EDUCATION (CBSE/UGC NET)

Detailed explanation-1: -Peroxyacyl nitrates are a family of compounds which result from photochemical reactions between contami-nants released to the atmosphere by combustion of organic fuels. Peroxyacetyl nitrate (PAN) is the most abundant member of this family and is responsible for serious plant injury in some polluted areas.

Detailed explanation-2: -Which of the following air pollutant effects plants the most? Explanation: Fluorine is the most dangerous air pollutant that affects plant, whereas SO2, PAN and HCl effects the leaf of the plant.

Detailed explanation-3: -PANs have many adverse effects in the human body such as reduced respiratory function (including emphysema and impaired breathing) and eye irritation. Human exposure to PANs typically occurs in urban centers where automobile and industrial emissions are high.

Detailed explanation-4: -Free radical reactions catalyzed by ultraviolet light from the sun oxidize unburned hydrocarbons to aldehydes, ketones, and dicarbonyl compounds, whose secondary reactions create peroxyacyl radicals, which combine with nitrogen dioxide to form peroxyacyl nitrates.

Detailed explanation-5: -The effects of pollution on plants include mottled foliage, “burning” at leaf tips or margins, twig dieback, stunted growth, premature leaf drop, delayed ma-turity, abortion or early drop of blossoms, and reduced yield or quality (Figure 1).