Mulch: the great cover-up - varieties and application techniques
WHEN A LEAF FALLS IN THE woods, it is not likely that anyone would pick it up. Leaves, plant litter and other organic debris cover the forest floor, grass layers build up over the prairie and rocks and gravel top off the sandy soil in desert areas. No matter what the climate or topography, the soil in nature is covered with some kind of mulch. It pays for us to apply this lesson in our home gardens as well, to reap the benefits that nature has enjoyed from the beginning.
FOUR REASONS TO MULCH
Smother out weeds. A mulch on top of your soil reduces weeds in two ways. First, it blocks the weed seeds that blow into the area from above by providing a less hospitable germination bed than bare soil. Second, it blocks many weed seeds already in your soil that may try to sprout up from below. The deeper the mulch, the more weeds you will block.
For more effective weed blocking, lay down a three-page layer of newspaper before applying your mulching material. The newspaper will provide an additional weed barrier and will decay into the soil over time.
Conserve moisture. Water evaporates more quickly from soil that is left naked. A mulch not only shades the soil from the hot sun, but organic mulches soften the earth and improve aeration as they slowly decompose. This softening encourages plant roots to reach down deeper, where they are more likely to find moisture on their own.
Sunday, March 30, 2008
Mulch: the great cover-up - varieties and application techniques
Mulch: the great cover-up - varieties and application techniques
WHEN A LEAF FALLS IN THE woods, it is not likely that anyone would pick it up. Leaves, plant litter and other organic debris cover the forest floor, grass layers build up over the prairie and rocks and gravel top off the sandy soil in desert areas. No matter what the climate or topography, the soil in nature is covered with some kind of mulch. It pays for us to apply this lesson in our home gardens as well, to reap the benefits that nature has enjoyed from the beginning.
FOUR REASONS TO MULCH
Smother out weeds. A mulch on top of your soil reduces weeds in two ways. First, it blocks the weed seeds that blow into the area from above by providing a less hospitable germination bed than bare soil. Second, it blocks many weed seeds already in your soil that may try to sprout up from below. The deeper the mulch, the more weeds you will block.
For more effective weed blocking, lay down a three-page layer of newspaper before applying your mulching material. The newspaper will provide an additional weed barrier and will decay into the soil over time.
Conserve moisture. Water evaporates more quickly from soil that is left naked. A mulch not only shades the soil from the hot sun, but organic mulches soften the earth and improve aeration as they slowly decompose. This softening encourages plant roots to reach down deeper, where they are more likely to find moisture on their own.
WHEN A LEAF FALLS IN THE woods, it is not likely that anyone would pick it up. Leaves, plant litter and other organic debris cover the forest floor, grass layers build up over the prairie and rocks and gravel top off the sandy soil in desert areas. No matter what the climate or topography, the soil in nature is covered with some kind of mulch. It pays for us to apply this lesson in our home gardens as well, to reap the benefits that nature has enjoyed from the beginning.
FOUR REASONS TO MULCH
Smother out weeds. A mulch on top of your soil reduces weeds in two ways. First, it blocks the weed seeds that blow into the area from above by providing a less hospitable germination bed than bare soil. Second, it blocks many weed seeds already in your soil that may try to sprout up from below. The deeper the mulch, the more weeds you will block.
For more effective weed blocking, lay down a three-page layer of newspaper before applying your mulching material. The newspaper will provide an additional weed barrier and will decay into the soil over time.
Conserve moisture. Water evaporates more quickly from soil that is left naked. A mulch not only shades the soil from the hot sun, but organic mulches soften the earth and improve aeration as they slowly decompose. This softening encourages plant roots to reach down deeper, where they are more likely to find moisture on their own.
The gentle art of forcing bulbs - Brief Article
The gentle art of forcing bulbs - Brief Article
Coax spring bulbs to flower indoors during winter
In the dead of winter, spring-blooming bulbs are especially welcome in the house. They can easily fill a room with a delightful perfume and remind you that spring really is just around the corner.
The process of getting flower bulbs to bloom ahead of schedule is called forcing. Depending on the kind of bulbs you choose, you could enjoy your first blooms in less than 10 weeks.
We list several popular bulbs, which you can find at most nurseries and garden centers this month or buy through mail-order catalogs. Note that many bulbs require a certain amount of chilling; some need to be refrigerated, others can be planted then chilled outdoors (see "Forcing tips" on page 83). Chilling periods given here are based on the recommendations of the Netherlands Flower Bulb Information Center.
CROCUS AND HYACINTHS must be chilled. They can be forced, one bulb per jar or vase, in water alone without any soil; there are special forcing jars and vases for crocus and hyacinths.
Crocus corms need to be refrigerated for 15 weeks. After chilling, place each corm in its own water-filled crocus forcing jar or vase at around 60[degrees]; flowers will emerge in about two weeks. Choose Crocus vernus in shades of purple, lavender, yellow, or white.
Hyacinth bulbs need to be refrigerated for 12 weeks. Then place each bulb in a water-filled hyacinth forcing jar or vase at around 70[degrees]; flowers follow in two or three weeks. Try fragrant Dutch hyacinths in shades of blue, purple, pink, or white.
Coax spring bulbs to flower indoors during winter
In the dead of winter, spring-blooming bulbs are especially welcome in the house. They can easily fill a room with a delightful perfume and remind you that spring really is just around the corner.
The process of getting flower bulbs to bloom ahead of schedule is called forcing. Depending on the kind of bulbs you choose, you could enjoy your first blooms in less than 10 weeks.
We list several popular bulbs, which you can find at most nurseries and garden centers this month or buy through mail-order catalogs. Note that many bulbs require a certain amount of chilling; some need to be refrigerated, others can be planted then chilled outdoors (see "Forcing tips" on page 83). Chilling periods given here are based on the recommendations of the Netherlands Flower Bulb Information Center.
CROCUS AND HYACINTHS must be chilled. They can be forced, one bulb per jar or vase, in water alone without any soil; there are special forcing jars and vases for crocus and hyacinths.
Crocus corms need to be refrigerated for 15 weeks. After chilling, place each corm in its own water-filled crocus forcing jar or vase at around 60[degrees]; flowers will emerge in about two weeks. Choose Crocus vernus in shades of purple, lavender, yellow, or white.
Hyacinth bulbs need to be refrigerated for 12 weeks. Then place each bulb in a water-filled hyacinth forcing jar or vase at around 70[degrees]; flowers follow in two or three weeks. Try fragrant Dutch hyacinths in shades of blue, purple, pink, or white.
Chlorofluorocarbons (CFCs)
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:
To enlarge the image, click on it.
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.
2 Causes of water pollution?
Water pollution can come from a number of different sources. If the pollution comes from a single source, such as an oil spill, it is called point-source pollution. If the pollution comes from many sources, it is called no point-source pollution.
Most types of pollution affect the immediate area surrounding the source. Sometimes the pollution may affect the environment hundreds of miles away from the source, such as nuclear waste, this is called Tran boundary pollution.
Domestic households, industrial and agricultural practices produce wastewater that can cause pollution of many lakes and rivers.
· Sewage is the term used for wastewater that often contains faces, urine and laundry waste.
· There are billions of people on Earth, so treating sewage is a big priority.
· Sewage disposal is a major problem in developing countries as many people in these areas don’t have access to sanitary conditions and clean water.
· Untreated sewage water in such areas can contaminate the environment and cause diseases such as diarrhea.
· Sewage in developed countries is carried away from the home quickly and hygienically through sewage pipes.
· Sewage is treated in water treatment plants and the waste is often disposed into the sea.
· Sewage is mainly biodegradable and most of it is broken down in the environment.
· In developed countries, sewage often causes problems when people flush chemical and pharmaceutical substances down the toilet. When people are ill, sewage often carries harmful viruses and bacteria into the environment causing health problems.
Industry is a huge source of water pollution, it produces pollutants that are extremely harmful to people and the environment.
· Many industrial facilities use freshwater to carry away waste from the plant and into rivers, lakes and oceans.
· Pollutants from industrial sources include:
o Asbestos – This pollutant is a serious health hazard and carcinogenic. Asbestos fibers can be inhaled and cause illnesses such as asbestosis, mesothelioma, lung cancer, intestinal cancer and liver cancer.
o Lead – This is a metallic element and can cause health and environmental problems. It is a non-biodegradable substance so is hard to clean up once the environment is contaminated. Lead is harmful to the health of many animals, including humans, as it can inhibit the action of bodily enzymes.
o Mercury - This is a metallic element and can cause health and environmental problems. It is a non-biodegradable substance so is hard to clean up once the environment is contaminated. Mercury is also harmful to animal health as it can cause illness through mercury poisoning.
o Nitrates – The increased use of fertilizers means that nitrates are more often being washed from the soil and into rivers and lakes. This can cause eutrophication, which can be very problematic to marine environments.
o Phosphates - The increased use of fertilizers means that phosphates are more often being washed from the soil and into rivers and lakes. This can cause eutrophication, which can be very problematic to marine environments.
o Sulphur – This is a non
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:
To enlarge the image, click on it.
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.
2 Causes of water pollution?
Water pollution can come from a number of different sources. If the pollution comes from a single source, such as an oil spill, it is called point-source pollution. If the pollution comes from many sources, it is called no point-source pollution.
Most types of pollution affect the immediate area surrounding the source. Sometimes the pollution may affect the environment hundreds of miles away from the source, such as nuclear waste, this is called Tran boundary pollution.
Domestic households, industrial and agricultural practices produce wastewater that can cause pollution of many lakes and rivers.
· Sewage is the term used for wastewater that often contains faces, urine and laundry waste.
· There are billions of people on Earth, so treating sewage is a big priority.
· Sewage disposal is a major problem in developing countries as many people in these areas don’t have access to sanitary conditions and clean water.
· Untreated sewage water in such areas can contaminate the environment and cause diseases such as diarrhea.
· Sewage in developed countries is carried away from the home quickly and hygienically through sewage pipes.
· Sewage is treated in water treatment plants and the waste is often disposed into the sea.
· Sewage is mainly biodegradable and most of it is broken down in the environment.
· In developed countries, sewage often causes problems when people flush chemical and pharmaceutical substances down the toilet. When people are ill, sewage often carries harmful viruses and bacteria into the environment causing health problems.
Industry is a huge source of water pollution, it produces pollutants that are extremely harmful to people and the environment.
· Many industrial facilities use freshwater to carry away waste from the plant and into rivers, lakes and oceans.
· Pollutants from industrial sources include:
o Asbestos – This pollutant is a serious health hazard and carcinogenic. Asbestos fibers can be inhaled and cause illnesses such as asbestosis, mesothelioma, lung cancer, intestinal cancer and liver cancer.
o Lead – This is a metallic element and can cause health and environmental problems. It is a non-biodegradable substance so is hard to clean up once the environment is contaminated. Lead is harmful to the health of many animals, including humans, as it can inhibit the action of bodily enzymes.
o Mercury - This is a metallic element and can cause health and environmental problems. It is a non-biodegradable substance so is hard to clean up once the environment is contaminated. Mercury is also harmful to animal health as it can cause illness through mercury poisoning.
o Nitrates – The increased use of fertilizers means that nitrates are more often being washed from the soil and into rivers and lakes. This can cause eutrophication, which can be very problematic to marine environments.
o Phosphates - The increased use of fertilizers means that phosphates are more often being washed from the soil and into rivers and lakes. This can cause eutrophication, which can be very problematic to marine environments.
o Sulphur – This is a non
Say goodbye to paper airline tickets
Say goodbye to paper airline tickets
All-electronic tickets will save money, add convenience for customers
NEW YORK - Next summer, paper airline tickets will go the way of vinyl records and rotary-dial phones: They won't entirely disappear, but they'll be hard to find.
On June 1, the industry association that handles ticketing for most major airlines will stop issuing paper tickets. Some small regional or foreign airlines will continue issuing paper tickets, but they'll be few and far between.
Indeed, even without the International Air Transport Association's directive, the vast majority of airline tickets are already electronic. IATA says paper tickets have fallen to less than 14 percent of the 400 million tickets it processes each year.
On its face, the move to all electronic ticketing is a no-brainer for the airline industry. Paper tickets cost airlines $10 to $17, on average, compared with $1 or less for electronic tickets. A fully electronic ticketing system will save the industry $3 billion a year, the IATA estimates.
"From the airline perspective, it's 100 percent upside," said Robert Mann, an airline consultant in Port Washington, N.Y.
dition to pure cost savings, electronic ticketing lets airlines record revenue more quickly on their balance sheets and track revenue patterns. Airlines used to have to bundle and ship tickets to a processing facility, where each ticket had to be fed into a computer, before revenue could be booked or analyzed.
The industry also says electronic ticketing is more convenient to customers, who can manage their own bookings and make changes online without needing to call a travel agent or airline representative.
"It's very simple for the customer and has far superior protections for the customer," said Tim Smith, a spokesman for American Airlines parent AMR Corp.
Mann has a slightly different take.
"What's really happened here is that a lot of the work has been outsourced to the customer," Mann said.
Travelers holding electronic tickets perform most of the functions that used to be handled by the airlines, including in many cases booking their flights at a Web site, printing their itinerary, checking in for their flights online and printing a boarding pass from an airport kiosk.
Many people prefer it that way, but those who don't will still have the option of booking through a travel agent or airline sales representative.
Lorne Riley, an IATA spokesman, says electronic tickets are more secure than the paper variety, which can be easily forged. Mann notes that many foreign countries require travelers to present a ticket for either onward or return travel to gain entry. Riley said printed itineraries are accepted in most cases as proof of electronic ticket-based travel plans.
Most airlines have already mostly phased out paper tickets — AMR's Smith estimates that more than 98 percent of American's tickets are electronic — so the IATA move largely just codifies an industry shift that has already occurred.
Some smaller airlines will likely stick with paper ticketing, for now.
"It's ones for whom moving to a fully electronic system doesn't make economic sense," such as small regional carriers that fly a few thousand customers a year, who will keep issuing paper tickets, Mann said.
"Some carriers ... they'll just continue to provide their own solution," said Riley.
Indeed, the IATA's move applies only to the 70 to 75 percent of overall airline tickets. The IATA does not represent low-cost carriers such as Ryanair Holdings PLC and Southwest Airlines.
"We do not have any plans of eliminating paper stock," said Jeannine Rahe, a spokeswoman for the Airline Reporting Corp., or ARC, a separate organization that processes 169 million airline transactions, including tickets and exchanges, each year.
Still, Rahe said 96.8 percent of the tickets ARC processes are electronic.
All-electronic tickets will save money, add convenience for customers
NEW YORK - Next summer, paper airline tickets will go the way of vinyl records and rotary-dial phones: They won't entirely disappear, but they'll be hard to find.
On June 1, the industry association that handles ticketing for most major airlines will stop issuing paper tickets. Some small regional or foreign airlines will continue issuing paper tickets, but they'll be few and far between.
Indeed, even without the International Air Transport Association's directive, the vast majority of airline tickets are already electronic. IATA says paper tickets have fallen to less than 14 percent of the 400 million tickets it processes each year.
On its face, the move to all electronic ticketing is a no-brainer for the airline industry. Paper tickets cost airlines $10 to $17, on average, compared with $1 or less for electronic tickets. A fully electronic ticketing system will save the industry $3 billion a year, the IATA estimates.
"From the airline perspective, it's 100 percent upside," said Robert Mann, an airline consultant in Port Washington, N.Y.
dition to pure cost savings, electronic ticketing lets airlines record revenue more quickly on their balance sheets and track revenue patterns. Airlines used to have to bundle and ship tickets to a processing facility, where each ticket had to be fed into a computer, before revenue could be booked or analyzed.
The industry also says electronic ticketing is more convenient to customers, who can manage their own bookings and make changes online without needing to call a travel agent or airline representative.
"It's very simple for the customer and has far superior protections for the customer," said Tim Smith, a spokesman for American Airlines parent AMR Corp.
Mann has a slightly different take.
"What's really happened here is that a lot of the work has been outsourced to the customer," Mann said.
Travelers holding electronic tickets perform most of the functions that used to be handled by the airlines, including in many cases booking their flights at a Web site, printing their itinerary, checking in for their flights online and printing a boarding pass from an airport kiosk.
Many people prefer it that way, but those who don't will still have the option of booking through a travel agent or airline sales representative.
Lorne Riley, an IATA spokesman, says electronic tickets are more secure than the paper variety, which can be easily forged. Mann notes that many foreign countries require travelers to present a ticket for either onward or return travel to gain entry. Riley said printed itineraries are accepted in most cases as proof of electronic ticket-based travel plans.
Most airlines have already mostly phased out paper tickets — AMR's Smith estimates that more than 98 percent of American's tickets are electronic — so the IATA move largely just codifies an industry shift that has already occurred.
Some smaller airlines will likely stick with paper ticketing, for now.
"It's ones for whom moving to a fully electronic system doesn't make economic sense," such as small regional carriers that fly a few thousand customers a year, who will keep issuing paper tickets, Mann said.
"Some carriers ... they'll just continue to provide their own solution," said Riley.
Indeed, the IATA's move applies only to the 70 to 75 percent of overall airline tickets. The IATA does not represent low-cost carriers such as Ryanair Holdings PLC and Southwest Airlines.
"We do not have any plans of eliminating paper stock," said Jeannine Rahe, a spokeswoman for the Airline Reporting Corp., or ARC, a separate organization that processes 169 million airline transactions, including tickets and exchanges, each year.
Still, Rahe said 96.8 percent of the tickets ARC processes are electronic.
6 Great Las Vegas Hotels
6 Great Las Vegas Hotels
Looking for tips on just the right place to stay on your Las Vegas vacation? There are a lot of great hotels in Vegas, but these six definitely stand out.
Wynn Hotel
The newest masterpiece by Vegas hotel legend Steve Wynn, the 50-story Wynn Hotel opened in 2004 with 2,716 rooms, an 18-hole golf course, 19 restaurants, and 54 private spa treatment rooms. His namesake hotel displays his amazing art collection, offers incredible shopping right on site, and has a posh private lobby for VIPs. And of course, there's an awesome state-of-the-art casino at it's heart.
Bellagio
Built by Steve Wynn in 1998, the lavish Bellagio has excellent rooms, awesome service, and an amazing water fountain show. In December 2004, just before the Wynn Hotel opened, the Bellagio added a special 928-room Spa Tower, boosting total capacity to 3,933 rooms. The Bellagio is so ritzy that they offer a 50-minute body bronzing treatment with real gold dust.
THEhotel at Mandalay Bay
This all-suite exclusive hotel within the larger Mandalay Bay property has 1,117 rooms that aim for a more cosmopolitan clientele than it's namesake parent. Each suite is 725 square feet of luxury with three flat-screen televisions, including one in the mega-swank bathrooms.
Four Seasons
Another swank luxury hotel within the Mandalay Bay complex, the Four Seasons occupies floors 35-39 and has rates much higher than the standard $119-$349 of its parent. Four Seasons guests have their own elevator and entrance, plus pools, spa, and restaurants in an adjacent building.
Ritz Carlton at Lake Las Vegas
The Ritz Carlton hotel is a half-hour's drive from the Strip, but it's renowned for it's golfing and outdoor activities. It nestles against manmade Lake Las Vegas where the water offers a refreshing alternative to the summertime heat. This three-year-old Tuscan-themed resort still maintains a touch of the glitz: Guests can stay on a special bridge with suites built to recreate Florence's legendary Ponte Vecchio (Bridge of Gold).
Venetian Resort Hotel Casino
Located near the Wynn, this 4,027-suite hotel is part of the Sands Hotel group. Rooms are luxuriously appointed and the casino is magnificent. Coming this summer is a new theater hosting Andrew Lloyd Webber's smash hit musical, the "Phantom of the Opera."
So, there you have it. Six great Vegas hotels that will never fail to dazzle and are guaranteed to impress even the most jaded repeat visitor. Just be sure to book ahead to get the best discounts on room rates and snag hard-to-get show tickets well in advance.
Looking for tips on just the right place to stay on your Las Vegas vacation? There are a lot of great hotels in Vegas, but these six definitely stand out.
Wynn Hotel
The newest masterpiece by Vegas hotel legend Steve Wynn, the 50-story Wynn Hotel opened in 2004 with 2,716 rooms, an 18-hole golf course, 19 restaurants, and 54 private spa treatment rooms. His namesake hotel displays his amazing art collection, offers incredible shopping right on site, and has a posh private lobby for VIPs. And of course, there's an awesome state-of-the-art casino at it's heart.
Bellagio
Built by Steve Wynn in 1998, the lavish Bellagio has excellent rooms, awesome service, and an amazing water fountain show. In December 2004, just before the Wynn Hotel opened, the Bellagio added a special 928-room Spa Tower, boosting total capacity to 3,933 rooms. The Bellagio is so ritzy that they offer a 50-minute body bronzing treatment with real gold dust.
THEhotel at Mandalay Bay
This all-suite exclusive hotel within the larger Mandalay Bay property has 1,117 rooms that aim for a more cosmopolitan clientele than it's namesake parent. Each suite is 725 square feet of luxury with three flat-screen televisions, including one in the mega-swank bathrooms.
Four Seasons
Another swank luxury hotel within the Mandalay Bay complex, the Four Seasons occupies floors 35-39 and has rates much higher than the standard $119-$349 of its parent. Four Seasons guests have their own elevator and entrance, plus pools, spa, and restaurants in an adjacent building.
Ritz Carlton at Lake Las Vegas
The Ritz Carlton hotel is a half-hour's drive from the Strip, but it's renowned for it's golfing and outdoor activities. It nestles against manmade Lake Las Vegas where the water offers a refreshing alternative to the summertime heat. This three-year-old Tuscan-themed resort still maintains a touch of the glitz: Guests can stay on a special bridge with suites built to recreate Florence's legendary Ponte Vecchio (Bridge of Gold).
Venetian Resort Hotel Casino
Located near the Wynn, this 4,027-suite hotel is part of the Sands Hotel group. Rooms are luxuriously appointed and the casino is magnificent. Coming this summer is a new theater hosting Andrew Lloyd Webber's smash hit musical, the "Phantom of the Opera."
So, there you have it. Six great Vegas hotels that will never fail to dazzle and are guaranteed to impress even the most jaded repeat visitor. Just be sure to book ahead to get the best discounts on room rates and snag hard-to-get show tickets well in advance.
1.write causes and consequences of air polluion?
1.write causes and consequences of air polluion?
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
To enlarge an image, click on it.
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:
To enlarge the image, click on it.
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.
2 Causes of water pollution?
Water pollution can come from a number of different sources. If the pollution comes from a single source, such as an oil spill, it is called point-source pollution. If the pollution comes from many sources, it is called no point-source pollution.
Most types of pollution affect the immediate area surrounding the source. Sometimes the pollution may affect the environment hundreds of miles away from the source, such as nuclear waste, this is called Tran boundary pollution.
Domestic households, industrial and agricultural practices produce wastewater that can cause pollution of many lakes and rivers.
· Sewage is the term used for wastewater that often contains faces, urine and laundry waste.
· There are billions of people on Earth, so treating sewage is a big priority.
· Sewage disposal is a major problem in developing countries as many people in these areas don’t have access to sanitary conditions and clean water.
· Untreated sewage water in such areas can contaminate the environment and cause diseases such as diarrhea.
· Sewage in developed countries is carried away from the home quickly and hygienically through sewage pipes.
· Sewage is treated in water treatment plants and the waste is often disposed into the sea.
· Sewage is mainly biodegradable and most of it is broken down in the environment.
· In developed countries, sewage often causes problems when people flush chemical and pharmaceutical substances down the toilet. When people are ill, sewage often carries harmful viruses and bacteria into the environment causing health problems.
Industry is a huge source of water pollution, it produces pollutants that are extremely harmful to people and the environment.
· Many industrial facilities use freshwater to carry away waste from the plant and into rivers, lakes and oceans.
· Pollutants from industrial sources include:
o Asbestos – This pollutant is a serious health hazard and carcinogenic. Asbestos fibers can be inhaled and cause illnesses such as asbestosis, mesothelioma, lung cancer, intestinal cancer and liver cancer.
o Lead – This is a metallic element and can cause health and environmental problems. It is a non-biodegradable substance so is hard to clean up once the environment is contaminated. Lead is harmful to the health of many animals, including humans, as it can inhibit the action of bodily enzymes.
o Mercury - This is a metallic element and can cause health and environmental problems. It is a non-biodegradable substance so is hard to clean up once the environment is contaminated. Mercury is also harmful to animal health as it can cause illness through mercury poisoning.
o Nitrates – The increased use of fertilizers means that nitrates are more often being washed from the soil and into rivers and lakes. This can cause eutrophication, which can be very problematic to marine environments.
o Phosphates - The increased use of fertilizers means that phosphates are more often being washed from the soil and into rivers and lakes. This can cause eutrophication, which can be very problematic to marine environments.
o Sulphur – This is a non-metallic substance that is harmful for marine life.
o Oils – Oil does not dissolve in water, instead it forms a thick layer on the water surface. This can stop marine plants receiving enough light for photosynthesis. It is also harmful for fish and marine birds.
o Petrochemicals – This is formed from gas or petrol and can be toxic to marine life.
Preventing:
If you want to help keep our waters clean, there are many things you can do to help. You can prevent water pollution of nearby rivers and lakes as well as groundwater and drinking water by following some simple guidelines in your everyday life.
· Conserve water by turning off the tap when running water is not necessary. This helps prevent water shortages and reduces the amount f contaminated water that needs treatment.
· Be careful about what you throw down your sink or toilet. Don't throw paints, oils or other forms of litter down the drain.
· Use environmentally household products, such as washing powder, household cleaning agents and toiletries.
· Take great care not to overuse pesticides and fertilizers. This will prevent runoffs of the material into nearby water sources.
· By having more plants in your garden you are preventing fertilizer, pesticides and contaminated water from running off into nearby water sources.
· Don't throw litter into rivers, lakes or oceans. Help clean up any litter you see on beaches or in rivers and lakes, make sure it is safe to collect the litter and put it in a nearby dustbin.
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
To enlarge an image, click on it.
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:
To enlarge the image, click on it.
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.
2 Causes of water pollution?
Water pollution can come from a number of different sources. If the pollution comes from a single source, such as an oil spill, it is called point-source pollution. If the pollution comes from many sources, it is called no point-source pollution.
Most types of pollution affect the immediate area surrounding the source. Sometimes the pollution may affect the environment hundreds of miles away from the source, such as nuclear waste, this is called Tran boundary pollution.
Domestic households, industrial and agricultural practices produce wastewater that can cause pollution of many lakes and rivers.
· Sewage is the term used for wastewater that often contains faces, urine and laundry waste.
· There are billions of people on Earth, so treating sewage is a big priority.
· Sewage disposal is a major problem in developing countries as many people in these areas don’t have access to sanitary conditions and clean water.
· Untreated sewage water in such areas can contaminate the environment and cause diseases such as diarrhea.
· Sewage in developed countries is carried away from the home quickly and hygienically through sewage pipes.
· Sewage is treated in water treatment plants and the waste is often disposed into the sea.
· Sewage is mainly biodegradable and most of it is broken down in the environment.
· In developed countries, sewage often causes problems when people flush chemical and pharmaceutical substances down the toilet. When people are ill, sewage often carries harmful viruses and bacteria into the environment causing health problems.
Industry is a huge source of water pollution, it produces pollutants that are extremely harmful to people and the environment.
· Many industrial facilities use freshwater to carry away waste from the plant and into rivers, lakes and oceans.
· Pollutants from industrial sources include:
o Asbestos – This pollutant is a serious health hazard and carcinogenic. Asbestos fibers can be inhaled and cause illnesses such as asbestosis, mesothelioma, lung cancer, intestinal cancer and liver cancer.
o Lead – This is a metallic element and can cause health and environmental problems. It is a non-biodegradable substance so is hard to clean up once the environment is contaminated. Lead is harmful to the health of many animals, including humans, as it can inhibit the action of bodily enzymes.
o Mercury - This is a metallic element and can cause health and environmental problems. It is a non-biodegradable substance so is hard to clean up once the environment is contaminated. Mercury is also harmful to animal health as it can cause illness through mercury poisoning.
o Nitrates – The increased use of fertilizers means that nitrates are more often being washed from the soil and into rivers and lakes. This can cause eutrophication, which can be very problematic to marine environments.
o Phosphates - The increased use of fertilizers means that phosphates are more often being washed from the soil and into rivers and lakes. This can cause eutrophication, which can be very problematic to marine environments.
o Sulphur – This is a non-metallic substance that is harmful for marine life.
o Oils – Oil does not dissolve in water, instead it forms a thick layer on the water surface. This can stop marine plants receiving enough light for photosynthesis. It is also harmful for fish and marine birds.
o Petrochemicals – This is formed from gas or petrol and can be toxic to marine life.
Preventing:
If you want to help keep our waters clean, there are many things you can do to help. You can prevent water pollution of nearby rivers and lakes as well as groundwater and drinking water by following some simple guidelines in your everyday life.
· Conserve water by turning off the tap when running water is not necessary. This helps prevent water shortages and reduces the amount f contaminated water that needs treatment.
· Be careful about what you throw down your sink or toilet. Don't throw paints, oils or other forms of litter down the drain.
· Use environmentally household products, such as washing powder, household cleaning agents and toiletries.
· Take great care not to overuse pesticides and fertilizers. This will prevent runoffs of the material into nearby water sources.
· By having more plants in your garden you are preventing fertilizer, pesticides and contaminated water from running off into nearby water sources.
· Don't throw litter into rivers, lakes or oceans. Help clean up any litter you see on beaches or in rivers and lakes, make sure it is safe to collect the litter and put it in a nearby dustbin.
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