Pollutant — Science definition

A substance released into the environment, usually by human activity, at a level high enough to harm organisms or ecosystems.

Where it is taught

In use

Evaluate a pollutant-specific mechanism, measurable outcome, and possible trade-offs rather than assuming one technology removes every hazard.

Pollution

Questions using pollutant

Problem 1

Why distinguish hazard from exposure when assessing pollutant effects?
Hints

State what the supplied observations or conditions establish, and separate that from any assumption.

Answer and explanation

A substance's harmful potential does not alone determine dose or risk; route, amount and duration matter.

Problem 2

An outlet flows 200 L/min at 3 mg/L. Find pollutant mass emitted in 1 h. Treatment captures 80% into sludge with no chemical destruction; find waterborne and captured mass.
Answer and explanation

Initial mass=200×60×3=36000 mg=36 g. Waterborne residual=7.2 g; captured mass=28.8 g. The captured material remains in the full system account.

Initial mass=200×60×3=36000 mg=36 g.

Waterborne residual=7.2 g; captured mass=28.8 g.

The captured material remains in the full system account.

Response criteria

  • Use the stated measurements or conditions, with correct units.
  • Connect the result to the physical or environmental mechanism or evidence relationship.
  • Identify the assumption, model limit or further evidence requested.

Problem 3

Independent chapter check: An outlet flows200 L/min at3 mg/L. Find pollutant mass emitted in1 h. Treatment captures80% into sludge with no chemical destruction; find waterborne and captured mass.
Answer and explanation

Initial mass=200×60×3=36000 mg=36 g. Waterborne residual=7.2 g; captured mass=28.8 g. The captured material remains in the full system account.

Initial mass=200×60×3=36000 mg=36 g.

Waterborne residual=7.2 g; captured mass=28.8 g.

The captured material remains in the full system account.

Response criteria

  • Use the stated measurements or conditions, with correct units.
  • Connect the result to the physical or environmental mechanism or evidence relationship.
  • Identify the assumption, model limit or further evidence requested.

Problem 4

Which air pollutant, released by burning coal and oil, is a major cause of acid rain?
  1. Nitrogen gas (N2)
  2. Water vapor
  3. Sulfur dioxide
  4. Oxygen
Answer and explanation

Sulfur dioxide

Sulfur dioxide (along with nitrogen oxides) dissolves in cloud water to form acids that fall as acid rain; oxygen, nitrogen gas, and water vapor are harmless components of clean air.

Taught alongside

Elsewhere

Browse all courses