Question

The PAN (peroxyacetyl nitrate) is an important constituent of photochemical smog, however, it is a
A. Corollary pollutant
B. Primary pollutant
C. Natural pollutant
D. Secondary pollutant

Answer 1

Hint: The full form of PAN is peroxyl acyl nitrates. The PANs are said to be powerful respiratory, phytotoxins, eye irritants, and bacterial mutagens. It is also because PANs dissolve more voluntarily in water than ozone. The PANs have the ability to detain the growth of the plant in both pitches and closed ecosystems. It is said that the electron system is inhabited by PANs, and it can damage the chloroplast. In turn, it can spoil all the enzyme systems which control cellular metabolism. However, we can say that PANs are the carrier for oxides of nitrogen into a rural area and causes the formation of ozone in the global troposphere.

Complete answer: PAN is a vital element among the photochemical smog, and these are secondary pollutants. PAN is formed by the reaction of hydrocarbons and nitrogen oxides under the presence of light.
These pollutants are not emitted directly. Primary pollutants photochemically produce secondary pollutants. And these are known as photochemical oxidants.
The Peroxyl acyl nitrates or PAN are formed by the mixture of Oxygen, nitrogen oxides, and ketone bodies. it is a major constituent of photochemical smog. Corollary pollutant is living substances that originate in places where its action is shown.
Natural pollutants are created by the material of natural origin such as sea salt particles, volcanic dust, photochemically produced ozone, etc. one can define the Primary pollutants as the pollutants, which are directly emitted from a source.
Hence, the correct answer is option D.

Additional Information:
Secondary pollutants are not emitted directly in the atmosphere but are formed from other pollutants by chemical reactions in the atmosphere. PAN affects plants and causes symptom syndrome, such as chlorosis, leaf drop, and collapse leaf. PANs are toxic, as well as irritating. PAN is a more stable oxidant than ozone.

Note:
PAN is a peroxy acyl nitrate.PANs are powerful respiratory, phytotoxins, eye irritants, and bacterial mutagens. As we already know, PAN is an important component of photochemical smog and is a secondary pollutant. These pollutants are not emitted directly. Primary pollutants photochemically produce secondary pollutants. And these are known as photochemical oxidants.PAN is formed by the reaction of hydrocarbons and nitrogen oxides under the presence of light. PAN inhibits the electron system, damages chloroplast, and spoils enzyme systems controlling cellular metabolism.