Tuesday, January 29, 2013

The Effects of Air Pollution: Acid Rain

Acid rain describes sulfuric and nitric acids deposited from the atmosphere. Often associated with precipitation, the term also applies to dry acidic materials. These acids commonly result from sulfur dioxide and nitrogen oxides reacting with moisture and other substances in the atmosphere. Although there are natural sources for these chemicals, much attention has been given to man-made sources, such as coal power plants. Acid rain is problematic due to acidification of soil, rivers, and lakes beyond the tolerance range of plants and animals. Acid rain can also erode man-made structures.

Acidifying Waters

Water resists rapid changes to pH --- a measure of the acidity of a substance with lower numbers indicating stronger acidity. However, even this resistance is overcome by prolonged and persistent exposure to acid rain. Ecosystems within lakes and rivers may be vulnerable to acidification of the water in surprising ways. For example, mayflies die off at a pH of 5.5, while trout and perch can survive in much more acidic water. However, with the decline of mayflies and other insects, trout may have insufficient food to support their population. At pH 5 many fish eggs fail to hatch and juvenile fish tend to be more susceptible to acidity, impairing the fish population's continued health. 


Direct contact with acid rain can weaken trees and destroy their leaves. This is especially true in high altitude forests where the trees are frequently immersed in an acid cloud. Acid rain can also harm trees in a more subtle fashion by reducing nutrient levels and increasing the level of toxic substances in the soil. The buffering capacity of soil varies greatly between different soil types, resulting in greater damage to forests in some areas than others, even though the acid rain exposure may be similar. 


Many people take great pride in maintaining the appearance of their vehicle, but acid rain can literally erode the vehicle's protective coating. To counter these effects, automobile manufacturer's have begun coating new vehicles with acid-resistant paints. 


Limestone and marble construction materials are especially damaged by acid rain. This is due to the calcite mineral content in these materials that is easily dissolved away. This damage is readily seen in older stone buildings and monuments where carvings placed in the stone have eroded. Not all stone is susceptible. Granite and sandstone have a chemical composition that does not react with acid rain, though some types of sandstone contain carbonate, which will react. 

Human Health

Physical contact with acid rain, either as droplets falling from the sky or from swimming in an acidic lake, has little direct impact on the health of humans. However, the pollutants responsible for the formation of acid rain are associated with an increase in respiratory disease and other illnesses. These pollutants may even infiltrate indoor spaces causing problems ranging from asthma to premature death. Laws such as the Clean Air Act strive to reduce the amount of pollution in the air. The U.S. Environmental Protection Agency reports that between 1980 and 2009, the national average for sulfur dioxide in the air decreased by 76 percent, and nitrogen dioxide decreased by 48 percent. 

What Can I Do to Decrease Acid Rain?

 Acid rain contaminates soil, pollutes water and even causes the death of plants and fish. Before carbon dioxide took center stage, acid rain was a major topic of discussion among environmental groups. Two pollutants, sulfur dioxide and nitrogen oxides, combine with water vapor and oxygen to make acid rain, which has higher concentrations of sulfuric and nitric acids than normal rain . By understanding the source of these pollutants, individuals can make a few lifestyle changes to reduce these emissions and, in turn, acid rain.

Emissions from Electricity

Most electricity in the United States comes from burning coal, which produces sulfur dioxide. Burning any fossil fuel for energy production, including oil and natural gas, releases nitrogen oxides. The result of efforts initiated in 1990 to reduce acid rain resulted in reductions in sulfur dioxide by 1998, while nitrogen oxide emissions remained at about the same levels, according to a General Accounting Office analysis released in 2000 . Efforts to control nitrogen oxide emissions from power plants, however, showed measurable success by 2004.

Vehicle Emissions

The apparent success of efforts to control nitrogen oxide emissions from power plants led researchers to conclude in a 2006 report that further reduction efforts should focus on mobile emission sources . On-road vehicles, followed by non-road equipment, electricity generation, fossil fuel combustion and industrial processes accounted for most of the nitrogen oxide emissions in 2005 .

Reducing Electricity Consumption

Reducing the amount of electricity the average home uses is a simple, direct method of decreasing emissions that cause acid rain. Supporting renewable-energy initiatives that reduce the dependence on fossil fuels is a bigger-picture solution. Overall, one of the best things you can do is upgrade old appliances; the Energy Star program identifies energy-efficient models of many products. Avoid wasting electricity when you use any appliance. For example, remove everything you need from the refrigerator for cooking once and put it back once. Use one oven cycle to bake several dishes at the same time. If you use a clothesline, the sun and the air will dry laundry free. Strive to reduce heating and cooling costs. Planting shade trees to block the sun eases the burden on your air-conditioner. Installing insulation helps maintain your home's temperature and reduce electric cooling or heating. 

Reducing On-Road Vehicle Exhaust

Every step you take to reduce the amount of nitrogen oxides emitted into the air from vehicles will help reduce acid rain. Walk or bike whenever possible. If you must ride, carpooling and using public transportation reduce the number of cars on the road. When you buy a vehicle, choose one with low emissions and maintain it.

Other Considerations

Manufacturers ship nearly everything you purchase at a store in trucks, planes or trains that produce nitrogen oxides, and acid rain; shopping for almost anything can have a ripple effect. Also, consider your personal use of non-road sources of nitrogen oxides, including recreational activities such as boating, snowmobiling or using an all-terrain vehicle. Other non-road sources to curtail the use of include equipment such as chainsaws, lawnmowers and leaf-blowers. 

Acid Rain Research Paper – What to Focus On?

 Global warming, environmental change, the carbon footprint, acid rain – all of these have been hot topics for decades. The impact of these forces on our world has been the major cause of debate, political conflict, environmental action and global change. Many students are quick to pick up on one of these widely discussed topics for their research paper assignments – but don’t be fooled; just because these topics are popular, doesn’t mean they’re easy. If you’ve chosen to write a research paper on acid rain, you may be treading into dangerous territory. Before you make a mess out of your paper, make sure you know what to focus on regarding acid rain – and what to avoid.

What to Avoid with Acid Rain

Acid rain is a hot topic, and literally thousands of writers have chosen to address this phenomenon. So much available literature, however, is truly beneficial: it can give you a solid idea of what not to focus on when you craft your research paper. If you want to avoid the biggest pitfall of all acid rain research papers, avoid this: talking about causes of acid rain. A research paper that revolves around the causes of acid rain will, inevitably, be passed over. Not only are the causes of acid rain widely known, but they are also one of the least debated and challenged topics regarding acid rain. There may be tons of evidence, research and reports that support theoretical and proven causes of acid rain, but don’t let the plethora fool you: talking about causation in your acid rain research paper will get you nowhere.
Somewhat similarly, but far less so is the effect of acid rain. Like acid rain causes, acid rain effects have been well-documented and studied. You’ll likely be repeating the same ideas of a dozen other research papers and boring your audience if you focus on acid rain effects.

What to Focus On

If you want to write a research paper about acid rain that will truly spark the interest of your readers, then talk about solutions. The causes and effects of acid rain and pretty easily documented, described and delivered; they won’t get much of a standing ovation from your audience. However, finding solutions to the acid rain problem is a much more ambitious and intriguing prospect. Astound your readers by examining acid rain and then promoting possible solutions. Use theories from various sources, experiments by research labs and other viable information to support your own conclusion. If your research paper focuses on solving the acid rain problem, it is much more likely to succeed academically.

Monday, January 28, 2013

Investigate Harmful Effects of Acid Rain

When vehicles release black smoke containing high content of carbon monoxide and other harmful gases, it is harmful for most living things. These gases remain in the atmosphere and  convert into certain acidic substances when it rains, causing damage to the land, plants, aquatic animals, and infrastructure. This type of rain in which the rainwater contains acidic substances is called acid rain. The harmful effects of acid rain can be demonstrated by means of a very simple experiment. There is no need to wait for acid rain to perform it. It just requires a few things which are easily available in your house and the following listed things should be available.

Things Required:

- Masking tape
- Pen
- 1 cup vinegar
- Measuring cup
- 2 pieces of white chalk
- 2 small clear drinking glasses

5 Steps For Investigate Harmful Effects of Acid Rain

  • Gather all materials

    Gather all the required materials in one single place so that you do not need to fetch them every now and then during the experiment.

    Two separate glasses
    With the help of a pen, pencil or marker, write “Water” on the first glass and “Vinegar” on the second glass to avoid any confusion. 
    Pouring Water & Vinegar

    Now pour about a cup of water in the glass labeled “Water” and in the same way, pour a cup of vinegar in the glass labeled “Vinegar”.

    Testing with Chalk

    Immerse a piece of chalk in both the glasses such that half part of the chalk is inside the glass and half is outside. Use support to position the chalks upright and place them at a safe place.

    Comparing two Chalks

    When you take the chalks out of both liquids to observe, it will be noticed that the chalk immersed in Vinegar has a changed condition as compared to the one in water. To be exact, it will be corroded and the one immersed in water will remain as it was.

Removing Acid Rain Stains from Auto Glass

An unfortunate and annoying product of today’s incessant air pollution is acid rain. Acid rain can take form as rain, snow, fog, and even dust. The damage it causes to car paint and windows can be permanent if not properly taken care of.

Let’s get down to the science of the matter. It is not the water that leaves marks or etches the glass. The minerals are the culprits. Calcium and magnesium seep into the pores of the glass. As for acid rain, the polluted elements of the rain are what cause the car harm.

There are two types of water spots—Stage One Corrosion and Stage Two Corrosion. Stage One Corrosion refers to light to moderate damage to the paint surface. Stage Two is concerned with more serious paint damage and acid rain.

Below surface, or etched, acidic watermarks are caused by an acidic solution or a destructive alkaline. These cause a chemical reaction that will etch the paint or window over time if left untreated. Etched acid rain spots are perhaps the most difficult to remove, often taking several attempts.

In short, acid rain stains can be difficult to remove from an automobile. Whether it is on your windows or paint, it can often take more than one attempt. With preventative cleaning or the proper products, however, those rain spots on your windshield and windows can become a thing of the past, or at the very least minimized.

Preventing Acid Rain Corrosion

Get your car professionally washed on a regular basis. If you prefer not to spend the money and time to consistently get it washed, wash your windows immediately after it rains or snows. The more immediate the cleaning, the more likely you are to eliminate acid rain before it seeps into the pores of the glass. Remember to always thoroughly dry your vehicle (including windows) after washing it. Applying a coat of wax regularly is also highly recommended to avoid spots on your paint.

Removing Existing Rain Spots

If you already find yourself looking through a windshield and windows covered in water stains, there are products available to get rid of them. One such product which we use to treat our customers’ vehicles is Nu-Glass from Duragloss. Nu-Glass is a blend of cleaners and selected abrasives formulated to remove water spots from glass surfaces without scratching.

Many drivers are rightfully concerned about unintentionally scratching their vehicle’s glass, but Nu-Glass has been specifically formulated to provide a pristine polish without scratching or distorting the glass.

Natural Acidity of Rainwater

Natural Acidity of Rainwater

Pure water has a pH of 7.0 (neutral); however, natural, unpolluted rainwater actually has a pH of about 5.6 (acidic).[Recall from Experiment 1 that pH is a measure of the hydrogen ion (H+) concentration.] The acidity of rainwater comes from the natural presence of three substances (CO2, NO, and SO2) found in the troposphere (the lowest layer of the atmosphere). As is seen in Table I, carbon dioxide (CO2) is present in the greatest concentration and therefore contributes the most to the natural acidity of rainwater.


Natural Sources


Carbon dioxide
Decomposition 355 ppm
Nitric oxide
Electric discharge 0.01 ppm
Sulfur dioxide
Volcanic gases 0-0.01 ppm

Table 1

Carbon dioxide, produced in the decomposition of organic material, is the primary source of acidity in unpolluted rainwater.
NOTE: Parts per million (ppm) is a common concentration measure used in environmental chemistry. The formula for ppm is given by:
Carbon dioxide reacts with water to form carbonic acid (Equation 1). Carbonic acid then dissociates to give the hydrogen ion (H+) and the hydrogen carbonate ion (HCO3-) (Equation 2). The ability of H2CO3 to deliver H+ is what classifies this molecule as an acid, thus lowering the pH of a solution.



Nitric oxide (NO), which also contributes to the natural acidity of rainwater, is formed during lightning storms by the reaction of nitrogen and oxygen, two common atmospheric gases (Equation 3). In air, NO is oxidized to nitrogen dioxide (NO2) (Equation 4), which in turn reacts with water to give nitric acid (HNO3) (Equation 5). This acid dissociates in water to yield hydrogen ions and nitrate ions (NO3-) in a reaction analagous to the dissociation of carbonic acid shown in Equation 2, again lowering the pH of the solution.




Acidity of Polluted Rainwater

Unfortunately, human industrial activity produces additional acid-forming compounds in far greater quantities than the natural sources of acidity described above. In some areas of the United States, the pH of rainwater can be 3.0 or lower, approximately 1000 times more acidic than normal rainwater. In 1982, the pH of a fog on the West Coast of the United States was measured at 1.8! When rainwater is too acidic, it can cause problems ranging from killing freshwater fish and damaging crops, to eroding buildings and monuments.

Sources of Excess Acidity in Rainwater

What causes such a dramatic increase in the acidity of rain relative to pure water? The answer lies within the concentrations of nitric oxide and sulfur dioxide in polluted air. As shown in Table II and Figure 1, the concentrations of these oxides are much higher than in clean air.


Non-Natural Sources


Nitric oxide
Internal Combustion 0.2 ppm
Sulfur dioxide
Fossil-fuel Combustion 0.1 - 2.0 ppm

Table II

Humans cause many combustion processes that dramatically increase the concentrations of acid-producing oxides in the atmosphere. Although CO2 is present in a much higher concentration than NO and SO2, CO2 does not form acid to the same extent as the other two gases. Thus, a large increase in the concentration of NO and SO2 significantly affects the pH of rainwater, even though both gases are present at much lower concentration than CO2.

Figure 1

Comparison of the concentrations of NO and SO2 in clean and polluted air.
About one-fourth of the acidity of rain is accounted for by nitric acid (HNO3). In addition to the natural processes that form small amounts of nitric acid in rainwater, high-temperature air combustion, such as occurs in car engines and power plants, produces large amounts of NO gas. This gas then forms nitric acid via Equations 4 and 5. Thus, a process that occurs naturally at levels tolerable by the environment can harm the environment when human activity causes the process (e.g., formation of nitric acid) to occur to a much greater extent.
What about the other 75% of the acidity of rain? Most is accounted for by the presence of sulfuric acid (H2SO4) in rainwater. Although sulfuric acid may be produced naturally in small quantities from biological decay and volcanic activity (Figure 1), it is produced almost entirely by human activity, especially the combustion of sulfur-containing fossil fuels in power plants. When these fossil fuels are burned, the sulfur contained in them reacts with oxygen from the air to form sulfur dioxide (SO2). Combustion of fossil fuels accounts for approximately 80% of the total atmospheric SO2 in the United States. The effects of burning fossil fuels can be dramatic: in contrast to the unpolluted atmospheric SO2 concentration of 0 to 0.01 ppm, polluted urban air can contain 0.1 to 2 ppm SO2, or up to 200 times more SO2! Sulfur dioxide, like the oxides of carbon and nitrogen, reacts with water to form sulfuric acid (Equation 6).


Sulfuric acid is a strong acid, so it readily dissociates in water, to give an H+ ion and an HSO4- ion (Equation 7). The HSO4- ion may further dissociate to give H+ and SO42- (Equation 8). Thus, the presence of H2SO4 causes the concentration of H+ ions to increase dramatically, and so the pH of the rainwater drops to harmful levels.



Environmental Effects of Acid Rain

Acid rain triggers a number of inorganic and biochemical reactions with deleterious environmental effects, making this a growing environmental problem worldwide.
  • Many lakes have become so acidic that fish cannot live in them anymore.
  • Degradation of many soil minerals produces metal ions that are then washed away in the runoff, causing several effects:
    • The release of toxic ions, such as Al3+, into the water supply.
    • The loss of important minerals, such as Ca2+, from the soil, killing trees and damaging crops.
  • Atmospheric pollutants are easily moved by wind currents, so acid-rain effects are felt far from where pollutants are generated.

Stone Buildings and Monuments in Acid Rain

Marble and limestone have long been preferred materials for constructing durable buildings and monuments. The Saint Louis Art Museum, the Parthenon in Greece, the Chicago Field Museum, and the United States Capitol building are all made of these materials. Marble and limestone both consist of calcium carbonate (CaCO3), and differ only in their crystalline structure. Limestone consists of smaller crystals and is more porous than marble; it is used more extensively in buildings. Marble, with its larger crystals and smaller pores, can attain a high polish and is thus preferred for monuments and statues. Although these are recognized as highly durable materials, buildings and outdoor monuments made of marble and limestone are now being gradually eroded away by acid rain.
How does this happen? A chemical reaction (Equation 9) between calcium carbonate and sulfuric acid (the primary acid component of acid rain) results in the dissolution of CaCO3 to give aqueous ions, which in turn are washed away in the water flow.


This process occurs at the surface of the buildings or monuments; thus acid rain can easily destroy the details on relief work (e.g., the faces on a statue), but generally does not affect the structural integrity of the building. The degree of damage is determined not only by the acidity of the rainwater, but also by the amount of water flow that a region of the surface receives. Regions exposed to direct downpour of acid rain are highly susceptible to erosion, but regions that are more sheltered from water flow (such as under eaves and overhangs of limestone buildings) are much better preserved. The marble columns of the emperors Marcus Aurelius and Trajan, in Rome, provide a striking example: large volumes of rainwater flow directly over certain parts of the columns, which have been badly eroded; other parts are protected by wind effects from this flow, and are in extremely good condition even after nearly 2000 years!

Even those parts of marble and limestone structures that are not themselves eroded can be damaged by this process (Equation 9). When the water dries, it leaves behind the ions that were dissolved in it. When a solution containing calcium and sulfate ions dries, the ions crystallize as CaSO4l 2H2O, which is gypsum. Gypsum is soluble in water, so it is washed away from areas that receive a heavy flow of rain. However, gypsum accumulates in the same sheltered areas that are protected from erosion, and attracts dust, carbon particles, dry-ash, and other dark pollutants. This results in blackening of the surfaces where gypsum accumulates.

An even more serious situation arises when water containing calcium and sulfate ions penetrates the stone's pores. When the water dries, the ions form salt crystals within the pore system. These crystals can disrupt the crystalline arrangement of the atoms in the stone, causing the fundamental structure of the stone to be disturbed. If the crystalline structure is disrupted sufficiently, the stone may actually crack. Thus, porosity is an important factor in determining a stone's durability. 

How to stop acid rain

Acid rain is a simple byproduct of burning fossil fuels and some other natural processes. When the fossil fuels are burnt they emit nitrogen oxides and sulfur dioxide into the air. The released gases bond with other agents and reside in the clouds as nitric acid and sulfur acid. When it rains, small quantities of acid fall with the precipitation resulting in corrosion of stone and buildings, as well as damaging plant life. The only principle way to stop this is to stop the formation of the acid, which means stopping the various processes that emit the base gases into the atmosphere. Other than stopping it outright is to somehow neutralize it before it can lead to any damaging effects.

The formation of these acids is a natural process that is important in order to keep the atmosphere free of the many different types of gases, and purifying the air on a continuous basis. Just like the formation of the acid, neutralizing it and coping with its effects are also natural. The only true problem lies in the quantity, as just a fraction of the current amount is easy to cope with.

To first solve the problem, it is important to eliminate the primary sources (as the natural secondary sources aren't the true problem). This can't be accomplished by simply removing all aspects that rely on fossil fuels. Such a scenario would remove too much of society and set efforts of control further back than leaving things the way they are. What's more important is switching society's reliance to another form that can replace the power plants, the fossil fuel reliant cars, and other applications.

Already there is a large movement to accomplish these tasks. Renewable energy is on the rise all over the world, replacing coal-burning power plants with wind, wave, undersea current and hydroelectric generators, as well as solar panels and geothermal energy. Nuclear energy will provide the bulk of electrical needs until the efficiencies and affordability of the renewable energies reaches a better state. Electric cars are becoming better for keeping charges for longer distances, and soon the rechargeable vehicles will draw electricity from the above mentioned processes. Other cars that use fuel cells and bio fuels (although not that different from fossil fuels) will dramatically reduce emissions that contribute to the formation of acid rain.

Finally, in order to neutralize the current threat of acid rain, there are options to reduce the damage by reducing the acidic level. This can be accomplished by adding more base pH leveled items in areas that are heavily affected by the acid, in forests or cities, and the acid content can be brought down to a level much closer to water. Risks of the extra base pH levels will have to be assessed in order to reduce the effects from too little acid in the rain water.

Acid Rain

Water supply acidification can have drastic consequences for survival of some plant and animal species.

  • Humans burning of fossil fuels contribute to ocean acidification.
  • When fuels are burned, CO2 is produced. The ocean absorbs approximately 25% of the CO2 produced through the burning of fossil fuels.
  • The decreasing pH of the ocean through carbonic acid formation is known as ocean acidification.
  • New research suggests that the ocean's pH will decrease by an additional .03 to 0.5 pH units before the end of the century.
  • Fossil fuel burning also creates a large amount of sulfur dioxides and nitrogen oxides. These compounds form strong acids when they react with water.
  • If sulfur dioxides and nitrogen oxides react with water in the air, a strong acid is formed and can fall to the ground as rain or snow. This is referred to as acid precipitation, which is when rain, snow, or fog has a pH of 5.2 or lower. A pH of 5.6 is normal for uncontaminated rain.
  • acid precipitation
    Acid rain is a rain or any other form of precipitation that is unusually acidic, meaning that it possesses elevated levels of hydrogen ions (low pH). It can have harmful effects on plants, aquatic animals, and infrastructure.
  • ocean acidification
    Ocean acidification is the name given to the ongoing decrease in the pH of the earth's oceans, caused by the uptake of anthropogenic carbon dioxide (CO2) from the atmosphere.


  • Ocean acidification leads to decreased levels of carbonate ions in oceans. Since carbonate ions and calcium are main building blocks of calcium carbonate skeletons and shells (Figure 2), ocean acidification can potentially lead to their dissociation.


    1. fig. 1
      What impact does human-generated carbon dioxide have on oceans?

      Carbon dioxide cycles from the atmosphere into the ocean where it is stored in various forms, including dissolved molecules that increase the acidity of ocean water.
    2. fig. 2
      Ocean acidification poses a major threat to coral reefs

      Coral reefs, like the healthy one pictured in the first image, can be severely damaged by ocean acidification. If CO2 levels continue to increase, the future of coral reefs will likely resemble the damaged coral reef shown in the second image.
    3. fig. 3
      Processes Involved in Acid Deposition

      Processes involved in acid deposition (note that only SO2 and NOxplay a significant role in acid rain).

      Water is one of the world's most precious renewable resources. Unfortunately, human activities, inclusive of rapid industrial growth, are contributing to the deterioration of global water quality.

      Since the beginning of the industrial revolution, atmospheric gases have been absorbed into precipitation and bodies of water around the globe rendering them incrementally more acidic. When atmospheric CO2, NO, and/or SO2 are dissolved in water, that water becomes acidic.

      When the aforementioned gases dissolve in rain water, we experience a phenomenon known as acid precipitation (Figure 3). While acid rain is most commonly referenced, acid precipitation also includes acidic, sleet, snow, and fog, all of which can have a very damaging effect on global ecosystems. In rivers, dams, and lakes, increased acidity can mean that some species of animals and plants will not survive. Acid precipitation has additional impacts on agriculture and thus the global food supply as it can degrade soil quality, producing metal ions that are washed into water systems.

      It is estimated that the surface pH of the globe's most reliable water supply, the ocean, has decreased by slightly more than 0.1 units on the logarithmic scale of pH, representing an approximately 29% increase in H+ since the industrial revolution. It is estimated that it will further decrease 0.3 to 0.5 pH units (an additional doubling to tripling of today's post-industrial acid concentrations) by the year 2100 as the oceans absorb more anthropogenic CO2 from the atmosphere.

      Ocean acidification is expected to impact ocean species to varying degrees. Photosynthetic algae and sea grasses may benefit from higher CO2 conditions in the ocean, as they require CO2 to live just like plants on land. On the other hand, studies have shown that a more acidic environment has a dramatic effect on some calcifying species, including oysters, clams, sea urchins, shallow water corals, deep sea corals, and calcareous plankton. When shelled organisms are at risk, the entire food web may also be at risk. Today, more than a billion people worldwide rely on food from the ocean as their primary source of protein. Many jobs and economies in the United States and around the world depend on the fish and shellfish in our oceans.

      Without quality water supply, life on this planet will become increasingly unsustainable. It is incumbent upon environmental policy makers to consider that the acidification of the global water supply has broad implications for global growth and global economies and to act to implement policies accordingly.

What are the causes and effects of acid rain on the environment?

Acid rain storms are caused by a number of industrialized countries such as UK, Germany, and Spain. For example, the Scandinavians have been left vulnerable to acid rain storms, admittedly not entirely of their own doing but more due to UK pollutants. Prevailing winds have resulted in the drift of acid rain clouds from the UK over parts of Scandinavia such as Norway. Overall, acid rain storms such as these are due to some of the following factors.

The main industrial process behind acid rain is the burning of fossil fuels. As such, this can include things such as processing of crude oil, iron and steel factories, and utility factories. These industrial processes that involve Sulphur give off Sulphur Dioxide into the atmosphere when it is burned.

While Sulphur is one of the acid rain gases, the other is that of Nitrogen Oxide. Nitrogen Oxide is the other chemical that causes acid rain storms. Such gases are largely produced by the chemical and car and automobile industries.

As such, as these gases have expanded into the atmosphere they then combine with the clouds, or water vapor. When Sulphur is combined with water vapour, Sulphuric acid is formed in the clouds. This can be summarized by the following chemical equation:

SO3 (g) + H2O (l) → H2SO4 (l)

In addition to this, Nitrogen Oxide also combines with water vapour which produces an acid. In this case Nitric acid emerges in the atmosphere, as summarized by this chemical equation:

NO2 + OH· → HNO3

As such, after Nitric and Sulphuric acid have emerged in the atmosphere acid rain storms are sure to follow. These acid rain storms can have some impact in relation to trees, buildings, ecosystems, plants and vegetation, and surface waters.

To begin with acid rain can erode some buildings. Any limestone, sandstone, and marble structures can be dissolved by acid rain during acid rain storms.

Acid rain has an impact in the forests. Acid rain can seep into the soil and neutralize a variety of minerals and nutrients. Toxic substances are then also dissolved into the soil during acid rain storms which can be absorbed by the plantation.

Acid rain also contributes to water pollution. Acid rain leaves chemicals in the water which increases their acidity. Excess Nitrogen in waterways can also result in eutrophication. This in turn can have an impact on the biodiversity of lakes and rivers.

So overall, acid rain is the result of a number of industrial processes involving the burning of fossil fuels and within the chemical industry. The resulting Sulphur and Nitrogen acids then cause acid rain storms in a variety of locations such as in Scandinavia. These storms can then impact buildings, forest ecosystems, and surface waters with their acidic pollutants. As such, protocols such as the Sulphur Emissions Reduction Protocol were introduced in 1979 which have reduced Sulphur Dioxide emissions in Europe.