Question

Find the cause of the irritant red haze in the traffic and congested places :
(A) Oxides of N
(B) Oxides of S
(C) Oxides of C
(D) All of the above.

Answer 1

Hint: (1) By the term haze, we mean the slight concealment of the lower part of the atmosphere caused by fine suspended particles.
(2) Haze is one of the categories that fall under the classification of horizontal obscuration, others are fog, mist, dust, snow, sand, volcanic ash etc.

Complete step-by-step answer: The atmospheric phenomenon of haze occurs when smoke and dust particles get accumulated in relatively dry air. When the smoke and other pollutants in the atmosphere are blocked by the weather conditions, they concentrate and create a kind of cover in the lower part of the atmosphere. This low-hanging cover impairs visibility and can lead to respiratory health problems.
Sometimes in traffic and congested places, a red haze is seen which is highly irritant. It has been found that this red haze is due to the oxides of nitrogen. Nitrogen dioxide is a highly poisonous gas and is deep red in color. When nitrogen dioxide is mixed with aerosols, it causes a reddish brown color of haze in traffic and congested places. The major source of nitrogen oxides is the fuel released from automobiles like cars, trucks etc. It is mainly present in automobile exhaust. When it is released from automobiles into the atmosphere, it gets mixed up with oxygen present in the air to form nitrogen dioxide.
Thus, the correct option is (A).

Additional information: Other sources of haze are wildfires, industry and farming in dry weather. Haze can also be termed as the aerial version of Tyndall effect as haze is spectrally selective.

Note: Unlike fog and mist, haze is the suspension of extremely small, dry particles in the air, not water droplets.