Pollutants are introduced through direct or indirect human intervention of substances into the environment. These pollutants result in harm to living organisms and pose acute or chronic hazards to human health.
Contaminants are high levels of extraneous often infectious, harmful substances higher than their natural levels of concentration.
The air in a room can be contaminated with cigarette smoke, which is a human intervention that has released an offensive, harmful substance to the air. Perfume can also be deemed a contaminant to the air, which can be a health hazard to someone who is asthmatic or allergic to odors.An example of a pollutant is smog when city air is polluted by emissions. Another is e-coli bacteria or high levels of Sulphur in water.