Ozone exists nearer to the Earth's surface, as well: it shows up in samples of "smog- over heavily populated cities in warmer climates like Los Angeles, Mexico City, and Cairo. Its sunlight-filtering effect can be observed in those cities when smog appears like a brown or yellow cloud, giving those cities a perpetually overcast sky (Makhijani, 31). Fortunately, carbon monoxide reduction and pollution controls have reduced smog and ozone to a great extent in North America and Europe. But above the inhabited layer of the atmosphere, the ozone layer is depleted by the presence of nitrites and nitrates in stratospheric cloud formations. .
As previously stated, ozone filters damaging ultraviolet rays out of sunlight before it reaches the surface of the earth. Ultraviolet light affects humans adversely in two specific ways: by damaging the retina, and by altering skin cells so that they become cancerous. Skin cancer is the primary risk that individuals living under holes in the ozone face. Retinal damage can be incurred anywhere on Earth that is exposed to the sun, but looking directly or indirectly at the sun can be up to twenty times more damaging in areas with thin or patchy stratospheric ozone coverage (Nilsson, 132). Many contemporary sunglass manufacturers have opted for polarized or UV-deflecting coatings in order to protect customers' eyes from retinal damage caused by increased UV levels. And the threat of skin cancer is only one of many skin complaints that have been linked to excessive UV exposure. .
Dangers of Ozone Depletion.
Ultraviolet light consists of the "fastest-moving- photons: this refers to their periodic or wave-like speed rather than their objective speed, which, like all other wavelengths of light, is around 3x108 m/s. Their increased energy damages any living cells they come into contact with (Makhijani, 108). The human body has a system in place to protect somewhat against ultraviolet light, which involves the release of melanin and pigments into the epidermis.
