In terms of environmental threats the Earth is currently facing, acid rain sounds like one of the most menacing.  When many people hear the term “acid rain,” their mind jumps to scenes out of a science fiction movie involving vicious precipitation dissolving everything in sight.  While this would admittedly be pretty cool, it is quite far from the truth.  However, acid rain still poses a serious threat to our environment and must be curtailed as we move further into the 21^st century.

Contrary to popular belief, acid rain, or acid deposition, is not necessarily liquid precipitation.  Although it certainly can take the form of rain, acid deposition can also be snow, hail, fog, or even dust.  The only defining characteristic of acid rain is that it must include acidic compounds, such as sulfuric acid or nitric acid.

Now that we know what acid rain is, what causes it?  The answer, like with so many other environmental problems, is pollution.  As humans continue to industrialize at a rapid pace, we constantly pump more and more pollutants into the air.  These chemicals then become absorbed into clouds or latch onto dust particles, causing acid rain to occur.  Today, things like manufacturing and burning of fossil fuels are largely responsible for the pollutants that cause acid rain.  Electric power generators are also a big problem, as two-thirds of sulfur dioxide and one-fourth of nitrogen oxides in the atmosphere come from this source.  As industry continues to grow worldwide, the amount of pollutants spilling into the atmosphere will also keep growing, possibly spelling trouble for many parts of our environment.

Fig. 1. EPA. Acid Rain Pathway.

Fittingly, the first known observation of acid rain took place in the middle of the 19^th century, at a time when many parts of the world were industrializing.  In fact, the term “acid rain” was coined in 1852 by the Scottish chemist Robert Angus Smith, who was studying the effects of the precipitation in areas in the United Kingdom.  Attention in the United States wasn’t turned toward this phenomenon until the 1950s, and by two decades later it was declared a regional environmental issue affecting eastern North America and Western Europe.  Since then, the U.S. and many parts of Europe have been able to put regulations in place and cut back on acid rain, but this problem is just now starting to rear its ugly head in developing countries like India and China.

At this point I realize that I still haven’t described acid rain’s effects on people or the environment in general.  Since we’re all living, breathing humans, I’ll first start with how acid rain affects us.  The good news: it doesn’t.  According to researchers from Georgia State University, “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.”  As acid rain presents no direct threat to humans, it’s easy to see how this problem can be ignored.  But we must be careful to not dispel the risks acid rain poses to the environment at large.

Acid rain has devastating effects on several parts of nature and can even be detrimental to things like buildings and statues.  Trees have been shown to be especially vulnerable to acid rain.  Acid rain harms trees by breaking down the protective coating on their leaves, as well as by lowering the pH of the soil, causing the growth of trees to be stunted.  One study from 2005 found that the health of spruce trees in Russia had been severely lowered due to the acidification of soil from acid rain.  The same study also warned about the possible effects on trees in the Adirondack and Catskill regions of New York, especially since the soil there is more likely to be negatively affected by acid rain.

Fig. 2. Reference.com. Acid Rain Forest.

Additionally, acid rain can affect the biodiversity of water ecosystems.  The acidity of most healthy lakes lies around a pH of 7 (neutral), with some lakes being closer to 6.5.  However, acid rain can drastically lower this pH to between 4 and 5.  Once the acidity reaches this level, most species of fish and other aquatic animals cannot survive, causing the lakes to become barren and uninhabited.

Finally, acid rain can have adverse effects on certain structures, especially those made of limestone.  These include buildings, statues, and even gravestones.  Acid rain causes their features and appearances to become somewhat distorted, leading to deterioration occurring at an accelerated rate.

Obviously, acid rain isn’t beneficial in any way, so it’s a necessity to take steps to eliminate it.  As mentioned, regulations and new technologies adopted by western countries have helped to relieve our forests and lakes from the acid rain crisis we had back in the 1980s.  However, if we are to get rid of acid rain worldwide, it will take a bigger commitment toward shifting our energy production away from fossil fuels and instead to renewable resources, like solar and wind power.

You can take steps to help, too.  The EPA recommends cutting down on use of automobiles and electricity as a way to help stop acid rain.  These utilities rely heavily on fossil fuel and are thus detrimental to solving the issue at hand.  Acid rain may not be as large of a problem as it once was, but as long as countries continue to industrialize, acid rain is not going anywhere, and it may just come back with more force than we realize.

In many parts of the world, environmental stability has been sacrificed in pursuit of economic progress.  This is especially true in China, who recently took over the top spot as the world’s largest economy (in terms of GDP).  However, to reach this status, China has emphasized economic expansion so much that the cleanliness of their air and water has suffered as a result.  This pollution has led to certain parts of the country having absurd rates of cancer among their inhabitants, with the government doing nothing but sitting back and watching the carnage.

Over the past thirty years, cancer mortality rates in China have soared 80%, driving it to become the leading cause of death in the country.  This coincides with China’s meteoric rise to the top of the global economy, possibly indicating a link between the two.  And if you talk to residents, this is something they will unanimously confirm.  A doctor who treats patients in China’s Liuchong village says, “All this pollution is illegal, but what can we do? We’re just ordinary people, and we’re stuck here.”  The doctor, who has had to remain anonymous due to threats from a Chinese factory owner, also says, “Patients come to see me every day because they feel weak and dizzy. I estimate 80 to 90 percent of the people in this village are suffering from low white blood cell counts or anemia.”

The presence of such staggering rates of sickness even led the Chinese government to issue an official statement about pollution and cancer villages.  A portion of the document reads, “China has been producing and utilizing toxic chemical products. Many places experienced a drinking water crisis and pollution caused serious social issues like the emergence of cancer villages.”  Although this statement doesn’t show the slightest bit of remorse, it does indicate that government officials understand how widespread the problem is.  China is currently home to an estimated 459 cancer villages which spread over the eastern and southern parts of the country.  In many of these towns, the rate of cancer is as much as 50% higher than in the rest of China.

Fig. 1. China.org.cn. Cancer Villages.

As previously mentioned, much of this is due to pollution, both in the air and water.  Government reports say that about 70% of Chinese lakes and rivers are polluted, leading to an estimated 190 million people drinking contaminated water, or about 1 in every 7 citizens.  This contamination is the direct byproduct of the presence of large factories, especially those along the banks of rivers.  China’s government has tried to crack down on factories pumping waste into sources of water, but many plants find ways around these regulations.  For example, Wei Dongying, an environmental activist in China, says, “Today, factories take care not to pollute during the day but when I’m fishing at night, I can see them pumping waste into the river.”  Stories like these are becoming increasingly common, as Chinese manufacturers continue to evade government intervention in pursuit of maximizing profit.

While government accountability for pollution in China continues to increase ever so slowly, officials are still incredibly dodgy and apprehensive to take responsibility.  Wei Dongying, the activist we were just discussing, has been arrested dozens of times and has her phone under government surveillance.  She even spent ten days in prison just for filing a complaint against a detergent factory.  These aren’t isolated incidents, either.  The anonymous doctor we previously mentioned has received death threats from factory owners, along with any other villagers who threaten to speak badly about the plant.  The doctor says of Zhong Shoubin, owner of Dasheng Chemical, “He has told us that if we say anything bad about his company, he’ll have us killed.”  The fact that top businessmen can get away with threats like these is incredibly concerning, and shows me that the Chinese government isn’t too serious about overcoming these obstacles.

Fig. 2. Schmitz, Rob. Dasheng Chemical.

Meanwhile, thousands of people continue to die of pollution-induced cancer every year, with only few signs of sympathy from the government.  This state of affairs has left citizens to take the lead on ensuring clean water for villagers.  One of these good Samaritans, known as Mr. Huo, has installed over 40 systems along the Upper Huai River to get fresh water to households, schools, and villages.  Huo works as part of the Waterkeeper Alliance, who describe themselves as “the largest and fastest growing nonprofit solely focused on clean water.”  The Alliance has a team of “Waterkeepers” throughout China who are working to diagnose, treat, and protect sources of clean water, so that all citizens can live worry-free.

In addition to the efforts of the Waterkeeper Alliance, the Chinese government passed a strict pollution control law that went into effect last year.  This law provides a lot of hope for the future, and it will be interesting to see if the quality of life in China improves as a result of it.  But although countless villages continue to be plagued by cancer, journalists sense a feeling of renewed hope among inhabitants.  This hope is that one day their neighbors and relatives won’t die of cancer at alarming rates.  Hope that they’ll be able to freely access clean water for drinking and bathing.  And hope that someday, they’ll be able to live normal lives.