Effects of Acid Rain on Humans

Acid rain looks, feels, and tastes just like clean rain. The harm to people from acid rain is not direct. Walking in acid rain, or even swimming in an acid lake, is no more dangerous than walking or swimming in clean water. The air pollution that causes acid rain is more damaging to human health. Sulfur dioxide and nitrogen oxides, the major sources of acid rain, can irritate or even damage our lungs.

The pollutants that cause acid rain can also reduce visibility, limiting how far into the distance we can see. The primary pollutants associated with acid rain and poor visibility are human-made sulfur dioxide emissions. These emissions form small sulfate particles, or aerosols, in the atmosphere. These aerosols reduce visibility by scattering light. Sulfate aerosols are the main cause of poor visibility in the eastern United States.

Nitrogen oxide emissions are also associated with the acid rain problem. They, too, can form aerosols in the atmosphere that significantly reduce visibility. Nitrate aerosols are often the main cause for poor visibility in the western United States where sulfur dioxide emissions and humidity are lower than in the east.

Making Acid in the Air

The final concentration of acids (mainly sulfuric acid, H₂SO₄ and nitric/nitrous acid, HNO₃/HNO₂) in precipition (acidity) is dependent on emissions of SO₂ and NO_x from sources, weather conditions andother chemicals present in the atmoshpere. The formation of sulfuric and nitric/nitrous acid in the atmosphere is a complex process involving several chemical reactions involving both solution and gas phase reactions.

SO₂

Gas phase	Solution phase
2SO2 + O2® 2SO3 very slow in the absence of a catalyst, therefore this is not a significant contributor	1) SO2 (aq)® H+ + HSO3- 2) HSO3- (aq)® H+ + SO32- The equilibrium concentraions for the above reactions are dependent upon such things as pH, droplet size, the "sticking coefficient" for SO2 on water, etc.
2SO3 + H2O® H2SO4 occurs quickly, therefore any formation of SO3 in the moist atmosphere is assumed to lead to the formation of sulfuric acid	1) HSO3- + H2O2® A- + H20 2) A- + H+® H2SO4 The dominant oxidation process occurs by hydrogen peroxide (formed in the gas phase from free radicals). The reaction involves the formation of an intermediate (A-), possibly a peroxymonosulfurous acid ion
1) HSO3- + H2O2® A- + H20 2) A- + H+® H2SO4 The dominant oxidation process occurs by hydrogen peroxide (formed in the gas phase from free radicals). The reaction involves the formation of an intermediate (A-), possibly a peroxymonosulfurous acid ion

NO_x

Gas Phase	Aqueous Phase
HO + NO2 (+M)® HONO2(+M) the principal contributor to the formation of nitric acid is the reaction with hydroxy radicals. These radicals are highly reactive and abundant in the atmosphere.	1. 2NO2(g) + H2O(l)® 2H+ + NO3- + NO2- 2. NO(g) + NO2(g) + H2O(l)® 2H+ + 2NO2- 3. 3NO2(g) + H2O(l)® 2H+ + 2NO3- + NO(g) Equilibria of three reactions define the aqueous oxidation of Nox and depend on the partial pressures of NOx present in the atmosphere, temperature, humidity and the low solubility of NOx.

What Region of the United States Is Most Affected by Acid Rain?

Acid rain didn't become an environmental problem until the burning of large quantities of fossil fuels during the industrial age. Some acid rain occurs naturally, but sulfur dioxide and nitrogen oxide emissions from smokestacks combine with rain to make sulfuric and nitric acid in amounts that harm the environment. The region of the United States most harmed by acid rain is the East Coast, including the Appalachian Mountains and the Northeast.

Lakes and Streams

In a study of the nation's lakes and streams that show acidic conditions, the National Surface Water Survey found that acid rain caused the acidity in 75 percent of the lakes and about 50 percent of the streams. Greatest acidity occurred along the Atlantic coast, where waters have naturally higher acidity to begin with. The highest rate of stream acidity, over 90 percent, occurs in the New Jersey Pine Barrens region. Little Echo Pond in Franklin, New York, had one of the most acidic conditions, according to the study, with a pH of 4.2.

Forests and Soils

Acid rain degrades soils by washing away chemicals such as calcium and magnesium, which buffer acidity and provide essential nutrients to plants. Acidity also releases potentially toxic dissolved aluminum into water. Appalachian forests from Maine to Georgia are particularly affected. Trees usually don't die outright but are weakened and more susceptible to pathogens, insects, drought or extreme cold. Scientists expect that the U.S. Environmental Protection Agency's Acid Rain Program, which reduces sulfur dioxide emissions, will significantly reduce acidification along the East Coast.

What Place in the World Receives the Most Acid Rain?

Acid rain is responsible for severe environmental destruction across the world and occurs most commonly in the North Eastern United States, Eastern Europe and increasingly in parts of China and India. According to the Environmental Protection Agency (EPA) acid rain can be particularly damaging to the young from many species of plant and wildlife.

What is Acid Rain?

Nitrogen oxide and sulfur dioxide are polluting byproducts of soft-coal-burning power plants and factories, and are the main culprits in the production of acid rain. When these chemicals combine with water and particulates in the atmosphere, the result is precipitation, which includes rain, snow and fog, laden with nitric and sulfuric acids, otherwise known as acid rain.

The Black Triangle

Covering areas of the Czech Republic, Germany and Poland, the Black Triangle is an area that received heavy acid rain throughout the 1970s and 80s. In parts of the Black Triangle, entire forests were dead or dying and even railroad tracks were being corroded by the acidic precipitation. The emissions of coal-burning factories in Eastern Europe came under strict regulation by the Geneva Convention of 1979 to prevent further acid rain pollution, a measure that has been successful in significantly reducing acid deposition in the region.

Eastern United States

Parts of the Eastern United States were also once plagued by some of the highest levels of acid rain in the world, due to emissions from Midwestern coal-burning power plants. In parts of New Jersey, for example, over 90 percent of freshwater streams are still acidic today due to acid rain, according to the U.S. Environmental Protection Agency. While the effects of acid rain are still felt in the region, acid rain itself has significantly decreased as a result of the Clean Air Act of 1970 and its subsequent amendments.

Changing Trends

Because of the laws enacted in the United States and Europe regulating emissions from coal-burning factories, and the adoption of mitigating technologies, such as limestone injection burners, reburners, flue gas desulphurizers and low-sulfur burners, these areas receive less acid rain today than in the past, according to a report from the environmental watchdog group Earthwatch Institute. The habitats in these countries suffered extensive damage and recovery is slow, but international concern over acid rain has since shifted focus to other parts of the world. In China and India, rapid industrial growth and lax pollution regulations could combine to produce the highest levels of acid rain in the developing world.

Acid Rain in Asia

Since the year 2000, levels of nitric and sulfuric acid in precipitation have been steadily increasing in Asian cities such as Beijing and New Delhi as domestic demand for electricity and manufactured goods increases. Without pollution regulations on the rapid industrial growth in the developing nations of China and India, acid rain could continue to grow in potency and reach until a similar crisis level as seen in Europe and the United States in the 1980s, according to a report by Science News.

Solutions and Ways Forward

In the United States, there are measures to protect the environment from the effects of acid rain including the EPA's Acid Rain program developed following the Clean Air Act Amendment of 1990 which aims to lower sulfur dioxide emissions from power plants. Responsible steps like these, towards lowering contaminants in the air can help to halt the destruction of acid rain.

Alternate Ways to Reduce The Acid Rain

Acid rain is a very serious environmental threat faced by our planet today. Millions of people get affected by it on a daily basis. Acid rain occurs when high levels of sulfur dioxide and nitrogen dioxide enter in the atmosphere and start undergoing chemical transformation. These harmful gases are absorbed by water droplets in the clouds and they fall on the earth during rains. They can damage the natural soil by increasing the acidity levels and pollute rivers and lakes. Acid rain is actually a broad term which is used to describe different types of acid that fall from the atmosphere on earth. It's mainly divided into wet and dry. Parts of the world which experience wet weather have acid rain, acid snow and fog. Other parts which experience dry weather for most of the year experience acid gas and acid dust.

Today people can see the effects of acid rain everywhere they go. Dead and weakened trees are a very common sign of acid rain, while in cities worn off or scarred buildings are also a result of acid rain. This problem is more prevalent in the northern hemisphere where there's a huge growth in the number of industries. Winds absorb more and more quantities of harmful gases produced by various kinds of industries. In addition to this, even natural sources like volcanoes, forest fires and lighting contribute to this man-made pollution.

How to Prevent Acid Rain

Acid rain has existed since the beginning of the Industrial Revolution which also marked the start of various factories. The harmful rain was discovered by an English scientist, Robert Angus Smith who came up with the term 'Acid Rain' in 1872, when he saw corrosion on the surfaces of buildings and plants because of rain. However, acid rain became an important government issue only after six to seven decades. 1980 marked the beginning of the 'Acid Deposition Act' in which environmental agencies started monitoring areas which were effected by acid rain. Since then a lot of research has been conducted and common people like us can do a lot to help environmental agencies prevent acid rain. Here are some pointers.

One of the main causes of acid rain is a sudden drop in the pH levels of water and that happens because of absorption of harmful gases by the atmosphere. The best way to restore the pH balance of water is to limit the use of items which run on gasoline. Instead use products which run on electricity; as they are much easier to run and maintain.

Another great thing that all people can do is to learn how to drive cars efficiently. While driving on roads there are a lot of things that can be done to reduce smoke emission from cars. Drivers should ease up as soon as the yellow light rather than slamming on the brakes and they shouldn't rush away as soon as the lights turn green. These small practices help reduce the wastage of gasoline and helps people save a lot of money on fuel.

Learn about the different sources of energy besides fossil fuels and try to implement them in daily usage. Many nations like France and Germany are using electrical, nuclear, wind and sun energy on large basis which has helped cut down on the pollution levels.

Another great tip which almost all of us can practice is to always keep the vehicle tires inflated. Tires having proper pressure will provide users with a better fuel economy.

Limit the use of buses or cars for small things, people can also make use of cycles or walk to cover small distances.

Turn off your lights, computers and other appliances when not in use and turn the thermostat of the house at 68°F in winter and 72°F in summer when the house is empty.

Nowadays, though people don't hear about acid rain anymore, it's still a global problem faced by many nations. It's very unfortunate to see that humans are the ones who have a very important role to play in this destruction.

Acid Rain

Showing  You  How  Environment  Reacts to us Polluting  Humans. Acidic Coffee is a Stimulant and Acid rain is a Death Warrant.

Acid rain is quite a popular term these days. Environmental scientists describe it as an adverse effect of increasing pollution due to recent human activities. But even before humans started evolving on earth, proof of acid rains have been found. It was around 250 million years ago; the most devastating case of mass extinction in earth’s history was caused by acid rain due to volcanic eruption in the Siberian region. It eradicated around 90% of marine and 70% of terrestrial species.

Acidity of rain is measured using the pH scale. The scale considers water as neutral (pH - 7). A pH of less than 7 is acidic and a pH greater than 7 is basic. Coffee is slightly acidic (pH - 5.5) whereas lemon juice is more acidic (pH - 2.5). This is a logarithmic scale, which means pH 4 is 10 times more acidic than pH 5 and 100 time more acidic than pH 6.

Surprisingly, rain is always acidic compared to water. Carbon dioxide in the atmosphere gets dissolved in the clouds to form a weak acid called carboxylic acid. So scientists consider a pH of 5.6 as neutral pH in the case of rainwater. Sulphur dioxide and Nitrogen dioxide, emitted from cars and various industries, make rainwater more acidic. Falling raindrops capture significant amount of these gasses and particles suspended in the air to form a complex mixture before arriving on the ground.

So how acidic could rainwater be? Studies say it could be as low as pH 2. This highly acidic water can directly affect human eye and skin. Fish and amphibians can die instantly. Leeching of nutrients from soil due to long term acidic rains leads to destruction of forest ecosystems. But fortunately, rains with high acidity are very rare. Alarmingly, acidic rains in highly polluted cities are being recorded all over the world.

Does Acid Rain Have an Effect on Agriculture?

Acid rain affects plants directly and decreases soil quality to reduce yields from agriculture. Its effects are particularly severe in locations near sources of sulfur dioxide and nitrogen oxides. In the United States, about two-thirds of sulfur dioxide and one-quarter of nitrogen oxides come from power generation plants burning fossil fuels, while the rest is from industrial and transportation sources.

Sources

Acid rain comes from chemical reactions in the atmosphere among oxygen, water and sulphur or nitrogen oxides. When sulfur dioxide dissolves in small droplets of water in clouds, it reacts with the hydrogen and oxygen of the water to form a weak solution of sulfuric acid. Similarly, nitrogen oxides form weak nitric acid in water droplets. The clouds can drift over hundreds of miles carrying their acid droplets. When conditions are right for rain, the droplets grow and fall to the ground. In many areas of the United States, such as the great plains, the acid rain falls mostly on land used for agriculture.

Plants

Acid rain influences both the quality and yield of agricultural products. Acid rain can damage the leaves of vegetables such as spinach and cause blemishes on delicate products such as tomatoes. The production and quality of root vegetables is reduced. The damage depends on the strength of the acids in the acid rain and the frequency with which the crops are exposed. In addition to cosmetic damage, there is the possibility that crops grown under acidic conditions have lower nutritional value with fewer minerals.

Soil

The acidic nature of acid rain leaches plant nutrients out of the soil and can make it less productive for agriculture. Soils with high alkaline content, such as those containing calcium carbonate or limestone, can neutralize the acids and are less sensitive. Other soils normally contain the minerals that plants need, but the acid in acid rain dissolves them and replaces the metallic ions with hydrogen. When the plants absorb water that normally contains the minerals, they get hydrogen instead and can't grow as large or as quickly as before. In severe cases, this lack of minerals can kill the plants.

Reduction

The U.S. Environmental Protection Agency has taken steps to reduce emissions of sulphur dioxide and nitrogen oxides and continues to monitor these pollutants. Car manufacturers are required to produce cars that emit less of these damaging gases and power plants have to install filters to reduce emissions. As an individual, you can reduce your use of electric power and make sure that the catalytic converter on your car is working properly. Smaller cars and cars with smaller engines produce less carbon dioxide. Insulating your home, using efficient heating and cooling systems and avoiding heating with oil can make a substantial contribution to reducing the effects of acid rain on agriculture.

Acid Rain: Scourge of the Past or Trend of the Present?

Acid Rain

It was a problem that largely affected U.S. eastern states. It began in the 1950s when Midwest coal plants spewed sulfur dioxide and nitrogen oxides into the air, turning clouds–and rainfall–acidic. As acid rain fell, it affected everything it touched, leaching calcium from soils and robbing plants of important nutrients. New England’s sugar maples were among the trees left high and dry.

Acid rain also poisoned lakes in places like New York’s Adirondack Mountains, turning them into a witches’ brew of low pH waters that killed fish and brought numbers of fish-eating birds like loons to the brink.

Then in 1970, the U.S. Congress imposed acid emission regulations through the Clean Air Act, strengthened two decades later in 1990. By the 2000s, sulfate and nitrate in precipitation had decreased by some 40 percent.

Is it Back?

Has acid rain now blown over? Or is there a new dark cloud on the horizon?

In findings recently published in the journal Water Resources Research, Charles Driscoll of Syracuse University and the National Science Foundation’s (NSF) Hubbard Brook Long Term Ecological Research (LTER) site in New Hampshire reports that the reign of acid rain is far from over.

It’s simply “shape-shifted” into a different form.

Hubbard Brook is one of 26 NSF LTER sites across the nation and around the world in ecosystems from deserts to coral reefs to coastal estuaries. Co-authors of the paper are Afshin Pourmokhtarian of Syracuse University, John Campbell

of the U.S. Forest Service in Durham, N.H., and Katharine Hayhoe of Texas Tech University. Pourmokhtarian is the lead author.

Acid Rain First Identified

Acid rain was first identified in North America at Hubbard Brook in the mid-1960s, and later shown to result from long-range transport of sulfur dioxide and nitrogen oxides from power plants. Hubbard Brook research influenced national and international acid rain policies, including the 1990 Clean Air Act amendments. Researchers at Hubbard Brook have continued to study the effects of acid rain on forest growth and on soil and stream chemistry.

Long-term biogeochemical measurements, for example, have documented a decline in calcium levels in soils and plants over the past 40 years. Calcium is leaching f

rom soils that nourish trees such as maples. The loss is primarily related to the effects of acid rain (and acid snow).

Now, Hubbard Brook LTER scientists have discovered that a combination of today’s higher atmospheric carbon dioxide (CO2) level and its atmospheric fallout is altering the hydrology and water quality of forested watersheds–in much the same way as acid rain.

“It’s taken years for New England forests, lakes and streams to recover from the acidification caused by atmospheric pollution,” says Saran Twombly, NSF program director for long-term ecological research. “It appears that these forests and streams are under threat again. Climate change will likely return them to an acidified state. The implications for these environments, and for humans depending on them, are severe.”

Climate projections indicate that over the 21st century, average air temperature will increase at the Hubbard Brook site by 1.7 to 6.5 degrees Celsius, with increases in annual precipitation ranging from 4 to 32 centimeters above the average from 1970-2000.

Monitoring the Effects

Hubbard Brook scientists turned to a biogeochemical model known as PnET-BGC to look at the effects of changes in temperature, precipitation, solar radiation and atmospheric CO2 on major elements such as nitrogen in forests. The model is used to evaluate the effects of climate change, atmospheric deposition and land disturbance on soil and surface waters in northern forest ecosystems.

It was created by linking the forest-soil-water model PnET-CN with a biogeochemical sub-model, enabling the incorporation of major elements like calcium, nitrogen, potassium and others.

The results show that under a scenario of future climate change, snowfall at Hubbard Brook will begin later in winter, snowmelt will happen earlier in spring, and soil and stream waters will become acidified, altering the quality of water draining from forested watersheds.

“The combination of all these factors makes it difficult to assess the effects of climate change on forest ecosystems,” says Driscoll. “The issue is especially challenging in small mountain watersheds because they’re strongly influenced by local weather patterns.”

The Hubbard Brook LTER site has short, cool summers and long, cold winters. Its forests are made up of northern hardwood trees like sugar maples, American beeches and yellow birches. Conifers–mostly balsam firs and red spruces–are more abundant at higher elevations.

The model was run for Watershed 6 at Hubbard Brook. “This area has one of the longest continuous records of meteorology, hydrology and biogeochemistry research in the U.S.,” says Pourmokhtarian.

The watershed was logged extensively from 1910 to 1917; it survived a hurricane in 1938 and an ice storm in 1998.

It may have more to weather in the decades ahead.

The model showed that in forest watersheds, the legacy of an accumulation of nitrogen, a result of acid rain, could have long-term effects on soil and on surface waters like streams.

Changes in climate may also alter the composition of forests, says Driscoll. “That might be very pronounced in places like Hubbard Brook. They’re in a transition forest zone between northern hardwoods and coniferous red spruces and balsam firs.”

The model is sensitive to climate that is changing now–and climate changes expected to occur in the future.

In scenarios that result in water stress, such as decreases in summer soil moisture due to shifts in hydrology, the end result is further acidification of soil and water.

Environmental Problems

The effect that humanity is having on the environment is becoming ever-more important. Through our actions we are destroying habitats and endangering the lives of future generations.

At this point there is no denying the fact that our environment is changing. Hundreds of studies have been conducted to demonstrate that this is happening and it is having an effect on life around us.

However, many may be unaware of the specific issues that have led to these changes. Terms like “climate change” and “genetic modification” are commonplace, but without additional information it is difficult to see why they actually matter.

To complicate the matter, many of these issues are linked to one another. The key is that they are all important challenges that need to be confronted.

Here we examine the biggest environmental problems facing our planet today and why they should matter to you.

Climate Change

The majority of the issues previously listed contribute or are linked to climate change. Statistics created by NASA state that global temperatures have risen by 1.7 degrees Fahrenheit since 1880, which is directly linked to a reduction in Arctic ice of 13.3% per decade.

The effects of climate change are widespread, as it will cause issues with deforestation, water supplies, oceans and ecosystems. Each of these have widespread implications of their own, marking climate change as the major environmental issue the planet faces today.

The Biggest Environmental Problems

Genetic Modification of Crops

Environmental issues caused by man-made chemicals are becoming clearer. For example, there has been a 90% reduction in the Monarch butterfly population in the United States that can be linked to weed killers that contain glyphosate.

There is also some speculation that genetically-modified plants may leak chemical compounds into soil through their roots, possibly affecting communities of microorganisms.

 Waste Production

The average person produces 4.3 pounds of waste per day, with the United States alone accounting for 220 million tons per year. Much of this waste ends up in landfills, which generate enormous amounts of methane.

Not only does this create explosion hazards, but methane also ranks as one of the worst of the greenhouse gases because of its high global warming potential.

Population Growth

Many of the issues listed here result from the massive population growth that Earth has experienced in the last century. The planet’s population grows by 1.13% per year, which works out to 80 million people.

This results in a number of issues, such as a lack of fresh water, habitat loss for wild animals, overuse of natural resources and even species extinction. The latter is particularly damaging, as the planet is now losing 30,000 species per year.

 Water Pollution

Fresh water is crucial to life on Earth, yet more sources are being polluted through human activities each year. On a global scale, 2 million tons of sewage, agricultural and industrial waste enters the world’s water every day.

Water pollution can have harmful effects outside of contamination of the water we drink. It also disrupts marine life, sometimes altering reproductive cycles and increasing mortality rates.

 Deforestation

The demands of an increasing population has resulted in increasing levels of deforestation. Current estimates state that the planet is losing 80,000 acres of tropical forests per day.

This results in loss of habitat for many species, placing many at risk and leading to large-scale extinction. Furthermore, deforestation is estimated to produce 15% of the world’s greenhouse gas emissions.

 Urban Sprawl

The continued expansion of urban areas into traditionally rural regions is not without its problems. Urban sprawl has been linked to environmental issues like air and water pollution increases, in addition to the creation of heat-islands.

Satellite images produced by NASA have also shown how urban sprawl contributes to forest fragmentation, which often leads to larger deforestation.

 Overfishing

It is estimated that 63% of global fish stocks are now considered overfished. This has led to many fishing fleets heading to new waters, which will only serve to deplete fish stocks further.

Overfishing leads to a misbalance of ocean life, severely affecting natural ecosystems in the process. Furthermore, it also has negative effects on coastal communities that rely on fishing to support their economies.

 Acid Rain

Acid rain comes as a result of air pollution, mostly through chemicals released into the environment when fuel is burned. Its effects are most clearly seen in aquatic ecosystems, where increasing acidity in the water can lead to animal deaths.

It also causes various issues for trees. Though it doesn’t kill trees directly, acid rain does weaken them by damaging leaves, poisoning the trees and limiting their available nutrients.

Ozone Layer Depletion

Ozone depletion is caused by the release of chemicals, primarily chlorine and bromide, into the atmosphere. A single atom of either has the potential to destroy thousands of ozone molecules before leaving the stratosphere.

Ozone depletion results in more UVB radiation reaching the Earth’s surface. UVB has been linked to skin cancer and eye disease, plus it affects plant life and has been linked to a reduction of plankton in marine environments.

Ocean Acidification

Ocean acidification is the term used to describe the continued lowering of the pH levels of the Earth’s oceans as a result of carbon dioxide emissions. It is estimated that ocean acidity will increase by 150% by 2100 if efforts aren’t made to halt it.

This increase in acidification can have dire effect on calcifying species, such as shellfish. This causes issues throughout the food chain and may lead to reductions in aquatic life that would otherwise not be affected by acidification.

 Air Pollution

Air pollution is becoming an increasingly dangerous problem, particularly in heavily-populated cities. The World Health Organization (WHO) has found that 80% of people living in urban areas are exposed to air quality levels deemed unfit by the organization.

It is also directly linked to other environmental issues, such as acid rain and eutrophication. Animals and humans are also at risk of developing a number of health problems due to air pollution.

 Lowered Biodiversity

Continued human activities and expansion has led to lowered biodiversity. A lack of biodiversity means that future generations will have to deal with increasing vulnerability of plants to pests and fewer sources of fresh water.

Some studies have found that lowered biodiversity has as pronounced an impact as climate change and pollution on ecosystems, particularly in areas with higher amounts of species extinction.

The Nitrogen Cycle

With most of the focus being placed on the carbon cycle, the effects of human use of nitrogen often slips under the radar. It is estimated that agriculture may be responsible for half of the nitrogen fixation on earth, primarily through the use and production of man-made fertilizers.

Excess levels of nitrogen in water can cause issues in marine ecosystems, primarily through overstimulation of plant and algae growth. This can result in blocked intakes and less light getting to deeper waters, damaging the rest of the marine population.

 Natural Resource Use

Recent studies have shown that humanity uses so many natural resources that we would need almost 1.5 Earths to cover our needs. This is only set to increase as industrialization continues in nations like China and India.

Increased resource use is linked to a number of other environmental issues, such as air pollution and population growth. Over time, the depletion of these resources will lead to an energy crisis, plus the chemicals emitted by many natural resources are strong contributors to climate change.

Transportation

An ever-growing population needs transportation, much of which is fueled by the natural resources that emit greenhouse gases, such as petroleum. In 2014, transportation accounted for 26% of all greenhouse gas emissions.

Transportation also contributes to a range of other environmental issues, such as the destruction of natural habitats and increase in air pollution.

Polar Ice Caps

The issue of the melting of polar ice caps is a contentious one. While NASA studies have shown that the amount of ice in Antarctica is actually increasing, these rises only amount to a third of what is being lost in the Arctic.

There is strong evidence to suggest that sea levels are rising, with the Arctic ice caps melting being a major contributor. Over time, this could lead to extensive flooding, contamination of drinking water and major changes in ecosystems.

The impact that human activities have on the environment around us is undeniable and more studies are being conducted each year to show the extent of the issue.

Climate change and the many factors that contribute to emissions could lead to catastrophic issues in the future.

More needs to be done to remedy the major environmental issues that affect us today. If this doesn’t happen, the possibility exists that great swathes of the planet will become uninhabitable in the future.

The good news is that many of these issues can be controlled. By making adjustments, humanity can have a direct and positive impact on the environment.

Please feel free to join the conversation in the comments section below or engage your friends in discussion about the environment on social media.

Acid Rain Effects on Health

Acid rain looks, feels, and tastes just like clean rain.The harm to people from acid rain is not direct.Walking in acid rain, or even swimming in an acid lake, is no more dangerous than walking or swimming in clean water. However, the pollutants that cause acid rain (sulfur dioxide (SO2) and nitrogen oxides (NOx)) also damage human health. These gases interact in the atmosphere to form fine sulfate and nitrate particles that can be transported long distances by winds and inhaled deep into people's lungs. Fine particles can also penetrate indoors. Many scientific studies have identified a relationship between elevated levels of fine particles and increased illness and premature death from heart and lung disorders, such as asthma and bronchitis. 

Based on health concerns, SO2 and NOx have historically been regulated under the Clean Air Act, including the Acid Rain Program. In the eastern United States, sulfate aerosols make up about twenty five percent of fine particles.By lowering SO2 and NOx emissions from power generation, the Acid Rain Program will reduce the levels of fine sulfate and nitrate particles and so reduce the incidence and the severity of these health problems.asthma and bronchitis. When fully implemented by the year 2010, the public health benefits of the Acid Rain Program are estimated to be valued at fifty billion dollars annually, due to decreased mortality, hospitaadmissions and emergency room visits. 

Decreases in nitrogen oxide emissions are also expected to have a beneficial impact on human health by reducing the nitrogen oxides available to react with volatile organic compounds and form ozone. Ozone impacts on human health include a number of morbidity and mortality risks associated with lung inflammation, including asthma and emphysema.

Mechanisms and Effects of Acid Rain on Environment

Abstract

This paper focuses on mechanisms and effects of air pollution on atmosphere. It’s been mentioned that the most causes of our world’s global climate change are totally different circumstances. Among them, acidic rain is one among the chronic problems for the global climate change and ecological deformation of our surroundings. It's been finished that usually, precipitation that includes a pH 5.6 is taken into account as air pollution. It’s fashioned, once sulphur oxides and gas oxides reacted with water throughout rain and as gases or fine particles. This air pollution affects a spread of plants and animals in our surroundings. because it is mentioned higher than below ways of hindrance acidic rain on environment; it's been reduced by pack up smokestacks and exhaust pipes furthermore as victimization alternatives energy sources for vehicles, fuel station and electricity generation for various purpose so as to measure in an exceedingly safe and appropriate atmosphere without concern of worldwide warming and inexperienced house gases.

Introduction

Acid rain is a broad term used to describe several ways that acids fall out of the atmosphere. A more precise term is acid deposition, which has two parts: wet and dry. Wet deposition refers to acidic rain, fog, and snow. As this acidic water flows over and through the ground, it affects a variety of plants and animals. Dry deposition refers to acidic gases and particles. About half of the acidity in the atmosphere falls back to earth through dry deposition . The wind blows these acidic particles and gases towards buildings, cars, homes and trees. Dry deposited gases and particles can also be washed from trees and other surfaces by rainstorms. When that happens, the runoff water adds those acids to the acid rain, making the combination more acidic than the falling rain alone. Precipitation that has a pH value of less than seven may contain acidic rain. This is due to the presence of acidic oxide emissions in the atmosphere from industries and vehicles. However, a rainfall that has a pH value of less than 5.6 is considered as acid rain . It is formed when sulphur dioxides and nitrogen oxides, as gases or fine reacts with rain water. Particles in the atmosphere combine with water vapour and precipitate as sulphuric acid or nitric acid in rain, snow, or fog. Therefore, the main objective of this paper was to assess the effect of acid rain on environment and to suggest the methods of preventing acid rain. Moreover, to review what have done on acid rain before and to forecast what will have done in the future. This is the first phase of the research. It will continued more on experimental result in the second phase of the paper.

Methodology

How do we measure acid rain?

Acid rain is measured using pH meter from 1 to 14 value scales with a pH of 7.0 being neutral, 0 to 7 being acidic, and 7 to 14 basic . When the PH value lowers, the acidity nature of rain increases. Pure water has a pH value of 7. However, normal rain is slightly acidic because different acidic oxide emissions react with rain that lowers the pH value about 5.6. According to 2000 report, the most acidic rain falling in the US has a pH of about 4.3 . This acid rain's pH and the chemicals that cause acid rain are monitored by two networks that are supported by EPA. The National Atmospheric Deposition Program measures wet deposition, and its Web site features maps of rainfall pH (follow the link to the isopleths maps) and other important precipitation chemistry measurements. The Clean Air Status and Trends Network (CASTNET) measures dry deposition. Its web site features information about the data it collects, the measuring sites, and the kinds of equipment it uses .

Discussions

Components of acid rain

The major components of acid rains are sulphur dioxide/sulphur trioxide, carbon dioxide and nitrogen dioxide dissolves in rain water. These components are deposited as dry and wet depositions. When these pollutants are dissolved in water during rain it forms various acids (Figure 1). The chemical reactions of these pollutants are discussed as follows.

Figure 1: Flow chart that shows the formation of acid rain and its interaction with environment.

• CO₂+H₂O → H₂CO₃ (carbonic acid)

• SO₂+H₂O → H₂SO₃ (sulphorous acid)

• NO₂+H₂O → HNO₂ (nitrous acid)+HNO₃ (nitric acid)

Causes for the formation of acid rain

Natural sources and human activities are the main causes for the formation of acid rain in the world. Natural source causes are emissions from volcanoes and biological processes that occur on the land, in wetlands, and in the oceans contribute acid-producing gases to the atmosphere; and Effects of acidic deposits have been detected in glacial ice thousands of years old in remote parts of the globe. Whereas, activities of human beings are burning of coal, using Oil and natural gas in power stations to produce electricity, cooking purpose and to run their vehicles are giving off oxide of sulphur, oxides of carbon, oxides of nitrogen, residual hydrocarbons and particulate matters to the environment. These emissions mix with water vapour and rainwater in the atmosphere producing weak solutions of sulphuric and nitric acids, which fall back as acid rain to the ocean, lake and land.

Areas affected by acid rain due to power plant

Canada and USA: Acid rain is a problem in Eastern Canada and the Northeastern USA. Large smelters in western Ontario and steel processing plants in Indiana, Ohio historically used coal as a source of fuel. The sulfur dioxide produced was carried eastward by the jet stream. Acid rain from power plants in the Midwest United States has also harmed the forests of upstate New York and New England. In many areas water and soil systems lack natural alkalinity such as lime base cannot neutralize acid.

Sulfur dioxide is emitted from industrial processes and the burning of fossil fuels. In particular, ore smelting, coal-fired power generators, and the processing of natural gas result in the greatest emissions of sulfur dioxide. In 2000, Canada emitted 2.4 million tons of sulfur dioxide. Moreover, the primary causes of oxides of nitrogen are a vehicle, which accounts about 60% of all nitrogen oxide emissions. However, emissions also come from furnaces, boilers and engines. In 2000, Canada emitted 2.5 million tones of nitrogen oxide. Therefore, these emissions are the main causes of acid rain all over the world.

Europe and Asia: Industrial acid rain is a substantial problem in China, Eastern Europe and Russia and areas down-wind from them. The effects of acid rain can spread over a large area, far from the source of the pollution. Research carried out in North America in 1982, revealed that sulphur pollution killed 51,000 people and about 200,000 people become ill due to this emissions.

Over the past decades, Norway has suffered a great damage due to the effect of acid rain. While Norway’s sulphur dioxide emissions have decreased significantly since the 1970s and 1980s, and nitrogen oxide emissions have decreased slightly, the damages from acid rain appear to be worsening in southern Norway. This is because it takes years for the ecosystems and the environment to recover from the effects of acidification. According to the State of the Environment in Norway, 18 salmon stocks have been lost and 12 are endangered, and have been wiped out of all of the large salmon rivers in southern Norway.

Hydrodesulphurization (HDS)

Hydro treating is a catalytic chemical process widely used to remove sulfur compounds from refined petroleum products such as gasoline or petrol, jet fuel, diesel fuel, and fuel oils. One purpose for removing the sulfur is to reduce the sulfur dioxide emissions resulting from using those fuels in automotive vehicles, aircraft, railroad locomotives, ships, or oil burning power plants, residential and industrial furnaces, and other forms of fuel combustion.

Another important reason for removing sulfur from the intermediate product naphtha streams within a petroleum refinery is that sulfur, even in extremely low concentrations, poisons the noble metal catalysts platinum and rhenium in the catalytic reforming units that are subsequently used to upgrade the of the naphtha streams .

Effects of acid rain on environment

Harmful to aquatic life: This is due to increasing the acidity character in water bodies that Stops eggs of certain organisms (e.g. fish) to stop hatching, Changes population ratios and affects their ecosystem.

Harmful to vegetation: Vegetables are destructed due to increased acidity in soil, Leeches nutrients from soil, and slowing plant growth, poisoning plants, creates brown spots in leaves of trees, impeding photosynthesis, allows organisms to infect through broken leaves.

Affects human health: Causes respiratory problems, asthma, dry coughs, headaches and throat irritations; Leeching of toxins from the soil by acid rain can be absorbed by plants and animals. When consumed these toxins it affect human’s life severely ,which cause brain damage, kidney problems and Alzheimer's disease have been linked to people who eat meat of "toxic" animals/plants by these pollutant.

Effect on transport: Currently, both the railway industry and the aeroplane industry have to spend a lot of money to repair the corrosive damage done by acid rain. Furthermore, bridges have collapsed in the past due to acid rain corrosion. Acid rain dissolves the stonework and mortar of buildings (especially those made out of sandstone or limestone). It reacts with the minerals in the stone to form a powdery substance that can be washed away by rain.

How do we prevent our environment from acidic rain?

There are several ways to reduce acid deposition and precipitation. These are:

Clean up smokestacks and exhaust pipes: Almost all of the electricity that powers modern life comes from burning fossil fuels like coal, natural gas, and oil. However, exhaust emission of these fuels are the main causes of acid deposition that released into the atmosphere. Coal fuel accounts for most US SO2 and a large portion of NOx emissions. Sulfur is present in coal as an impurity, and it reacts with air when the coal is burned to form SO2. In contrast, NOx is formed when any fossil fuel is burned. There are several options for reducing SO2 emissions, including using coal containing less sulfur, washing the coal, and using devices called scrubbers to chemically remove the SO2 from the gases leaving the smokestack and recycling to use as a raw material. Power plants can also switch fuels; for example burning natural gas creates much less SO2 than burning coal. Certain approaches will also have additional benefits of reducing other pollutants such as mercury and carbon dioxide. Understanding these "co-benefits" has become important in seeking cost-effective air pollution reduction strategies. Finally, power plants can use technologies that don't burn fossil fuels. Each of these options has its own costs and benefits, however; there is no single universal solution. Similar to scrubbers on power plants, catalytic converters reduce NOx emissions from cars. These devices have been required for over twenty years in the US, and it is important to keep them working properly and tailpipe restrictions have been tightened recently. EPA has also made, and continues to make, changes to gasoline that allows it to burn cleaner dioxide of sulfur (SO2) and NOx.

Use alternative energy sources: There are other sources of electricity besides fossil fuels such as nuclear power, hydropower, wind energy, geothermal energy, and solar energy. Of these, nuclear and hydropower are used most widely; wind, solar, and geothermal energy have not yet been harnessed on a large scale. There are also alternative energies available to power automobiles, including natural gas powered vehicles, battery-powered cars, fuel cells, biofuels and biodiesel and combinations of alternative and gasoline powered vehicles. All sources of energy have environmental costs as well as benefits. Some types of energy are more expensive to produce than others. Nuclear power, hydropower, and coal are the cheapest forms today, but changes in technologies and environmental regulations may shift that in the future. All of these factors must be weighed when deciding which energy source to use today and which to invest for tomorrow.

Liming: Powdered limestone added to water and soil to neutralize acid. It is commonly used in Norway and Sweden. However, it is more expensive and short-term remedy. Acid deposition penetrates deeply into the fabric of an ecosystem, changing the chemistry of the soil as well as the chemistry of the streams and narrowing, sometimes to nothing, the space where certain plants and animals can survive. Because there are so many changes, it takes many years for ecosystems to recover from acid deposition, even after emissions are reduced and the rain becomes normal again. For example, while the visibility might improve within days, and small or episodic chemical changes in streams improve within months, chronically acidified lakes, streams, forests, and soils can take years to decades or even centuries (in the case of soils) to heal. However, there are some things that people do to bring back lakes and streams more quickly. Limestone or lime (a naturally-occurring basic compound) can be added to acidic lakes to "cancel out" the acidity. This process, called liming. Liming tends to be expensive, has to be done repeatedly to keep the water from returning to its acidic condition, and is considered a short-term remedy in only specific areas rather than an effort to reduce or prevent pollution. Furthermore, it does not solve the broader problems of changes in soil chemistry and forest health in the watershed, and does nothing to address visibility reductions, materials damage, and risk to human health. However, liming does often permit fish to remain in a lake, so it allows the native population to survive in place until emissions reductions reduce the amount of acid deposition in the area.

Conclusion

Generally, rainfall that has a pH value less than 5.6 is considered as acid rain. It is formed when sulphur dioxides and nitrogen oxides reacted with water during rain and as gases or fine. Acids rain is described in terms of wet and dry depositions. The wet deposition refers to acidic rain, frog and snow whereas dry deposition refers to acidic gases and particles. This acid rain affects a variety of plants and animals (Harmful to aquatic life, Harmful to vegetation, affects human health and Transport) in our environment. As it is discussed above under Methods of prevention of acidic rain on environment; we reduce it by Clean up smokestacks and exhaust pipes as wells as using alternative energy sources for vehicles and electricity generation for different purpose in order to live in a safe and suitable environment without fare of global warming.

Toxic Rain: The Effect of Acid Rain on the Environment

Two vacation places that we frequently visit all throughout the year are Southampton, Long Island, and the Adirondacks, New York. These places have become great destinations for me when we want to forget about my worries and relax. Whether we are skiing down White face Mountain or boogie boarding the huge waves at Copper Beach, the placid atmosphere of these two places engulfs me and it is my way of relieving the stress that has accumulated during the past week or so. Even though these two places are far from major cities, We have recently become aware that parts of Long Island and the Adirondacks have been experiencing acid deposition for a couple of decades. This worries me, because if we humans do not do something about this quick, these places might become so polluted that we may never have the chance again to go back to the clean environments that we once enjoyed and treasured. We have known these two places since we was a few months old, and the thought that in future years they might not be the same for my grandchildren and their family is really upsetting.

So, what is acid deposition?

Acid deposition, also called acid rain, is rain or gases that have been polluted by high amounts of chemicals and acids in the atmosphere. It can result from decaying plants and animals or natural cataclysms, such as volcanoes, but the major cause of acid rain is the releasing of chemicals by humans. The main gases that lead to acid rain are sulfur dioxide and nitrogen dioxide. When they come into contact with water and oxygen they turn into acids. Acid Deposition can be in the form of precipitation, which is called wet deposition, or it could be in the form of gases and microscopic particles floating the air, which is called dry deposition.

Scientists can measure how much acid is in rain or a body of water by using the pH scale. There are 14 numbers on it, ranging from 0 through 14. If a lake has a low pH, that tells us that there is a high amount of acid in the lake. If a lake has a pH 8 or above, it is alkaline, which means there is not a lot of acid in it. When a body of water has a pH of 7, it is neutral, since it is in the middle. New York State's rain pH level is between 4 and 4.5. That is 30 times more acidic than the normal level!

Remember: All bodies of water have acid in it, but the problem with acid rain is that too much acid is accumulating, and the effects are harmful.

Where does Sulfur dioxide and nitrogen dioxide come from?

One of the central sources of sulfur dioxide and nitrogen oxide come from power plants. When power plants generate electricity, they are burning the fossil fuel, coal. Coal is sometimes dubbed as the dirty fuel source because when it is burned, it lets out sulfur, nitrogen, and other gases. The more coal we use, the more sulfur and nitrogen we are admitting into our atmosphere. Fumes and emissions from cars and other vehicles are also another source of sulfur dioxide and nitrogen oxide.

Harmful effects of acid deposition

Acid deposition is very dangerous for trees and forests because it rids the soil of very important nutrients trees need to survive, like magnesium and calcium. Without these vital nutrients, the trees are more vulnerable to infections and damage by cold weather and insects. Acid rain also allows aluminum to seep into the soil, and with too much aluminum in the soil, the trees have a very hard time collecting water. Acid rain is even thought to destroy leafs' outer-coat and when it finally wears down, the acid can make its way into the tree, which prevents photosynthesis from taking place. Photosynthesis makes food and energy for the plant, and without it, the plant or tree dies.

Not only are plants affected by acid deposition, but humans are too. If we breathe in the infinitesimal acid particles, we are prone to getting lung and respiratory problems and diseases such as asthma, chronic bronchitis (long-term), and pneumonia. Just in the United States and Canada alone, there were 1520 visits to the emergency room because of dry deposition. Yet, if you swim in a body of water with a high acidity level, nothing will happen to your body.

Acid Rain proposes a very harmful affect on the ecosystems as well. The acidity in the water can cause many fish and sea life to die, and that can throw off the whole food-chain. A test was done and the results, which were published in 1990, showed that most of the lakes in the Adirondack area had low pH levels and that the lakes with these low levels had no fish.

What is the United States doing to help the issues of acid disposition?

In 1985, the Clean Coal Technology Program was established to help make the burning of coal "cleaner." Four billion dollars have been donated by the coal industry and two billion dollars by the federal government to help with this goal. There are many ways coal can become cleaner, such as crushing it and washing it before using it, because by doing so some of the sulfur is being removed. Companies also install flue gas desulfurization systems, otherwise known as a scrubber, which have the potential to remove about 90% of the sulfur dioxide before its gets emptied out into the atmosphere. This system works by spraying a limestone and water mixture on the pipe where the smoke from the coal is released. When the lime meets the smoke, with the sulfur in it, the smoke is absorbed into it and becomes a gooey liquid or powder and the most of the sulfur is trapped. You can then recycle the liquid or powder to make objects such as concrete blocks. These are just some of the ways coal can cause less pollution, and there are many more ways.

In 1990, Congress passed the Clean Air Act. This act stated that the EPA, Environmental Protection Agency, should do their part and help protect the air we breathe, so the Acid Rain Program was initiated. This program strives hard to achieve both environmental and health satisfaction by limiting the amount of sulfur dioxide and nitrogen oxide admitted into the air by power plants.

If we reduce air pollution, acid rain might become a thing of the past! Think of a place that you really love to go and picture it polluted in future years. Not a nice thought, right? This is why we have to try our best to protect the air that we live and breathe every day!

Acid Rain: 5 Important Measures to Control Acid Rain

Some of the major procedures that must be followed to control acid rain are as follows:

The phenomenon of acid rain is highly interactive problem and remedial measures to control it are very expensive.

1. Reduce amount of sulphur dioxide and oxides of nitrogen released into the atmosphere 

i. Use less energy (hence less fuel burnt)

ii. Use cleaner fuels

iii. Remove oxides of sulphur and oxides of nitrogen before releasing

(a) Flue gas desulphurization

(b) Catalytic Converters

2. Use cleaner fuels

i. Coal that contains less sulphur

ii. “Washing” the coal to reduce sulphur content

iii. Natural Gas

3. Flue Gas Desulphurisation (FGD)

i. Removes sulphur dioxide from flue gas (waste gases)

ii. Consists of a wet scrubber and a reaction tower equipped with a fan that extracts hot smoky stack gases from a power plant into the tower

iii. Lime or limestone (calcium carbonate) in slurry form is injected into the tower to mix with the stack gases and reacts with the sulphur dioxide present

iv. Produces pH-neutral calcium sulphate that is physically removed from the scrubber

iv. Sulphates can be used for industrial purposes

4. Use other sources of electricity (i.e. nuclear power, hydro-electricity, wind energy, geothermal energy, and solar energy)

i. Issue of cost

5. Reducing the effects of Acid Rain by Liming

i. Powdered limestone/limewater added to water and soil to neutralize acid

ii. Used extensively in Norway and Sweden

iii. Expensive, short-term remedy

Way out to Acid Rain

    Cleaning up Exhaust Pipes and Smokestacks

Most of the electric power supporting the modern-day energy requirements comes from combusting fossil fuels such as oil, natural gas, and coal that generate nitrogen oxides (NOx) and sulfur dioxide (SO2) as the chief contributors to acid rain. Burning coal largely accounts for SO2 emissions while NOx emissions are mostly from fossil fuel combustions.

Washing coal, use of coal comprised of low sulfur, and use of devices known as “scrubbers” can provide technical solution to SO2 emissions. “Scrubbing” also called flue-gas desulfurization (FGD) typically work to chemically eliminate SO2 from the gases leaving smokestacks. It can eliminate up to 95% of SO2 gases. Power generation facilities can also shift to using fuels that emit much less SO2 such as natural gas instead of burning coal. These methods are simply called emission reduction strategies.

Similarly, NOx emissions from automobile fossil fuel combustions are mitigated upon by use of catalytic converters. Catalytic converters are fixed on the exhaust pipe system to reduce NOx emission. Improvement of gasoline that combusts cleaner is also a strategy for reducing emission of NOx gases.

    Restoring Damaged Environments

Use of limestone or lime, a process called liming, is a practice that people can do to repair the damage caused by acid rain to lakes, rivers and brooks. Adding lime into acidic surface waters balances the acidity. It’s a process that has extensively been used, for instance in Sweden, to keep the water pH at optimum. Even though, liming is an expensive method and has to be done repeatedly. Furthermore, it only offers a short-term solution at the expense of solving the broader challenges of SO2 and NOx emissions and risks to human health. Nevertheless, it helps to restore and allow the survival of aquatic life forms by improving chronically acidified surface waters.

    Alternative Energy Sources

Besides fossil fuels, there is a wide range of alternative energy sources that can generate electrical power. These include wind energy, geothermal energy, solar energy, hydropower, and nuclear power. Harnessing these energy sources can offer effective electrical power alternatives instead of using fossil fuels. Fuel cells, natural gas, and batteries can also substitute use of fossil fuel as cleaner energy sources. As of today, all energy sources have environmental and economic costs as well as benefits. The only solution is using sustainable energy that can protect the future.

    Individual, National/State, and International Actions

Millions of people directly and indirectly contribute to SO2 and NOx emissions. Mitigation of this challenge requires individuals to be more informed about energy conservation and ways of reducing emissions such as: turning off lights or electrical appliances when not using them; use public transport; use energy efficient electrical appliances; and use of hybrid vehicles or those with low NOx emissions.

How Acid Rain Affects The World

What is Acid Rain?

Acid rain refers to a mixture of deposited material, both wet and dry, coming from the atmosphere containing more than normal amounts of nitric and sulfuric acids. Simply put, it means rain that is acidic in nature due to the presence of certain pollutants in the air due to cars and industrial processes. It is easily defined as rain, fog, sleet or snow that has been made acidic by pollutants in the air as a result of fossil fuel and industrial combustions that mostly emits Nitrogen Oxides (NOx) and Sulfur Dioxide (SO2). Acidity is determined on the basis of the pH level of the water droplets. Normal rain water is slightly acidic with a pH range of 5.3-6.0, because carbon dioxide and water present in the air react together to form carbonic acid, which is a weak acid. When the pH level of rain water falls below this range, it becomes acid rain.

When these gases react with water molecules and oxygen among other chemicals found in the atmosphere, mild acidic chemical compounds such as sulfuric and nitric acid are formed resulting to acid rain. Acid rain generally leads to weathering of buildings, corrosion of metals, and peeling of paints on surfaces. Erupting volcanoes contains some chemicals that can cause acid rain. Apart from this, burning of fossil fuels, running of  factories and automobiles due to human activities are few other reasons behind this activity.

Presently, large amounts of acid deposition is witnessed in the southeastern Canada, northeastern United States and most of Europe, including portions of Sweden, Norway, and Germany. In addition, some amount of acid deposition is found in parts of South Asia, South Africa, Sri Lanka, and Southern India.

Forms of Acid Rain

There are two forms in which acid deposition occurs – wet and dry. Both are discussed below:

    Wet Deposition: When the wind blows the acidic chemicals in the air to the areas where the weather is wet, the acids fall to the ground in the form of rain, sleet, fog, snow or mist. It removes acid from the atmosphere and deposit them on the earth’s surface. When this acid flows through the ground, it affects large number of plants, animals and aquatic life. The water from drain flows into rivers and canals which is them mixed up with sea water, thereby affecting marine habitats.

    Dry Deposition: If the wind blows the acidic chemicals in the air to the areas where the weather is dry, the acidic pollutants slip into dust or smoke and fall to the ground as dry particles. These stick to the ground and other surfaces such as cars, houses, trees and buildings. Almost 50% of the acidic pollutants in the atmosphere fall back through dry deposition. These acidic pollutants can be washed away from earth surface by rainstorms.

It was discovered way back in 1800s during the Industrial Revolution. A Scottish chemist, Robert Angus Smith, was first to discover this phenomenon in 1852 as a relationship between acid rain and atmospheric pollution in Manchester, England. But it gained public attention mainly in 1960s. The term was coined in 1972 when the NY Times published reports about the climate change effects which started arising due to the occurrence of acid rain in the Hubbard Brook Experimental Forest in New Hampshire.

Causes of Acid Rain

Both natural and man-made sources are known to play a role in the formation of acid rain. But, it is mainly caused by combustion of fossil fuels which results in emissions of sulfur dioxide (SO2) and nitrogen oxides (NOx).

1. Natural Sources

The major natural causal agent for acid rain is volcanic emissions. Volcanoes emit acid producing gases to create higher than normal amounts of acid rain or any other form of precipitation such as fog and snow to an extent of affecting vegetation cover and health of residents within the surrounding. Decaying vegetation, wildfires and biological processes within the environment also generate the acid rain forming gases. Dimethly sulfide is a typical example of a major biological contributor to sulfur containing elements into the atmosphere. Lighting strikes also naturally produces nitric oxides that react with water molecules via electrical activity to produce nitric acid, thereby forming acid rain.

2. Man-made sources

Human activities leading to chemical gas emissions such as sulfur and nitrogen are the primary contributors to acid rain. The activities include air pollution sources emitting sulfur and nitrogen gases like factories, power generations facilities, and automobiles. In particular, use of coal for electrical power generation is the biggest contributor to gaseous emissions leading to acid rain. Automobiles and factories also release high scores of gaseous emissions on daily basis into the air, especially in highly industrialized areas and urban regions with large numbers of car traffic. These gases react in the atmosphere with water, oxygen, and other chemicals to form various acidic compounds such as sulfuric acid, ammonium nitrate, and nitric acid. As a result, these areas experience exceedingly high amounts of acid rain.

The existing winds blow these acidic compounds over large areas across borders and they fall back to the ground in the form of acid rain or other forms of precipitation. Upon reaching the earth, it flows across the surface, absorbs into the soil and enters into lakes and rivers and finally gets mixed up with sea water.

The gases i.e. i.e. sulfur dioxide (SO2) and nitrogen oxides (NOx) are primarily gases occurring from electric power generation by burning coal and responsible for acid rain.

Effects of Acid Rain

Acid rain has significant effects on the world environment and public health.

    Effect on Aquatic Environment: Acid rain either falls directly on aquatic bodies or gets run off the forests, roads and fields to flow into streams, rivers and lakes. Over a period of time, acids get accumulated in the water and lower the overall pH of the water body. The aquatic plants and animals need a particular pH level of about 4.8 to survive. If the pH level falls below that the conditions become hostile for the survival of aquatic life. Acid rain tendency of altering pH and aluminum concentrations greatly affects pH concentration levels in surface water, thereby affecting fish as well as other aquatic life-forms. At pH levels below 5, most fish eggs cannot hatch. Lower pHs can also kill adult fish. Acid rain runoff from catchment areas into rivers and lakes has also reduced biodiversity as rivers and lakes become more acidic. Species including fish, plant and insect types in some lakes, rivers and brooks have been reduced and some even completely eliminated owing to excess acid rain flowing into the waters.

    Effect on Forests: It makes trees vulnerable to disease, extreme weather, and insects by destroying their leaves, damaging the bark and arresting their growth. Forest damage due to acid rain is most evident in Eastern Europe – especially Germany, Poland and Switzerland.

    Effect on Soil: Acid rain highly impacts on soil chemistry and biology. It means, soil microbes and biological activity as well as soil chemical compositions such as soil pH are damaged or reversed due to the effects of acid rain. The soil needs to maintain an optimum pH level for the continuity of biological activity. When acid rains seep into the soil, it means higher soil pH, which damages or reverses soil biological and chemical activities. Hence, sensitive soil microorganisms that cannot adapt to changes in pH are killed. High soil acidity also denatures enzymes for the soil microbes. On the same breadth, hydrogen ions of acid rain leach away vital minerals and nutrients such as calcium and magnesium.

    Vegetation Cover and Plantations: The damaging effects of acid rain on soil and high levels of dry depositions have endlessly damaged high altitude forests and vegetation cover since they are mostly encircled by acidic fogs and clouds. Besides, the widespread effects of acid rain on ecological harmony have lead to stunted growth and even death of some forests and vegetation cover.

    Effect on Architecture and Buildings: Acid rain on buildings, especially those constructed with limestone, react with the minerals and corrode them away. This leaves the building weak and susceptible to decay. Modern buildings, cars, airplanes, steel bridges and pipes are all affected by acid rain. Irreplaceable damage can be caused to the old heritage buildings.

    Effect on Public Health: When in atmosphere, sulfur dioxide and nitrogen oxide gases and their particulate matter derivatives like sulfates and nitrates, degrades visibility and can cause accidents, leading to injuries and deaths. Human health is not directly affected by acid rain because acid rain water is too dilute to cause serious health problems. However, the dry depositions also known as gaseous particulates in the air which in this case are nitrogen oxides and sulfur dioxide can cause serious health problems when inhaled. Intensified levels of acid depositions in dry form in the air can cause lung and heart problems such as bronchitis and asthma.

    Other Effects: Acid rain leads to weathering of buildings, corrosion of metals, and peeling of paints on surfaces. Buildings and structures made of marble and limestone are the ones especially damaged by acid rain due to the reactivity of the acids in the rain and the calcium compounds in the structures. The effects are commonly seen on statues, old grave stones, historic monuments, and damaged buildings. Acid rain also corrodes metals like steel, bronze, copper, and iron.