Other Env St Midterm 3 lecture notes

Other Env St Midterm 3 lecture notes - Lec 14 Lecture 14...

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Lec 14 12/03/2009 17:31:00 Lecture 14 Particulates- a major group of air pollutants, are small particles of dust (including  soot and asbestos fibers) released into the atmosphere by many natural processes and  human activities.  Modern farming and the burning of oil and coal add many particulates into  atmosphere Dust storms, fires, volcanic eruptions as well Asbestos- a term for several minerals that take the form of small, elongated  particles or fibers Industrial use- fire prevention, protection from overheating of materials,  insulation Excessive contact has led to asbestosis (a lung disease caused by inhalation)  and cancer Chrysolite (white) asbestos is greatly feared. Spent tons of money/resources to remove it from community, but no evidence  of its harm. Are we wasting our time? Need more evidence. Electromagnetic Fields Part of everyday urban life. o Electric motors, electric transmission lines for utilities, and electrical  appliances (toasters, blankets, and computers) all produce EMF’s Initially thought harmless. o This is because fields drop off quickly with distance from source, so in  most cases, not harmful because of small dose. Early studies did indicate risk, but later studies did not. o Studies first linked EMF’s to leukemia, but after redesigning  experiment, concluded that there was no link. Still think that they may cause diseases (brain cancer leukemia) o Still risks are relatively small and hard to quantify.
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Lecture: Speed of light, wavelength frequency C= WF o C= Speed of light, 3E8 m/sec.  W= Wavelength (m) F= Frequency (1/sec or Hertz (Hz)) o E= Electromagnetic radiation energy (Joules) E= hF where h= 6.6E-34 Joule-sec (Planck’s constant) E= h*C/W o Wavelength units Micron= E-6 Meters Nanometer= E-9 meters o Wavelength and frequency are inversely related EMR energy is directly proportional to Frequency or inversely to  Wavelength Ionizing EMR occurs at W<visible All bodies radiate thermal EMR
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Lec 15 (Ch 13- Earth’s Atmosphere and Climate) 12/03/2009 17:31:00 Polar Bears Largest carnivore in America (2.5 m and 700 kg) Thinning ice has become a problem o 40% over past 40 yrs, 10% less area  o Response to global warming Need ice to hunt seals, move to land for 8 months and hibernate o Thinning ice restricts hunting, decline in fat on Polar bears as well as  less cubs. Global temperature is rising
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Other Env St Midterm 3 lecture notes - Lec 14 Lecture 14...

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