What causes photochemical haze?

• A. Water vapor and carbon dioxide
• B. Nitrogen dioxide and stagnant air
• C. Volatile organic compounds and sunlight
• D. Methane and particulate matter

Answer: (B)

Photochemical haze is primarily caused by the interaction of volatile organic compounds (VOCs) and sunlight. When VOCs, which are often released from sources such as vehicle emissions, industrial processes, and even household products, enter the atmosphere, they react under the influence of sunlight. This reaction leads to the formation of ozone and other secondary pollutants, which contribute to the haze that can obscure visibility and impact air quality.

While nitrogen dioxide and stagnant air may play a role in air quality and contribute to various forms of atmospheric pollution, they do not specifically generate photochemical haze. The conditions that lead to photochemical haze are more directly related to VOCs and sunlight, making the correct option focused on these components in their interaction. Understanding the significance of each component helps clarify the mechanisms behind air pollution phenomena like photochemical haze.