This is the link to our video:
http://www.youtube.com/watch?v=o_vGstgQT4c
Question:
1.Discuss why is Ozone important in the Stratosphere layer.
2.Explain why people living in Australia have a higher chance of getting skin cancer.
By: Htoo(8),Qianhong(17),Jieling(18),Wang Yu(23)
Q1 .Importance of Ozone in the Stratosphere layer.
ReplyDeleteAbout 90% of the ozone in the Earth's atmosphere is found in the region called the stratosphere. Ozone forms a kind of layer in the stratosphere, where it is more concentrated than anywhere else. Ozone and oxygen molecules in the stratosphere absorb ultraviolet light from the Sun, providing a shield that prevents this radiation from passing to the Earth's surface. While both oxygen and ozone together absorb 95 to 99.9% of the Sun's ultraviolet radiation, only ozone effectively absorbs the most energetic ultraviolet light, known as UV-C and UV-B. This ultraviolet light can cause biological damage like skin cancer, tissue damage to eyes and plant tissue damage. The ozone layer
Q2. why people living in Australia have a higher chance of getting skin cancer.
Ultraviolet (UV) light
People who live in places with year-round, bright sunlight have a higher risk of skin cancer. The highest rate of skin cancer in the world is in Australia.
Sunlight is the main source of ultraviolet (UV) radiation, which can damage the genes in skin cells. UV light is thought to be the major risk factor for most skin cancers. Tanning lamps and booths are another source of UV radiation. People with high levels of exposure to UV light are at greater risk for skin cancer.
The amount of UV exposure depends on the strength of the light, how long the skin was exposed, and whether the skin was covered with clothing and sunscreen. Many studies show that being exposed to a lot of sun when you are young is an added risk factor.
-By Group 8 (Jing Jing, Yaling, Sarah, Bonnie)
Question 1)
ReplyDeleteOzone is critical for life in the stratosphere as it protects all life on Earth from the solar ultraviolet radiation, especially UV-B, a band of ultraviolet radiation with wavelengths from 280–320 nanometers produced by the sun. Other Ultraviolet radiation with wavelengths from 320–400 nanometers, UVA, is not absorbed, and it is much less dangerous to life when reaching the surface of the Earth. The ozone layer stretches around the entire globe of the Earth, filtering out the harmful ultraviolet radiation, like UVB, from the sun. Destruction of the ozone layer increases the amount of dangerous ultraviolet radiation that reaches the earth’s surface which can cause severe effects on human health (e.g. skin cancer and genetic mutations) and the environment (devastating effects on crops, terrestrial ecosystems, aquatic ecosystems, and biogeochemical cycles. (referring to the cycling of chemicals such as carbon and energy throughout the Earth system.)
Question 2)
The major cause of skin cancer is the over-exposure to ultraviolet (UV) radiation from the sun. Australia has one of the highest rates of skin cancer in the world, with two in three Australians developing some form of skin cancer before they reach the age of 70. Even with skin cancer being one of the most preventable cancers, each year, around 2,000 Australians die from skin cancer. Every additional decade of high sun exposure increases the risk of melanoma (the most dangerous form of skin cancer) Australia experiences some of the highest levels of UV radiation in the world as they are close to the equator and have a higher amount of clear blue-sky days than other countries further from the equator. The Earth's orbit also enables countries in the southern hemisphere (like Australia) closer to the sun in the summer than countries in the northern hemisphere during their summer. In addition, people with fairer skin are more likely to have a higher risk of skin cancer than people with naturally very dark brown or black skin due to the melanin in naturally very dark skin, which offers some protection against the harmful effects of UV radiation, lowering the risks of skin cancer.
~~Group 7- Ming Chung, Yee Jian, Ya Ning, Yan Chong
1) Ozone is important in the stratosphere as it helps to shield off the solar radiation reaching the earth's surface. Ozone is a sort of 'protective shield' that helps to reduce the amount of UV radiation reaching earth as well. Ozone thus plays an important role in helping to reduce such radiation from reaching the earth's surface which could potentially cause eye damage, genetic mutation and skin cancer. However, as the ozone is being destroyed due to the presents of CFCs, the ozone layer over some country is being depleted and have resulted in a 'hole' in the ozone layer. This has resulted in more solar and UV radiation reaching the earth's surface, and could potentially lead to more people suffering from the effects of it.
ReplyDelete2) There are many characteristics of the Australian population that put them at high risk for skin cancer. The continent is mostly populated by light-skinned people of northern European descent, the group at highest risk for skin cancer worldwide. This population is living in a tropical to sub-tropical region of the world with very high ambient levels of ultraviolet radiation. The popularity of sports and other out-door recreational activities in Australia brings people out into the sun frequently, especially during childhood. Physical ideals such as the “healthy tan” are popular in Australia, as in the US. Sun exposure is believed to help many conditions such as rashes and neonatal jaundice. Some people still intentionally sun infants, thinking it will help them develop a protective tan or cause the skin to adapt to life in the tropics. Intentional sun exposure, especially for children, greatly increases the risk for skin cancer later in life.
By: Group 4 (Duncan, Zhi Yuan, Joe, Ngai Chun)