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Every child quickly learns that what goes up must come down. This is true of baseballs and footballs – and it’s true of the gases and minute particles that are emitted from smokestacks, vehicles, and many household products.
Rising from sources in Maryland and in states to the west and south, the gases and particles combine and react in the atmosphere to form pollution. That eventually causes health problems such as asthma and other respiratory illnesses back on the ground.
In Maryland, it is an unfortunate fact that we have a summertime problem with ozone and a year-round problem with fine particle pollution. Although we have made substantial progress the past several years on improving air quality, we still have a way to go before declaring success.
Ozone is a pollutant that is formed when oxides of nitrogen and/or volatile organic compounds are heated by the sun. Oxides of nitrogen (NOx) are created and emitted when fossil fuels, such as coal and gasoline, are burned. Volatile organic compounds (VOCs) are found in many products we use in our everyday lives including fuels, paints, solvents, and a variety of personal hygiene products. As we use these products, VOCs are released into the atmosphere.
There are many sources of ozone-forming pollution in Maryland. Power plants, vehicles (both on and off-road), factories, yard maintenance equipment, and boilers that provide heat and steam for many buildings and institutions are the main sources. At the same time, activities in other states contribute to our ozone problem. Weather patterns and prevailing winds bring a large amount of ozone to Maryland through much of the summer. This ozone is formed in the Midwest as a result of NOx emissions from large, coal-fired power plants, some as far away as Indiana. It is then transported aloft into Maryland, where it can mix with the pollution generated locally. A similar phenomenon takes place starting in states to the south from as far away as Georgia, although the results are not as significant.
Fine particles pollute when they are emitted into the atmosphere directly as a particle, such as diesel smoke or soot. Particles can also be formed through chemical reactions involving gases released into the atmosphere. Fine particles are also transported into Maryland, generally from the same group of states and from many of the same sources that produce ozone.
As a result of the Clean Air Act Amendments of 1990, Maryland continues to take significant steps to improve air quality. Familiar programs include: the vehicle emissions inspection program, the clean cars program, and the Maryland Healthy Air Act. Important but less familiar programs include: requirements for low-VOC paints and solvents, leak-proof gasoline cans, and personal hygiene products that do not cause as much pollution.
The next edition of eMDE will provide details on the programs and policies that have reduced air pollution, how much of an improvement has taken place over the past two decades, and the next steps to more progress in reducing air pollution.
Click here for more information on state programs.
For more information on the Clean Air Act visit http://www.epa.gov/air/caa/
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