define Air pollution - the presence in or introduction into the air of a substance which has harmful or poisonous effects., types of air pollution? - Natural sources,Human activity, Photochemical Smog - Photochemical Smog forms when exhaust from vehicles or pollution from factories reacts with light., where is the ozone layer located? - The ozone layer is part of the atmosphere. It’s located about 15-35 km above earth’s surface.,

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