Pollution Facts | Types of Pollution

Pollution is the introduction of a contaminant into a natural environment, usually by humans. While most people think of pollution as chemical waste dumped into rivers, or factories spewing toxins into the air, it can also include light pollution or sound pollution.

The health effects of pollution affect more than 100 million people worldwide — more widespread than global pandemics such as AIDS. 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 pollution: Land can become polluted by household garbage and by industrial waste. In 2010, Americans produced about 250 million tons of garbage consisting of product packaging, grass clippings, furniture, clothing, bottles, food scraps, newspapers, appliances, paint and batteries. That's about 4.3 pounds of waste per person per day, according to the Environmental Protection Agency. A little over half of the waste — 54 percent — is gathered in landfills. About 34 percent is recycled or composted, and 12 percent is burned at combustion facilities.

Air Pollution
Credit: Viktor Fiker | Dreamstime

Commercial or industrial waste is a significant portion of solid waste. 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: 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. Worldwide, more than 500 million people drink water that could be harmful to their health. Water pollution can also affect marine life: oil and chemical pollutants can harm anything living in water. Sewage causes pathogens to grow, while organic and inorganic compounds in water can change the composition of the precious resource. Warming water can also harm quality — thermal pollution 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.

Air pollution: 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. [Air Pollution Linked with Stillbirth Risk]

Another common type of air pollution is the release of 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 — secondhand smoke is a large problem in many buildings. In developed countries, people often spend 80 percent or more of their time inside the home, so exposure to chemicals or smoke there can also be harmful. Finally, air pollution can take the form of greenhouse gases — such as carbon dioxide or sulfur dioxide — that are warming the planet through the greenhouse effect.

Noise pollution: Even though humans can’t see or smell noise pollution, it still impacts 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. 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 — not that different from making people scream to be heard their whole lives.

Light pollution: Most people think that electricity-powered lights are modern convenience, and couldn’t imagine living without them. For the natural world, though, lights have changed the way that days and nights work. 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.

Turning on so many lights may not be necessary: researchers estimate that over-illumination wastes the equivalent of about 2 million barrels of oil per day. Light pollution also makes it difficult for astronomers, both professional and amateur, to properly see the stars.

Interesting Pollution Facts:

  • Americans generate 30 billion foam cups, 220 million tires, and 1.8 billion disposable diapers every year.
  • Forty percent of America’s rivers and 46 percent of America’s lakes are too polluted for fishing, swimming, or aquatic life.
  • According to the World Health Organization, an estimated 6,400 people die every year in Mexico City and more than 1 million suffer from permanent breathing problems because of air pollution.
  • 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.


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Katherine Harmon Courage

Katherine Harmon

Katherine Harmon Courage is an award-winning freelance journalist and contributing editor for Scientific American. She has written for The New York Times, Wired, Gourmet, Popular Science, Prevention, and others, covering everything from breaking science news to features about food. She is the author of the book Octopus! The Most Mysterious Creature In the Sea, and her work was featured in The Best American Science and Nature Writing 2013. She graduated from Vassar College with an honor's degree in English and earned a master's degree from the University of Missouri's School of Journalism. She lives in Colorado, where she also competes in marathons and triathlons. Follow her on Twitter @KHCourage, and read more on her website
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