Chapters 5,10,18,19,20 Test Study Guide FRQ -Air Pollution= Is the presence of chemicals in the troposphere in high concentrations high enough to harm organisms, ecosystems, or materials, and high enough to alter climate. -Outdoor Pollutants= mostly human inputs, occur in industrialized and urban areas where people, cars, and factories are concentrated. (burning fossil fuels in power plants, factories, and cars) -Two Types of Outdoor Pollution -Primary Pollutants= Harmful substances that are emitted directly into the air. (most hydrocarbons and suspended particles) -Secondary Pollutants= Some primary pollutants reacting with one another or with the basic components of air to form new harmful pollutants. (Most NO3- AND SO42- Salts)