The stratosphere stretches 17-50 km above the earth’s surface. Its lower portion holds enough ozone gas (O3) to filter out 95% of the sun’s harmful UV rays.…
Loss of the Ozone layer • 1980s: found that chlorofluorocarbons (CFCs) depleting ozone layer o CFCs: “dream chemicals” used as coolant in air conditioners & fridges; propellant for aerosol spray cans; cleaners • Depletion of ozone layer damaging to wildlife and humans as more UV radiation reaches earth – more eye cataracts, sunburns, skin cancer • International treaty to ban CFCs – Montreal Protocol (1987) • Air pollution: presence of chemicals in the atmosphere in concentrations high enough to harm organisms, ecosystems and human-‐made materials o Natural sources: dust, wildfires, volcanic eruptions, plants o Human sources: burning of fossil fuels for power and industrial purposes (stationary) and cars (mobile sources) o Primary pollutants: emitted directly into troposphere from source (CO, HCs, SO2, NO2) o Secondary pollutants: reaction with primary pollutants (or component of air) to create a new pollutant (SO3, NO3, H2SO4, O3) Six Critical Air Pollutants • Carbon oxides • Nitrogen oxides and nitric acid • Sulfur dioxide and sulfuric acid • Particulate matter • Ozone • Volatile organic compounds 1) Carbon Oxides • Carbon monoxide (CO) • Colorless and odorless • Sources: combustion of carbon containing fuels – 50% from vehicle exhaust • Impacts: “driver fatigue”, heart disease, respiratory ailments • Levels fluctuate daily in urban areas – why?…
U.S Environmental Protection Agency (2014, March 12). The AQI Guide for Ozone [Graph]. Retrieved from…
The ozone layer is one of the most debated scientific subjects of the last decade. The growing problem of its depletion is being researched heavily all over the world, and methods are being researched to try and solve the problem. There have also been many debates concerning the relationship between the ozone layer and the onset of global warming. Before solutions can be developed, however, what the ozone layer actually does and what is causing it to be depleted must be understood.…
The formation of ozone occurs when hydrocarbons react with nitrogen oxides or carbon monoxides in the presence of heat and sunlight. The ozone layer protects our planet from ultraviolet rays. However, the ozone found at ground level causes respiratory problems. It also damages plants, reduces farm yields and affects plant health.…
4. CFCs (Chlorofluorocarbons) are inorganic man-made chemicals that have been in production for more than 50 years in Canada. They were thought to be sensational substances due to their stability, nonflammable characteristic, low in toxicity, and inexpensive. However, research on CFCs showed that they have long life spans allowing them to resist being washed away in rain. Through the aid of wind, CFCs rise up into the stratosphere and into the ozone layer where they decompose into chlorine and bromine, from the ultraviolet radiation. These two chemicals are responsible for damaging the ozone layer. Some atmospheric chlorine are caused by natural occurrences such as large fires and volcanic eruptions, yet most chlorine in the ozone layer is due to CFCs from man-made products such as refrigerators, aerosols, solvents and other household items. Studies show that for every one chlorine atom that is released into the ozone layer, 100000 ozone molecules are destroyed. According to the statistics recorded in 1979, the ozone layer has decreased every single decade nearly 4% to 6% in mid-latitudes and 10% to 12% in higher southern latitudes. This constant decrease has left the ozone layer permanently damaged. Even though production of CFCs has drastically decreased over the past couple of years, the ozone layer is unable replace itself.…
Ozone is produced when highly energetic solar radiation strikes molecules of oxygen O2 this causes them to split and produce O molecules. They then join with the remaining O2 and produce O3 molecules. These O3 molecules are what are known as Ozone. The "hole" in the ozone layer is not actually a hole it is a thinning of the ozone layer due to seasonal changes.…
References: Carlowicz, M.; Lindsey, R. Earth Observatory: The World We Avoided by Protecting the Ozone Layer, Earth Observatory, Goddard Space Flight Center, NASA, May 13, 2009: http://earthobservatory.nasa.gov/Features/WorldWithoutOzone/ page1.php [accessed Feb 2013]. Wiscombe, W. Aura: A Mission Dedicated to the Health of the Earth’s Atmosphere, Earth Observatory, Goddard Space Flight Center, NASA: http://earthobservatory.nasa.gov/ Features/Aura/ [accessed Feb 2013]. Allen, J. Chemicals in the Air: Latest Results from NASA’s Aura Satellite, ChemMatters, April 2008, 26 (2), pp 15–17. The ozone hole is shown in purple above the Antarctic on Sept. 16 in the years 1979, 1987, 2006, and 2011. The Sept. 16 date was chosen because it is the International Day for the Preservation of the Ozone Layer. The maps were produced with data collected by statellite istruments, including the Ozone Monitoring Instrument on the Aura Satellite. They show that the ozone hole kept increasing from 1979 to 2011, although to a lesser degree between 2006 and 2011. 14 ChemMatters, APRIL 2013 www.acs.org/chemmatters Mike Carlowicz is a science writer from Massachusetts and the author of three books on the sun, moon, and space weather. He is the editor of the NASA Earth Observatory.…
Ozone layer depletion decreases our atmosphere’s natural protection from the sun’s harmful ultraviolet (UV) rays. This Web page provides a quick overview of the major health problems linked to overexposure to UV radiation. Understanding these risks and taking a few sensible precautions will help you enjoy the sun while lowering your chances of sun-related health problems.…
The ozone layer protects us from ultraviolet B (UVB) radiation. UVB radiation damages human DNA, weakens the immune system, and is the primary cause of skin cancer (Donnatelle, 2010).…
• UVB causes skin damage and skin cancer. Ozone stops most UVB from reaching the earth's surface.…
The atmosphere is a complex dynamic natural gaseous system that is essential to support life on planet Earth. Stratospheric ozone depletion due to air pollution has long been recognized as a threat to human health as well as to the Earth's ecosystems.…
Ozone quality: Ozone is a gas that shields the earth’s and occurs naturally in the earth’s upper atmosphere. It protects the earth from harmful ultraviolet radiation. Without the Ozone layer there would be no life on earth! Chemicals such as…
"And God said, let there be light and there was light and then God saw the…
has a pleasant odor in concentrations of less than 2 ppm, and is irritating and…