The types of pollution problems confronting people in the United States get described in general terms related to either the ecosystem, such as air pollution or ocean pollution, or to a human sense, such as noise pollution or light pollution.
Scientists studying these different types of pollution tend to focus on two separate but interrelated questions:
|Air Pollution Issues
Acid Rain in Europe
Air Pollution in the Grand Canyon
Air Pollution in Mexico
Environmental Externalities and Air Pollution
The term smog, first used by H.A. Des Voex in 1905, described the foggy conditions in urban areas resulting from the sulfur dioxide emissions coming from the newly created smokestacks of the industrial revolution.
Today's urban smog problems, primarily photochemical smog, result when sunlight breaks down chemicals such as volatile organic compounds (VOCs) and nitrogen oxides (NOX) into their constituent parts. Once broken down, the now free oxygen molecules can link up with the oxygen in the air (O2) and create ozone
Volatile Organic Compounds (VOCs), a group of chemical compounds, share some common characteristics. First, the organic designation means that the compound is almost always composed of carbon (C) and hydrogen (H) molecules. Volatility refers to the evaporative quality of the compound. Anyone pumping their own gasoline and immediately notices the smell of gas experiences a quick lesson regarding gasoline's high degree of volatility.
Motor vehicle emissions represent the primary source of VOC emissions. However, evaporation of gasoline, solvents, oil-based paints, and hydrocarbons from the petrochemical industry are also significant sources. NOx result from the combustion of fossil fuels such as oil and gas, with motor vehicles the primary primary source, followed by fuel burning in homes, businesses, factories and power plants.
|Ten Largest Lakes
Lake Superior (31,700 sq. miles)
Lake Huron (23,000 sq. miles)
Lake Michigan (22,300 sq miles)
Lake Erie (9,910 sq miles)
Lake Ontario (7,340 sq. miles)
Great Salt Lake (2,117 sq. Miles)
Lake of the Woods (1,485 sq. miles)
Iliamna Lake (1,014 sq. miles)
Lake Oahe (685 sq miles)
Lake Okeechobee (662 sq. miles)
Water pollution issues also easily divides into fresh water and salt water categories. Fresh water from rivers and lakes, for example, provides drinking water for large populations. The recent example of a harmful blue-green algal bloom in Lake Erie closing down Toledo's water system exemplifies the dangers associated with the management of fresh water resources.
Algal blooms also threaten salt water environments, causing concern for both human health and economics. Red Tide in the Gulf of Mexico, for example, can cause paralytic shellfish poisoning and consequently halt the local shell fish industry.
Mississippi River Pollution
Oil Spills and Environment
Hydraulic Fracturing and Water Pollution
The Gulf of Mexico dead zone, the largest in the United States, results from agriculture run off from the farm belt around the Mississippi River. The run off flows to the Gulf of Mexico causing a seasonal dead zone.
Since it was first discovered in 1972, researchers from the National Oceanic and Atmospheric Administration (NOAA) studied the Gulf dead zone causes and effects. The forty year dead zone history shows that, despite attempts to reduce agriculture run off levels, the dead zone maintains itself and occasionally reaches record levels.
Natural causes serve as the primary triggers for the second type of dead zone. For example, irregular northerly summer winds along the Oregon Coast cause coastal waters to upwell, or turn over. The colder water that is pushed to the surface contains sufficient nutrients to support the algae bloom and decomposition process.
The 2006 dead zone episode lasted close to four months and covered the northern half of the Oregon coast with probable intrusion into the southern Washington coast. Dead crabs, sea cucumbers and other marine organisms were documented along the length of the dead zone.
Because the ocean animals associated with dead zone episodes suffer losses, area coastal communities economically dependent on their offshore waters also suffer losses.
Separating types of pollution into air and water pollution represents an idealized approach to the topic. Various issues such as Mining and the Environment and Trade and the Environment create a variety of air and water pollution problems, depending on the specific issue under consideration. The links in the boxes on the right hand side of the column point to articles that examine a variety of common air and water pollution issues.
© 2011-2014 Patricia A. Michaels