April 30, 2013
The Impact of Air Pollution Plants are more sensitive than humans and animals to the effects of air pollution. The three most important pollutants are ozone, sulphur dioxide, and nitrogen dioxide, with a greater impact on annual crops than perennial crops. The Gauteng State of the Environment Report (1995) highlighted the most significant air quality issues as follows; Global warming due to the generation of greenhouse gases such as carbon dioxide, ozone and methane, acid deposition where sulphates and nitrates in the atmosphere are deposited in rain, mist or through dry deposition, acid deposition can lead to the salination and acidification of water resources and of soil, salination of water resources is caused by the accumulation of sulphates and nitrates on the land surface, and their transport into dams and lakes, sulphates and nitrates can increase soil acidity, concentrations of toxic metals in the soil solution may increase which can impact on plant growth.
Description of Air Pollution Air pollution is a mixture of natural and man-made substances in the air we breathe such as fine particles produced by the burning of fossil fuels, ground-level ozone, which is a reactive form of oxygen that is a primary component of urban smog, and noxious gases such as sulfur dioxide, nitrogen oxides, carbon monoxide, and chemical vapors. The health effects of air pollution have been reported in research studies over the past 30 years. These effects include respiratory diseases such as asthma, cardiovascular diseases, changes in lung function, and death. There is mounting evidence that exposure to air pollution has long-term effects on lung development in children.
Physical & Ecological Characteristics of Air Pollution Sulfur dioxide, nitrogen oxide and other air pollutants can enter the pores of developing plants and break down the waxy coating that protects them from disease and excess water loss. The internal combustion engines of cars and other vehicles produce carbon monoxide, which is a highly poisonous gas. According to the American Heart Association (AHA), breathing this form of air pollution over a long period of time can cause serious respiratory problems. The effects of air pollution can be felt thousands of miles from its original source. China's industrial pollution can be felt in western parts of the United States. Aerial transport has also caused pesticides from farms in South America to arrive in Antarctica. Volcanic activity can be one of the most significant natural sources of air pollution. When volcanoes erupt, they spew large amounts of ash and toxic chemicals into the air. Desert areas create dust storms that contribute to particulate matter in the atmosphere. Forest and grass fires also produce smoke that causes chemical pollutants to enter the air. Also, the quality of air is being reduced by industrial modernization. Cement factories, mines, steel manufacturers and thermal-power plants are among some of the leading producers of air pollution. Outdoor air pollution is one of China’s most serious environmental problems. Coal is still the major source of energy, constituting about 75 percent of all energy sources. Consequently, air pollution in China predominantly consists of coal smoke, with suspended particulate matter and sulfur dioxide as the principal air pollutants. In large cities, however, with the rapid increase in the number of motor vehicles, air pollution has gradually changed from the conventional coal combustion type to the mixed coal combustion/motor vehicle emission type. Currently, inhalable
particles and nitrogen dioxide are the criteria pollutants of concern in China. Generally, particulate matter levels in cities in the north are higher than those in the south, whereas sulfur dioxide and nitrogen dioxide levels do not differ much. In 2004, the annual average particulate matter 10