contamination: a hazardous substance such as a toxin, disease agent or radioactive material; exposure of an individual or the environment to such a substance; introduction of such a substance into water, air or soil at a concentration that makes the water, air or soil unsuitable for its intended use (also applies to surfaces of objects, buildings and products)
pollution: substances such as vehicle emissions and wastes that cause damage to the environment or adverse health effects; introduction of such substances to the environment