Pollution

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Pollutant Noun

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[puh-loo-tnt]

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Pollutant

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Any substance or form of energy that is introduced into the environment and causes harm or adverse changes.

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Example: This image shows harmful substances, or pollutants, like smoke and smog being released into the air from factories and buildings in a city.

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Point-source pollution Noun

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[point-sors puh-loo-shun]

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Point-source pollution

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Pollution that originates from a single, identifiable source, such as a factory smokestack or a specific discharge pipe.

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Example: This image shows pollution coming from a single, identifiable location—the car's exhaust pipe—which is the definition of point-source pollution.

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Nonpoint-source pollution Noun

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[non-point-sors puh-loo-shun]

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Nonpoint-source pollution

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Pollution that comes from many diffuse sources rather than a single identifiable point, such as agricultural runoff.

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Example: Rainfall and irrigation carry pollutants like fertilizers from a wide area, such as a farm field, into rivers and lakes through runoff.

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Biodegradable Adjective

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[bai-oh-di-grey-duh-buhl]

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Biodegradable

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A substance that can be broken down into simpler, often less harmful, components by natural processes like bacterial decomposition.

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Example: This image shows several examples of biodegradable materials, such as wood, cotton, and wheat, which are materials that can be broken down naturally by microorganisms.

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Nonbiodegradable Adjective

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[non-bai-oh-di-grey-duh-buhl]

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Nonbiodegradable

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A substance that cannot be broken down by natural processes and thus persists and accumulates in the environment.

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Example: This image shows a bin full of nonbiodegradable waste, such as plastic bottles and metal cans, which do not break down naturally in the environment.

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Bioaccumulation Noun

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[bai-oh-uh-kyoo-myoo-ley-shun]

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Bioaccumulation

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The process where nonbiodegradable pollutants build up in an organism's tissues, becoming more concentrated at higher trophic levels.

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Example: Pollutants from the environment, like in the water, enter and build up inside a single organism over its lifetime, as shown by the arrow pointing to the whale.

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Eutrophication Noun

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[yoo-tro-fi-key-shun]

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Eutrophication

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The process where a body of water becomes overly enriched with nutrients, leading to excessive growth of plant life.

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Example: Fertilizer runoff into water causes excessive algae growth, which blocks sunlight, dies, and depletes oxygen, leading to the suffocation of fish.

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Algal bloom Noun

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[al-guhl bloom]

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Algal bloom

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A rapid increase or accumulation in the population of algae in an aquatic system, often caused by eutrophication.

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Example: This image shows an algal bloom, where excess nutrients in the water cause a rapid, dense growth of algae, turning the water green and harming aquatic life.

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Dead zone Noun

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[ded zohn]

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Dead zone

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An area in a body of water with extremely low oxygen levels where most aquatic life cannot survive.

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Example: This diagram compares a healthy aquatic environment with one where excess nutrients cause an algal bloom, leading to oxygen depletion and creating a 'dead zone'.

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Primary pollutant Noun

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[prahy-mer-ee puh-loo-tnt]

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Primary pollutant

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A harmful substance that is emitted directly into the atmosphere from a source, such as carbon monoxide from exhaust.

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Example: This image shows examples of primary pollutants by categorizing their sources into two groups: human-induced (like power plants) and natural (like volcanic eruptions).