One of the most appreciated and portrayed images by human beings is the sunset. Surely you must have a memory, a photograph, a special memory that has the end of the day and the orange sky as the background. But have you ever noticed that on some days or places the end of the day can have different colors and be more beautiful than others?
Firstly we need to understand how the colors of our sky and sunset are formed. The indigo blue tone of the sky is the result of the decomposition of light into different wavelengths. Sunlight is white, it is the sum of all colors, but the human eye can only see a certain number of colors, which have different frequencies or wavelengths.
Blue is the predominant color in the sky, because it has a higher frequency than other colors, as the light passes through the atmosphere, the blue color spreads more and more. At the end of the day, and at sunrise too, the sky takes on red and orange tones, as these colors have a longer wavelength and are the last tones visible to the human eye.
The more layers or elements visible light needs to pass through, the more it will spread and the more intense its color will be. For this reason, sunsets have very vibrant colors, red light needs to pass through the entire atmosphere, clouds, dust and pollution to be the last spectrum of light visible to the human eye.
So, if the air is polluted with soot, particulate matter and other polluting gases, the sunlight will need to pass through more layers and consequently the red and orange colors will become more intense and cause a more beautiful sunset effect, but if the Pollution is excessive, which is common in large cities and capitals, particulate matter can obscure the sun and leave it with an opaque tone, having the opposite effect.
The main source of air pollution is soot and particulate matter from the burning of fossil fuels, mainly in the transport sector, fires and energy generation in industries.
According to the World Health Organization (WHO), air pollution is a risk factor for non-communicable diseases and is strongly associated with cases of vascular diseases, stroke, chronic obstructive pulmonary disease and a series of other allergies and system diseases. respiratory.
Despite giving the sun a more beautiful color at the end of the day, air pollution represents a danger to human health, in addition to intensifying the effects of climate change. To improve air quality, the WHO recommends that governments develop a system for managing and monitoring air quality in large cities, adopting objectives to reduce the number of pollutants, encouraging the use of renewable fuels and the use of more efficient engines. in transport.
References:
Does pollution really cause sunsets? | Natuurondernemer (essnature.com)
The science behind sunsets – eCycle
Does pollution really make the sky more beautiful? | Science and Health | G1 (globo.com)
