polar stratospheric clouds (PSC) Clouds that form in the stratosphere when it is es-
pecially cold; PSCs are necessary for the breakup of CFCs.
Points to Consider
- Since mercury bioaccumulates and coal-fired power plants continue to emit mercury
into the atmosphere, what will be the consequence for people who like to eat tuna and
other large predatory fish? - What are the possible causes of rising asthma rates in children?
- A ban has been imposed on CFCs and some other ozone-depleting substances. How
will the ozone hole change in response to this ban?
22.3 Reducing Air Pollution.
Lesson Objectives
- Describe the major ways that energy use can be reduced.
- Discuss new technologies that are being developed to reduce air pollutants, including
greenhouse gases. - Describe the difference between placing caps on emissions and reducing emissions.
Introduction
The Clean Air Act of 1970 and the amendments since then have done a great job in requiring
people to clean up the air over the United States. Emissions of the six major pollutants
regulated by the Clean Air Act, carbon monoxide, lead, nitrous oxides, ozone, sulfur dioxide,
and particulates, have decreased by more than 50%. Cars, power plants, and factories
individually release less pollution than they did in the mid-20thcentury. But there are many
more cars, power plants and factories. Many pollutants are still being released and some
substances have been found to be pollutants that were not known to be pollutants in the
past. There is still much work to be done to continue to clean up the air.
Ways to Reduce Air Pollution
Air pollution can be reduced in a number of ways. Using less fossil fuel is one way to
lessen pollution. People use less fuel by engaging in conservation, which means not using a
resource or using less of it. For example, riding a bike or walking instead of driving doesn’t
use any fossil fuel. Taking a bus uses less than driving or riding by yourself in a car, as does
carpooling. If you need to drive, buying a car that has greater fuel efficiency is important.