47. NCERT Exemplar XXIX

 

Air pollution is mostly caused by the burning of fossil fuels (coke, petroleum, and LPG gascoal, petroleum, and natural gascarbon, petroleum, and syn gas) in automobiles, industries, and thermal power plants.

(i). Base rainAcid rainIce rain: The harmful gases, i.e., oxides of sulphur and nitrogen emitted by the burning of fossil fuels, react with water in the atmosphere to form $H_2SO_4$ and $HNO_3$, respectively. Acid rain is formed when these acids react with rainwater and fall. Acid rain increases the acidity of the soil, lowering its fertility.

(ii). Carbon monoxide poisoningCarbon monosulfide poisoningCarbon dioxide poisoning: Carbon monoxide is produced by the incomplete burning of fossil fuels. It affects the central nervous system. When $CO$ present in large quantities in air, it can also lead to carbon monoxide poisoning, reduction in oxygen availability to body tissues, leading to suffocation and death.

(iii). Green houseGlobal warmingGlobal warning: The burning of fossil fuels releases large amounts of greenhouse gases into the atmosphere, including carbon dioxide, methane, and nitrogen oxides. These greenhouse gases trap the infra-red radiations reflected by the earth. This led to an increase in the earth’s temperature, which is termed global warming. This global warming further causes the melting of polar ice caps, eventually raising the sea level and flooding coastal regions.

(iv). SmogFoggSmoke: The burning of fossil fuels also increases the amount of suspended particles in the air. These suspended particles could be unburnt carbon particles or substances like hydrocarbons. Their presence in the air lowers the visibility of air, especially during cold weather. This is known as smog and causes allergies, heart diseases and cancer.