Pollution is the process of making land, water, air or other parts of the environment dirty and not safe or suitable to use. This can be done through the introduction of a contaminant into a natural environment, but the contaminant doesn't need to be tangible. Things as simple as light, sound and temperature can be considered pollutants when introduced artificially into an environment.
Toxic pollution affects more than 200 million people worldwide, according to Pure Earth, a non-profit environmental organization. In some of the world's worst polluted places, babies are born with birth defects, children have lost 30 to 40 IQ points, and life expectancy may be as low as 45 years because of cancers and other diseases. Read on to find out more about specific types of pollution.
Land can become polluted by household garbage and by industrial waste. In 2014, Americans produced about 258 million tons of solid waste, according to the U.S. Environmental Protection Agency. A little over half of the waste — 136 million tons— was gathered in landfills. Only about 34 percent was recycled or composted.
Organic material was the largest component of the garbage generated, the EPA said. Paper and paperboard accounted for more than 26 percent; food was 15 percent and yard trimmings were 13 percent. Plastics comprised about 13 percent of the solid waste, while rubber, leather and textiles made up 9.5 percent and metals 9 percent. Wood contributed to 6.2 percent of the garbage; glass was 4.4 percent and other miscellaneous materials made up about 3 percent.
Commercial or industrial waste is a significant portion of solid waste. According to the University of Utah, industries use 4 million pounds of materials in order to provide the average American family with needed products for one year. Much of it is classified as non-hazardous, such as construction material (wood, concrete, bricks, glass, etc.) and medical waste (bandages, surgical gloves, surgical instruments, discarded needles, etc.). Hazardous waste is any liquid, solid or sludge waste that contain properties that are dangerous of potentially harmful to human health or the environment. Industries generate hazardous waste from mining, petroleum refining, pesticide manufacturing and other chemical production. Households generate hazardous waste as well, including paints and solvents, motor oil, fluorescent lights, aerosol cans, and ammunition.
Water pollution happens when chemicals or dangerous foreign substances are introduced to water, including chemicals, sewage, pesticides and fertilizers from agricultural runoff, or metals like lead or mercury. According to the Environmental Protection Agency (EPA), 44 percent of assessed stream miles, 64 percent of lakes and 30 percent of bay and estuarine areas are not clean enough for fishing and swimming. The EPA also states that the United State's most common contaminants are bacteria, mercury, phosphorus and nitrogen. These come from the most common sources of contaminates, that include agricultural runoff, air deposition, water diversions and channelization of streams.
Water pollution isn't just a problem for the United States. According to United Nations, 783 million people do not have access to clean water and around 2.5 billion do not have access to adequate sanitation. Adequate sanitation helps to keep sewage and other contaminants from entering the water supply.
According to National Oceanic and Atmospheric Administration (NOAA), 80 percent of pollution in marine environment comes from the land through sources like runoff. Water pollution can also severely affect marine life. For example, sewage causes pathogens to grow, while organic and inorganic compounds in water can change the composition of the precious resource. According to the EPA, low levels of dissolved oxygen in the water are also considered a pollutant. Dissolved oxygen is caused by the decomposition of organic materials, such as sewage introduced into the water.
Warming water can also be harmful. The artificial warming of water is called thermal pollution. It can happen when a factory or power plant that is using water to cool its operations ends up discharging hot water. This makes the water hold less oxygen, which can kill fish and wildlife. The sudden change of temperature in the body of water can also kill fish. According to the University of Georgia, it is estimated that around half of the water withdrawn from water systems in the United States each year is used for cooling electric power plants.
"In nearly all cases, 90 percent of this water is returned to its source, where it can raise the water temperature in an area immediately surrounding the water discharge pipe. Depending on water flow, the water temperature quickly returns to ambient temperatures that do not harm fish." Donn Dears, former president of TSAugust, a not for profit corporation organization focused on energy issues, told Live Science.
Nutrient pollution, also called eutrophication, is another type of water pollution. It is when nutrients, such as nitrogen, are added into bodies of water. The nutrient works like fertilizer and makes algae grow at excessive rates, according to NOAA. The algae blocks light from other plants. The plants die and their decomposition leads to less oxygen in the water. Less oxygen in the water kills aquatic animals.
The air we breathe has a very exact chemical composition; 99 percent of it is made up of nitrogen, oxygen, water vapor and inert gases. Air pollution occurs when things that aren't normally there are added to the air. A common type of air pollution happens when people release particles into the air from burning fuels. This pollution looks like soot, containing millions of tiny particles, floating in the air.
Another common type of air pollution is dangerous gases, such as sulfur dioxide, carbon monoxide, nitrogen oxides and chemical vapors. These can take part in further chemical reactions once they are in the atmosphere, creating acid rain and smog. Other sources of air pollution can come from within buildings, such as secondhand smoke.
Finally, air pollution can take the form of greenhouse gases, such as carbon dioxide or sulfur dioxide, which are warming the planet through the greenhouse effect. According to the EPA, the greenhouse effect is when gases absorb the infrared radiation that is released from the Earth, preventing the heat from escaping. This is a natural process that keeps our atmosphere warm. If too many gases are introduced into the atmosphere, though, more heat is trapped and this can make the planet artificially warm, according to Columbia University.
Air pollution kills more than 2 million people each year, according to a study published in the journal of Environmental Research Letters. The effects of air pollution on human health can vary widely depending on the pollutant, according to Hugh Sealy, professor and director of the environmental and occupational health track at the Department of Public Health and Preventive Medicine, St. George's University, St. George's, Grenada. If the pollutant is highly toxic, the effects on health can be widespread and severe. For example, the release of methyl isocyanate gas at Union Carbide plant in Bhopal in 1984 killed over 2,000 people, and over 200,000 suffered respiratory problems. An irritant (e.g. particulates less than 10 micrometers) may cause respiratory illnesses, cardiovascular disease and increases in asthma. "The very young, the old and those with vulnerable immune systems are most at risk from air pollution. The air pollutant may be carcinogenic (e.g. some volatile organic compounds) or biologically active (e.g. some viruses) or radioactive (e.g. radon). Other air pollutants like carbon dioxide have an indirect impact on human health through climate change," Sealy told Live Science.
Even though humans can't see or smell noise pollution, it still affects the environment. Noise pollution happens when the sound coming from planes, industry or other sources reaches harmful levels. Research has shown that there are direct links between noise and health, including stress-related illnesses, high blood pressure, speech interference, hearing loss. For example, a study bythe WHO Noise Environmental Burden on Disease working group found that noise pollution may contribute to hundreds of thousands of deaths per year by increasing the rates of coronary heart disease. Under the Clean Air Act, the EPA can regulate machine and plane noise.
Underwater noise pollution coming from ships has been shown to upset whales' navigation systems and kill other species that depend on the natural underwater world. Noise also makes wild species communicate louder, which can shorten their lifespan.
Most people can't imagine living without the modern convenience of electric lights. For the natural world, though, lights have changed the way that days and nights work. Some consequences of light pollution are:
- Some birds sing at unnatural hours in the presence of artificial light.
- Scientists have determined that long artificial days can affect migration schedules, as they allow for longer feeding times.
- Streetlights can confuse newly hatched sea turtles that rely on starlight reflecting off the waves to guide them from the beach to the ocean. They often head in the wrong direction.
- Light pollution, called sky glow, also makes it difficult for astronomers, both professional and amateur, to properly see the stars.
- Plant's flowering and developmental patterns can be entirely disrupted by artificial light.
- According to a study by the American Geophysical Union, light pollution could also be making smog worse by destroying nitrate radicals that helps the dispersion of smog.
Turning on so many lights may not be necessary. Research published by International Journal of Science and Research estimates that over-illumination wastes about 2 million barrels of oil per day and lighting is responsible for one-fourth of all energy consumption worldwide.
Other pollution facts:
- Americans generate 30 billion foam cups, 220 million tires, and 1.8 billion disposable diapers every year, according to the Green Schools Alliance.
- According to the WHO, ambient air pollution contributes to 6.7 percent of all deaths worldwide.
- The Mississippi River drains the lands of nearly 40 percent of the continental United Sates. It also carries an estimated 1.5 million metric tons of nitrogen pollution into the Gulf of Mexico each year, resulting in a dead zone each summer about the size of New Jersey.
- Pollution in China can change weather patterns in the United States. It takes just five days for the jet stream to carry heavy air pollution from China to the United States, where it stops clouds from producing rain and snow.
- About 7 million premature deaths annually linked to air pollution, according to WHO. That is one in eight deaths worldwide.
someone who offers opposition
The students are united by shared suffering, and by a common adversary.New York Times (Nov 10, 2014)
great coolness and composure under strain
I wish I had handled it with aplomb.New York Times (May 18, 2014)
in fear or dread of possible evil or harm
Virga still feels apprehensive when visiting an unfamiliar zoo.New York Times (Jul 3, 2014)
I was recently asked in an interview, what is more valued by companies – aptitude or attitude? Forbes (Sep 12, 2014)
You make sure to be extra attentive to your friend.Time (Oct 2, 2014)
send away from a place of residence, as for punishment
Napoleon loses so big that he is banished to an island.New York Times (Dec 5, 2014)
block off with barriers
The Secret Service ordered nearby streets and parking lots barricaded for security.Washington Times (Dec 1, 2014)
frighten someone by pretending to be stronger than one is
Sporting a pith helmet, Nixon observed that “whoever is talking the loudest is pretty sure to be bluffing.”New York Times (Sep 19, 2014)
Brackish water can be used, but freshwater is easier and less costly.New York Times (May 14, 2014)
move or swing back and forth
Hart brandished a “Free Hugs” sign as he stood alone in front of a police barricade.MSNBC (Nov 30, 2014)
the size of something as given by the distance around it
That's almost 10 times the circumference of the Earth, which is a surprisingly small 24,859.82 miles.BBC (Dec 1, 2014)
Moments later came commotion, followed by shouts of “Stop pushing me!”MSNBC (Sep 26, 2014)
any foodstuff made by combining different ingredients
There are some food combos that blend beautifully with each other to create truly tasty concoctions.US News (Sep 4, 2014)
obvious to the eye or mind
Today, the link is more conspicuous: highlighted in blue, it appears directly beneath the site’s login form.New York Times (Oct 23, 2014)
a tortuous and twisted shape or position
There was tumbling, human pyramids and bodies stretched into extraordinary contortions.BBC (Aug 25, 2013)
speak in response
The seller can then accept, counter or reject the offer.US News (Dec 9, 2014)
shrewdness as demonstrated by being skilled in deception
Moreover, it was no secret that Cleopatra had ruthless cunning and superior intelligence.Sterling Biographies®: Cleopatra: Egypt's Last and Greatest Queen
the remains of something that has been destroyed
The blast rattled their homes and sent debris flying onto nearby properties, they said.Washington Times (Dec 4, 2014)
a hostile challenge
Schools still could expel students for violating school rules or laws and could suspend students for willful defiance of authorities in grades 4 through 12.Washington Times (Sep 27, 2014)
skillful in physical movements; especially of the hands
To make it work requires a deft hand.Forbes (Sep 25, 2014)
the place designated as the end, as of a race or journey
Airports get stacked up with planes that can’t take off for their destinations.Forbes (Dec 9, 2014)
decrease in size, extent, or range
By Friday morning, most of the heavy rain is expected to diminish.Los Angeles Times (Dec 10, 2014)
lack of respect accompanied by a feeling of intense dislike
In the visage of Grumpy Cat, it seems, her fans found the perfect holy expression of indifferent disdain for all things.Washington Post
It’s been a pretty dismal month, as far as world events go, but the news wasn’t all bad thanks to some very entertaining on-air mishaps.Time (Aug 28, 2014)
force to go away
For most of us, dispelling the darkness is as simple as turning on a light.Time (Oct 23, 2014)
listen without the speaker's knowledge
They eavesdrop on the noises that other birds make while hiding food in order to steal the stash later, new research shows.Science Magazine (Nov 21, 2014)
conspicuously and outrageously bad or reprehensible
Prosecutors questioned him about killings and other egregious human rights abuses perpetrated by his regime.Los Angeles Times (Oct 4, 2014)
a hot, smoldering fragment of wood left from a fire
“Every hot spot is an ember that, if not contained, can become a new fire,” Obama said.Los Angeles Times (Dec 2, 2014)
come out into view, as from concealment
They say that program has helped them emerge from the shadows, making possible a work permit, a Social Security number and enhanced self-respect.Washington Post
consume all of one's attention or time
I don’t know how long I was reading; I was so engrossed in the paper that I did not hear any footsteps.Long Walk to Freedom
a feeling of annoyance
Like many a teenager on his school holidays, Parys is in bed, his mother explains with exasperation.The Guardian (Aug 2, 2014)
fill with sublime emotion
“To see Yosemite Falls coming to life this morning is truly exhilarating,” Park Superintendent Don Neubacher said in a statement. Los Angeles Times (Dec 3, 2014)
move hesitatingly, as if about to give way
“The rocket has faltered, but it won’t crash,” he said.New York Times (Nov 20, 2014)
seeing ahead; knowing in advance; foreseeing
But nobody had the wherewithal or foresight to think that day would actually happen.MSNBC (Jul 3, 2014)
a distinctive odor that is pleasant
After 30 minutes in the oven, what hits you first is the enticing, warm fragrance that fills your kitchen.Washington Post
secret and sly or sordid
What muffled whispers do they share, what furtive games are they playing?The Guardian (Dec 18, 2012)
characterized by effort to the point of exhaustion
As of Dec. 19, 22 students will have made it through a grueling curriculum that requires about 700 hours of computer code.Washington Times (Dec 10, 2014)
vigorous and enthusiastic enjoyment
They each approach their tasks with gusto that can only be admired, even if the results can’t.Washington Times (Aug 21, 2014)
the act of dwelling in or living permanently in a place
Although the area is not fit for human habitation, many poor people who work in the coal mines live here.BBC (Aug 13, 2013)
speed up the progress of; facilitate
Rather than wait for that day, he set out to hasten its arrival.Scientific American (Sep 3, 2014)
At times, you feel like you’re struggling to run forward, going through the motions but making no headway, frozen in place.Washington Post
cause to start burning
Firefighters say the blaze started when stain-soaked rags ignited on the front porch.Washington Times (Dec 10, 2014)
make free from confusion or ambiguity
The problem is that for illuminating answers, you need to ask the right questions.New York Times (Dec 6, 2014)
close in time; about to occur
First, he gives the enemy 12 days of warning about impending air attacks.Washington Post
having or showing arrogant superiority
It was a little scary how quickly he flipped from friendly to imperious.New York Times (Sep 4, 2013)
talk in a noisy, excited, or declamatory manner
A parrot jabbered atop its cage and a monkey squealed and battered at its bronze ring, until its owner brought bananas.Bartlett, Paul Alexander
technical terminology characteristic of a particular subject
Steer clear of jargon, me-too claims, and statements without substance.Forbes (Dec 5, 2014)
make one's way by pushing or shoving
In Jerusalem, great religions have crowded and jostled their way down through millenniums.Los Angeles Times (Nov 21, 2014)
extend out or project in space
From its long beak juts a fearsome tooth.New York Times (Nov 10, 2014)
call forth, as an emotion, feeling, or response
Recently in class I saw the fire of an idea flicker in a first-year student’s eyes—and so to kindle it I cold-called him.Forbes (Sep 16, 2014)
a small natural hill
The home, set on a quarter-acre knoll, has views of the city, the Hollywood Reservoir and the Hollywood sign.Los Angeles Times (Aug 9, 2014)
softly bright or radiant
It was briefly one of the most luminous stars in the galaxy.New York Times (Sep 3, 2014)
“Memory is so malleable or volatile that each time we see something, the memory is actually influenced and re-created.”Washington Times (Oct 18, 2014)
come into being; become reality
By the time people reach their 70s, they’re beginning to look back at the plans they made and dreams they had that never materialized.Time (Nov 25, 2014)
move or cause to move in a sinuous or circular course
Instead of straight paths and noisy throngs, the new park will have meandering walkways and quiet places for picnicking nestled in gently sloping "lawn valleys."Chicago Tribune (Jul 26, 2014)
marked by extreme care in treatment of details
It's a six-page scene and very meticulous, step by step.Los Angeles Times (Aug 24, 2014)
uneasiness about the fitness of an action
Quite a few said they had come despite the misgivings of parents who wanted them to focus on studying.New York Times (Sep 26, 2014)
an impelling force or strength
Mitchell believed that a song’s momentum should always push upward, ascending like the slope of a mountain into the unknown.Washington Post
sounded or spoken in a tone unvarying in pitch
Unfortunately, their monotonous verbiage reminds me of Charlie Brown’s teacher in the “Peanuts” TV shows.Washington Post
a large indefinite number
They surround you in their multitudes - hundreds, maybe thousands of them, swooping and stinging and injecting venom into your flesh.BBC (Oct 9, 2014)
gather or bring together
Fans chanted and hollered and enriched the arena with as much life as they could possibly muster.New York Times (Dec 10, 2014)
give a detailed account of
Standing amid bags of garbage, he starts sorting, tearing open plastic bags and narrating his finds.Los Angeles Times (Oct 15, 2014)
not clearly understood or expressed
The book contains little plot, an abundance of obscure poetry and the untimely death of three protagonists.Los Angeles Times (Dec 5, 2014)
threatening or foreshadowing evil or tragic developments
“Evil forces around the world want to harm Americans every day,” an ominous voiceover states.Time (Oct 7, 2014)
conspicuously or grossly unconventional or unusual
Not everything in the show is outlandish; some events are all too realistic.New York Times (Nov 16, 2014)
It says, “together, if we face obstacles and counter the negative with a persistent positive, we might just change the world.”Seattle Times (Dec 1, 2014)
having precise or logical relevance to the matter at hand
You write about things that feel pertinent and urgent to you, and that varies depending on what stage of life you are going through. MSNBC (Jul 11, 2014)
affording an abundant supply
"The harvest truly is plenteous, but the labourers are few."Wilson, J. M. (James Maurice)
existing in possibility
What potential global threat should policymakers pay more attention to?US News (Dec 11, 2014)
a very steep cliff
"Every minute of every day, we were on the precipice of failure, which is an exciting place to be," Marsh says.Los Angeles Times (Nov 25, 2014)
completely free from dirt or contamination
Back at the jail, Snow White is getting under Anna's skin a bit -- shaking her once pristine view of the princess.Los Angeles Times (Dec 8, 2014)
overcome or allay
The White House has tried to quell anxieties about the danger of Ebola spreading in the United States.Washington Post
one who lives in solitude
Long before his days as the world’s most famous recluse, Howard Hughes flew planes fast and far.New York Times (Jul 14, 2014)
restore to good health or strength
Sleep is the time when your body recuperates and rebuilds from the day’s stress.US News (Jun 24, 2014)
fill something that had previously been emptied
They bring in dredged sand to replenish the beach.Washington Post
offensive to the mind
The truth is that we need only look at recent human history to find real, live, utterly repugnant evil.Salon (Sep 4, 2014)
a sum of money paid in compensation for loss or injury
While restitution is paid to the victim, criminal fines and felony assessments are paid to a crime victims’ fund.Washington Times (Nov 21, 2014)
destroy property or hinder normal operations
“We want at least a district that won’t sabotage the dreams of its youths.”Los Angeles Times (Nov 21, 2014)
a small and inadequate amount
Water—its scarcity, quality and the regulations affecting it—is becoming a new corporate headache.Economist (Nov 6, 2014)
move about or proceed hurriedly
Ever wonder how cockroaches scurry around in the dark while you fumble to switch on the kitchen light?Science Magazine (Dec 3, 2014)
the absence of mental stress or anxiety
The surrounding waters and beautiful pools that surround the hotel create a real sense of calm and luxurious serenity.Forbes (Jul 25, 2014)
friendly and pleasant
Running with others is really sociable and great fun.BBC (Apr 10, 2014)
grave or even gloomy in character
It was also the day before one of the most somber of American anniversaries: Pearl Harbor was bombed 73 years ago Sunday.Washington Post
an example regarded as typical of its class
The researchers detected it in older starfish samples, museum specimens from as early as 1942.Reuters (Nov 17, 2014)
enduring strength and energy
A 6-year-old might not want to walk the mile into Petra, but teenagers have enough physical and intellectual stamina to appreciate going to these places.New York Times (Dec 5, 2014)
wear off or die down
The virus has a history of subsiding, then flaring up again.Washington Post
a proud stiff pompous gait
The Giants had arrived here with the swagger of a team that had won two of the last four World Series titles.New York Times (Oct 3, 2014)
move in large numbers
In “ Swarm” mode, the robots instead follow one another, like children chasing a soccer ball.New York Times (Dec 1, 2014)
a plan for attaining a particular goal
Technology has been used as a crime-fighting tactic, but not as a tool to determine what happens during a police action.New York Times (Dec 4, 2014)
brief and to the point
It’s a request to which Dipper responds, with terse eloquence, “Weird.”New York Times (Nov 21, 2014)
allowing light to pass through diffusely
It comes in several colors, including attractive translucent ones.Washington Times (Jul 30, 2014)
surpassing the ordinary or normal
The Dark Sky App tells you the weather where you are with an uncanny accuracy. Forbes (Jun 26, 2014)
unpleasant to look at
But that’s just a quibble, an unsightly pimple on what is a greater problem.The Guardian (Oct 14, 2014)
able to move freely in all directions
Eggs are among the most versatile foods and the proteins change when you heat them, beat them or mix them with other ingredients.US News (Dec 10, 2014)
carefully observant or attentive
Because there are so many scammers out there, banks are vigilant about verifying that you are who you say you are.Washington Post
capable of being wounded or hurt
Second, older cells are more vulnerable to this damage—or less able to repair themselves.Scientific American (Dec 9, 2014)
be driven or carried along, as by the air
The birds were chirping, and a warm breeze wafted through the screens.Washington Post
pause or hold back in uncertainty or unwillingness
He is tough as nails, never wavers, speaks the truth and stays focused.New York Times (Oct 13, 2014)
face and withstand with courage
You even get subjected to ridicule, and you have to weather that storm.Los Angeles Times (Dec 10, 2014)
a feeling of strong eagerness
The enthusiasm has caught on among his regulars, who come often, linger and talk about pumpkins with the zeal of converts.Washington Post