A pollutant is a substance or energy introduced into the environment that has undesired effects, or adversely affects the usefulness of a resource. Pollutants can be artificial substances, such as pesticides and PCBs, or naturally occurring substances, such as oil or carbon dioxide, that occur in harmful concentrations in a given environment.
Pollutants emitted directly into the air are called "primary pollutants." "Secondary" pollutants" are formed in the air, when they react with other pollutants . Ground-level ozone is an example of a secondary pollutant that forms when nitrogen oxides (NOx) and volatile organic compounds (VOCs) react in the presence of sunlight.
Related Journals of Pollutants
Earth Science & Climatic Change, Ecosystem & Ecography, Advances in Recycling & Waste Management, International Journal of Waste Resources, European Respiratory Journal, International Journal of Andrology, International Journal of Hygiene and Environmental Health.