E-42 Environmental Chemistry

1. E-42 Environmental Chemistry

2. About this “E”… In the following slides, you will learn about how chemical elements and compounds are involved in the following environmental issues: • On the Ground: • Heavy Metal Poisoning • Radon (Rn) • In the Air: • Air Pollution/Smog • Acid Rain • The Greenhouse Effect/Global Warming • Ground Level Ozone/Ozone Hole • Solutions: • Recycling • Alternative Energy

3. Heavy Metal Poisoning What Are Heavy Metals? …Heavy metals are toxic metals found in the transition metals section of the Periodic Table (See the examples below.). The Effects of Heavy Metals on People …general body toxicity, metabolic problems, learning and memory problems, permanent brain damage, and, even, death!!! Examples of Heavy Metals: • Lead (Pb) • Cadmium (Cd) • Mercury (Hg) • Chromium (Cr) Mad as a Hatter? …In Alice and Wonderland the Mad Hatter was based on the Victorian hat makers who went “crazy” from long term exposure to the mercury used to soften beaver fur for hats. How You Can Protect Your Family From Heavy Metal Poisoning …Check your home for lead based paint and professionally remove or repair cracked paint and paint chips; Do not purchase or use mercury thermometers or other mercury instruments; and gather all items containing heavy metals and take them to a hazardous waste facility. Lead (Pb) Mercury (Hg)

4. Radon (Rn) Where its found …in the granite bedrock under much of the United States. The Effects of Radon on People …radon combines with atmospheric dust and then sticks to lung tissue where it is believed to play a significant role in causing lung cancers. An Invisible Killer …radon is a colorless, odorless gas. How You Can Protect Your Family From Radon Poisoning? …Have your home tested for radon. If it is discovered, install the appropriate ventilation systems.

5. The Chemical Composition of the Atmosphere Most Abundant Elements • Nitrogen (N) • Oxygen (O2) • Argon (Ar) Most Abundant Compounds • (More than one element) • Carbon dioxide (CO2) • Water Vapor (H2O) Important note: The composition of air is usually given for dry air because water vapor content in air varies greatly from place to place and by season (Air can range from less than 1% to more than 4% water vapor.).

6. Air Pollution … AKA Smog • Air pollution– harmful substances that get into the air (ex. carbon monoxide (CO),carbon dioxide (CO2), sulfur dioxide (SO2), nitrogen oxides (NO2, N2O4), hydrocarbons(CnH2n+2), lead (Pb), and mercury (Hg)). The burning of fossil fuels and automobile exhaust are major sources of air pollution. Air pollution can cause asthma, allergies, lung disease, and even death in humans! • Temperature inversion– a dangerous condition in which a layer of colder, polluted air is trapped below a layer of warm air and cannot disperse. This happens in California where polluted Pacific air becomes trapped near the surface causing smog (NO2).

7. Rain Gone Bad … Acid Rain!!! All rain is somewhat naturally acidic, but when chemicals from car and factory exhaust (CO, CO2, NO, NO2, N2O4 SO, SO2) combine with rainwater (H2O), they can produce HIGHLY acidic rains (H2CO3) that damage buildings and monuments and kill plants and fish (ex. H2O + CO2 →H2CO3).

8. Layers of the Atmosphere 1 Did you know… 99% of the mass of the atmosphere is located within 32 km (20 miles) of the Earth’s surface!!! Mount Everest, the highest elevation above sea level, is only about 8.8 km high, keeping it in the bottom layer of the atmosphere. The Earth's atmosphere is composed of several layers: We live in the Troposphere where Global Warming/The Greenhouse Effect takes place and almost all weather occurs (ex. wind, clouds, fog, rain, hail, sleet, snow and storms). Above the Troposphere is the Stratosphere, which contains the Ozone Layer, which blocks out harmful UV rays. Commercial airliners (ex. a 747) usually fly in the troposphere,whereas supersonic jet airliners (ex. the Concorde) fly in the lower stratosphere.

9. Layers of the Atmosphere 2 Thermosphere • Lower region called ionosphere. • Upper region called exosphere. • Nitrogen and oxygen atoms absorb deadly gamma and X rays here, explaining the unexpected increase in temperature. Mesosphere • Coldest layer of the atmosphere. Stratosphere • The Ozone Layer absorbs harmful UV Rays here, explaining another unexpected increase in temperature. Troposphere • Greenhouse Gases trap infrared rays (heat) in here causing Global Warming. • All weather change occurs here. • Temperature within this layer decreases as altitude increases because there is an increase in distance from the warming effect of sunlight absorbed by the Earth’s surface.

10. The Electromagnetic Spectrum • Types of Waves in the Electromagnetic Spectrum (from highest to lowest energy): • Gamma Rays • X Rays • Ultraviolet • Visible light • Infrared • Microwaves • Radio waves • TV waves Important note:The shorter the wavelength, the more energetic the wavelength is and the more harmful the wave is to human tissue!!!

11. Infrared Radiation: Heat! When infrared rays pass through an object, you feel them as warmth or heat. • Infrared rays heat rocks, soil, water and other Earth materials on the ground. • These heated objects reradiate longer wavelengths of infrared radiation. These longer wavelengths of radiation are then trapped by the carbon dioxide and water vapor in the Earth’s atmosphere on their way back up into the sky.

12. Outgoing Radiation and The Greenhouse Effect • Greenhouse Effect – the process by which visible light and shorter waves of infrared radiation enter the Earth’s atmosphere from the Sun, strike the Earth’s surface, are reradiated as longer wavelengths of infrared radiation, and are then trapped by carbon dioxide (CO2) and water (H2O) vapor in the atmosphere. Do You like summer? This trapping of heat causes the Earth’s surface and troposphere (the bottom layer of the atmosphere) to be warmer than if there was no atmosphere at all.

13. The Greenhouse Effect: the Big Picture

14. The Global Warming: Many Factors Manmade (ex. the burning of hydrocarbon fossil fuels, CnH2n+2) and natural (ex. volcanic eruptions) releases of “Greenhouse gases” into the atmosphere may increase temperatures on the Earth over the next century, leading to the melting of glaciers; disruptions in weather patterns, climate zones, and habitats; increasingly severe storms; massive coastal flooding; and crop failures unless the Earth can compensate (by storing carbon dioxide in rocks and seashells and by encouraging the growth of more photosynthetic organisms).

15. UV Rays … Energetic and Harmful!!! Since they have relatively short, fairly energetic wavelengths, ultraviolet or UV rays are the harmful to humans … Ozone (O3) in the stratosphere absorbs most UV waves before they reach the Earth’s surface.

16. Ozone (O3): Important Substance in the Atmosphere • Ozone (O3) is a form of oxygen found in the stratosphere. • Before Earth had an ozone layer, all life lived under the oceans … NONE could live above them! • Ozone absorbs harmful ultraviolet radiation (UV rays) coming from the sun. • Ultraviolet radiation can cause severe burns, cancers, mutations, and even death! • Ozone can be destroyed by: CFC propellants in old aerosol spray cans, Freon coolant from refrigerants in old refrigerators and air conditioners, and the burning of supersonic aircraft fuel.

17. Ozone: a Little Chemistry O2 + light -> O + O (1) O + O2 -> O3 (2) Ozone is created when ultraviolet radiation (UV rays) from the Sun strikes and splits oxygen molecules (O2) to atomic oxygen (O). The atomic oxygen (O) quickly combines with further oxygen molecules to form ozone (O3): CFCs are chemicals that interfere in this ozone making process. It should be noted that ground level ozone, which is produced by hydrocarbons that react with sunlight, is a pollutant itself. Ground level ozone causes SERIOUS lung irritation!!!

18. Recycling • Biodegradable– things that can be broken down quickly in the natural environment (ex. egg shells, apple and potato peels, and string.) • Nonbiodegradable– things that remain in the environment for long periods of time unchanged (ex. plastic, glass, and steel.) • Recycling– saving and reusing materials (See examples below.). • Materials that can • be recycled: • Paper (organic compound) • Cardboard (organic compound) • Plastics (organic compounds) • Glass (based on SiO2) • Aluminum (Al) • Steel (an iron alloy)

19. All of the following can be recycled…

20. Alternative Energy Running Out of Gas? …Most experts agree that we will run out of fossil fuels in our lifetime, even if we don’t, alternative energy would free us from the rising cost of petroleum based fuels and the politics that accompany them… Sources of Alternative Energy: • Wind Power • Water Power • Hydrothermal Power • Solar Power

21. More On Wind Power …A Source We Can Use Here! Wind power is one of several potential sources of cleaner, alternative energy. At our latitude (approximately 40°N), wind power might be able to supply a substantial fraction of the energy we need to generate electricity. The Equator and 30 latitude contain the areas called the doldrums and the horse latitudes which contain unpredictable winds. As a result, wind turbines would not be a reliable alternate energy source for these areas. Mid American Energy is now collecting money to create wind farms to meet OUR energy needs here in the QCA!!!

22. The End!