Atmosphere

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Sun and air are common in the sense that they are both essential for life on Earth, and they are both widely available and accessible. 

Sunlight is essential for human health and well-being. It is the primary source of vitamin D which is necessary for key biological processes to take place in the body, such as supporting healthy bones, managing calcium levels, reducing inflammation, and supporting the immune system and glucose metabolism. 

Sunlight also has many other health benefits, such as reducing the risk of type 1 diabetes, multiple sclerosis, and several forms of cancer, including colon, breast, and prostate cancer and non-Hodgkin lymphoma.

Sunlight is also essential for the growth of plants and crops, which are necessary for the survival of animals, including humans. 

The best time for sun exposure depends not only on the time of day, but also on the time of year, geographical coordinates, weather conditions as well as skin particularities such as content of melanin, sunscreen or sunblock use, clothing choice etc.

Air is a mixture of different gases, primarily nitrogen and oxygen, that is essential for life on Earth. Humans and animals need air to breathe and live, as it provides oxygen for respiration, which is the process of converting food into energy. Plants also need air to survive, as they use carbon dioxide from the air to produce food through photosynthesis. Air also helps regulate the Earth’s temperature and protects us from harmful radiation from the sun.

Air quality can have a significant impact on our health. Breathing in polluted air can cause inflammation, oxidative stress, immunosuppression, and mutagenicity in cells throughout our body, leading to diseases such as stroke, lung cancer, and heart disease. Long-term exposure to air pollution can also cause damage to the nerves, brain, kidneys, liver, and other organs. Children, the elderly, and people with pre-existing health conditions are particularly vulnerable to the effects of air pollution.