Ozone Layer

O3

Absorbs the sun’s UV radiation Stratosphere 20-50km above the Earth’s

surface

Ultraviolet Radiation

Good: Causes Vitamin D production in humans

Bad: Causes skin cancer, cataracts, and mutations, blindness, sunburn. Severe crop damage Destroy microorganisms at bottom

of food chain

Ozone Depletion

Antarctic Ozone Hole http://ozonewatch.gsfc.nasa.gov/

The Chemistry

CFC’s = Chlorofluorocarbons CFC’s in UV radiation release a Cl Cl + O3 ClO + O2 ClO + O Cl + O2

IT’S A CYCLE!!! US Banned CFC’s in many products in 1978

Montreal Protocol

Complete Phaseout of CFC’s by 1996

Good Example of countries coming together for the benefit of the environment

Ozone depleting substancesC o m m o n n a m e C o m p o u n d

A c tiv e E le m e n t

A p p lic a tio n s

C F C s (c h lo ro flu o ro c a rb o n s) F re o n - 1 1

C F C l3 C l c h lo rin e

re fri g e ra tio n a n d a e ro so l sp ra y s

C F C s (c h lo ro flu o ro c a rb o n s) F re o n - 1 2

C F 2 C l2 C l c h lo rin e

re fri g e ra tio n a n d a e ro so l sp ra y s

C F C s (c h lo ro flu o ro c a rb o n s) F re o n - 1 1 3

C 2 F 3 C l3 C l c h lo rin e

re fri g e ra tio n a n d a e ro so l sp ra y s

C F C s (c h lo ro flu o ro c a rb o n s) F re o n 1 1 4

C 2 F 4 C l2 C l c h lo rin e

re fri g e ra tio n a n d a e ro so l sp ra y s

h a lo n s C F 3 B r, C F 2 B rC l, C 2 F 4 B r2

C l a n d B r c h lo rin e a n d b ro m in e

fire e x tin g u ish e rs

m e th y lc h lo ro fo rm 1 ,1 ,1 - T C E (tric h lo ro e th a n e )

C l c h lo rin e

c le a n in g so lv e n t a n d w id e l y u se d a s a n in d u s tria l so lv e n t.

c a rb o n te tra c h lo rid e C C l4 C l c h lo rin e

fire e x tin g u ish e rs , c l e a n i n g so lv e n t a n d w id e l y u se d a s a n in d u s tria l so lv e n t fo r la c q u e rs , v a rn ish e s a n d v a rio u s o rg a n ic c o m p o u n d s .

Question: What does the hole in the ozone layer mean for us? What can we do to protect ourselves from UV radiation?

GRAPH: How has the Antarctic Ozone Hole Changed over time???