Natural sources, such as forest fires, are not considered primary sources of air pollution as they are not directly caused by human activities.

Smog is a type of air pollution that is characterized by the presence of high levels of ozone, which is formed through chemical reactions between other pollutants in the presence of sunlight.

Acid rain is caused primarily by the release of sulfur dioxide and nitrogen oxides into the atmosphere, which react with water vapor to form sulfuric acid and nitric acid.

Emission control refers to the methods and technologies used to reduce the release of pollutants into the atmosphere.

Recycling is a waste management technique that involves reusing or processing discarded materials, rather than disposing of them as waste. It is not a direct method of emission control.

Air quality monitoring serves multiple purposes, including assessing compliance with standards, providing early warnings, and tracking long-term trends.

The AQI typically has six categories: Good, Moderate, Unhealthy for sensitive groups, Unhealthy, Very unhealthy, and Hazardous.

Public awareness and education campaigns aim to achieve multiple goals, including informing the public, promoting individual actions, and encouraging support for policies.

All of the options listed are common methods of public awareness and education about air pollution.

Government agencies play a multifaceted role in public awareness and education about air pollution, including developing campaigns, providing funding, and enforcing regulations.

While public apathy can be a challenge in some cases, it is not a common challenge in public awareness and education about air pollution.

Public participation plays a crucial role in air pollution control efforts by raising awareness, influencing policies, and promoting individual actions.

While recycling and composting are important environmental practices, they do not directly reduce air pollution.

International cooperation is crucial for addressing air pollution issues that transcend national boundaries and promoting global efforts to improve air quality.

Public awareness and education efforts aim to achieve multiple goals, including creating an informed public, promoting actions, and influencing policy decisions.