Ozone depletion is the
catalytic destruction of ozone by
atomic chlorine and bromine.
Image of "Ozone Hole" over Antarctica
http://irelandconservation.org/wp-content/uploads/2009/10/Global-Warming-And-Ozone-Layer-Depletion-300x288.jpg
The main source of these
halogen atoms in the
stratosphere is Chlorofluorocarbon (CFC) compounds, commonly called
Freons, and of
Bromofluorocarbon compounds known as Halons.
http://en.wikipedia.org/wiki/Ozone_depletion
These substances are commonly referred to as ozone-depleting substances (ODS). The ozone layer prevents most harmful
UVB type of ultraviolet light (UV light) from passing through the Earth's atmosphere. UVB rays exposure is suspected to cause skin cancer, cataracts, damage to plants, and reduction of
plankton in the ocean.
The use and production of these ODS was banned under the Montreal Protocol.
http://en.wikipedia.org/wiki/Montreal_Protocol
So does that mean we have solved the problem? Sadly the answer is NO.
These ODS stay in the environment for a very long time and Earth will continue to face its affects for many years to come.
Another big problem is that the ban is not effective in many parts of the world. The following are a few examples:
• Many under developed countries have no access to new technology and continue the use equipments with ODS as they cannot afford change over to new technology.
• Some sensitive technology such as nuclear plants, and industries in some countries still use ODS.
• Old equipments containing ODS have a lot of leakages which results in significant amounts of ODS still being released into the atmosphere.
Example 1: The photo shows a Halon Plant on an old ship “Genie” still being used as a fire fighting system. This photo was taken by my father on 4th March 2010 (just 2 weeks ago in Singapore). This ship will be broken down soon in India or Bangladesh. Thousands of litres of this HALON gas may be let off into the atmosphere due to lack of regulatory control and poor technology.
Halon Extinguishers on Ship "Genie" Dt 04 March 2010
(Source: My father’s technical papers)
Example 2: Visit this website.
http://www.tradekey.com/selloffer_view/id/2964281.htm
Can you believe they are still selling Halon 1301? I had a closer look at the rules and under Montreal Protocol, some ODS can actually continue to be used till year 2030.
However there is good news too. The world has been able to control this destruction to a large extent through tight controls. I must say that long term impacts are still unknown, so we should not be so happy. That’s why the world should immediately take following action to prevent further depletion of the ozone layer.
• Rapid transfer of new CFC and Halon free technology to poor nations
• Monitory assistance to the poor countries to manage their ODS
inventory
• Tougher sanction and punishment for breach of rules.
The following photographs show some of the ways in which the world is trying to control air pollution and preventing spread of ODS.
Example 3: When an industry complies with the rules they are issues certificates by authorities
A certificate given to a ship which complies with the rules.
Example 4: This website gives interesting write up about alternative substances.
http://205.153.241.230/P2_Opportunity_Handbook/3_III_2.html
Example 5: An example of fire fighting system which does not use Halon
.png)
High Expansion foam is also being used as an alternative to Halon
Example 6: New technology refrigerator with does not use CFC
A refrigerator using CFC Free coolant
Some interesting facts –
! Ozone gas by itself is highly poisonous to the humans. Fortunately it is present on the surface in minute quantities and does not cause any harm.
Glossary:
1. Catalyst –A substance which speeds up chemical reaction but does not take part in the reaction. For example, small amounts of catalyst (Halon) can speed up destruction of large amounts of ozone layer for many years.
2. Atom – the smallest unit of which matter is made of
3. Halon – Halon is a type of Ozone depleting substance commonly used for fire fighting and other industrial applications
4. Stratosphere - The stratosphere is the second major layer of Earth's atmosphere, just above the troposphere, and below the mesosphere
5. Freon – A DuPont trade name for chlorofluorocarbon (CFC)
6. Bromofluorocarbon – Bromofluorocarbon is a type of ODS containing Bromine
7. UVB Rays – UVB and UVC rays are more harmful types of UV rays of shorter wavelength.
8. Plankton - Plankton consist of any drifting organisms (animals, plants, or bacteria) that lie in oceans, seas, or bodies of fresh water.
9. Inventory - Inventory is a list for goods and materials, or those goods and materials themselves, held available in stock by a business.
.png)
.png)
