Tag: environmental pollution and industries

A major threat to Taj Mahal is from Mathura oil refinery due to polluting gases like sulphur dioxide, hydrogen sulphide and nitrogen oxides.  When moisture gets accumulated in polluted environment, the oxides of sulfur, carbon and nitrogen from weak sulfuric, carbonic and nitric acids which are corrosive of stone, metals, paints and textiles.  Many priceless works of art have suffered more damage in the last 20 years due to increased sulfur-dioxide in the atmosphere.

Leaves are directly exposed to air pollutants and effects of air pollution are first seen on leaves. Deposition of particulate matter hampers gaseous exchange and deposition of soot interfere with the capture of sunlight. Sulphur dioxide causes the destruction of chlorophyll and necrosis. Nitrogen oxides cause defoliation, necrosis, dieback and death of plants. Other than this, acid rain damages plant by a direct effect on foliage and growing points by chlorosis, necrosis, defoliation and dieback.

A thermal inversion takes place when a layer of warm air settles over a layer of cooler air that lies just above the ground. The warm air holds down the cool air and prevents pollutants from rising and scattering.

Inhalation of SO$ _2$ irritates the nose, throat, and airways to cause coughing, wheezing, shortness of breath, or a tight feeling around the chest. The effects of sulphur dioxide are felt just after 10-15 min of inhalation.

The Mathura Refinery situated close to the Taj Mahal is a threat to the marble of the Taj Mahal because the Refinery releases the air pollutants in the form of oxides of sulphur, oxides of nitrogen and oxides of carbon. These oxides then react with water and precipiate in the form of nitric acid and sulphuric acid called acid rains. Acid rains have resulted in the corrosion of the marble, making it to appear yellow. Hence, the correct answer is 'Air Pollutants from Mathura Refinery'.

Air pollution is responsible for various pulmonary or respiratory diseases like asthma, emphysema, bronchitis etc. 

In a thermal inversion, the cold air holds up the pollutants and prevents it from rising and scattering.

The heat island is a phenomenon where heat can no longer escape. The high temperature in urban areas as compared to rural areas can be called heat island effect. With the loss of vegetation and land surface in urban areas, heat gets trapped between buildings and dense areas which cause a warming effect. The air pollution due to greenhouse gases is responsible for this. Bigger cities have large heat island effects, the waste heat from energy use, seasonal changes, local weather also contribute to heat islands.

• Classical smog, also known as London smog or Sulphurous smog, is formed when there is high concentration of sulphur dioxide and particulate matter produced due to combustion of fuels. It occurs in cold and humid climate and has reducing nature.
• Photochemical smog, also known as Los Angeles smog, is formed when sunlight acts on the oxides of nitrogen and hydrocarbons produced from factories or by automobiles. It occurs in warm and dry climate and has oxidising nature.