What are the harmful effects of photochemical smog and how can they be controlled?

Explanation

Harmful Effects of Photochemical Smog.
The main constituents of photochemical smog are:
ozone, oxides of nitrogen, actolein, formaldehyde and peroxyacetylnitrate (PAN). These are responsible for the harmful effects. A few out of these are listed.
(i) Ozone and nitric oxide cause irritation in nose as well as in throat. Throat. Their high concentration usually causes headache and chest pain.
(ii) The gases which constitute photochemical smog, usually cause dryness of throat, cough and are responsible for breathing problems.
(iii) Photochemical smog causes substantial damage to plant life.
(iv) It also results in corrosion of metals, building materials, rubber and painted surface surface etc.
How to control Photochemical Smog
Following measures can check the pollution caused by photochemical smog to some extent.
(i) Use of catalytic converters in the engines of automobiles will check the release of both `NO_(2)` and certain hydrocarbons known as primary precursors. This will automatically check the formation of secondary precursors such as ozone and PAN which are harmful.
(ii) Certain plants like pinus, pyrus, vitis quercus etc. are capable of causing the metabolism of the oxides of nitrogen which are quite harmful. Their plantation will definitely help in checking the spread of these gases in the atmosphere.