Home sweet home . . .Home sweet home . . .

Or is it????Or is it????

Breathing!Breathing!

Some basicsSome basics

What is in our atmosphere?What is in our atmosphere?

Normal chemical composition of our atmosphere:

(N2) 78%

(O2) 21%

Trace gases (water, argon, carbon dioxide, other pollutants) 1%

Pollution terminologyPollution terminology

• Pollutant

• Source

• Effect

Article: EPA Proposes New Article: EPA Proposes New Ozone StandardOzone Standard

• EPA = Environmental Protection Agency

Pollution unitsPollution units

Parts per thousand (ppt)

Parts per million (ppm)

Parts per billion (ppb)

Smog and ozone form togetherSmog and ozone form together

1. N2 + O2 2NO

2. 2NO + O2 2NO2

3. NO2 + UV radiation NO + O

4. O + O2 O3

Primary pollutants come directly Primary pollutants come directly from a sourcefrom a source

• Mobile sources

Mobile sourcesMobile sources

Stationary SourcesStationary Sources

• Power plants

RefineriesRefineries

Secondary pollutants form in Secondary pollutants form in atmosphere as gases reactatmosphere as gases react

• Smog, ground level ozone and acid rain

Secondary pollutants form in Secondary pollutants form in atmosphere as gases reactatmosphere as gases react

• Step two: 2NO + O2 2NO2

• NO2 is smog – a yellow brown gas

• Causes lung and eye irritation, makes asthma, bronchitis and emphysema worse

Ozone formationOzone formation

Step 3: NO2 + UV radiation NO + O

Step 4:O + O2 O3

Ozone slows photosynthesis, eye and lung irritant, makes asthma, emphysema, bronchitis worse

Check out ozone formationCheck out ozone formation

• Texas Commission on Environmental Quality– EPA: National/Federal Regulatory agency– TCEQ: state regulatory agency

• ozone animation

Houston Clean Air Network Map

AQI: set at 100 for each criterion AQI: set at 100 for each criterion pollutant level. pollutant level.

Ozone 100 AQI = 85ppbOzone 100 AQI = 85ppb

Smog and ozone form togetherSmog and ozone form together

1. N2 + O2 2NO2. 2NO + O2 2NO2

3. NO2 + UV radiation NO + O4. O + O2 O3

Ozone season: March- NovemberOzone daily formation: noon-early

evening

VOCs – a second route for OVOCs – a second route for O33

formationformation• Volatile Organic Compounds:

– Methane (CH4)

– Propane– Chlorofluorocarbons (CFC)

– VOCs can break O2 into free oxygen atoms (free radicals)

– VOC + O2 VOC + 2O

– O + O2 O3

We're #?We're #?

• . . . .for the number of days exceeding allowable ground level ozone levels.

• American Lung Association State of the Air

We're #?We're #?

• . . . .for the number of days exceeding allowable ground level ozone levels.

• American Lung Association State of the Air

Measuring pollutantsMeasuring pollutants

• parts per thousand = ppt

• parts per million = ppm

• Parts per billion = ppb

• Parts per trillion = ppt (must know from context)

Clean Air ActClean Air Act

• Passed by Congress in 1970, updated in 1990, ‘93, 97, 2008.

• Required EPA (Environmental Protection Agency) to identify criteria pollutants and to establish minimum standards: EPA came up with NAAQ’s

National Ambient Air Quality National Ambient Air Quality StandardsStandards

• Six criterion pollutants: NOx, SOx, O3, Pb, CO, particulates

• Established minimum standards: 1hr and 8 hr

• EPA is working to have greenhouse gases added by Congress to the NAAQs

HoustonHouston’’s special issuess special issues

• 1/3 of all US petrochemicals pass through our refineries

• Refineries separate crude oil into many different products from asphalt tar to gasoline to butane

Refineries create carcinogenic Refineries create carcinogenic air pollutantsair pollutants

Benzene, toluene, ethylbenzene, xylenes

So what is being done about So what is being done about this? - City monitoringthis? - City monitoring

45 mobile monitoring stations45 mobile monitoring stations

State monitoringState monitoring

• Flexible permitting – each facility has total cap emissions limit, but flexibility in how they meet that limit.

• TCEQ issues permits for emitting certain amount of pollutants

• Facilities do “self reporting”

Check your understanding!Check your understanding!

• What is the difference between a primary and a secondary air pollutant?

• Give an example of a mobile source.

• Give an example of a stationary source.

• Which layer of the atmosphere are you in RIGHT NOW?!!!!

• What is the normal chemical composition of our atmosphere?