Jerebu Asia Tenggara

Jerebu di Asia Tenggara pada 2006 adalah antara yang paling buruk sejak 1998 apabila musim kering adalah agak panjang berikutan kesan el Nino. Jerebu akibat pembakaran tidak terkawal di Indonesia tersebar hingga ke selatan Thailand dan menyebabkan kerugian kira-kira RM32.71 bilion kepada pelancongan, pengangkutan dan industri pertanian.

Pada 19 September 1997 Sarawak mengisytiharkan darurat buat pertama kali dalam sejarahnya apabila jerebu paling buruk melanda negeri itu setelah Indeks Pencemaran Udara (IPU) mencecah 625 iaitu jauh lebih tinggi daripada paras berbahaya antara 301 dan 500.

Kerajaan-kerajaan Asia Tenggara pernah mengadakan mesyuarat di peringkat pemimpin negara dan peringkat menteri. Hasilnya pada 2002, Perjanjian ASEAN mengenai Jerebu Merentas Sempadan telah ditandatangani. Namun masalah jerebu masih terus berulang dan menjejaskan reputasi negara rantau ini

Indonesia

Menteri Pengangkutan Indonesia, Hatta Radjasa menjelaskan jerebu berlaku akibat kegiatan membakar untuk membersihkan tanah di Sumatera dan Kalimantan. Gambar satelit yang diambil pada 4 Oktober menunjukkan 561 "kawasan panas" yang menunjukkan kawasan yang dibakar di Borneo.

Para pegawai di negara jiran sering mengadu bahawa kerajaan Indonesia tidak melakukan apa-apa untuk memberhentikan pembakaran ini. Sebagai balasan pegawai Kementerian Perhutanan menyatakan bahawa anggota bomba dan pesawat tentera telah dikerahkan untuk memadamkan kebakaran di tanah kerajaan, namun mereka mengaku bahawa kebanyakan pembakaran berlaku di tanah milik persendirian [1]. Media Indonesia pula sering menyalahkan syarikat perladangan dari Malaysia yang melakukan pembakaran hutan di Sumatera, antaranya ialah Guthrie dan Tabung Haji. Kerajaan Malaysia pula meminta Indonesia segera mendakwa mana-mana syarikat perladangan yang melakukan pembakaran terbuka di sana [2].

Jerebu ini telah mengakibatkan penutupan sekolah, penerbangan tertangguh dan dibatalkan, mengganggu perkapalan dan memaksa sebahagian penduduk memakai topeng kesihatan. Sekolah-sekolah di Palangkaraya, Kalimantan Tengah telah diarahkan ditutup [3]. Jerebu juga dipersalahkan apabila sebuah penerbangan Mandala Airlines tergelincir semasa mendarat di Balikpapan, Kalimantan Timur pada 3 Oktober, apabila darjah penglihatan dilaporkan sekitar 400 meter [4]. Di Kepulauan Riau dan Jambi pula, kes masalah pernafasan dilaporkan meningkat [5].

Malaysia

Kesan jerebu bermula sejak awal Julai dan menjejaskan negeri-negeri di utara Semenanjung Malaysia dengan agak teruk. Namun demikian, cuaca mula bertambah baik sejak 29 Ogos dengan ketibaan musim hujan. Ini melegakan rakyat Malaysia yang menyambut Hari Kemerdekaan pada 31 Ogos.

Walau bagaimanapun, jerebu ini kembali pada akhir September. Ini berlaku akibat perubahan arah angin yang disebabkan oleh Taufan Xangsane. Tempat yang paling teruk ialah Kuching, di mana IPU hampir mencapai 300, iaitu kategori bahaya. Berita jerebu di Sarawak ini disiarkan oleh CNN pada 5 Oktober 2006. Manakala di Semenanjung Malaysia, tempat yang paling terjejas ialah di Johor Bahru dengan bacaan IPU 150 pada 7 dan 8 Oktober. Orang ramai kini mula memakai topeng pernafasan [6].

Kerajaan Malaysia bersedia melakukan pembenihan awan atau hujan tiruan. Namun masalah angin Angin Monsun Barat Daya sekarang ini tidak cukup berkesan untuk menghasilkan hujan tiruan. Angin Tenggara dari benua Australia akan melintasi garisan Khatulistiwa. Arah angin ini akan berubah menjadi Angin Monsun Barat Daya kerana bentuk bumi yang sfera (hampir bulat) [7].

Terbaru, Jabatan Alam Sekitar Malaysia (JAS) pada 8 Oktober menyatakan kualiti udara di empat negeri sebagai tidak sihat iaitu di Johor, Melaka, Pahang dan Terengganu [8]. JAS turut melaporkan bahawa laman webnya tergendala sebentar akibat kesesakan luar biasa [9].

Jabatan Penerbangan Awam Malaysia (DCA) akan menutup lapangan terbang jika tahap IPU mencapai 300. Jarak penglihatan di Lapangan Terbang Antarabangsa Kuching sekitar 1,000 meter dan selamat untuk operasi pelepasan dan pendaratan pesawat. Begitu juga di Lapangan Terbang Antarabangsa Kuala Lumpur. Hal yang sama juga diumumkan oleh Kementerian Pelajaran Malaysia yang mengarahkan sekolah-sekolah ditutup jika IPU mencapai 300 [10]. Ini pernah berlaku pada tahun sebelumnya

Ministry to charge companies over Lojing environs damage

MACHANG: Eight companies given concessions to develop the Lojing Highlands at Gua Musang will be charged with endangering the environment early next month

The National Resources and Environment Ministry will charge the eight with several counts of polluting the rivers and streams in the area, the ministry's parliamentary secretary Datuk Sazmi Miah said.

He said the investigation papers were completed and the prosecution was now in the midst of fine-tuning the case.

“We needed a long time to build up a case against the errant companies because we faced all kinds of constraints and implications, as the issue concerned both state and private land,” Sazmi said after opening the Risda “Plantation Day” celebrations at the Air Belaga mini-estate here yesterday.

He added that several officials with the state government, including state executive councillors, could be subpoenaed as witnesses.

On the Pasir Puteh district council, which allegedly ignored a warning from the state department of environment (DOE) to not conduct open burning at its solid waste landfill in Bukit Gedombak, Sazmi said such an incident should not have occurred.

He said the council should have taken a proactive step to protect the environment under its jurisdiction.

If the council was facing difficulty disposing the waste, it should have liased with the DOE or ministry, he said.

In a related development, council secretary Nik Mustapa Nik Hassan claimed he was unaware of the issue of air pollution.

He said the Federal Government was scheduled to take over the management of all landfills and waste disposal sites from the local authorities next year so it should no longer be an issue.

State DOE director Mokhtar Abdul Majid had informed the council to cover up the waste at Bukit Gedombak with sand and to control open-burning activities.

USM develops air filter system

PENANG: Universiti Sains Malaysia (USM) has developed a practical and cost-effective method of tackling air pollution.

Local researchers have developed a workable system, known as Rice Husk Ash-Based Sorbent/Catalyst As A Novel Industrial Gas Cleaning Technology, to this end.

The innovation won USM the most distinguished Higher Education Minister Award during the recent International Exposition of Research and Inventions of Institutions of Higher Learning (Pecipta) 2007, held at the Kuala Lumpur Convention Centre.


Pollutant remover: Dr Lee and USM School of Chemical Engineering lecturer associate professor Dr Azlina Harun showing a model of the air filter at their campus Monday.
USM School of Chemical Engineering lecturer Prof Dr Abdul Rahman Mohamed initiated the research work seven years ago.

Project leader and department lecturer Dr Lee Keat Teong said the system was ready for commercialisation.

“We are even prepared to market this system in the United States,” he said.

The technology requires a custom-built model that channels the gas or waste from any agricultural factory to a filter bag, flowing through an absorber made from the ash of rice husks.

“It can remove 100% of the air pollutant,” Dr Lee said after a press conference to announce the outcome of the Pecipta event held in Kuala Lumpur from Aug 10 to 12.

Dr Lee said the rice-husk ash method could be used to remove pollutants, such as sulphur dioxide and nitrogen dioxide from the burning of industrial fuels, which caused acid rain and global warming.

pencemaran udara

PENCEMARAN UDARA

Pencemaran udara boleh didefinasikan sebagai terdapatnya gas, cecair atau zarah yang terkandung di udara sehingga berlakunya perubahan dan menjejaskan kehidupan atau bahan-bahan lain. Bahan-bahan tersebut terampai di udara dan memberi kesan negatif kepada manusia, tumbuh-tumbuhan dan haiwan. Ini sebabkan bahan-bahan ini akan masuk ke tubuh manusia melalui pernafasan dan berupaya menyekat pengaliran oksigen ke dalam salur-salur darah. Ini boleh menimbulkan pelbagai penyakit seperti penyakit kekejangangan, barah, asma, kekejangan dan anemia.

Habuk, asap, kabus, wap atau bahan-bahan lain yang boleh menghalang penglihatan mata merupakan pelbagai bentuk pencemaran udara.

Klasifikasi Pencemaran Udara

Pencemaran udara dibahagikan kepada dua bahagian, iaitu:

Pencemaran Udara Primer
Penghasilan sulfur monoksida dan karbon monoksida akibat daripada proses pembakaran yang tidak lengkap adalah punca pencemaran udara primer. Proses ini menyebabkan zarah-zarah yang halus terampai-ampai di udara dan memberi kesan sampingan kepada kesihatan kita.

Kebanyakan pencemaran udara primer ini dilepaskan melalui ekzos kenderaan, kawasan industri dan penggunaan dapur arang atau kayu.

Pencemaran Udara Sekunder
Pencemaran udara sekunder pula adalah tindak balas sulfur dioksida yang bergabung dan membentuk dengan gas-gas yang tidak diperlukan oleh benda hidup.

Sulfur dioksida memerlukan gas seperti karbon monoksida dan sufur monoksida (pencemar primer) untuk membentuk gas-gas lain. Sebagai contoh, gabungan sulfur dioksida, sulfur monoksida dan wap air akan menghasilkan asid sulfurik. Tindakbalas antara pencemar primer dengan gas-gas terampai di atmosfera akan menghasilkan peroksid asetil nitrat (PAN).

Jenis-jenis Bahan Pencemar

Antara jenis-jenis bahan pencemar adalah seperti berikut :

Sulfur dioksida
Karbon monoksida
Nitrogen dioksida dan ozon
Alergen
Plumbum dan logam-logam lain
Punca Pencemaran

Pencemaran udara boleh berpunca daripada :

Pelepasan asap kenderaan
Proses industri - penghasilan bahan pencemaran oleh kilang-kilang asbestos/ simen/ bateri kereata
Pembakaran di tempat pelupusan - pembakaran terbuka di bandar
Pembakaran hutan
Pelepasan habuk - pembakaran sisa kayu/ sekam padi
Bahan-bahan sisa bandaran - sampah-sarap , sisa-sisa makanan
Aktiviti Masyarakat - membakar sampah, memasak menggunakan arang/ kayu, merokok
Kesan Pencemaran

Kesan-kesan pencemaran udara :

Kesihatan terjejas
Pertanian yang tidak produktif
Kemalangan mudah berlaku - akibat penglihatan yang kabur
Mengotorkan persekitaran - habuk
Sumber :

Pencemaran Alam Sekitar, Siri Pencemaran Alam, Jasiman Ahmad, Eddiplex Sdn. Bhd. 1996
Pencemaran Udara dan Bunyi, Siri Utamakan Alam Sekitar Anda, Jasman Ahmad & Siti Razmah Idris, Penerbit Mikamas, 1996

effect

How can air pollution hurt my health?

Air pollution can affect our health in many ways with both short-term and long-term effects. Different groups of individuals are affected by air pollution in different ways. Some individuals are much more sensitive to pollutants than are others. Young children and elderly people often suffer more from the effects of air pollution. People with health problems such as asthma, heart and lung disease may also suffer more when the air is polluted. The extent to which an individual is harmed by air pollution usually depends on the total exposure to the damaging chemicals, i.e., the duration of exposure and the concentration of the chemicals must be taken into account.
Examples of short-term effects include irritation to the eyes, nose and throat, and upper respiratory infections such as bronchitis and pneumonia. Other symptoms can include headaches, nausea, and allergic reactions. Short-term air pollution can aggravate the medical conditions of individuals with asthma and emphysema. In the great "Smog Disaster" in London in 1952, four thousand people died in a few days due to the high concentrations of pollution.
Long-term health effects can include chronic respiratory disease, lung cancer, heart disease, and even damage to the brain, nerves, liver, or kidneys. Continual exposure to air pollution affects the lungs of growing children and may aggravate or complicate medical conditions in the elderly. It is estimated that half a million people die prematurely every year in the United States as a result of smoking cigarettes.
Research into the health effects of air pollution is ongoing. Medical conditions arising from air pollution can be very expensive. Healthcare costs, lost productivity in the workplace, and human welfare impacts cost billions of dollars each year.
Additional information on the health effects of air pollution is available from the Natural Resources Defense Council. A short article on the health effects of ozone (a major component of smog) is available from the B.A.A.Q.M.D.

indoor air pollution

Indoor Air Pollution

Many people spend large portion of time indoors - as much as 80-90% of their lives. We work, study, eat, drink and sleep in enclosed environments where air circulation may be restricted. For these reasons, some experts feel that more people suffer from the effects of indoor air pollution than outdoor pollution.
There are many sources of indoor air pollution. Tobacco smoke, cooking and heating appliances, and vapors from building materials, paints, furniture, etc. cause pollution inside buildings. Radon is a natural radioactive gas released from the earth, and it can be found concentrated in basements in some parts of the United States. Additional information about the radon problem is available from the USGS and the Minnesota Radon Project.
Pollution exposure at home and work is often greater than outdoors. The California Air Resources Board estimates that indoor air pollutant levels are 25-62% greater than outside levels and can pose serious health problems.
Both indoor and outdoor pollution need to be controlled and/or prevented.
How can we prevent the damaging effects of air pollution?

outdoor pollution

Outdoor Air Pollution

Smog is a type of large-scale outdoor pollution. It is caused by chemical reactions between pollutants derived from different sources, primarily automobile exhaust and industrial emissions. Cities are often centers of these types of activities, and many suffer from the effects of smog, especially during the warm months of the year. Additional information about smog and its effects are available from Environment Canada and the Air Quality Management District (AQMD) in southern California.
For each city, the exact causes of pollution may be different. Depending on the geographical location, temperature, wind and weather factors, pollution is dispersed differently. However, sometimes this does not happen and the pollution can build up to dangerous levels. A temperature inversion occurs when air close to the earth is cooler than the air above it. Under these conditions the pollution cannot rise and be dispersed. Cities surrounded by mountains also experience trapping of pollution. Inversion can happen in any season. Winter inversions are likely to cause particulate and cabon monoxide pollution. Summer inversions are more likely to create smog.
Another consequence of outdoor air pollution is acid rain. When a pollutant, such as sulfuric acid combines with droplets of water in the air, the water (or snow) can become acidified . The effects of acid rain on the environment can be very serious. It damages plants by destroying their leaves, it poisons the soil, and it changes the chemistry of lakes and streams. Damage due to acid rain kills trees and harms animals, fish, and other wildlife. The U.S. Geological Survey (USGS), the Environmental Protection Agency (EPA), and Environment Canada are among the organizations that are actively studying the acid rain problem.
The Greenhouse Effect, also referred to as global warming, is generally believed to come from the build up of carbon dioxide gas in the atmosphere. Carbon dioxide is produced when fuels are burned. Plants convert carbon dioxide back to oxygen, but the release of carbon dioxide from human activities is higher than the world's plants can process. The situation is made worse since many of the earth's forests are being removed, and plant life is being damaged by acid rain. Thus, the amount of carbon dioxide in the air is continuing to increase. This buildup acts like a blanket and traps heat close to the surface of our earth. Changes of even a few degrees will affect us all through changes in the climate and even the possibility that the polar ice caps may melt. (One of the consequences of polar ice cap melting would be a rise in global sea level, resulting in widespread coastal flooding.) Additional resources and information about the Greenhouse Effect and global warming are available from the Environmental Defense Fund (EDF), the Science Education Academy of the Bay Area (SEABA) and the Society of Environmental Journalists (SEJ).
Ozone depletion is another result of pollution. Chemicals released by our activities affect the stratosphere , one of the atmospheric layers surrounding earth. The ozone layer in the stratosphere protects the earth from harmful ultraviolet radiation from the sun. Release of chlorofluorocarbons (CFC's) from aerosol cans, cooling systems and refrigerator equipment removes some of the ozone, causing "holes"; to open up in this layer and allowing the radiation to reach the earth. Ultraviolet radiation is known to cause skin cancer and has damaging effects on plants and wildlife. Additional resources and information about the ozone depletion problem are available from the National Oceanic and Atmospheric Administration (NOAA) and Ozone ACTION

What is air pollution

What is Air Pollution?

Air is the ocean we breathe. Air supplies us with oxygen which is essential for our bodies to live. Air is 99.9% nitrogen, oxygen, water vapor and inert gases. Human activities can release substances into the air, some of which can cause problems for humans, plants, and animals.
There are several main types of pollution and well-known effects of pollution which are commonly discussed. These include smog, acid rain, the greenhouse effect, and "holes" in the ozone layer. Each of these problems has serious implications for our health and well-being as well as for the whole environment.
One type of air pollution is the release of particles into the air from burning fuel for energy. Diesel smoke is a good example of this particulate matter . The particles are very small pieces of matter measuring about 2.5 microns or about .0001 inches. This type of pollution is sometimes referred to as "black carbon" pollution. The exhaust from burning fuels in automobiles, homes, and industries is a major source of pollution in the air. Some authorities believe that even the burning of wood and charcoal in fireplaces and barbeques can release significant quanitites of soot into the air.
Another type of pollution is the release of noxious gases, such as sulfur dioxide, carbon monoxide, nitrogen oxides, and chemical vapors. These can take part in further chemical reactions once they are in the atmosphere, forming smog and acid rain.
Pollution also needs to be considered inside our homes, offices, and schools. Some of these pollutants can be created by indoor activities such as smoking and cooking. In the United States, we spend about 80-90% of our time inside buildings, and so our exposure to harmful indoor pollutants can be serious. It is therefore important to consider both indoor and outdoor air pollution.

Air Pollution Causes and Effects

by Tom Socha


08/12/2007

History

Humans probably first experienced harm from air pollution when they built fires in poorly ventilated caves. Since then we have gone on to pollute more of the earth's surface. Until recently, environmental pollution problems have been local and minor because of the Earth's own ability to absorb and purify minor quantities of pollutants. The industrialization of society, the introduction of motorized vehicles, and the explosion of the population, are factors contributing toward the growing air pollution problem. At this time it is urgent that we find methods to clean up the air.

The primary air pollutants found in most urban areas are carbon monoxide, nitrogen oxides, sulfur oxides, hydrocarbons, and particulate matter (both solid and liquid). These pollutants are dispersed throughout the world's atmosphere in concentrations high enough to gradually cause serious health problems. Serious health problems can occur quickly when air pollutants are concentrated, such as when massive injections of sulfur dioxide and suspended particulate matter are emitted by a large volcanic eruption.

Air Pollution in the Home

You cannot escape air pollution, not even in your own home. "In 1985 the Environmental Protection Agency (EPA) reported that toxic chemicals found in the air of almost every American home are three times more likely to cause some type of cancer than outdoor air pollutants". (Miller 488) The health problems in these buildings are called "sick building syndrome". "An estimated one-fifth to one-third of all U.S. buildings are now considered "sick". (Miller 489) The EPA has found that the air in some office buildings is 100 times more polluted than the air outside. Poor ventilation causes about half of the indoor air pollution problems. The rest come from specific sources such as copying machines, electrical and telephone cables, mold and microbe-harboring air conditioning systems and ducts, cleaning fluids, cigarette smoke, carpet, latex caulk and paint, vinyl molding, linoleum tile, and building materials and furniture that emit air pollutants such as formaldehyde. A major indoor air pollutant is radon-222, a colorless, odorless, tasteless, naturally occurring radioactive gas produced by the radioactive decay of uranium-238. "According to studies by the EPA and the National Research Council, exposure to radon is second only to smoking as a cause of lung cancer". (Miller 489) Radon enters through pores and cracks in concrete when indoor air pressure is less than the pressure of gasses in the soil. Indoor air will be healthier than outdoor air if you use an energy recovery ventilator to provide a consistent supply of fresh filtered air and then seal air leaks in the shell of your home .

Sources of Pollutants

The two main sources of pollutants in urban areas are transportation (predominantly automobiles) and fuel combustion in stationary sources, including residential, commercial, and industrial heating and cooling and coal-burning power plants. Motor vehicles produce high levels of carbon monoxides (CO) and a major source of hydrocarbons (HC) and nitrogen oxides (NOx). Whereas, fuel combustion in stationary sources is the dominant source of sulfur dioxide (SO2).

Carbon Dioxide

Carbon dioxide (CO2) is one of the major pollutants in the atmosphere. Major sources of CO2 are fossil fuels burning and deforestation. "The concentrations of CO2 in the air around 1860 before the effects of industrialization were felt, is assumed to have been about 290 parts per million (ppm). In the hundred years and more since then, the concentration has increased by about 30 to 35 ppm that is by 10 percent". (Breuer 67) Industrial countries account for 65% of CO2 emissions with the United States and Soviet Union responsible for 50%. Less developed countries (LDCs), with 80% of the world's people, are responsible for 35% of CO2 emissions but may contribute 50% by 2020. "Carbon dioxide emissions are increasing by 4% a year". (Miller 450)

In 1975, 18 thousand million tons of carbon dioxide (equivalent to 5 thousand million tons of carbon) were released into the atmosphere, but the atmosphere showed an increase of only 8 billion tons (equivalent to 2.2 billion tons of carbon". (Breuer 70) The ocean waters contain about sixty times more CO2 than the atmosphere. If the equilibrium is disturbed by externally increasing the concentration of CO2 in the air, then the oceans would absorb more and more CO2. If the oceans can no longer keep pace, then more CO2 will remain into the atmosphere. As water warms, its ability to absorb CO2 is reduced.

CO2 is a good transmitter of sunlight, but partially restricts infrared radiation going back from the earth into space. This produces the so-called greenhouse effect that prevents a drastic cooling of the Earth during the night. Increasing the amount of CO2 in the atmosphere reinforces this effect and is expected to result in a warming of the Earth's surface. Currently carbon dioxide is responsible for 57% of the global warming trend. Nitrogen oxides contribute most of the atmospheric contaminants.

N0X - nitric oxide (N0) and nitrogen dioxide (N02)

-Natural component of the Earth's atmosphere.
-Important in the formation of both acid precipitation and photochemical smog (ozone), and causes nitrogen loading.
-Comes from the burning of biomass and fossil fuels.
-30 to 50 million tons per year from human activities, and natural 10 to 20 million tons per year.
-Average residence time in the atmosphere is days.
-Has a role in reducing stratospheric ozone.

N20 - nitrous oxide

-Natural component of the Earth's atmosphere.
-Important in the greenhouse effect and causes nitrogen loading.
-Human inputs 6 million tons per year, and 19 million tons per year by nature.
-Residence time in the atmosphere about 170 years.
-1700 (285 parts per billion), 1990 (310 parts per billion), 2030 (340 parts per billion).
-Comes from nitrogen based fertilizers, deforestation, and biomass burning.

Sulfur and chlorofluorocarbons (CFCs)

Sulfur dioxide is produced by combustion of sulfur-containing fuels, such as coal and fuel oils. Also, in the process of producing sulfuric acid and in metallurgical process involving ores that contain sulfur. Sulfur oxides can injure man, plants and materials. At sufficiently high concentrations, sulfur dioxide irritates the upper respiratory tract of human beings because potential effect of sulfur dioxide is to make breathing more difficult by causing the finer air tubes of the lung to constrict. "Power plants and factories emit 90% to 95% of the sulfur dioxide and 57% of the nitrogen oxides in the United States. Almost 60% of the SO2 emissions are released by tall smoke stakes, enabling the emissions to travel long distances". (Miller 494) As emissions of sulfur dioxide and nitric oxide from stationary sources are transported long distances by winds, they form secondary pollutants such as nitrogen dioxide, nitric acid vapor, and droplets containing solutions of sulfuric acid, sulfate, and nitrate salts. These chemicals descend to the earth's surface in wet form as rain or snow and in dry form as a gases fog, dew, or solid particles. This is known as acid deposition or acid rain.

Chlorofluorocarbons (CFCs)

CFCs are lowering the average concentration of ozone in the stratosphere. "Since 1978 the use of CFCs in aerosol cans has been banned in the United States, Canada, and most Scandinavian countries. Aerosols are still the largest use, accounting for 25% of global CFC use". (Miller 448) Spray cans, discarded or leaking refrigeration and air conditioning equipment, and the burning plastic foam products release the CFCs into the atmosphere. Depending on the type, CFCs stay in the atmosphere from 22 to 111 years. Chlorofluorocarbons move up to the stratosphere gradually over several decades. Under high energy ultra violet (UV) radiation, they break down and release chlorine atoms, which speed up the breakdown of ozone (O3) into oxygen gas (O2).

Chlorofluorocarbons, also known as Freons, are greenhouse gases that contribute to global warming. Photochemical air pollution is commonly referred to as "smog". Smog, a contraction of the words smoke and fog, has been caused throughout recorded history by water condensing on smoke particles, usually from burning coal. With the introduction of petroleum to replace coal economies in countries, photochemical smog has become predominant in many cities, which are located in sunny, warm, and dry climates with many motor vehicles. The worst episodes of photochemical smog tend to occur in summer.

Smog

Photochemical smog is also appearing in regions of the tropics and subtropics where savanna grasses are periodically burned. Smog's unpleasant properties result from the irradiation by sunlight of hydrocarbons caused primarily by unburned gasoline emitted by automobiles and other combustion sources. The products of photochemical reactions includes organic particles, ozone, aldehydes, ketones, peroxyacetyl nitrate, organic acids, and other oxidants. Ozone is a gas created by nitrogen dioxide or nitric oxide when exposed to sunlight. Ozone causes eye irritation, impaired lung function, and damage to trees and crops. Another form of smog is called industrial smog.

This smog is created by burning coal and heavy oil that contain sulfur impurities in power plants, industrial plants, etc... The smog consists mostly of a mixture of sulfur dioxide and fog. Suspended droplets of sulfuric acid are formed from some of the sulfur dioxide, and a variety of suspended solid particles. This smog is common during the winter in cities such as London, Chicago, Pittsburgh. When these cities burned large amounts of coal and heavy oil without control of the output, large-scale problems were witnessed. In 1952 London, England, 4,000 people died as a result of this form of fog. Today coal and heavy oil are burned only in large boilers and with reasonably good control or tall smokestacks so that industrial smog is less of a problem. However, some countries such as China, Poland, Czechoslovakia, and some other eastern European countries, still burn large quantities of coal without using adequate controls.

Pollution Damage to Plants

With the destruction and burning of the rain forests more and more CO2 is being released into the atmosphere. Trees play an important role in producing oxygen from carbon dioxide. "A 115 year old Beech tree exposes about 200,000 leaves with a total surface to 1200 square meters. During the course of one sunny day such a tree inhales 9,400 liters of carbon dioxide to produce 12 kilograms of carbohydrate, thus liberating 9,400 liters of oxygen. Through this mechanism about 45,000 liters of air are regenerated which is sufficient for the respiration of 2 to 3 people". (Breuer 1) This process is called photosynthesis which all plants go though but some yield more and some less oxygen. As long as no more wood is burnt than is reproduced by the forests, no change in atmospheric CO2 concentration will result.

Pollutants such as sulfur dioxide, nitrogen oxides, ozone and peroxyacl nitrates (PANs), cause direct damage to leaves of crop plants and trees when they enter leaf pores (stomates). Chronic exposure of leaves and needles to air pollutants can also break down the waxy coating that helps prevent excessive water loss and damage from diseases, pests, drought and frost. "In the midwestern United States crop losses of wheat, corn, soybeans, and peanuts from damage by ozone and acid deposition amount to about $5 billion a year". (Miller 498)

Reducing Pollution

You can help to reduce global air pollution and climate change by driving a car that gets at least 35 miles a gallon, walking, bicycling, and using mass transit when possible. Replace incandescent light bulbs with compact fluorescent bulbs, make your home more energy efficient, and buy only energy efficient appliances. Recycle newspapers, aluminum, and other materials. Plant trees and avoid purchasing products such as Styrofoam that contain CFCs. Support much stricter clean air laws and enforcement of international treaties to reduce ozone depletion and slow global warming.

Earth is everybody's home and nobody likes living in a dirty home. Together, we can make the earth a cleaner, healthier and more pleasant place to live.


--------------------------------------------------------------------------------

Works Cited:
Breuer, Georg, Air in Danger: Ecological Perspectives of the Atmosphere. New York: Cambridge University Press, 1980.
Stewart, T. Charles, Air Pollution, Human Health and Public Policy. New York: Lexington Books, 1979
Miller, G. Tyler, Living in the Environment: an introduction to environmental science. Belmont: Wadsworth, 1990.

--------------------------------------------------------------------------------

Additional Sources of Information:
Home, Sick Home — Johns Hopkins Science & Technology
Safety and Comfort in Your Home
Air Pollution and Respiratory Health — Centers for Disease Control & Prevention
Indoor Air Pollution
Clean Energy Gains Support

Outdoor Air Pollution
Cancer Epidemic: Symptom of an Unsustainable Society
Air Pollution Linked to Birth Defects
Inflammation is a Secret Killer
Clean energy and efficiency investments would create 3.3 million jobs, says study
State of the Air: 2004 — American Lung Association
Air Pollution — National Library of Medicine
Second National Report on Human Exposure to Environmental Chemicals — Centers for Disease Control & Prevention
Toxic Releases and Health: A Review of Pollution Data and Current Knowledge on the Health Effects of Toxic Chemicals
New Report Finds Cancer Risk From Air Pollution Nearly 500 Times Greater Than Clean Air Act Standard
Weatherization and Indoor Air Quality: Minimizing entry of outdoor air pollutants
Air Pollution: Our Children at Risk
Air pollution causes lung disease in school-age children
Air Pollution Causes Blood Vessels to Constrict — American Heart Association
Energy Department Data Confirm that President's Global Warming Plan Would Accelerate Pollution
How industry-funded "experts" twist the environmental debate
Mold (health effects, economic effects, mitigation, etc.)
Heavy Metal Toxicity
Fire's dangers drift far beyond flames
Tobacco Related Diseases
Real-Time Air Pollution and Visibility Monitoring (multiple outdoor web cams)


NOTE: You can help to reduce air pollution by improving energy efficiency so that less fossil fuel is burned. This will help you to endure the oil shortages and natural gas shortages.

The Donora Smog Disaster October 30-31, 1948

Manuscript Group 190: James H. Duff Papers, Subject File, Letter of Mrs. Lois Bainbridge of Webster, PA, to the Governor, October 31, 1948. One page, fountain pen ink on paper.


On October 30 and 31, 1948, atmospheric conditions in the vicinity of Donora, Pennsylvania, contributed to the deaths of nineteen people within a 24-hour period. Of the fatalities, two had active pulmonary tuberculosis. The other seventeen were known to have had chronic heart disease or asthma. All were between 52 and 85 years of age. In addition, approximately five hundred residents of the area became ill, reporting symptoms of respiratory problems. No doubt, countless others suffered in silence.

Donora is located on the western bank of the Monongahela River in Washington County. During the late Colonial period (1760s and 1770s), the area was known as "Horseshoe Bottom, because there the river curved into that shape. Nearby hills rise approximately 400 feet above the river's surface, and their peaks are approximately one mile apart. Early settlers grew grain in the fertile valley which led two of them to build a grain mill and lay out streets around it. By 1815, the village, then known as Columbia, contained twenty houses. In 1819, the postal authorities changed the name to West Columbia. Other small communities developed in the area including Bisselltown, Sunnyside, Bakertown, and Webster, which emerged on the other side of the river. These places remained little more than villages throughout the nineteenth century.

Modern Donora began in 1900 with the development of heavy industry in the area. The town was incorporated in 1901. Its name is a combination of Nora Mellon, wife of R. B. Mellon, and W. H. Donner, the purchasers of the land along the river on which their Union Steel Company constructed a rod mill that later became the American Steel and Wire Works. In 1902, the Carnegie Steel Company completed a facility that consisted of two blast furnaces, twelve open hearth furnaces, and a forty foot blooming mill furnace. At the same time, the Matthew Woven Wire Fence Company erected a facility. A third rod mill was constructed in 1916. A year earlier the Donora Zinc Works began production. Such industrial expansion required more effective transportation facilities than the river barges and short-line railroads could provide. The Pennsylvania Railroad bought what had been the Monongahela Valley Company and expanded rail service. By 1908, the Donora station had the largest volume of freight in the "Mon Valley." Of course, these industries needed workers, and job-seekers flocked to the area, especially recently arrived immigrants. In 1948, 14,000 people resided in Donora, and additional thousands lived in towns in the immediate vicinity.

The causes of the incident are difficult to identify conclusively, nevertheless, there are several obvious possibilities. Residents, such as Mrs. Lois Bainbridge, who wrote to Governor James T. Duff about the situation, stated that people in the area had complained for years abut the industrial pollutants that "eats the paint off your houses" and prevents fish from living in the river. Indeed, an investigation supervised by the director of the state government's Bureau of Industrial Hygiene revealed an extraordinarily high level of sulfur dioxide, soluble sulphants, and fluorides in the air on October 30 and 31. According to the agency's report and complaints by residents, such contamination of the atmosphere was caused by the zinc smelting plant, steel mills' open hearth furnaces, a sulphuric acid plant, with slag dumps, coal burning steam locomotives, and river boats also contributing to the problem. An unusually dense fog, the likes of which even long-time residents could not remember, may have been held in the valley by the surrounding hills. The fog probably kept the pollutants close to the earth's surface where the residents inhaled them.

Solutions to the problem were obvious. Mrs. Bainbridge charged that the zinc company officials "for years" had discussed moving the plant; however, they did not do it. As her letter indicates, she was certain that "there is something in the Zinc Works causing these deaths." She observed that when the "smelting plant" closed briefly after the crisis, "you could breathe normally…." She proposed also the installation of more modern equipment that "would help consume the fumes." Because the plants' owners had not acted to eliminate the pollutants, she proposed Washington County "Smoke Control" laws similar to those that were enacted in Pittsburgh a few years earlier.

Such solutions were difficult to implement. Moving or closing the offending industries could cost workers their jobs, as Mrs. Bainbridge acknowledged. Nevertheless, to her, men's jobs were less important than people's lives. The acquisition of new equipment and the use of new procedures could be costly which would affect adversely the profitability and practicality of manufacturing the product. Politicians were aware of the complexity of these issues and were reluctant to legislate on them.

The Donora Smog Disaster attracted attention to this problem. Although smog's effect on the people in and around Donora on October 30 and 31, 1948 was extreme, residents of other communities also suffered from environmental contaminants. Consequently in 1949, the state government established the Division of Air Pollution Control to study the matter. Eventually, members of Pennsylvania's General Assembly felt the pressure to cleanse Pennsylvania's atmosphere of harmful substances. Consequently, the legislature passed the clean streams law in 1965 and began to enact state wide clean air regulations in 1966. In 1970, the legislature passed an "Environmental Bill of Rights" which stated that "the people have a right to clean air, [and] pure water…." Simultaneously, the national government established the Environmental Protection Agency, and Congress passed the Clean Air Act. A few years later, Pennsylvania established the Department of Environmental Resources, one of the prominent objectives of which was "to ensure future generations of Commonwealth residents a quality environment." This function is carried on today by the Department of Environmental Protection. It might be noted too that many of the contaminating industries have left the state and some have left the nation. Whether there is a "cause and effect" relationship between environmental legislation and the loss of heavy industry is not clear.

The Donora Fluoride Fog : A Secret History of America's Worst Air Pollution Disaster

This article appears in the Fall 1998 Earth Island Journal
by Chris Bryson



The anniversary of the worst recorded industrial air pollution accident in US history - which occurred 50 years ago this October in Donora, Pennsylvania -will go virtually unmarked. The Donora incident, which killed 20 and left hundreds seriously injured and dying, was caused by fluoride emissions from the Donora Zinc Works and steel plants owned by the US Steel Corporation.

In the aftermath of the accident, US Steel conspired with US Public Health Service (PHS) officials to cover up the role fluoride played in the tragedy. This charge comes from Philip Sadtler, a top industrial chemical consultant who conducted his own research at the scene of the disaster.

Fifty years later, Earth Island Journal has learned, vital records of the Donora investigation are missing from PHS archives. Fifty years later, US Steel continues to block access to their records of the Donora disaster, including a crucial air chemical analysis taken on the final night of the tragedy.


The "Donora Death Fog"
Horror visited the US Steel company-town of Donora on Halloween night, 1948, when a temperature inversion descended on the town. Fumes from US Steel's smelting plants blanketed the town for four days, and crept murderously into the citizens' homes. If the smog had lasted another evening "the casualty list would have been 1,000 instead of 20," said local doctor William Rongaus at the time. Later investigations by Rongaus and others indicated that one-third of the town's 14,000 residents were affected by the smog. Hundreds of residents were evacuated or hospitalized. A decade later, Donora's mortality rate remained significantly higher than neighboring areas.
The "Donora Death Fog", as it became known, spawned numerous angry lawsuits and the first calls for national legislation to protect the public from industrial air pollution.

A PHS report released in 1949 reported that "no single substance" was responsible for the Donora deaths and laid major blame for the tragedy on the temperature inversion. But according to industry consultant Philip Sadtler, in an interview taped shortly before his 1996 death, that report was a whitewash. "It was murder," said Sadtler about Donora. "The directors of US Steel should have gone to jail for killing people." Sadtler charged that the PHS report helped US Steel escape liability for the deaths and spared a host of fluoride- emitting industries the expense of having to control their toxic emissions. (A class-action lawsuit by Donora victims families was later settled out of court.)

In 1948, Sadtler was perhaps the nation's leading expert on fluorine pollution. He had gathered evidence for plaintiffs across the country, including an investigation of the Manhattan Project and the DuPont company's fluoride pollution of New Jersey farmland during World War II [see "Fluoride and the A-Bomb", 1997-98 EIJ].

For giant fluoride emitters such as US Steel and the Aluminum Company of America (Alcoa), the cost of a national fluoride clean-up "would certainly have been in the billions," said Sadtler. So concealing the true cause of the Donora accident was vital. "It would have complicated things enormously for them if the public had been alerted to [the dangers of] fluoride."


A 50-Year Cover-up
US industry was well-placed to orchestrate a whitewash of the Donora investigation. The PHS was then a part of the Federal Security Agency. The FSA, in turn, was headed by Oscar R. Ewing, a former top lawyer for Alcoa. Neither his old industry connections, nor the fact that Alcoa had been facing lawsuits around the country for its wartime airborne fluoride pollution was mentioned in Ewing's introduction to the official report on Donora.

Sadtler remembers seeing a PHS van in Donora conducting air testing after the disaster. "I looked in and the chemist said, 'Phil, come on in.' Very friendly. He says, 'I know you are right, but I am not allowed to say so.' He must have been influenced by US Steel."

Sadtler blamed fluoride for the Donora disaster in an account published in the December 13, 1948 issue of Chemical and Engineering News. He reported fluorine blood levels of dead and hospitalized citizens to be 12 to 25 times above normal, with "primary symptoms of acute fluorine poisoning, dyspnea (distressed breathing similar to asthma) ... found in hundreds of cases." He recommended that, "Changes should be made in suspect processes to prevent emission of fluorine-containing fumes."

Industry moved quickly to silence Sadtler, who had been a contributor to Chemical and Engineering News for many years. (C&EN is published by the American Chemical Society.) "I had a call from the editor that I was not to send them any more [articles]," Sadtler said. The editor told Sadtler that the head of the Alcoa and the US Steel-funded Mellon Institute, Dr. [first name] Weidline (who also had served as a director of the American Chemical Society) "went to Washington and told [the magazine's editors] that they were not to publish any more of what I wrote," Sadtler said.


Looking Back on Donora
Today, 50 years later, researchers examining the Donora disaster face two troubling obstacle: (1) vital records are missing from the PHS archives and (2) US Steel's records are closed to reporters, researchers and investigators. In her 1994 doctoral dissertation ("The Death-Dealing Smog Over Donora, Pennsylvania: Industrial Air Pollution, Public Health Policy and the Politics of Expertise, 1948-1949"), Lynne Page Snyder of the University of Pennsylvania, described the response to the disaster.

The following excerpts were published in the Spring 1994 issue of the Environmental History Review.

"Pollution from the Donora Zinc Works smelting operation and other sources containing sulfur, carbon monoxide and heavy metal dusts, was trapped by weather conditions in the narrow river valley in and around Donora and neighboring Webster.

"Air pollution problems were recognized from the facility as early as 1918, when the plant owner paid off the legal claims for causing pollution that affected the health of nearby residents.

"In the 1920s, residents and farmers in Webster took legal action again against the company for loss of crops and livestock. Regular sampling of the air was begun in 1926 and stopped in 1935."

From local accounts of the time, Snyder provided this description of the 1948 disaster. "By Friday evening (October 2), local residents were crowding into nearby hospitals and dozens of calls were made to the area's eight physicians. While Fire Department volunteers administered oxygen to those unable to breathe, Board of Health member Dr. William Rongaus led an ambulance by foot through darkened streets to ferry the dead and dying to hospitals or on to a temporary morgue.

"On Rongaus' advice, those with chronic heart or respiratory ailments began to leave town late Friday evening, but before noon on Saturday, 11 people died. "Conditions had not improved by Saturday night, and with roads congested by smog and traffic, evacuation became impossible. The company operating the Donora Zinc Works finally ordered the plant shut down at 6 a.m. Sunday morning. By mid-day Sunday, rain had dispersed the smog.

"Pittsburgh itself escaped the episode primarily because it had just begun to enforce a smoke control ordinance and was cutting back on the use of bituminous coal as a fuel source. The Donora Smog gained national attention when Walter Winchell broadcast news of the disaster on his national radio show.

"The Pennsylvania Department of Health, United Steelworkers, Donora's Borough Council and the US Public Health Service all participated in the investigation of the air pollution incident. The investigation was the first time there was an organized effort to document the health impacts of air pollution in the United States. Commenting on the studies of the incident, the Monessen Daily Independent wrote that damage from air pollution from the Zinc Works was 'something no scientific investigation is necessary to prove. All you need is a pair of reasonably good eyes.'

"Before the Donora smog, neither manufacturers nor public health professionals considered air pollution an urgent issue. At the annual meeting of the Smoke Prevention Association in May 1949, a leading industrial physician and consultant to insurance companies dismissed air pollution as a threat, except 'on rare occasions [when] Mother Nature has played us false.''

"The studies of the Donora Smog did not fix blame and could not document levels of pollution beyond workplace limits set at the time. The Public Health Service recommended a warning system tied to weather forecasts and an air sampling system be installed to avoid future incidents. The lessons learned at Donora resulted in the passage of the 1955 Clean Air Act and began modern air pollution control efforts in the Commonwealth.

Snyder learned that US Steel had conducted an air analysis on the final night of the smog. But despite her numerous requests for the Donora records, Snyder recalls, US Steel officials finally informed her that they didn't "have anything for me." Equally frustrating to Snyder was the missing PHS records. At the time, Donora was the largest environmental investigation the government agency ever had mounted. "The kinds of papers I would expect to find are the correspondence files, the original and carbon copies of responses sent out, typed-up site visits, typed-up telephone conversations, maps, rough drafts of reports, photos," Snyder explained. But all these records have vanished.

"You have to suspect the worst. Not only of US Steel, but of the Public Health Service," Snyder says. Now herself a PHS historian, she concludes of the Donora records, "Someone may have decided they were too hot to handle and got rid of them. I'm open to that prospect."

Transcripts of Philip Sadtler's historic full interview are available from Earth Island Journal.

-------------------------------

Chris Bryson is a New York-based investigative reporter and co-author with Joel Griffiths of Fluoride and the A-Bomb (Winter 97-98 EIJ).This report was compiled with research assistance by Ellie Rudolph

-------------------------------


Death in Donora
I have felt the fog in my throat --
The misty hand of Death caress my face;
I have wrestled with a frightful foe
Who strangled me with wisps of gray fog-lace.
Now in my eyes since I have died.
The bleak, bare hills rise in stupid might
With scars of its slavery imbedded deep;
And the people still live -- still live -- in the poisonous night.

Folklorist Dan G. Hoffman reported collecting the ballad "Death in Donora" from area resident John P. Clark

-------------------------------

Sidebar: Fluoride and the Mohawks

Cows crawled around the pasture on their bellies, inching along like giant snails. So crippled by bone disease they could not stand up, this was the only way they could graze. Some died kneeling, after giving birth to stunted calves. Others kept on crawling until, no longer able to chew because their teeth had crumbled down to the nerves, they began to starve.

These were the cattle of the Mohawk Indians on the New York-Canadian St. Regis Reservation during the period 1960-75, when fluoride pollution from neighboring aluminum plants devastated the herd and the Mohawks' way of life. Crops and trees withered, birds and bees fled from this remnant of land the Mohawk still call Akwesasne, "the land where the partridge drums."

Today, nets cast into the St. Lawrence River by Mohawk fishers bring up ulcerated fish with spinal deformities. Mohawk children, too, have shown signs of damage to bones and teeth.

In 1980, the Mohawks filed a $150 million lawsuit for damage to themselves and their property against the companies responsible for the pollution: the Reynolds Metals Co. and the Aluminum Co. of America. But five years of legal costs bankrupted the tribe and they settled for $650,000 in damages to their cows. The court left the door open for a future Mohawk suit for damage to their own health. After all, commented human rights lawyer Robert Pritchard, "What judge wants to go down in history as being the judge who approved the annihilation of the Indians by fluoride emissions?" -- Joel Griffiths


The lessons learned at Donora resulted in the passage of the 1955 Clean Air Act America's worst air pollution disaster may have been caused by fluoride emissions: 50 years later, vital records are still missing.

World Environment Day : Cars choking and killing us with ozone

The exhaust fumes of every vehicle on the road contributes to ground level ozone, pushing it to levels harmful to humans.


KUALA LUMPUR: Look out of your window. On a good day, you’ll have a nice view, but chances are your view will be obscured by smog, caused largely by vehicle emissions.


From the first day a car is on the road till it is abandoned, usually about 20 years later, it gulps 80,000 to 100,000 litres of fuel. While the emissions from one car might not be much, multiply this by the seven million cars on the road every day and the results are horrific.

Add to this, the 500,000 new cars that hit the roads each year, increasing the ground-level ozone produced by their exhaust fumes.

Experts say the only way to reduce hazardous ground level ozone is to switch to public transportation. Just doing that reduces ground level pollution by a factor of 10 for those travelling by bus, and 200 by LRT.

A study by Universiti Kebangsaan Malaysia transport expert Prof Dr Rahim Mat Noor showed that ground level ozone in Kuala Lumpur increased by 203 per cent over nine years.

"If motorists, especially in the Klang Valley, do not switch to public transportation, then the level of ground level ozone will become harmful to humans," he said, adding that levels were on the rise in other parts of the country as well.

Unlike ozone depletion in the upper atmosphere, caused by greenhouse gases, ground level ozone is caused by air pollution at ground level. It is a by-product of the chemicals released from car exhausts, and it is the prime ingredient of urban smog.

Heat and sun play a crucial role in the formation of ground level ozone, a particular danger in tropical cities like Kuala Lumpur. His analysis showed ground level ozone was increasing at a rate of 22.6 per cent per year.

"Our estimates show that ground level ozone will soon increase from 30 parts per billion (ppb) to 91 ppb. By 2010, it will go up to 114 ppb."



Each part per billion represents a dot out of a billion dots of sand.

He added that health problems such as asthma and other upper respiratory tract problems could increase when the ground ozone level hits 50 ppb.

Ground level ozone is highly caustic, and prolonged exposure to elevated levels can damage lung tissues, causing respiratory problems and decreasing lung function.

"Short-term exposure can result in choking, coughing, burning eyes, and nasal and respiratory irritation," Rahim said. "Repeated exposure can diminish the body’s ability to fight off respiratory infections, and may be linked to the scarring of lung tissue."



Using public transport would help to reduce the production of ground level ozone, he added.

"Global warming is here and the effects are scary. People should sacrifice a small bit of comfort to save the earth."


Posted by Azizi Abu Bakar::.

CFC???

Air pollution
Environmental issue - Chlorofluorocarbon?

Since the late 1970s the use of CFCs has been heavily regulated because of its destructive effects on the ozone layer. After the development of his atmospheric CFC detector, James Lovelock was the first to detect the presence of CFC's in the air, finding a concentration of 60 parts per trillion of CFC-11 over Ireland. In a self-funded research expedition ending in 1973, Lovelock went on to measure the concentration of CFC-11 in both the arctic and Antarctic, finding the presence of the gas in each of 50 air samples collected, but incorrectly concluding that CFC's are not hazardous to the environment. The experiment did however provide the first useful data on the presence of CFC's in the atmosphere. The damage caused by CFC's discovered by Sherry Rowland and Mario Molina who, after hearing a lecture on the subject of Lovelocks work, embarked on research resulting in the first published paper suggesting the connection in 1974. It turns out that one of CFCs' most attractive features—their unreactivity—has been instrumental in making them one of the most significant pollutants. CFCs' lack of reactivity gives them a lifespan which can exceed 100 years in some cases. This gives them time to diffuse into the upper stratosphere. Here, the sun's ultraviolet radiation is strong enough to break off the chlorine atom, which on its own is a highly reactive free radical. This catalyzes the break up of ozone into oxygen by means of a variety of mechanisms, of which the simplest is:

Cl· + O3 → ClO· + O2
ClO· + O3 → Cl· + 2 O2

Since the chlorine is regenerated at the end of these reactions, a single Cl atom can destroy many thousands of ozone molecules. Reaction schemes similar to this one (but more complicated) are believed to be the cause of the ozone hole observed over the poles and upper latitudes of the Earth. Decreases in stratospheric ozone may lead to increases in skin cancer.
In 1975, the US state of Oregon enacted the world's first ban of CFCs (legislation introduced by Walter F. Brown). The United States and several European countries banned the use of CFCs in aerosol spray cans in 1978, but continued to use them in refrigeration, foam blowing, and as solvents for cleaning electronic equipment. By 1985, scientists observed a dramatic seasonal depletion of the ozone layer over Antarctica. International attention to CFCs resulted in a meeting of world diplomats in Montreal in 1987. They forged a treaty, the Montreal Protocol, which called for drastic reductions in the production of CFCs. On March 2, 1989, 12 European Community nations agreed to ban the production of all CFCs by the end of the century. In 1990, diplomats met in London and voted to significantly strengthen the Montreal Protocol by calling for a complete elimination of CFCs by the year 2000. By the year 2010 CFCs should be completely eliminated from developing countries as well.

Ozone-depleting gas trends

Because the only available CFC gases in countries adhering to the treaty is from recycling, their prices have gone up considerably. A worldwide end to production should also terminate the smuggling of this material, such as from Mexico to the United States.
A number of substitutes for CFCs have been introduced. Hydrochlorofluorocarbons (HCFCs) are much more reactive than CFCs, so a large fraction of the HCFCs emitted break down in the troposphere, and hence are removed before they have a chance to affect the ozone layer. Nevertheless, a significant fraction of the HCFCs do break down in the stratosphere and they have contributed to more chlorine buildup there than originally predicted. Development of non-chlorine based chemical compounds as a substitute for CFCs and HCFCs continues. One such class are the hydrofluorocarbons (HFCs), which contain only hydrogen and fluorine. One of these compounds, HFC-134a, is now used in place of CFC-12 in automobile air conditioners.
There is concern that halons are being broken down in the atmosphere to bromine, which reacts with ozone, leading to depletion of the ozone layer (this is similar to the case of chlorofluorocarbons such as freon). These issues are complicated: the kinds of fires that require halon extinguishers to be put out will typically cause more damage to the ozone layer than the halon itself, not to mention human and property damage. However, fire extinguisher systems must be tested regularly, and these tests may lead to damage. As a result, some regulatory measures have been taken, and halons are being phased out in most of the world.
In the United States, purchase and use of freon gases is regulated by the Environmental Protection Agency, and substantial fines have been levied for their careless venting. Also, licenses, good for life, are required to buy or use these chemicals. The EPA website discusses these rules in great detail, and also lists numerous private companies that are approved to give examinations for these certificates.

There are two kinds of licenses. Obtaining a "Section 609" license to use CFCs to recharge old (pre-1993 model year) car air conditioners is fairly easy and requires only an online multiple choice test offered by several companies. Companies that use unlicensed technicians for CFC recharge operations are subject to a US$15,000 fine per technician by the EPA.
The "Section 608" license, needed to recharge CFC-using stationary and non-automobile mobile units, is also multiple choice but more difficult. A general knowledge test is required, plus separate exams for small size (such as home refrigerator) units, and for high and low pressure systems. These are respectively called Parts I, II, and III. A person who takes and passes all tests receives a "Universal" license; otherwise, one that is endorsed only for the respectively passed Parts. While the general knowledge and Part I exams can be taken online, taking them before a proctor (which has to be done for Parts II and III) lets the applicant pass these tests with lower scores.