Final answer:
During the daytime, the atmosphere is more active and the vapor disperses more, resulting in a lower concentration of vapor in the surrounding air.
Step-by-step explanation:
During the daytime, the atmosphere is more active and the vapor disperses more, resulting in a lower concentration of vapor in the surrounding air.
The area that reaches toxic levels will depend on the specific vapor being considered. For example, ground-level ozone (O3) is likely to reach unhealthy levels on hot sunny days in urban environments, while sulfuric acid droplets formed from sulfur dioxide (SO2) and water (H2O) can be found in a thick cloud layer in the upper troposphere.
It is important to note that different pollutants have different levels at which they become toxic.