In Search of Air Pollution
Beckendorf, Kirk, Science Scope
Byline: Kirk Beckendorf
Air pollution is no longer just a local issue; it is a global problem. The atmosphere is a very dynamic system. Pollution not only changes in chemical composition after it is emitted, but also is transported on local and global air systems hundreds and even thousands of miles away. Some of the pollutants that are major health concerns are not even emitted, but are formed during chemical reactions within the atmosphere. Tropospheric ozone (different from the good ozone layer in the stratosphere) reaches unhealthy levels in many urban and even rural areas during the summer. Measurements have revealed that ozone can reach extremely high abundances in rural areas, where crop and forest damage are of concern.
Ozone, however, is not released as a pollutant; rather it forms as a result of chemical reactions involving nitrogen oxides (NO[sub]X[/sub]) and volatile organic compounds (VOC). Some NO[sub]X[/sub] compounds are released during combustion, such as burning wood, and burning fuels in vehicles and power plants. Throw in some VOC, add sunlight as a catalyst, and chemical reactions occur causing ozone levels to soar. VOCs have both human and natural sources. Gasoline fumes, industrial solvents and natural compounds (from trees and other vegetation) are examples of these organic chemicals. In general, the more NO[sub]X[/sub], the more VOC, and the more sunlight will result in more ozone produced in the atmosphere.
Areas in rural New England and Canada, including Acadia National Park, produce very little air pollution. However, these rural areas have often been in violation of EPA air pollution standards. Pollutants spewing out from the metropolitan areas of the midwestern and northeastern United States follow the prevailing air currents and travel in a northeasterly direction into these rural areas, then out across the Atlantic and into Europe. This plume of pollution is called the "tailpipe of North America." As the pollution migrates it chemically evolves.
As one of NOAA's Teachers at Sea, I had the opportunity to spend a month with more than 30 scientists in search of air pollution in New England. The research project, called the New England Air Quality Study (NEAQS), has the goal of improving understanding of the atmospheric processes that influence air pollutants in the region. As a result of this experience, I have written a four-part lesson in which students look at real data about pollution in their own states and counties (see Activity Sheet).
Using EPA and NOAA websites, students are able to view pollution inventories (the amounts and kinds of pollution released in a given location) and follow pollution along its estimated path of travel. This lesson guides students in the use of the websites and what data to collect. Following this data collection, questions lead students to higher-order thinking and an understanding of how their own local activities have impacts on large global systems.
The lesson is web-based, so teachers should preview the sites to become familiar with what information is available and how to navigate through them. Computer access is usually at a premium, so I like students to work in pairs. These activities will take several days of computer time. If that is not an option, groups can be established and each group can be responsible for collecting data for a different part of the lesson. Back in the classroom, the data can then be compiled. If students have no access to computers, the data and maps may be printed or displayed on an overhead for student analysis.
In the first part of the lesson, students use an EPA website to discover how their own lifestyles contribute to air pollution in their state. In the next part, students learn how the amount of air pollution produced in their county compares to the rest of their state. In the third part, students track air pollution from the state's polluters. …