear about stars and moon with great amusement
from their parents and will try hard to see stars in sky
which will remain hidden from their view behind the
atmosphere filled with smoke and haze. This description
may be a reality if air pollution is not controlled.
Air pollution in most of cities of India has increased
tremendously over last few years. In fact, in most of
the twenty three cities with million-plus populations,
air-pollution levels exceed World Health Organisation
recommended health standards .According to Brandon and
Hommann 40,000 people die prematurely in India due to
air pollution in 36 cities of India. This figure for
Delhi is 7,500.
Adverse effects of air pollution on human health
Air pollution has its adverse effect on almost every
part and system of human body. These vary with respect
to following factors:
1. Nature of the pollutant;
2. Concentration of the pollutant;
3. Duration of exposure;
4. State of health of the patient; and
5. Age of the patient.
Generally, the susceptibility to the effects of the air
pollutants is greater among the infants, young children,
and the elderly. It is also greater among those who
suffer from chronic diseases of heart and lungs. Another
important point to note is that effect of air
pollution on human health is worst during winters. Some
important effects of air pollution on health are as
follows:
A) General effects:
1. Increased susceptibility to infections;
2. Growth retardation;
3. Increased incidence of cancer;
4. Overall increase in mortality and morbidity rates;
etc.
B) Effects on mental sphere:
1. Confusion;
2. Anxiety
3. Restlessness;
4. Inability to take quick decisions; etc.
C) Effects on head and face:
1. Repeated headaches;
2. Discolouration of hairs;
3. Eye irritation;
4. Reduced visibility;
5. Nose and throat irritation;
6. Odour nuisance;
7. Acid taste in mouth;
8. Flourosis and mottling of teeth;
9. Cosmetic effects; etc
D) Effects on respiratory system:
1. Naso-laryngo-tracheo-bronchial irritation;
2. Increased incidence of asthma and other C.O.P.Ds.
3. Increased incidence of carcinoma of lungs; etc
E) Effects on Cardio-vascular systems:
1. Increase in blood pressure, increased incidence of
hypertension;
2. Increased incidence of heart attacks; etc.
F) Other effects:
1. Infertlity;
2. Adverse effects on skin;
3. Occupational health hazards; etc
Some important adverse effects of specific pollutants
on human health are given below:
A) HYDROCARBONS
Hydrocarbons form an important constituent of pollutants
released from every kind of fuel. Effects of
hydrocarbons on human health include:
1. Irritation, redness and watering of eyes;
2. Irritation of respiratory mucosa, coughing;
3. Drowziness, etc.
Aldehydes
Some aldehydes are suspected to be potential
carcinogenic. Aldehydes are absorbed by respiratory &
gastrointestinal tract, and have a wide range of adverse
effects on health. Some of these are:
1. Eye irritation;
2. Irritation and inflammation of nasal and respiratory
mucosa;
3. Cough;
4. Nausea;
5. Skin allergy, etc.
Benzene
Significant percentage of benzene inhaled is absorbed in
fat tissues as it has high liposolubility.Adverse
effects of benzene on human health include:
1.Lung and blood cancer(benzene is a group I
carcinogenic agent);
2.Inflammation of respiratory tract;
3.Cough,haemoptysis(benzene causes lung haemmorhage);
4.Damage to central nervous system;
5.Sudden exposure to high levels may be fatal.
Lead
Lead is absorbed in greater proportion by children in
comparison to adults. Lung deposition rate of lead in
children is up to 2.7 times more than adults. Harmful
effects of lead include:
1. Inorganic lead causes damage to gastrointestinal
tract, liver, kidneys.
2. Abnormalities in fertility and pregnancy;
3. Defective mental development in children;
4. Blood levels of 80 to 100 microgrammes of lead per
decilitre may result in central nervous system defects
and behavioural defects.
Oxides of carbon
Carbon monoxide has strong affinity for combining with
haemoglobin and form caboxyhaeamoglobin, thus reducing
the overall oxygen carrying capacity of the blood.
Harmful effects of carbon monoxide are:
1. Listlessness;
2. Diziness;
3. Headache;
4. Nausea;
5. Reduced mental activity and mental alertness;
6. Its effect on central nervous system affects
perception and reflexes;
7. Carbon monoxide is also responsible for increased
incidence of heart attacks and high mortality from
cardiovascular causes. Chronic heart patients seem to be
more sensitive to carbon monoxide.
Some effects of carbon monoxide at different levels
are:
1. At 30 ppm (up to 12 hours)-Elevated carbon in
haemoglobin, reduced oxygen carrying capacity;
2. At 50 ppm (for 90 minutes)-Impaired interval
discrimination for non-smokers;
3. At 100 ppm (intermittently)-Impaired performance in
psychomotor test;
4. At more than 100 ppm (for 10 minutes)-Physiological
stress on patients with heart diseases.
Oxides of sulphur
Sulphur dioxide
Sulphur dioxide is an irritant gas which affects the
mucus membranes when inhaled. It is readily absorbed by
mucus membranes of respiratory tract. Children
(especially those under five), elderly, and patients of
lung and heart diseases are more sensitive to sulphur
dioxide. Exposure to high levels can cause laryngo-tracheal
and pulmonary edema. Some effects of sulphur dioxide at
different levels of concentration are:
1. At 0.037 to 0.092 ppm with smoke (chronic
exposure)-Increased respiratory symptoms and lung
diseases;
2. At 0.11 to 0.19 ppm with low SPM level (episodes of
several days duration)-Increased hospitalisation;
3. At 0.19 ppm with low SPM level (several
days)-increased deaths;
4. At 0.25 ppm with particulates (3-4 days)-Increased
illness for elderly;
5. At 0.25 ppm with smoke (3-4 days)-Increased deaths.
Sulphur trioxide
Sulphur trioxide is a very strong irritant, much
stronger than sulphur dioxide, causing severe broncho-spasms
at relatively low levels of concentrations.
Oxides of nitrogen
Of seven oxides of nitrogen, only two affect human
health. These are nitrogen oxide and nitric oxide.
Oxides of nitrogen cause irritation of alveoli with long
term effect of exposure leading to emphysema.
Nitrogen dioxide
Adverse effects of nitrogen dioxide are mainly
manifested in respiratory symptoms.Repeated exposure to
nitrogen dioxide makes one more prone to catch viral
infections.Some effects of nitrogen dioxide at different
levels of concentration are:
1. At less than 0.05 ppm(long term)-Evidence of increase
in heart and lung disease in general population;
2. At 0.05 to 0.1 ppm \(chronic exposure)-Increase in
chronic bronchitis;
3. At 10 to 40 ppm (intermittent exposure)-May cause
chronic fibrosis and emphysema;
4. At 50 to 100 ppm (about 60 minutes)-May cause
bronchopneumonia;
5. At 150 ppm (5 to 8 minutes)-Potentially fatal.
Ozone
Ozone has irritant action affecting eyes and respiratory
tract. It is important to note that its effect is much
deeper in lungs than oxides of sulphur.
Smoke
Smoke causes irritation of eyes, nose, respiratory
tract, cough, hoarseness, laryngitis, etc. Smoke like
smog reduces visibility.
Suspended Particulate Matter
Irritation of respiratory tract and decrease in lung
function are main adverse effects of suspended
particulate matter. Some effects of SPM at different
levels of concentration in combination with sulphur
dioxide are:
1. At 100 to 200 microgramme cubic metre with 0.05 to
0.08 ppm of sulphur dioxide levels-Increase in incidence
of bronchitis;
2. At 300 microgramme per cubic metre with 0.21 ppm of
sulphur dioxide levels-Significant increase in
bronchitic symptoms;
3. At 1000 microgramme per cubic metre with 0.21 ppm
sulphur dioxide-increase in mortality from all causes
including respiratory and cardiac causes;
4. At 2000 microgramme per cubic metre with 0.4 ppm of
sulphur dioxide (exposure for several days)-Increase in
deaths due to bronchitis.
Smog
Smog causes eye irritation and reduction in visibility.
Prolonged exposure may result in high mortality rate
especially in elderly and in those who have been
suffering from chronic bronchitis, asthma,
bronchopneumoia, heart disease etc.
Thus, from the above it is clear that depending upon the
adverse effects of pollutants on human health, all
pollutants can be divided into following three groups:
1. Pollutants having irritant effect like oxides of
nitrogen and sulphur, ozone etc.;
2. Pollutants having toxic effects on health like carbon
monoxide and lead etc.;
3. Pollutants having carcinogenic effect like aldehydes,
benzene, etc.
Author would like to end this article by reminding that
an average man breathes 22,000 times a day and takes in
about 16 kgs of air each day. Polluted air has not only
life supporting properties but also life damaging
properties. With increase in pollution levels life
damaging properties will out weigh its life supporting
properties. Author would like to ask everyone following
question.
"Would you like to give your young ones (including
those yet to be born) a city in inheritance in which
polluted air goes in with the first breath they take? A
city in which first breath makes them sick instead of
making them healthy, a city in which our children and
coming generations would not get a breath of fresh air,
would you like your children and the coming generations
to perpetually suffer ? "
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