Air pollution

Any undesirable change in the physical, chemical or biological characteristics of air causes air pollution. Such changes may be natural or manmade.
Air pollution causes degradation of air quality and natural atmospheric conditions. It is one of the biggest threats for the environment.

Air pollution and its control is a global issue demanding international cooperation.
The U.S. Environmental Protection Agency (EPA) is authorized by The Clean Air Act to protect public health by regulating the emissions of these harmful air pollutants.
The Natural Resources Defense Council (NRDC) has been a leading authority on this law since it was established in 1970.
Paris Agreement to fight against climate change could save about a million lives a year worldwide by 2050 through reductions in air pollution alone.
WHO and partners organized the first Global Conference on Air Pollution and Health in Geneva on 29 October – 1 November 2018. The aim of this conference was to raise awareness of this growing public health challenge and share information and tools on the health risks of air pollution and its interventions.

World Environment Day is held each year on June 5.
An air pollutant may be gas or particulate matter.  
Natural sources of air pollution are dust storms, forest fires, ash from smoking volcanoes, decay of organic matter and pollen grains floating in the air. Population explosion, deforestation, urbanisation and industrialisation are man made sources of air pollution.

The consequences of air pollution on the environment

Clouds, high temperatures, wind and rain transport and disperse the polluted air to very large distances from its point of origin.

• Air pollution prevents photosynthesis and it shows impact on the purification of the air we breathe.
• It causes greenhouse effect and global warming which leads to excessive heating of earth's atmosphere. This increased temperature causes melting of ice caps and glaciers, resulting in floods and rise in sea level. Rise in sea level leads to the submersion of low lying areas such as Mumbai, Chennai, Kolkata etc.
• Air pollution also causes depletion of the ozone layer due to which harmful ultraviolet radiations can reach the earth’s surface.
• Air pollution causes the formation of acid rain, atmospheric precipitation in the form of frost, snow or fog and smog. Acid rain affects the chemical nature of soil and freshwater, affecting food chains. Acid rain makes the soil acidic and damages crop plants, trees, and also buildings, monuments, statues and metal structures.
• Air pollution causes Eutrophication where a high amount of nitrogen present in some pollutants gets deposited on the surfaces of water bodies and causes the development of algae. This will adversely affect fish, plants and animal species.

The consequences of air pollution on human health

• Primarily, air pollution affects the human respiratory system causing difficulty in breathing and respiratory diseases such as bronchitis, asthma, lung cancer, tuberculosis and pneumonia. Suspended particulate matter in the lower atmosphere or troposphere causes and aggravates human respiratory illness like asthma, chronic bronchitis, etc.
• It also causes allergies, conjunctivitis, cardiovascular problems, lung or skin cancers and vision problems.
• Ultraviolet radiation reaching the earth due to the depletion of ozone layer causes skin cancer, damage to eyes and immune system.
• Carbon monoxide poisoning causes suffocation, cardiovascular problems and death.
• Nitrogen oxides cause reddish brown haze in traffic congested city air and cause heart and lung problems and may be carcinogenic.
• Lead pollution causes anaemia, brain damage, convulsions and death.
• Certain metals cause problems in the kidney, liver, circulatory system and nervous system.
• Fungicides cause nerve damage and death.
• Pesticides like DDT cause kidney disorders and problems of the brain and circulatory system.
• Smog can irritate the eyes and throat and also damage the lungs.
• Mold and allergens from trees, weeds, and grass cause runny nose, fever, itchy eyes, and other symptoms.
  

Precautions

• Air polluted areas such as busy roads, industrialized areas and residential neighbourhoods on winter nights should be avoided. Resident neighbourhoods emit pollutants into the air by operating wood stoves and fireplaces
• Before going out or engaging in outdoor activities, the air quality of the area has to be verified by air quality index and precautions to safeguard the health should be taken.
• If suffering from heart or respiratory problems, as a precaution, the medication should be kept along with and has to follow doctor’s instructions properly to keep the symptoms under control.
• Physically active persons should limit physical activity and reduce its intensity.
• Special attention should be paid outdoors to symptoms such as difficulty in breathing. If any difficulty occurs in breathing, staying indoors is preferred.
• Methods of transportation such as Public transport or Walk or bike (when air quality is good) that help reduce the amount of pollutants in the air are needed
• Use of fireplaces and wood stoves in the winter should be limited because such appliances will contribute to smog formation during the cold season.
• Proper attention to maintain indoor air quality is needed by avoiding indoor smoking, smoke from fireplaces and wood stoves, mold and other contaminants associated with excessive humidity, volatile organic compounds mainly formaldehyde, household products such as paints and varnishes, construction material, carbon monoxide emitted by some appliances during the combustion of wood, fuel, etc.
• To prevent mold growth, water infiltration has to be fixed.
• Healthy and environmentally friendly household products and materials should be opted.
• Windows should be kept open regularly and shut when outdoor air quality is poor particularly during periods of extreme cold.
• Central ventilation system (also known as an air exchanger), should be operated according to the instructions of manufacturers.
• The range hood should always be turned on while cooking.
• If the outdoor air quality is bad, it is better to stay inside with windows closed.