Which statement correctly describes the identity of ozone in photochemical smog?

Which statement correctly describes the identity of ozone in photochemical smog?

• A. Ozone is benign and not a pollutant
• B. Ozone is the most common photochemical oxidant and irritant
• C. Ozone originates from sulfur emissions
• D. Ozone is entirely sunlight dependent with no health effects

Answer: (B)

In photochemical smog, ozone functions as the most common photochemical oxidant and irritant. It is formed in the lower atmosphere when sunlight drives chemical reactions between nitrogen oxides and volatile organic compounds released from vehicles, industry, and other sources. This ozone is not emitted directly; it forms in the air and then can penetrate the respiratory system, causing irritation, coughing, chest discomfort, and it can worsen asthma. It is not benign, and it does have health effects, so the idea that it’s harmless is incorrect. It isn’t produced from sulfur emissions, which makes the option about sulfur origins incorrect. While sunlight fuels its formation, that doesn’t eliminate its health impacts, so the statement that it’s solely sunlight-dependent with no health effects is false.

In photochemical smog, ozone functions as the most common photochemical oxidant and irritant. It is formed in the lower atmosphere when sunlight drives chemical reactions between nitrogen oxides and volatile organic compounds released from vehicles, industry, and other sources. This ozone is not emitted directly; it forms in the air and then can penetrate the respiratory system, causing irritation, coughing, chest discomfort, and it can worsen asthma. It is not benign, and it does have health effects, so the idea that it’s harmless is incorrect. It isn’t produced from sulfur emissions, which makes the option about sulfur origins incorrect. While sunlight fuels its formation, that doesn’t eliminate its health impacts, so the statement that it’s solely sunlight-dependent with no health effects is false.