Final answer:
The main subject of the hook about pollution is Air Quality, especially in reference to its effects on human health, the environment, and economic aspects like the Sustainable Development Goals and environmental legislation.
Step-by-step explanation:
The main subject of the provided hook about pollution relates to Air Quality. This is evident from multiple references to air pollution and its effects on human health and the environment.
Pollution's impact on air quality is highlighted by issues such as the distribution of pollutants in outdoor and indoor environments, the significance of the Air Quality Index (AQI) for public health, and the broader implications for global health and environmental sustainability.
Moreover, pollution is identified as not only an ecological and health issue but also an economic one, with references to the global Sustainable Development Goals and environmental legislation such as the Clean Water Act and the Paris Agreement, which seek to address these complex concerns.
The main subject of the hook about pollution is Air Quality, especially in reference to its effects on human health, the environment, and economic aspects like the Sustainable Development Goals and environmental legislation.