Hi. I'm Jensen Morgan. We're going to talk about some great concepts in environmental science. Today's topic is air pollution. So let's get started. We are going to talk about air pollution and its various sources. Air pollution is essentially harmful materials that are present in the air. It is considered an air pollutant if it is harmful to humans and/or the environment.
The vast majority of pollution in the air is produced by human activities. This includes both indoor pollutants, which are pollutants present in homes and buildings, as well as outdoor pollutants, present in open spaces. Pollutants are produced by a variety of sources in three main categories, mobile, stationary, and natural sources.
Mobile is any source that can move about, such as cars, boats, or airplanes. Mobile air polluters are considered nonpoint sources because they are difficult to track and manage, much like water nonpoint polluters. Stationary sources of air pollution are fixed. They are considered point source polluters. And much like water point pollution sources, they are easier to monitor and control. Examples of stationary sources would be a coal fired power plant, oil refinery, or gas station. Approximately 50% of human made polluters are stationary.
And the third source are natural causes such as volcanoes or forest fires, like the one depicted in this photo. Smog created by volcanoes can lead to acid rain, while forest fires like this one can produce carbon monoxide and nitrogen oxides, which contribute to air pollution and negative human health impacts.
Let's focus on outdoor air pollutants for a moment. Major outdoor air pollutants are greenhouse gases, which contribute to the greenhouse effect and climate change, such as carbon dioxide and methane, which primarily come from coal, oil, and natural gas consumption. Chlorofluorocarbons, or CFCs, come from aerosol sprays and refrigerators. Sulfur and nitrogen oxide come from coal, oil, and natural gas. In the US, 60% of sulfur dioxides come from power plants.
PMs, or particulate matter, come from industry and manufacturing combustion of fossil fuels and their waste. While naturally created ozone protects the earth from solar radiation high in the atmosphere in what is called the ozone layer, ground level ozone can damage human health. Ground level ozone comes from burning fossil fuels in lawn mowers, construction vehicles, and automobiles.
Lead and other heavy metals are another outdoor air pollution and come from burning fossil fuels, as well as carbon monoxide, which comes from burning fossil fuels as well. Approximately 60% of carbon monoxide emissions come from mobile non-road sources and highway vehicles. Nationally in the US, the type and amount of pollution varies from region to region and state to state.
Now let's have a recap. Today, we talked about air pollution, it's many sources, and some major outdoor air pollutants. Well, that's all for this tutorial. I hope these concepts have been helpful. And I look forward to next time. Bye.