Air pollution can come from just about everything that happens in an industrialized society: Automobiles, power plants, dry cleaners, road paving and maintenance, manufacturing facilities; even the paint, carpet, and commercial products within your home can emit air pollution. Here is an overview of some of the more prominent sources:
- Coal-burning power plants
- Cars & trucks
- Trains
- Airplanes
- Shipping vessels (which typically burn bunker fuel, an especially dirty energy source)
- Fracking & oil-drilling operations
- Plants that make plastics, paper, metal, or chemicals
- Other industrial factories
- Local printers (printing plants have emissions that can be especially toxic to children)
- Dry cleaners
- Air fresheners & household cleaning products
- Wildfires
- Restaurants
- Cement factories
- Military installations
The biggest polluters
Coal-fired power plants contribute around 42% of all air pollution in the U.S. by weight, emitting around 400,000 tons of lead, mercury, chromium, arsenic, and hydrochloric acid into the air each year. They also contribute about 60% of the nation’s sulfur dioxide. (Shabecoff & Shabecoff, 2010, p. 73) Power plants emit things like formaldehyde, toluene, and an assortment of heavy metals, along with sulfur dioxide (which produces acid rain), smog-forming nitrogen oxides, soot, and an assortment of other pollutants. Cumulatively, it’s estimated that power plants spew 48 tons of mercury into the atmosphere each year, or about 40% of the nation’s airborne mercury total.
Motor vehicle emissions contribute around one-third of the airborne particulate matter in urban areas. (Copeland, 5-26-2011) While some strides have been made in reducing vehicle emissions, there’s still work to be done. Dan Becker, who directs the Safe Climate Campaign at the Center for Auto Safety, notes that “the current testing protocol lets companies routinely measure their most efficient, least polluting models and then extrapolate across their entire production, projecting company wide mileage to demonstrate whether they are meeting government standards. This allows them to deliver the most optimistic, though not necessarily accurate, reports.” (Becker & Gertstenzang, 2015) A switch to diesel engines is also fueling smog, even in cities with good environmental protection standards in place. Though better for the climate than gas powered cars, diesel vehicles actually emit more of the pollutants that are harmful to humans. (Worland, 2016) Air pollution is present on airplane flights, too. Only the recently launched Boeing 787 filters the “bleed air” – air that bleeds into the cabin from the engines and can contain toxic hydrocarbons. This is mainly a problem for flight crew who are constantly in the air; but consistent exposure leads to dizziness, nausea, and potentially neurological effects.
The type of air pollution you experience varies depending on the region. For example, the Eastern and Midwest United States are home to more coal-fired power plants, which means things like mercury exposure are higher. Along the west coast in places like California cars and traffic congestion contribute to most of the air pollution, so particulate matter is a bigger problem. If you’re in a fracking town, ozone might be your biggest concern.