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Contents:

General introduction Chapter 01: Acid Rain

1- Definition……………………………………………………..……..4 2- The reasons of formation of acid rain………………………...…..…4 3- Acid rain is a problem that can travel……………………….………5 4- Effects of acid rain

a. Effects of acid rain on Forests…………………………..…..…..4 b. Effects of acid rain soils…………………………………...……7 c. Effects of acid rain aquatic ecosystem…………………….……8 d. Effects of Acid Rain on Man-Made Materials…………….……9

Chapter 02: The Smog

1- History of smog………………………………………………….11 2- Introduction in the smog…………………………………………13 3- Definition………………………………………………..…….…13 4- Summary of Pollutant Characteristics, Sources and General Health and Ecological Effects………………………………….….….14 5- How the smog formed…………………………………….….…15 6- Index of smog …………………………………………....……..16 7- Who most at risk of smog……………………………………….17 8- Effects of smog

8-a effect on the health…………………………….….……….…..17 8-b economic impacts of smog …………………….………….…..19

Conclusion

Acid rain and the smog

By : MESSEGUEM Hemza 2

General Introduction

very day, the average adult breathes about 15,000 to 20,000 liters of air. Air is a mixture of gases that makes up our atmosphere and is vital to life on earth. It largely consists of oxygen (21%) and nitrogen (78%).

However, as a result of both natural and human processes, the atmosphere also contains a number of gases that, at elevated concentrations, can be a health threat to people and animals and damaging to plants.

These gases include ground-level ozone (O3), nitrogen oxides (NOx), sulphur dioxide (SO2), and carbon monoxide (CO), as well as a range of organic gases and vapours referred to as volatile organic compounds (VOCs). The atmosphere also contains tiny particles, known as ‘particulate matter’ (PM) that may be either solid or liquid. All of these potentially toxic gases and substances are together referred to as air pollutants. Combined, they are the principal ingredients of smog and acid rain.

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Introduction to acid rain

umans make use of many things found in nature. For example, we use trees to build our homes and cotton to make our clothes. Things that are not made by people, but instead occur naturally, are called natural resources. Some examples of natural

resources are plants, minerals, and water. All of these things are important to humans because they provide us with the materials we need to make the things we use every day. Some of the products made from natural resources are obvious to us, like the timber and stone that make buildings.

Other natural resources are not as noticeable, like the underground water table where our drinking water comes from. Natural resources that humans use to generate electricity are called energy resources. Most energy in the United States comes from burning fossil fuels such as coal, oil, and natural gas. Coal, oil, and natural gas are called fossil fuels because they were formed millions of years ago from dead plants and animals.

People burn fossil fuels for many reasons, we burn oil and coal to make the electricity that we need to light buildings and run appliances like televisions and computers. We burn gas to heat our homes and to power cars, buses, and airplanes. Many human activities, including the burning of fossil fuels, cause pollution. Pollution is the release of harmful substances called pollutants into the environment. The air pollution created when fossil fuels burn does not stay in the air forever. Instead it can travel great distances, and fall to the ground again as dust or rain.

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Rainwater, snow, fog, and other forms of precipitation then mix with the sulfuric and nitric acids in the air and fall to Earth as acid rain (EPA, 2008).

The principal reactions which lead to formation the acid rain are (RAMADE, 2006): SO2 + ½ O2 + H2O H2SO4

2NO2 + ½ O2+ H2O 2HNO3

NO2 + SO2+ H2O H2SO4 + NO

3- Acid rain is a problem that can travel

The chemical reactions that cause acid rain can take several hours to several days to occur. Years ago, when smokestacks were only a few stories high, pollution from smokestacks usually stayed near the ground and settled on the land nearby. This caused unhealthy conditions for people, plants, and animals near those smokestacks. To reduce this pollution, the government passed laws for the construction of very tall smokestacks. At that time, people thought that if the pollution were sent high into the air it would no longer be a problem.

Scientists now know that this is incorrect. In fact, sending pollution high into the sky increases the time that the pollution stays in the air. The longer the pollution is in the air, the greater the chances that the pollutants will form acid rain. In addition, the wind can carry these pollutants for hundreds of miles before they become joined with water droplets to form acid rain. For that reason, acid rain, or wet deposition, can be a problem in areas far from sources of pollution. Dry deposition is usually greater near the cities and industrial areas where the pollutants are released (EPA, 2008).

4- Dry Deposition: Acid rain does not account for all of the acidity that falls

back to Earth from pollutants. About half of the acidity in the atmosphere is deposited onto buildings, cars, homes, and trees— anything!—as particles and gases. This process is called dry deposition. In some instances, these gases and particles can damage or alter the things on which they settle. Dry deposition (gases and particles) is sometimes washed from trees and other surfaces by rainstorms. When that happens, the runoff water contains acid from acid rain and dry deposition, making the combination more acidic than the falling rain alone. The combination of acid rain (wet deposition) plus dry deposition is called acid deposition.

Dry Deposition: The falling of small particles and gases to the Earth without rain or snow.

Runoff: Water that flows off land into lakes and streams.

Acid Deposition Acidic material that falls from the atmosphere to the Earth in either wet (rain, sleet, snow, fog) or dry (gases, particles) forms.



Wet Acid Deposition, 1989-1991 Wet Acid Deposition, 2003-2005

Fig. 02: These maps show how the Acid Rain Program has reduced the amount of wet acid

deposition (acid rain) in the United States. In these maps, the dark areas represent places with high amounts of acid rain. Notice how the areas with lots of acid rain in 1989–1991 have shrunk since the Acid Rain

Program started

5- Effects of Acid Rain on Ecosystems :

a. Effects of acid rain on Forests:

cid rain causes significant damage to forests. It directly affects trees and other plants which are important to the ecosystem as a whole because they are primary producers. Primary producers are organisms that produce their own food through

photosynthesis, a series of chemical reactions that convert water into sugar using light from the sun to provide energy. Plants and some microscopic animals have this ability. Plants are important to ecosystems because they feed everything else, and provide important habitat for other animals. If trees and plants are damaged by acid rain, the effects are felt throughout the entire ecosystem. Acid rain causes trees in forests to grow more slowly, and in some sensitive species it can even make the leaves or needles turn brown and fall off. Red Spruce and Sugar Maple, two species of trees found mainly in the East and in New England, are very susceptible to acid rain damage.

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Fig.03: Sugar Maple leaves turn brilliant shades of red, orange, and yellow in the fall. People from all over the United States and the world travel to New England to see colorful autumn leaves like

those of the Sugar Maple.(EPA)

Acid rain damages trees by dissolving the calcium in the soil and in the leaves of trees. This hurts the tree, because calcium is a mineral that trees need to grow. Once the calcium is dissolved, the rain washes it away so the trees and other plants cannot use it to grow. Acid rain washes other minerals and nutrients from the soil in a similar fashion, causing Nutrient Deficiency. This is why acid rain can cause trees to grow more slowly (EPA, 2008).

b. Effects of acid rain on soil: Spring shower in the forest washes leaves and the rain falls through the trees to the forest floor below. Some of the water soaks

into the soil. Some trickles over the ground and runs into a stream, river, or lake. Soil sometimes contains substances, like limestone, that buffer acids or bases. Some salts in soil may also act as buffers. The soil may neutralize, or make less acidic, the acid rainwater.

This ability of the soil to resist ph change is called buffering capacity. A buffer resists changes in pH. Without buffering capacity, soil pH would change rapidly. Midwestern states like Nebraska and Indiana have soils that are well buffered. Places in the mountainous northeast, like New York’s Adirondack Mountains, have soils that are less able to buffer acids. Other soils, like those in the Southern Appalachian Region, hold acids from acid rain, making them more susceptible to damage from acid rain. Since there are many natural sources of acids in forest soils, soils in forest areas are especially sensitive to effects from acid rain (EPA, 2008).

ABuffering : Capacity The ability of a substance to resist changes in pH when acids or bases are added. Buffer: A substance, such as soil, bedrock, or water, capable of neutralizing either acids or bases.



c. Effects of acid rain aquatic ecosystem: he effects of acid rain are most clearly seen in aquatic environments such as streams, lakes, and marshes. Acid rain flows to streams, lakes, and marshes after falling on forests, fields, buildings, and roads. Acid rain also falls directly on aquatic habitats.

Most lakes and streams have a pH between 6 and 8, because the buffering capacity of soil usually neutralizes slightly acidic, clean rain. Lakes and streams become acidic (pH value goes down) when the rainwater itself is so acidic that the surrounding soil cannot buffer the rain enough to neutralize it. For this reason, some lakes in areas where soil does not have a lot of buffering capacity are naturally acidic even without acid rain. (EPA, 2008) The acidic deposition changed the lake chemistry in the Adirondack region of New York (Table 1).

Table.1: Chemical characteristics of three studies stream in the western Adirondack region of New York (1991- 2001) (modified from Lowrence et al., 2001).

Parameters Mean of six monthly samples January - June 2001 Buck creeck Bald mountain brook Pond outlet

pH 5.55 6.22 7.11 SO4

- µmol-1 60 54 52 NO3

- µmol-1 35 32 25 K+ µmol-1 7.1 7.5 15

Mg+2 µmol-1 18 22 43

During 1970’s in southern Norway over 20% of lakes have lost their fishes (Wright and Henriksen, 1983). Losses of sport fish populations have occurred in acidified lakes and river in Canada. Due to acidic precipitation, fishes showed increases in mortality rate, reproductive failure, reduced growth rate skeletal deformities and increased uptake of heavy metals (Watt et al., 1983).

Fig.3: PH Tolerance Chart on Aquatic Life:

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In areas like the northeastern United States where soil buffering is poor, acid rain has made already slightly acidic lakes very acidic, with some lakes having a pH value of less than 5. As lakes and streams become more acidic, the numbers and types of fish and other aquatic plants and animals that live in these waters decrease. Some types of plants and animals are able to tolerate acidic waters. Others, however, are acid-sensitive and will leave or die as the pH declines. Some acidic lakes have no fish, because at pH 5 most fish eggs cannot hatch. At lower pH levels, adult fish can die. Substances like aluminum that wash into the water from the soil can also harm and kill fish.

d. Effects Of Acid Rain On Man-Made Materials:

cid rain eats away at stone, metal, paint—almost any material exposed to the weather for a long period of time. Human-made materials gradually deteriorate even when exposed to unpolluted rain, but acid rain speeds up the process. Acid rain can rust

metals and cause marble statues carved long ago to lose their features.

This happens because marble is made of a compound called calcium carbonate, which can be dissolved by acids. Calcium carbonate is also found in limestone. Many buildings and monuments are made of marble and limestone and are damaged by acid rain.

*- How Acid Rain Affects Stonework

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Picture was taken in 1908 Picture was taken in 1968

After 60 years



*- How Acid Rain Affects Metal



Chapter 02: The Smog

1. History of Smog ir pollution first became a serious problem in the late 19th century. Throughout the first half of the 20th century, heavy air pollution in a number of cities resulted in the deaths of hundreds, and on some occasions even thousands, of

people. Three of the worst episodes were the following: • In 1930 in the Meuse Valley in Belgium, an industrial area filled with steel mills and coal-fired industry, an incident of air pollution caused the deaths of 63 people, with hundreds of others experiencing respiratory symptoms. • In 1948 in Donora, Pennsylvania — another industrialized valley — 20 people out of a population of 14,000 died, and more than 40% of the population became ill, 10% of them severely, as a result of an air pollution episode. • The most dramatic air pollution episode took place in London, England, in December 1952, when a stagnant air mass, combined with greater-than-normal coal burning during a cold spell, was associated with 4,000 deaths.

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Fig. 4 the smog in London December 1952



Fig.05: Smoggy day in Québec, February 02, 2005

Fig. 06: A woman wears a mask while riding a bicycle on the street during severe pollution on

January 23, 2013 in Beijing, China. While masks may keep out some larger pollution particles, they are not very effective against fine particles.



2. Introduction to Smog: The question of air quality in polluted regions represents one of the issues of

geochemistry with direct implications for human well-being. Human health and well-being, along with the well-being of plants, animals, and agricultural crops, are dependent on the quality of air we breathe. Since the start of the industrial era, air quality has become a matter of major importance, especially in large cities or urbanized regions with heavy automobile traffic and industrial activity. Concern over air quality existed as far back as the 1600s. Originally, polluted air in cities resulted from the burning of wood or coal, largely as a source of heat. The industrial revolution in England saw a great increase in the use of coal in rapidly growing cities, both for industrial use and domestic heating.

London suffered from devastating pollution events during the late 1800s and early 1900s, with thousands of excess deaths attributed to air pollution (Brimblecombe, 1987). With increasing use of coal, other instances also occurred in continental Europe and the USA. These events were caused by directly emitted pollutants (primary pollutants), including sulfur dioxide (SO2), carbon monoxide (CO), and particulates. They were especially acute in cities with northerly locations during fall and winter when sunlight is at a minimum. These original pollution events gave rise to the term “smog” (a combination of smoke and fog).

3. Definition: mog is a type of air pollution; the word "smog" was made in the early 20th century as a portmanteau of the words smoke and fog to refer

to smoky fog.[1] The word was then intended to refer to what was sometimes known as pea soup fog, a familiar and serious problem in London from the 19th century to the mid 20th century. This kind of smog is caused by the burning of large amounts of coal within a city; this smog contains soot particulates from smoke, sulfur dioxide and other components. Modern smog, as found for example in Los Angeles, is a type of air pollution derived from vehicular emission from internal combustion engines and industrial fumes that react in the atmosphere with sunlight to form secondary pollutants that also combine with the primary emissions to form photochemical smog. The atmospheric pollution levels of Los Angeles, Mexico City and other cities are increased by inversion that traps pollution close to the ground. (Free encyclopedia).

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Summer Smog and Winter smog

Summer Smog : Caused by mixture of pollutants from: road vehicles; fuels used to provide electricity and heating in offices, factories and homes; vapours from petrol and certain industrial premises.

Formed by: Action of sunlight on these pollutants forms low-level ozone close to the grounde. In hot sunny days

Winter Smog: Caused by mixture of pollutants from: road vehicles; fuels used to provide electricity and heating in offices, factories and homes

Formed by: Pollutants building up at ground level in urban areas. The 'lid' of cold air above the warm air traps the pollutants in cold, calm days, often after a clear, cloudless night and an early-morning frost or mist close to the ground.



4. Summary of Pollutant Characteristics, Sources and General Health and Ecological Effects:



5. How the Smog Formed?

mog is formed in the lower atmosphere, just above the Earth’s surface when a variety of sources release smog forming pollutants into the air. These pollutants are usually warmer than the surrounding air and tend to rise. While being dispersed by the wind,

heat and sunlight cause chemical reactions to occur between pollutants, forming ground-level ozone. PM is also released into the air or is formed later within the atmosphere through chemical reactions. These particles, together with ground-level O3, are the two main components of smog. Smog will remain in an area until a weather system, such as a heavy rainfall, washes most of the pollutants out of the local atmosphere. High wind speeds can increase dispersion of pollutants, thereby lowering the concentration levels of the pollutants in an area.

Smog pollutants can be generated by either naturally occurring processes or by human activities. Natural sources of pollutants include forest fires and volcanoes, which add particles and gases to the air; trees, which emit VOCs; soil erosion, which produces dust; and biological processes in soil that creates NOx. The largest source of air pollution affecting human health and the environment, however, is human activity, and primarily the burning (or “combustion”) of fossil fuels (petroleum, natural gas and coal) to transport people and goods, heat and cool buildings, make electricity and operate industries (EPA, 2008).

Weather plays a significant role in determining smog levels: During the summertime, heavy smog episodes will usually occur when a stagnant high

pressure system moves into an area. In the northern hemisphere, winds in high pressure systems spiral clockwise and outwards, bringing warm air up from the south. The air tends to sink near high pressure centers, warming as it descends and evaporating any clouds or precipitation that may be present in the air. This is why high pressure systems tend to bring bright and sunny days.

These systems, combined with warm summertime temperatures and little or no wind, will usually result in stagnant air being trapped close to the ground. When trapped by high pressure, VOCs and NOx will bake in the hot sun, creating O3. In addition, stagnant air masses prevent pollutants from being dispersed.

Fig.7 the role of weather on the formation of smog

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The severity of smog is also increased with the occurrence of a “temperature inversion”. When the air close to the earth is cooler than the air above it, the lower, cooler air does not rise but remains still, with the warmer air above it creating a “lid”. This may result from a cold front moving through a region or from cool sea air blown over land by an onshore breeze. Under these conditions, the pollutants cannot rise and disperse; the smog is kept close to the ground thus maximizing any damaging effects. The severe inversion over Donora, Pennsylvania in 1948 was associated with respiratory illnesses in more than 6,000 people and the deaths of 20 people.

6. Index of the Smog: 6.1 Index of USA (according to EPA):

6.2 Index of Ontario , Canada (according to ministry of environment):

We take the Toronto west like example; the ministry of environment measured the index of this town:



Note: the difference between the USA index and Ontario index is the scale of index that’s all, but the effects of ground level of ozone and the particulate matter according to category is the same.

7. Who is most at risk from Smog?



8. Effects of the Smog : Because the ozone is important reason of formation of smog, we have to know her

effects in the health and economy:

a. Effect of smog on the health: Scientists have been studying the effects of ozone on human health for many years. So far,

they have found that ozone can cause several types of short-term health effects in the lungs:

*- Ozone can irritate the respiratory system: When this happens, you might start coughing, feel an irritation in your throat, and/or

experience an uncomfortable sensation in your chest. These symptoms can last for a few hours after ozone exposure and may even become painful.

*- Ozone can reduce lung function: When scientists refer to “lung function,” they mean the volume of air that you draw in

when you take a full breath and the speed at which you are able to blow it out. Ozone can make it more difficult for you to breathe as deeply and vigorously as you normally would. When this happens, you may notice that breathing starts to feel uncomfortable. If you are exercising or working outdoors, you may notice that you are taking more rapid and shallow breaths than normal. Reduced lung function can be a particular problem for outdoor workers, competitive athletes, and other people who exercise outdoors.

*- Ozone can aggravate asthma: When ozone levels are high, more asthmatics have

asthma attacks that require a doctor’s attention or the use of additional medication. One reason this happens is that ozone makes people more sensitive to allergens, which are the most common triggers for asthma attacks. (Allergens come from dust mites, cockroaches, pets, fungus, and pollen.) Also, asthmatics are more severely affected by the reduced lung function and irritation that ozone causes in the respiratory system. Ozone can inflame and damage the lining of the lung. Some scientists have compared ozone’s effect on the lining of the lung to the effect of sunburn on the skin. Ozone damages the cells that line the air spaces in the lung. Within a few days, the damaged cells are replaced and the old cells are shed— much in the way that skin peels after sunburn. If this kind of damage occurs repeatedly, the lung may change permanently in a way that could cause long term health effects and a lower quality of life.

What I do for protect my health? • Avoid outdoor strenuous work or exercise. • Stay indoors in a cool, well ventilated place. • Avoid being outside around high traffic areas and during peak rush hour times to minimize your exposure to smog. • If you must be outside, stay out of the sun and drink lots of water. (NUGENT, 2002)



*- Scientists suspect that ozone may have other effects on

people’s health:

Ozone may aggravate chronic lung diseases, such as emphysema and bronchitis. Also, studies in animals suggest that ozone may reduce the immune system’s ability to fight off bacterial infections in the respiratory system. Most of these effects are considered to be short-term effects because they eventually cease once the individual is no longer exposed to elevated levels of ozone. However, scientists are concerned that repeated short-term

b. Economic Impacts of Smog: mog impacts the economy on several levels, the most serious being related to health-care costs. However, the smog problem in Canada also affects the economy through reductions in agricultural yields and the potential loss of tourism dollars as a result of

decreased visibility at scenic tourist destinations.

Health-Care Costs: The serious health effects of smog also have significant economic impacts. According to the Ontario Medical Association, air pollution is estimated to cost the province more than $1 billion per year due to hospital admissions, emergency room visits and absenteeism. When the costs of pain, suffering and loss of life from polluted air are added to this figure, the total annual economic loss is estimated to be $10 billion a year. This amount is expected to increase to $12 billion by the year 2015. According to two reports, however, it is possible to significantly reduce these escalating health care costs. A 1996 Ontario government report calculated that reducing key smog pollutants by 45% would result in 190 fewer cardiac and respiratory hospital admissions, 6,200 fewer emergency room visits for asthma, and between 3 and 4 million fewer episodes of acute respiratory symptoms per year. Studies in Greater Vancouver have found that more than 2,700 premature deaths and 33,000 emergency room visits could be avoided over 30 years with a 25% reduction in PM.

Agricultural Costs: As discussed earlier, smog damages farm crops and vegetation, thereby reducing yields of economically important crops, such as soybeans, kidney beans, wheat and cotton. In the United States, agricultural losses due to O3 have been estimated to be between $1 and $3 billion annually.

Tourism Dollars: With visibility reduced by as much as 80% in some areas as a result of air pollution, the loss of tourism dollars, particularly in areas where people are drawn to the “fresh air” and scenic landscapes of national parks and wilderness areas, could be substantial.

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Conclusion: What can I do to limit of acid rain and the smog?

Keep the motor vehicle regularly serviced and the tyres inflated to the manufacturer's specifications. This will ensure the car is running efficiently and not emitting excessive pollutants.

When you trade in your old car, replace it with a fuel-efficient, low emission car. Check out the fuel consumption label, which now has to be displayed on new cars. For commercial vehicles (3.5 tonnes gross vehicle mass and over), the Alternative Fuels Conversion Program is available.

Instead of using a car, try riding a bike or walking, and use buses, trams or trains whenever you can.

Use energy efficient appliances. Look for the Energy Star logo when buying a computer, printer or scanner, TV, VCR, audio or DVD product; or the Energy Rating on the next air conditioner, clothes dryer, washing machine, dishwasher, fridge or freezer you purchase.

If renovating or building, use energy-efficient designs and materials. Turn off unnecessary electrical appliances at the power point wherever possible. Make it your goal to purchase 'green power'—power generated from clean, renewable

energy sources. Generate you own green power—investigate the State Government's Solar Hot Water

Rebate, Photo-voltaic Rebate and the Remote Renewable Power Generation grants. Limit the wood fires at home. Wear warmer clothes as your first action to keep warm.

If you are buying a slow combustion wood heater, make sure it meets the Australian Standard AS4013 and is installed correctly, according to AS2918.

Schools can get involved with Air watch, a program for primary and secondary schools where students can become pollution watchdogs in their local area



Bibliography:

http://www. epa.gov/acidrain/education/teachguide.pdf

http://www.epa.gov/sunwise/doc/summertime.pdf

http://www.epa.gov/airnow/teachers/ozone-lesson-teacher.pdf

http://legacy.london.gov.uk/mayor/environment/air_quality/docs/50_years_on.pdf

http://www.ec.gc.ca/Publications/AD024B6B-A18B-408D-ACA2-59B1B4E04863%5CCanadianSmogScienceAssessmentHighlightsAndKeyMessages.pdf

http://www.lung.ca/protect-protegez/pollution-pollution/outdoor-exterior/smog-smog_e.php

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