Jessica Weber Spring 2008 Updated from Dan Gloudemans, Spring 2005

 VOC’s  Ozone  Formation, natural/other  VOC’s  Destruction, natural/other  CFC’s  Measurement / EPA AQI  Ozone hole Phenomenon  What is being done about Ozone?  OTC  CARB  Recent News  Fun Facts  Questions

 Organic Compound – contains carbon and hydrogen  Ie: octane, butane…, sugar  VOC = Volatile Organic Compound, organics that evaporate easily  VOC’s are compounds that lead to the formation of ground level Ozone – “smog”  VOC’s can be found in anything from paints to deodorant

 Ozone is beneficial in Stratosphere  blocks many ultra violet rays ( λ < 320 nm)  90% of ozone is found here  Ozone is harmful in Troposphere  it is a highly reactive gas that can affect the normal functioning of the lungs  Thickness of the ozone varies seasonally and geographically  Greatest concentrations are between 15 and 40 km, ranging from 2-8 ppm  Found during the spring in mid-to-high latitudes  Lowest concentration is found during Sept –Oct over Antarctica (ozone hole phenomenon)

 Ozone first formed - ~500 million years ago  Ozone formation – atomic Oxygen  O 3 is unstable, creates ozone-oxygen cycle  Most natural ozone formation occurs in the Tropics “Chapman reactions” So called after S. Chapman who is famous for his paper 'A theory of upper-atmosphere ozone, Mem. Roy. Meteorol. Soc.' in 1930 which set out the first theoretical explanation of the ozone layer in the stratosphere.

 Photochemical reaction of NOx (Nitrogen oxides: collectively NO and NO 2 ) with peroxy radicals in the presence of sunlight  HO2 + NO → OH + NO2  NO2 + h ν → NO + O  O + O2 → O3  Results in commonly known “Summertime Air Pollutant”  Sources of Nox  Motor vehicles, Industrial Commercial Residential Fuel Combustion, Utilities  Sources of VOC  Industrial Commercial Processes, Motor Vehicles, Consumer Solvents

 VOC production (2004)

 Ozone destruction by UV radiation  Ozone dissociates by absorbing a UV proton with λ <240 nm, photolysis  O + O 3 → 2 O 2  Large volcanic eruptions can affect ozone levels  Increases stratospheric chlorine concentrations by producing aerosols

 Free radical catalysts (NO, OH, Cl, Br)  Causing ozone levels in the northern hemisphere to drop approximately 4% per decade.  CFC (choloroflurocarbon) compounds Photodissociation of CFCs  Contain chlorine and bromine radicals  CFCl 3 + h ν → CFCl 2 + Cl  Once separate from parent compound can react with ozone  Cl + O 3 → ClO + O 2 ClO + O → Cl + O 2  A single Cl atom can continuously destroy ozone for 2 years

 Destruction allows more UV radiation through at harmful wavelengths causing increased genetic damage to living creatures and organisms.  Fortunately, where DNA is easily damaged, such as by wavelengths shorter than 290 nm, ozone strongly absorbs UV.  At the longer wavelengths where ozone absorbs weakly, DNA damage is less likely.  If there were a 10% decrease in ozone, the amount of DNA damaging UV radiaton increases by about 22%.  DNA damage can most commonly lead to skin cancer  Increased UV radiation is expected to affect crop yields  UV rays kill cyanobacteria on roots of rice plants

 Reported in Dobson Units (DU)  G.M.B. Dobson developed a spectrophotometer that was used to measure stratospheric ozone  Measure concentration of ozone in a column  1 DU = 0.01 mm of Ozone  300 DU a typical value  Thus, 300 DU = 3 mm O 3 spread evenly across earth

 Measures presence of 5 pollutants  ground-level ozone  particle pollution  carbon monoxide  sulfur dioxide  nitrogen dioxide  Scale  100 is National Air quality standard  ~200 – unhealthy - whole population could be affected  >300 - Hazardous

 Over Antarctica  First discovered/measured in 1985 by the British Antarctic Survey  TOMS ( T otal O zone M apping S pectrometer)  During the winter season, a vortex of winds develops around the pole and isolates the polar stratosphere  As temperatures drop below -78°C (-109°F), thin clouds form of ice, nitric acid, and sulphuric acid  Chemical reactions on the surfaces of ice crystals in the clouds release active forms of CFCs

 US adopted Montreal Protocol in 1987 – limit CFCs  States most dangerous CFCs phased out by 2000  With compliance of the Montreal Protocol; the ozone layer is expected to begin to recover in coming decades due to declining ozone- depleting substance concentrations (2005 article)  In 2006, the ozone layer saw the worst level of depletion in recorded ozone history.

 Clean Air Act (1963)  All class I substances outlawed by Jan  chlorofluorocarbon-11 (CFC–11) chlorofluorocarbon-12 (CFC– 12) + others  All class II substances outlawed by Jan  hydrochlorofluorocarbon-21 + various other  In 2007, President Bush added the 20-in-10 Bill  Proposed to reduced gasoline consumption by 20% in the next 10 years.  Ozone “Action Days”  Days > 90°F, little or no wind  Encourage to reduce emissions  World Ozone day – September 16 th  Started in 1994 by the United Nations General Assembly

 OTC = Ozone Transport Commission  Several northeastern states (13 total)  Created under Clean Air Act (CAA) amendments in 1990  Focus on Ground Level Ozone - specifically NOx emissions - during May – Sept ~“Ozone Season”  Northeast and Mid-Atlantic regions of US  NOx Budget Program – sell or store unused allowances  Regional emissions trading program

 OTC recommended to EPA to set a standard for the primary ozone level to ppm.  As well as forming a secondary standard for protection of crops during the growing season  March 13, 2008 – EPA set standard to.075ppm (a less protective threshold) and did not include a secondary standard  Previous standard was.09 ppm exposure measured over one hour (2005)  OTC claims that if the standard had been set lower benefits to the people in this region would include:  Decreased respiratory problems, greater work productivity, and reduced ER visits due to asthma incidences

 California Air Resource Board (CARB)  In addition to NOx, regulate VOC emissions  Overseas all air pollution control efforts in California  Money from violations goes to the California Air Pollution Control Fund  Provides support for various pollution-related research project and programs  Recent News  Sited three companies for failure to comply with the Periodic Smoke Inspection program  Program that regulates the smoke emissions from fleet vehicles  Fines totaled over $57,000, companies also agreed to attend classes conducted by the California Council on Diesel Education and Technology

 Fox River Valley  Most smog in Wisconsin  Madison rates 47 AQI  Milwaukee rates 48 AQI  Wisconsin During Action Days  Combining errands  Fueling car gas tanks at night  Emissions are less likely to produce ground level ozone  Mowing lawns after 6:00 p.m  Properly inflating vehicle tires  Carpooling, biking, walking or riding the bus to work

 NASA completed a study (Aug. 2005) that when a hurricane increasing in strength, the ozone level drops  These results can be used to forecast hurricanes which could possibly strike areas of high population  If the ozone layer were brought down to the Earth's surface, air pressure and temperature conditions would compress the ozone into a layer only 2 to 5 mm thick  SmogCity.com  Decide weather conditions (temp, wind speed, cloud cover), population level, and emissions levels  Shows ozone levels throughout “created” day, and gives health warnings if levels are very high

 “Sick Building Syndrome”  VOC exposure indoors  Sources: photocopiers, carpets, and furnishings  Most common is formaldehyde  Also tobacco smoke can contribute to high levels of VOCs  EPA has found that in some cases the VOC concentration can be 2-5 times higher indoors than outdoors

 The CO 2 emissions that produce near-surface global warming in return cool the stratosphere which is expected to produce an increase in O 3 depletion  The chemicals which deplete the ozone are also greenhouse gases  Contributing to both ozone depletion and global warming

 How does a city comply with new Ozone Standards?  Largest producer targeted  How long does it take to implement a new standard?  Can we lab-produce ozone and “insert” into atmosphere?  Can be lab-produced by electrolysis or with a D-cell battery  General reaction: 3 O2 — electricity → 2 O3

EPA – “air Now” How VOCs Contribute To Formation Of Ground-Level Ozone. Chemical & Engineering News, 1/24/2005, Vol. 83 Issue 4, p26, 1/3p; ( AN ) How VOCs Contribute To Formation Of Ground-Level Ozone. Chemical & Engineering News; 1/24/2005, Vol. 83 Issue 4, p25, 3p, 1c “ SMOG, POLICY AND CHEMISTRY.” Chemical & Engineering News “Ozone Science: The facts Behind the Phaseout” “Ozone levels drop when hurricanes are strengthening” “EPA’s New Ozone Standard Falls Short in Protecting the Public Health, Says Ozone Transport Commission. Ozone Transport Commission.” March 13, 2008 “California Adopts New Ozone Standard.” California Environmental Protection Agency. April 28,