This document discusses the ozone layer and its depletion. It begins with an introduction to the discovery of ozone layer depletion by scientists in the 1970s. It then discusses the formation and location of stratospheric and tropospheric ozone. The main causes of ozone layer depletion are chlorofluorocarbons (CFCs) and other ozone depleting substances like halons. The impacts of depletion include increased UV radiation reaching Earth's surface, harming human health, agriculture and plants. International agreements like the Montreal Protocol have sought to phase out the production and use of ozone depleting substances to protect the ozone layer.
Ozone Layer (components, formation and depletion)Aneela Rafiq
ozone layer is a like a protection shield around earth. it protects living things from harmful radiation effect. but due to rapid urbanization and usage of lethal chemicals, it has some depletion.
this presentation elaborate the ozone layer and its components.
This presentation is about Ozone Layer and chemicals known to cause its depletion.
It also covers information about Ozone Hole and Correlation between Ozone depletion and skin diseases due to Ultra Violet light.It also contains no. of ways to limit ozone deterioration.
Ozone Layer (components, formation and depletion)Aneela Rafiq
ozone layer is a like a protection shield around earth. it protects living things from harmful radiation effect. but due to rapid urbanization and usage of lethal chemicals, it has some depletion.
this presentation elaborate the ozone layer and its components.
This presentation is about Ozone Layer and chemicals known to cause its depletion.
It also covers information about Ozone Hole and Correlation between Ozone depletion and skin diseases due to Ultra Violet light.It also contains no. of ways to limit ozone deterioration.
hi everyone it is the most usefull of our some solution of routine life like what is responsibility of our envoronment and atmosphere...so see the ppt and know the problem,solution and many more future of deplating our ozone layer.......
Ozone layer
Ozone hole
Characteristics of Ozone layer
Cause of O3 depletion:
Form of UV coming from sun:
Effects of UV rays
Ozone hole improvement
Importance of CFCs at the beginning
Alternative sources of CFCs
How does the Global worming take place??
Greenhouse gases
Impacts of Global Warming
ozone layere and share the bomdin with other becsause it creagte lovews and affection for manmyt tiumes with tthje passion and motrr eenmdsjkdd dtill we thinks thar we nered more and more opassiob fnju meeroijmsndi
Ozone is the one and only layer to protect our earth from harmful UV radiation. There are a lot of initiatives taken by many countries to save the ozone layer. Ozone depletion is nowadays one of the hot topics in conferences and seminars. In this presentation, I have briefed on the cause and side effects of ozone depletion. The students from school to master's may take advantage of this presentation
"Understanding the Carbon Cycle: Processes, Human Impacts, and Strategies for...MMariSelvam4
The carbon cycle is a critical component of Earth's environmental system, governing the movement and transformation of carbon through various reservoirs, including the atmosphere, oceans, soil, and living organisms. This complex cycle involves several key processes such as photosynthesis, respiration, decomposition, and carbon sequestration, each contributing to the regulation of carbon levels on the planet.
Human activities, particularly fossil fuel combustion and deforestation, have significantly altered the natural carbon cycle, leading to increased atmospheric carbon dioxide concentrations and driving climate change. Understanding the intricacies of the carbon cycle is essential for assessing the impacts of these changes and developing effective mitigation strategies.
By studying the carbon cycle, scientists can identify carbon sources and sinks, measure carbon fluxes, and predict future trends. This knowledge is crucial for crafting policies aimed at reducing carbon emissions, enhancing carbon storage, and promoting sustainable practices. The carbon cycle's interplay with climate systems, ecosystems, and human activities underscores its importance in maintaining a stable and healthy planet.
In-depth exploration of the carbon cycle reveals the delicate balance required to sustain life and the urgent need to address anthropogenic influences. Through research, education, and policy, we can work towards restoring equilibrium in the carbon cycle and ensuring a sustainable future for generations to come.
Characterization and the Kinetics of drying at the drying oven and with micro...Open Access Research Paper
The objective of this work is to contribute to valorization de Nephelium lappaceum by the characterization of kinetics of drying of seeds of Nephelium lappaceum. The seeds were dehydrated until a constant mass respectively in a drying oven and a microwawe oven. The temperatures and the powers of drying are respectively: 50, 60 and 70°C and 140, 280 and 420 W. The results show that the curves of drying of seeds of Nephelium lappaceum do not present a phase of constant kinetics. The coefficients of diffusion vary between 2.09.10-8 to 2.98. 10-8m-2/s in the interval of 50°C at 70°C and between 4.83×10-07 at 9.04×10-07 m-8/s for the powers going of 140 W with 420 W the relation between Arrhenius and a value of energy of activation of 16.49 kJ. mol-1 expressed the effect of the temperature on effective diffusivity.
Artificial Reefs by Kuddle Life Foundation - May 2024punit537210
Situated in Pondicherry, India, Kuddle Life Foundation is a charitable, non-profit and non-governmental organization (NGO) dedicated to improving the living standards of coastal communities and simultaneously placing a strong emphasis on the protection of marine ecosystems.
One of the key areas we work in is Artificial Reefs. This presentation captures our journey so far and our learnings. We hope you get as excited about marine conservation and artificial reefs as we are.
Please visit our website: https://kuddlelife.org
Our Instagram channel:
@kuddlelifefoundation
Our Linkedin Page:
https://www.linkedin.com/company/kuddlelifefoundation/
and write to us if you have any questions:
info@kuddlelife.org
Natural farming @ Dr. Siddhartha S. Jena.pptxsidjena70
A brief about organic farming/ Natural farming/ Zero budget natural farming/ Subash Palekar Natural farming which keeps us and environment safe and healthy. Next gen Agricultural practices of chemical free farming.
Diabetes is a rapidly and serious health problem in Pakistan. This chronic condition is associated with serious long-term complications, including higher risk of heart disease and stroke. Aggressive treatment of hypertension and hyperlipideamia can result in a substantial reduction in cardiovascular events in patients with diabetes 1. Consequently pharmacist-led diabetes cardiovascular risk (DCVR) clinics have been established in both primary and secondary care sites in NHS Lothian during the past five years. An audit of the pharmaceutical care delivery at the clinics was conducted in order to evaluate practice and to standardize the pharmacists’ documentation of outcomes. Pharmaceutical care issues (PCI) and patient details were collected both prospectively and retrospectively from three DCVR clinics. The PCI`s were categorized according to a triangularised system consisting of multiple categories. These were ‘checks’, ‘changes’ (‘change in drug therapy process’ and ‘change in drug therapy’), ‘drug therapy problems’ and ‘quality assurance descriptors’ (‘timer perspective’ and ‘degree of change’). A verified medication assessment tool (MAT) for patients with chronic cardiovascular disease was applied to the patients from one of the clinics. The tool was used to quantify PCI`s and pharmacist actions that were centered on implementing or enforcing clinical guideline standards. A database was developed to be used as an assessment tool and to standardize the documentation of achievement of outcomes. Feedback on the audit of the pharmaceutical care delivery and the database was received from the DCVR clinic pharmacist at a focus group meeting.
2. Learning objective:-
• Introduction
• Ozone Layer
• Formation of Ozone
• Ozone layer depletion
• Ozone layer depletion substance
• Impacts of Ozone Layer Depletion
• Measures to prevent the ozone layer depletion
• Conclusion
• Reference
3. Introduction
• In 1969 Dutch chemist Paul Crutzen published a paper that described the major nitrogen oxide
catalytic cycle affecting ozone levels. Crutzen demonstrated that nitrogen oxides can react with
free oxygen atoms, thus slowing the creation of ozone (O3), and can also decompose ozone into
nitrogen dioxide (NO2) and oxygen gas (O2).
• In 1974, American chemists Mario Molina and F. Sherwood Rowland of the University of
California at Irvine recognized that human-produced chlorofluorocarbons (CFCs)—molecules
containing only carbon, fluorine, and chlorine atoms—could be a major source of chlorine in the
stratosphere. They also noted that chlorine could destroy extensive amounts of ozone. One chlorine
can destroy 100,000 molecules of ozone. It is destroyed more quickly than it is created.
• Ozone depletion, gradual thinning of Earth’s ozone layer in the upper atmosphere caused by the
release of chemical compounds containing gaseous chlorine or bromine from industry and other
human activities. The thinning is most pronounced in the polar regions, especially over Antarctica.
• Montreal Protocol was proposed in 1987 to stop the use, production and import of ozone-depleting
substances and minimize their concentration in the atmosphere to protect the ozone layer of the
earth.
3
4. Ozone Layer:-
• Ozone (O3) is a highly reactive gas composed of three oxygen atoms. It is both a natural
and a man-made product that occurs in the Earth's upper atmosphere (the stratosphere)
and lower atmosphere (the troposphere). Depending on where it is in the atmosphere,
ozone affects life on Earth in either good or bad ways.
• Stratospheric ozone is formed naturally through the interaction of solar ultraviolet (UV)
radiation with molecular oxygen (O2). The "ozone layer," approximately 10 through 31
miles above the Earth's surface, reduces the amount of harmful UV radiation reaching
the Earth's surface.
• Tropospheric or ground-level ozone – what we breathe – is formed primarily from
photochemical reactions between two major classes of air pollutants, volatile organic
compounds (VOC) and nitrogen oxides (NOx). these pollutants form ozone molecules in
the presence of sunlight.
4
6. Formation of Ozone
6
Stratospheric ozone Stratospheric ozone is formed when solar energetic ultraviolet (UV) radiation dissociates molecules of
oxygen, O2, into separate oxygen atoms. Free oxygen atoms can recombine to form oxygen molecules
but if a free oxygen atom collides with an oxygen molecule, it joins up, forming ozone.
Creation
• An oxygen molecule is split (photolyzed) by higher frequency UV light (top end of UV-B, UV-C and above) into two
oxygen atoms.
O2 + ℎν(<242 nm) → 2 O.
• Each oxygen atom then quickly combines with an oxygen molecule to form an ozone molecule:
O + O2 → O3
The ozone–oxygen cycle
• The ozone molecules formed by the reaction above absorb radiation having an appropriate wavelength between UV-C
and UV-B. The triatomic ozone molecule becomes diatomic molecular oxygen plus a free oxygen atom.
O3 + ℎν(240–310 nm) → O2 + O
• The atomic oxygen produced quickly reacts with another oxygen molecule to reform ozone:
O + O2 + A → O3 + A
Removal:
• If an oxygen atom and an ozone molecule meet, they recombine to form two oxygen molecules:
O3 + O → 2 O2
• And if two oxygen atoms meet, they react to form one oxygen molecule:
2 O → O2
7. Formation of Troposhere Ozone
• Tropospheric O3 is considered as the most widespread secondary pollutant and one of the
components of global climate change.
• Tropospheric ozone is formed by the interaction of sunlight, particularly ultraviolet light, with
hydrocarbons and nitrogen oxides, which are emitted by automobile tailpipes and smokestacks. In
urban areas, high ozone levels usually occur during warm summer months.
8. Ozone layer Depletion
• Ozone depletion is a major environmental problem because it increases the amount of ultraviolet
(UV) radiation that reaches Earth’s surface, which increases the rate of skin cancer, eye cataracts,
and genetic and immune system damage.
• Ozone depletion, gradual thinning of Earth’s ozone layer in the upper atmosphere caused by the
release of chemical compounds containing gaseous chlorine or bromine from industry and other
human activities. The thinning is most pronounced in the polar regions, especially over Antarctica.
8
11. Ozone layer depletion substances
Ozone depleting substances are chemicals that destroy the earth’s protective ozone layer.
They include:
• Chlorofluorocarbons (CFCs)
• Halons
• Carbon tetrachloride (CCl4)
• Methyl chloroform (CH3CCl3)
• Hydrobromofluorocarbons (HBFCs)
• Hydrochlorofluorocarbons (HCFCs)
• Methyl bromide (CH3Br)
• Bromochloromethane (CH2BrCl)
The use of these chemicals is controlled by the Montreal Protocol on substances that Deplete
the Ozone Layer.
12. Chlorofluorocarbons (CFCs)
• Chlorofluorocarbons (CFCs) are nontoxic, nonflammable chemicals containing atoms of carbon,
chlorine, and fluorine. CFCs are classified as halocarbons, a class of compounds that contain atoms
of carbon and halogen atoms.
• Refrigerators in the late 1800s and early 1900s used the toxic gases, ammonia (NH3), methyl
chloride (CH3Cl), and sulfur dioxide (SO2), as refrigerants. After a series of fatal accidents in the
1920s when methyl chloride leaked out of refrigerators, a search for a less toxic replacement begun
as a collaborative effort of three American corporations- Frigidaire, General Motors, and Du Pont.
• CFCs were first synthesized in 1928 by Thomas Midgley, Jr. of General Motors, as safer chemicals
for refrigerators used in large commercial appilications.
12
13. Sources of CFCs:-
• Refrigerators and Air Conditioners.
• Aircraft Halon.
• Aerosol Sprays.
• Rogue CFCs*.
A mysterious spike in emissions of an ozone-destroying gas has been tracked to northeast China,
where scientists suspect that the chemical is being produced and used in violation of international
law.The chemical — trichlorofluoromethane, also known as CFC-11 — was once commonly used in
spray-foam insulation for refrigerators and buildings. CFC-11 is one of the most potent chemicals
responsible for creating the ozone hole in the stratosphere over the Southern Hemisphere.
13
15. Halons
• Halon, chemical compound formerly used in firefighting. A halon may be any of a group of
organohalogen compounds containing bromine and fluorine and one or two carbons. The
effectiveness of halons in extinguishing fires arises from their action in interrupting chain reactions
that propagate the combustion process.
• Halons are both atmospheric ozone depleters and greenhouse gases. In accordance with the
Montreal Protocol, their manufacture and consumption were phased out in industrialized nations by
Jan. 1, 2000.
15
16. Carbon tetrachloride
• Carbon Tetrachloride is a clear, colorless, volatile and very stable chlorinated hydrocarbon. Carbon
Tetrachloride is used as a solvent for oils and fats, as a refrigerant and as a dry-cleaning agent.
• Inhalation of its vapors can depress central nervous system activity and cause degeneration of the
liver and kidneys. Carbon Tetrachloride is reasonably anticipated to be a human carcinogen based
on evidence of carcinogenicity in experimental animals.
• Carbon tetrachloride is a manufactured chemical that does not occur naturally. It is a clear liquid
with a sweet smell that can be detected at low levels. It is also called carbon chloride, methane
tetrachloride, perchloromethane, tetrachloroethane, or benziform.
• Carbon tetrachloride was originally synthesized by the French chemist Henri Victor Regnault in
1839 by the reaction of chloroform with chlorine, but now it is mainly produced from methane.
• Carbon tetrachloride was also widely used as a precursor to chlorofluorocarbons (CFCs)
16
17. Methyl chloroform
• The organic compound 1,1,1-trichloroethane, also known as methyl chloroform, is a chloroalkane.
This colorless, sweet-smelling liquid was once produced industrially in large quantities for use as a
solvent. It is regulated by the Montreal Protocol as an ozone-depleting substance and its use is
being rapidly phased out.
• 1,1,1-trichloroethane appears as a colorless liquid. May irritate skin, eyes and mucous membranes.
In high concentrations the vapors may have a narcotic effect. Nonflammable, but may decompose
and emit toxic chloride fumes if exposed to high temperatures. Used as a solvent.
17
18. Hydrobromofluorocarbons
• Hydrobromofluorocarbons (HBFCs) are composed of molecules containing one, two or three
carbon atoms and at least one atom each of hydrogen, bromine and fluorine.
• Hydrobromofluorocarbons have ozone-depleting potential (ODP); thus, they are identified as
ozone-depleting substances (ODS).
• Ozone depleting potential is a measure of how much damage a chemical can cause to the ozone
layer compared with a similar mass of trichlorofluoromethane (CFC-11). CFC-11, with an ozone
depleting potential of 1.0, is used as the base figure for measuring ozone depletion potential. The
higher the number, the more damage a chemical can cause to the ozone layer.
Bromotrifluoromethane (halon-1301) has an ozone depleting potential of 10.0. Carbon dioxide
(CO2) is a naturally occurring greenhouse gas, but has an ozone depleting potential of 0.
18
19. Hydrochlorofluorocarbons
• Hydrochlorofluorocarbons (HCFCs) are compounds made up of hydrogen , chlorine , fluorine, and
carbon atoms . HCFCs and their cousins, hydrofluorocarbons (HFCs), were created in the 1980s as
substitutes for chlorofluorocarbons (CFCs) for use in refrigeration and a wide variety of
manufacturing processes.
19
20. Methyl bromide
• Bromomethane is a manufactured chemical. It also occurs naturally in small amounts in the ocean
where it is formed, probably by algae and kelp. It is a colorless, nonflammable gas with no distinct
smell. Other names for bromomethane are methyl bromide, mono-bromomethane.
• Bromomethane is used to kill a variety of pests including rats, insects, and fungi. It is also used to
make other chemicals or as a solvent to get oil out of nuts, seeds, and wool.
• Bromomethane is a one-carbon compound in which the carbon is attached by single bonds to three
bromine atoms and one hydrogen atom. It is produced naturally by marine algae. Methyl bromide
appears as colorless highly toxic volatile liquid or gas.
20
23. Impacts of Ozone Layer Depletion
Harm To Human Health:-
• More skin cancers, sunburns and premature aging of the skin.
• More cataracts,blindness and other eyes disease.
Advance Impacts on Agriculture:-
• Plant growth especially in seedling, is harmed by more intense UV radiation.
• Major crop species are particularly vulnerable to increased UV, resulting in reduced growth,
photosynthesis and flowering.
23
24. Effects on Plants:-
• Physiological and development processes of plants are affected by UV-B radiation, even by the amount
of UV-B is present day sunlight.
24
25. Effects on animals:-
• In domastic animal, UV over exposure may cause eyes and skin cancers.
• Species of marine animals in their developmental stage, eg. young fish, shrimp larvae and crab larvae
have been threatened in recent years by the increased UV radiation under the antarctic ozone hole.
25
26. Measures to prevent the ozone depletion:-
• Limit private vehicle driving.
• Use eco-friendly household cleaning products.
• Avoid using pasticides.
• Developing stringent regulations for rocket launches.
• Banning the use of dengerous nitrogen oxide.
26
27. Conclusion
• there is no doubt that the problem of ozone depletion exists
and deserves extensive research and attention. With the
release of each and every CFC, our ozone layer takes one
small steps towards its destruction. The decision to ban
completely CFCs sooner than later cannot be decided by
united nations. The entire world must unite in order to expel
this problem forever.
27
A mysterious spike in emissions of an ozone-destroying gas has been tracked1 to northeast China, where scientists suspect that the chemical is being produced and used in violation of international law.The chemical — trichlorofluoromethane, also known as CFC-11 — was once commonly used in spray-foam insulation for refrigerators and buildings. CFC-11 is one of the most potent chemicals responsible for creating the ozone hole in the stratosphere over the Southern Hemisphere.