AIR POLLUTION One of the formal definitions of air pollution i...

AIR POLLUTION One of the formal definitions of air pollution is as follows – ‘The presence in the atmosphere of one
or more contaminants in such quality and for such duration as is injurious, or tends to be injurious,
to human health or welfare, animal or plant life.’ It is the contamination of air by the discharge of
harmful substances. Air pollution can cause health problems and it can also damage the
environment and property. It has caused thinning of the protective ozone layer of the atmosphere,
which is leading to climate change.
Modernization and progress have led to air getting more and more polluted over the years.
Industries, vehicles, increase in the population, and urbanization are some of the major factors
responsible for air pollution. The following industries are among those that emit a great deal of
pollutants into the air: thermal power plants, cement, steel, refineries, petrol chemicals, and mines.
Air pollution results from a variety of causes, not all of which are within human control. Dust storms
in desert areas and smoke from forest fires and grass fires contribute to chemical and particulate
pollution of the air. The source of pollution may be in one country, but the impact of pollution may
be felt elsewhere. The discovery of pesticides in Antarctica, where they have never been used,
suggests the extent to which aerial transport can carry pollutants from one place to another.
Probably the most important natural source of air pollution is volcanic activity, which at times pours
great amounts of ash and toxic fumes into the atmosphere.
Listed below are the major air pollutants and their sources.
Carbon monoxide (CO) is a colourless, odourless gas that is produced by the incomplete burning
of carbon-based fuels including petrol, diesel, and wood. It is also produced from the combustion
of natural and synthetic products such as cigarettes. It lowers the amount of oxygen that enters
our blood . It can slow our reflexes and make us confused and sleepy.
Carbon dioxide (CO2) is the principle greenhouse gas emitted as a result of human activities
such as the burning of coal, oil, and natural gases.
Chloroflorocarbons (CFC) are gases that are released mainly from air-conditioning systems and
refrigeration. When released into the air, CFCs rise to the stratosphere, where they come in
contact with few other gases, which lead to a reduction of the ozone layer that protects the earth
from the harmful ultraviolet rays of the sun.
Lead is present in petrol, diesel, lead batteries, paints, hair dye products, etc. Lead affects
children in particular. It can cause nervous system damage and digestive problems and, in some
cases, cause cancer.
Ozone occurs naturally in the upper layers of the atmosphere. This important gas shields the earth
from the harmful ultraviolet rays of the sun. However, at the ground level, it is a pollutant with
highly toxic effects. Vehicles and industries are the major source of ground-level ozone emissions.
Ozone makes our eyes itch, burn, and water. It lowers our resistance to colds and pneumonia.
Nitrogen oxide (Nox) causes smog and acid rain. It is produced from burning fuels including
petrol, diesel, and coal. Nitrogen oxides can make children susceptible to respiratory diseases in
winters.

2- Segundo o texto, Qual das situações abaixo foi citada no texto sobre o monóxido de
carbono?
a. ( ) Afeta o sistema nervoso
b. ( ) Prejudica o sistema respiratório
c. ( ) Provoca câncer
d. ( ) Desregula o sistema hormonal
e. ( ) Diminui a quantidade de oxigênio do sangue

03- Segundo o contexto, a melhor interpretação para “Carbon dioxide” é:
a. ( ) Gás natural
b. ( ) Fumaça proveniente de queimadas
c. ( ) Poluição industrial
d. ( ) Gás carbônico
e. ( ) Gás emitido por veículos automotores