Air Pollution: Concepts that may be confusing

The concepts we’ll deal with today

• The difference between stratospheric and tropospheric ozone

• Photochemical smog– Inversion layers

• Acid rain

• Global change– Especially predicted effects on Oklahoma

Where is ozone the “good guy”?

trophosphere

stratosphere

In the stratosphere….

• Ozone blocks incoming Ultra-violet radiation --- That’s Good!

• Ultraviolet radiation– Skin cancer– Cataracts– Plant Damage

But, what’s happening to ozone in the Stratosphere?

1979-1985

1986-1992

Deeper purple color meansLess ozone above Antartica

Why?• Chlorofluorocarbons (CFC) are very stable

compounds that we produce at earth’s surface

• They migrate to the stratosphere• Their chlorine gets excited by ultraviolet

light• After excitation, chlorine attacks ozone

layer, depleting it.

So, we’ve reduced use of CFC’s • Their long life span means that they will be

in the stratosphere for a long time, still destroying ozone.

• However, the rate of increase of ozone depletion has slow, showing we are on the right track

• By the way, ozone “holes” are opening up in places other than Antarctica

Where is ozone the “bad guy”?

trophosphere

stratosphere

Photochemical Smog

VOCs breakCycle, allowingPAN to form fromNO +VOC

NOx + VOC Ozone + Panlight

reactants products

Chemical Equation for Photochemical Smog

Where reactants come from

• NOx primarily from transportation

• VOC from a variety of sources, including refining, other industries, etc.

Inversion layers trap cold air, allowing pollutants to build up in concentrations,

including the compounds needed for photochemical smog

Cold air

Warm air

Ozone’s bad features

• Extremely reactive will burn leaves, lungs, synthetic compounds (e.g. rubbers, plastics)

• Because of reactivity, is toxic in very long concentrations (parts per billion)

We’re not the only ones concerned about photochemical smog

Acid Rain: Where it comes from

Acid Rain: Where it goes

Some Effects of Acid RainHuman HealthEffects include EmphysemaAnd Other RespiratoryDiseases

Structures &Buildings AlsoAffected

A Mini-Quiz:How will Acid Rain affect Soil

Cation Exchange?

What can we do about Air Pollution?

Venturi Filter

This type of filter along withOther forms known as scrubbersAre one way to reduce Smoke stack emissions. WhatElse can be done?

Global Change• Global Change includes all of the large

scale effects humans are having on the global system– Greenhouse Gases: Global Warming– Reduced Ozone Layer– Habitat Changes– Loss of Biodiversity

• These changes are strongly interactive

What are predictions for effects of Global Change on Oklahoma?

What are predictions for effects of Global Change on Oklahoma?

What are predictions for effects of Global Change on Oklahoma?

What are some other predicted effects?

And some more predicted effects

• Human health effects are also expected as disease vectors find a warmer world a more hospitable place to be– Includes diseases like

malaria and cholera

The latest report

• Out this fall– the United Nation’s Science Council’s latest model on global warming has found by looking at climate data over the past decade that they underestimated the amount of warming expected

• Now expect to see 10o F increase in air temperature within the new century!