Observation of ozone day

Observation of World Ozone Day, Ozone Chemistry, health effects

1. OBSERVATION
OF
WORLD OZONE DAY, 2021”
MR. BISHU KARMAKAR

2. TheUnitedNationGeneralAssemblyon23.01.95
adoptedaresolution49/114whichproclaims16th
SeptemberastheInternationalDayforthe
PreservationoftheOzoneLayer,tocommemoratethe
signingoftheMontrealProtocolontheSubstancesthat
DepletetheOzoneLayerwhichwassignedon16th
September,1987.
IndiabecomepartytotheMontrealProtocolinJune1992
andpreparedthecountryprogramin1993forphasing
outtheOzoneDepletingSubstances.Inaccordancewith
theUNresolution49/114,theOzoneCell,Governmentof
IndiahasbeencelebratingtheInternationalOzoneDay
forthePreservationoftheOzoneLayersince1995atthe
nationalandstatelevel.
HISTORY OF OZONE DAY

3. 2021 :“MontrealProtocol-KeepingUs,OurFood
andVaccinesCool”
2020 :“OzoneForLife:35YearsofTheOzoneLayer”
2019 :“Protection“32years&Healing”
2018 :“KeepCoolandCarryon”
2017 :“Caringforalllifeunderthesun”
2016 :“Ozoneandclimate:“Restoredbyaworld
united”
2015 :“Ozone:AllthereisbetweenyouandUV”
YEARWISE THEMES FOR WORLD OZONE DAY

4. How Ozone Allowed Life to Evolve on the
Surface of the Earth
•Earlyintheplanet’shistory,lifeexistedonlyintheoceanswhere
theharmfulUVradiationwasabsorbedandscatteredbywave
action,bubbles,anddebrisfloatinginthewater.
•PhotosynthesisinoceanplantsconvertedCO2andH2OintoO2
andthesugarsthatprovidetheenergytomaketheplantsgrow.
WhentheoceanbecamesaturatedwithO2,theamountof
oxygenintheatmospheregraduallyincreased.
•Gas-phaseoxygenwasconsumedbytwomechanisms:
(i)newlifeformsusedO2andsugarstoproduceCO2,H2O,and
energyinthereverse-photosynthesisprocesscalledrespiration,
and
(ii)O3wasformedbythephotochemicaldestructionofO2.
•Asconcentrationsofozoneintheatmospherebegantoincrease,
lessUVradiationreachedtheEarth’ssurface.Becausetheozone
absorbedtheDNAdamagingradiation,lifecouldbegintoexist
ontheEarth’ssurfaceratherthanjustunderwater.

5. HOW OZONE ALLOWED LIFE TO EVOLVE ON THE
SURFACE OF THE EARTH

6. OZONE IN ATMOSPHERE
Ozoneisagasthatisnaturallypresentinouratmosphere.
OzoneisderivedfromtheGreekwordOZEIN,meaning“to
smell.”
OzonehasapungentodorthatallowsOzonetobedetected
eveninverylowamounts.
EachOzonemoleculecontainsthreeatomsofoxygenandis
denotedchemicallyasO
3.
Ozoneisfoundprimarilyintworegionsoftheatmosphere.
About10%ofatmosphericOzoneisintheTROPOSPHERE,the
regionclosesttoEarth(upto10-16kmofaltitude).
TheremainingOzone(90%)residesintheSTRATOSPHERE,
primarilybetweenthetopofthetroposphereandabout40KM
ofaltitude.
Ozonerapidlyreactswithmanychemicalcompoundsandis
explosiveinconcentratedamounts.

7. Ozoneisformedthroughouttheatmosphereinmultistep
chemicalprocessesthatrequiresunlight.
Inthestratosphere,theprocessbeginswiththebreakingofan
Oxygenmolecule(O
2)intooxygenradicalbyUltraviolet
RadiationfromtheSun.Theoxygenmoleculecombinewith
oxygenradicaltoformO3.
CHEMISTRY OF OZONE FORMATION IN THE ATMOSPHERE

8. ThelargeamountofOzoneinthestratosphereisoften
referredtoasthe“OzoneLayer”.
Theozonelayerresidesinthestratosphereandsurroundsthe
entireEarth.
THE OZONE LAYER THE OZONE LAYER

10. Ozonelayerprotectstheharmful
UVradiationfromthesun.
UV-Bradiation(wavelength:280-
315nm)fromtheSunispartially
absorbedinOzonelayer.
UV-A(wavelength:315-to-400-nm)
&othersolarradiationarenot
stronglyabsorbedbytheozone
layer
Human exposuretoUV-B
increasestheriskofskincancer,
cataracts,andasuppressed
immunesystem.UV-Bexposure
canalsodamageterrestrialplant
life,singlecellorganismsand
aquaticecosystems.
IMPORTANCE OF OZONE LAYER

11. GOOD OZONE VS BAD OZONE
GOOD OZONE
Ozoneinthestratosphereabsorbs
someoftheSun’sbiologically
harmfulultravioletradiation.
Becauseofthisbeneficialrole,
stratosphericozoneisconsidered
“GoodOzone.”
TheabsorptionofUV-Bradiation
byozoneisasourceofheatinthe
stratosphere.
Thishelpstomaintainthe
stratosphereasastableregionof
theatmospherewithtemperatures
increasingwithaltitude.
Asaresult,ozoneplaysakeyrole
incontrollingthetemperature
structureofEarth’satmosphere.
BAD OZONE
Ozoneisalsoformednear
Earth’ssurfaceinnatural
chemicalreactionsandbythe
presenceofmanmadepollutant
gases.Ozoneproducedby
pollutantsisknownas“Bad
Ozone”asmoreOzonecomesin
directcontactwithhumans,
plantsandanimals.
Increasedlevelsofozoneare
generallyharmfultoliving
systemsasitreactsstronglyto
destroyoraltermanyother
molecules.
Excessiveozoneexposure
reducescropyieldsandforest
growth.

12. Ozonelayerisbeingdestroyedbyagroupofmanufactured
chemicalsthatarecalledOzoneDepletingSubstances
(ODS)andthedestructioniscalledOzoneDepletion.
ODSareverystableandnontoxicintheloweratmosphere.
Theirverystabilityallowsthemtofloatup,intact,tothe
stratosphere.Instratosphere,theybreakdownbyUVrays
releasinghighlyreactivechlorineatoms(withothers)that
inachainreactionbreaktheOzone.
ThemainODSarethefollowing:
•Chlorofluorocarbons (CFC 11, CFC 12, CFC 13)
•Methyl bromide (CH
3Br)
•Halons(halon-1211, halon-1301, halon-2402)
•Carbon tetrachloride (CCI4)
•Hydrochloroluorocarbons (HCFC 22 and HCFC 123)
OZONE DEPLETION

13. •Anothercategoryofhalogensourcegasescontains
bromine.Themostimportantofthesearethe“halons”and
methylbromide(CH
3Br)
•Halonsarehalogenatedhydrocarbongasesoriginally
developedtoextinguishfires
•Halonsarewidelyusedtoprotectlargecomputers,military
hardware,andcommercialaircraftengines.Becauseof
theseuses,halonsareoftendirectlyreleasedintothe
atmosphere.
•Halon-1211andHalon-1301arethemostabundanthalons
emittedbyhumanactivities
•Methylbromide,usedprimarilyasanagricultural
fumigant,isalsoasignificantsourceofbrominetothe
atmosphere.
OZONE DEPLETING SUBSTANCES

14. OZONE DEPLETION

15. ANTARCTIC OZONE HOLE
Themostwidelyusedimagesof
Antarcticozonedepletionarethosefrom
space-basedmeasurementsoftotalozone
byTotalOzoneMappingSpectrometer
(TOMS).
SatelliteimagesmadeduringAntarctic
winterandspringshowalargeregion
centeredneartheSouthPoleinwhichtotal
ozoneishighlydepleted.
Thisregionhascometobecalledthe
“OZONEHOLE”astheconcentrationof
ozonebecomeless.
Theareaoftheozoneholehasreached
25X10
6
Km
2
.Minimumvaluesoftotal
ozoneinsidetheozoneholehavefallenas
lowas100Dobsonunits(DU)compared
withnormalspringtimevaluesofabout300
DU.


16. Themostcommon usesofOzoneDepleting
Substancesas
Refrigerants incommercial, home and
vehicleAirconditioners,
Foamblowingagents,
Aerosolspraypropellants,
Fireextinguishingagents
Solvents,
USES OF OZONE DEPLETING SUBSTANCES

17. EFFECTS OF OZONE DEPLETION
Harm to human health:
•Skincancer
•Eyedamagesuchascataracts
•Immunesystemdamage
Adverse impacts on agriculture, forestry and natural
ecosystems:
Reduced growth, photosynthesis and flowering in
Plants.
Damage to marine life:
•Reduction in phytoplankton could disrupt the
fresh and saltwater food chains
•Loss of biodiversity in our oceans, rivers and
lakes could reduce fish yields for commercial and
sport fisheries.
Animals:
•In domestic animals, UV overexposure may
cause eye and skin cancers.
Skin Cancer
Cataracts
Pterygium

18. •Regularcheckingourairconditionerunitsand
refrigeratorsforleaksandrepairleakyairconditioning
unitsasearlyaspossible.
•Properdisposalofrefrigerationorairconditioning
equipment.
•Protectourselfagainstsunburn,wearsunglassesand
protectiveclothingwithatightwave.
•Useabroadspectrumsunscreenwithasunprotection
factor(SPF)atleast15and30isbetter.
•Themostimportantthingwecandoisspreading
awareness.Ourindividualeffortswillgoalongwayin
savingtheearthsblanketandkeepourplanetearth
livableforusandourfuturegenerations.
MEASURES TO BE TAKEN

19. MEASURES TO BE TAKEN

20. ATTEMPTS FOR PHASING OUT ODS TO PROTECT OZONE LAYER
•Afterrealisingtheharmfuleffectsoftheozone
depletion,effortsarebeingmadeofINTERNATIONAL
LEVELtominimizeorphaseouttheuseofCFCsand
otherozonedepletingsubstances(ODS)suchas
halonsandcarbons.
•Vienna convention, 1981
•Montreal protocol, 1987
•Vienna meet, 1995
•Kyto protocol, 1997
•Global environment facility ( GEF)

21. Completephase-outofHCFC-141bason1st
January,2020infoamsector,underOzone
DepletingSubstances(RegulationandControl)
AmendmentRules,2014and2019,issuedunder
Environment(Protection)Act,1986.
TheissuanceofimportlicenseforHCFC-141bis
prohibitedfrom1stJanuary,2020underOzone
DepletingSubstances(RegulationandControl)
AmendmentRules,2019S.O.No.4724(E)dated31st
December,2019.
ATTEMPTS FOR PHASING OUT ODS TO PROTECT OZONE LAYER

22. Signs of Recovery???
There have been some signs of recovery
–1997satelliteshowedadeclineofseveralknown
ozone-depletinggases
–Satelliteimagesshowsomeslowingdownofozone
loss
However…. Recovery is slow
www.coolantarctica.com/. ../ozone_hole.htm
Antarctica -Dec. 2005

23. 24 November 2021 Dr U Mishra, Professor, NIT, Agartala 23
Images of Antarctica Taken Indicate A Slow
Recovery

24. 24
EFFORTS NEED TO BE CONTINUED
•EffectiveEnforcementofMontrealProtocol:
–Toreduceconcentrationsofchemicalsresponsibleforozone
depletion.
•MoreScientificStudies:
–Togainabetterunderstandingoftheeffectsofozone
depletiononorganismslivingwithindifferentecosystems.
•MonitoringofChemicalsbeingemitted.
•ApplicationofMolecularNanotechnologytomake
alternativesofODS.