Primary Air Pollution consists of harmful chemicals that enter directly into the atmosphere. The major chemicals are:
Carbon oxide are the gases carbon monoxide (CO) and carbon dioxide (CO2). Carbon monoxide, a colorless, odorless, and tasteless gas produced in the largest quantities of any atmospheric pollutant except carbon dioxide, is poisonous and reduces the blood's ability to transport oxygen. Carbon dioxide, also colorless, tasteless, and odorless, traps heat in the atmosphere and is therefore involved global climate change.
Nitrogen oxides are gases produced by the chemical interactions between nitrogen and oxygen. They consist of nitric oxide and nitrogen oxide. Nitrogen oxides inhibit plant growth and, when breathed, aggravate health problems such as asthma. They are involved in the production of smog, acid deposition, and global warming. Nitrogen oxides cause metals to corrode and textiles to deteriorate.
Sulfur oxides are gases produced by the chemical reactions between sulfur and oxygen. Sulfur dioxide, a colorless, nonflammable gas with a strong, irritant odor, is a major sulfur oxide emitted as a primary air pollutant. Another major sulfur oxide is sulfur trioxide, a secondary air pollutant that forms when sulfur dioxide reacts with oxygen in the air.
Hydrocarbons are a diverse group of organic compounds that contain only hydrogen and carbon. Some hydrocarbons are straight or branched chains, and some are cyclic (form rings); the simplest is methane. Methane, is a colorless, odorless gas that is the principle component of natural gas? Methane is involved in global climate change.
Particulates consist of thousands of different solid and liquid particles that are suspended in the atmosphere. They include soil, soot, lead, asbestos and sulfuric acid droplets. All particulate matter settles out of the atmosphere, but it is possible for small particulate, some of which are harmful to humans, to remain suspended in the atmosphere for weeks even years. Particulate reduces visibility by scattering and absorbing sunlight. Urban areas receive less sunlight than rural areas, partly as a result of greater qualities of particulate matter in the air.
Secondary Air Pollution is harmful chemicals that form from other substances that have been released into the atmosphere. Ozone is secondary, because it is formed by chemical reactions that take place in the atmosphere.
THE OZONE AND THE OZONE DEPLETION PROCESS
Ozone is a form of oxygen that is considered a pollutant in one part of the atmosphere but an essential component in another. In the stratosphere, which extends from 10 to 45 kilometers above the Earth's surface, oxygen reacts with ultraviolet radiation coming from the sun to form ozone. Stratospheric ozone prevents much of the solar ultraviolet radiation from penetrating to the Earth's surface. Unfortunately, human-made pollutants are attacking stratospheric ozone. Ozone in the troposphere, the layer of atmosphere closest to the Earth's surface is a human-made air pollutant. The most harmful component of ozone is photochemical smog; ozone reduces air visibility and causes health problems. Ozone also stresses plants and reduces their vigor. Chronic exposure to ozone lowers crop yields and is a possible contributor to forest decline.
The
ozone depletion process begins with CFCs and other ozone depleting substances lead from equipment (1). Winds efficiently mix the troposphere and evenly distribute the gases. CFCs are extremely stable, and they do not dissolve in rain. After a period of several years, ODS molecules reach the stratosphere, about 10 kilometers above the Earth's surface (2). Strong UV light breaks apart the ODS molecule and releases bromine atoms (3). It is these atoms, which actually destroys ozone, not the molecule. It is estimated that one chlorine atom can destroy over 100,000 ozone molecules before finally being removed from the stratosphere (4). Since ozone filters out harmful UVB radiation, less ozone means higher UVB levels at the surface. The more depletion, the larger the increase in incoming UVB (5).
When dealing with the ozone and the UVB radiation levels we need to understand that there are serious health risks that go along with air pollution. The major health risk is melanoma skin cancer. Melanoma is a very serious form of skin cancer. It begins in melanocyte cells that make the skin pigment called melanin. It causes the most skin cancer-related death. The good news is that melanoma is often curable if its detected and treated in its early stages.
How common is melanoma?
The number of new melanomas diagnosed in the United States is increasing. Since 1973, the rate of new melanomas diagnosed per year has doubled from 6 per 100,000 to 12 per 100,000.
The American Cancer Society estimates that about 44,200 new melanomas will be diagnosed in the United States during 1999, a 6% increase from 1998. About 7,300 Cancer Statistics deaths will attributed to malignant melanoma in 1999.
URBAN AIR POLLUTION
Air Pollution that is localized in urban areas, where it reduces visibility, is often called smog. The word "smog" was coined at the beginning of the 20th century for the smoky fog that was so prevalent in London because of coal combustion. Today there are several different types of smog. Industrial smog is the principle pollutants in industrial smog are sulfur oxides and particulate matter. The worst episodes of industrial smog typically occur during winter months, when household fuel combustion is high.
Another important type of smog is photochemical smog, a brownish orange haze formed by chemical reactions involving sunlight. One of the photochemical reactions occurs among nitrogen oxides (largely from automobile exhaust), volatile hydrocarbons, and oxygen in the atmosphere to produce ozone; the reaction requires solar energy. The ozone formed this way then reacts with other air pollutants including hydrocarbons, to form more than 100 different secondary air pollutants for which can injure plant tissues, irritate eyes, and aggravate respiratory illnesses in humans.
Automobiles are not the only source of smog; you will be surprised to know that bakeries and dry cleaners are also significant contributors of the air pollutants that cause smog. When bread is baked, yeast byproducts are released that are converted to ozone by sunlight. The volatile fumes from dry cleaners contribute to photochemical smog.
HOW DOES CLIMATE AND TOPOGRAPHY AFFECT AIR POLLUTION?
Variation in temperature during the day usually results in air circulation patterns that help to dilute and blow away air pollutants. As the sun increases the surface temperatures, the air near the ground is warmed. This heated air expands and rises to higher levels in the atmosphere, causing a low-pressure area near the ground; the surrounding air then moves into the low-pressure area. Thus, under normal conditions, air circulation patterns prevent toxic pollutants from increasing to dangerous levels near the ground.
During periods of thermal inversion, in which the air near the ground is colder than the air at higher levels, polluting gases and particulate matter remain trapped in high concentrations close to the ground, where people live and breathe. Thermal inversions only persist for only a few hours before they are broken up by atmospheric turbulence. There are several types of topography that increase the likelihood of thermal inversion. Cite located in valleys, near the coast, or on the leeward side of mountains are prime candidates for thermal inversions. (441)
AIR POLLUTION IN THE UNITED STATES
In the 1970's the Clean Air Act was first passed and has been reauthorize twice since then, in 1977 and 1990. Air quality in the United States is slowly improving. The most important improvement has been the amount of lead in the atmosphere, which showed a 95.5 percent decrease between 1970 and the 1990's, primarily because of the switch from leaded to unleaded gasoline. Although air quality has been gradually improving, the atmosphere in many urban areas still contains higher levels of pollutants than are recommended based on health standards. Photochemical smog continues to be a major problem in metropolitan areas. With the provisions of the Clean Air Act of 1990 they made the development of "superclean" cars, which lowers the amounts of nitrogen oxides and hydrocarbons, and the use of cleaner-burning gasoline in the country's most polluted cities, these changes are being phased by the year 2000. The 1990 Clean Air Act requires a 90 percent reduction in the atmospheric emissions of 189 toxic and cancer-causing chemicals by 2003. Both small businesses such as dry cleaners and large manufacturers such as chemical companies will have to install pollution control equipment. Sulfur dioxide and nitrogen oxide emissions from coal-fired power plants will be reduced by the year 2000. The provisions for stratospheric ozone depletion initially required the United States to phase out the production of ozone-destroying chemicals by the year 2000. (11)
When looking at the cities in the United States, I would like to focus on just one, Los Angeles, California. Los Angeles has some of the worst smog in the world. They have sunny climate, large populations and high automobile density, which is the formation for thermal inversions that trap photochemical smog near the ground. California in 1969 was the first state to enforce emission standards on motor vehicles, simply because of the major air pollution problems. Today, Los Angeles has a smog control that regulates everything from automobiles to lawn mower emissions to paint vapors.
You're probably wondering what lawn mowers have to do with air pollution, well lawn mowers give off hydrocarbons and carbon monoxide which causes air pollution. According to the EPA, gas powered mowers, blowers, and other small machines produce 10 percent of air pollution. One hour of mowing releases as many hydrocarbons as a car driven 50 miles. When refueling lawn equipment, users spill as estimated 17 million gallons of fuel each year, which is 6 million gallons more than that released in the Exxon Valdez spill.
HOW CAN WE CONTROL AIR POLLUTANTS?
The way we can control this problem is by having smaller, more fuel-efficient automobiles that produce fewer emissions. Smokestacks that have been fitted with electrostatic precipitators, fabric filters, scrubbers, or other technologies remove particulate matter. We can control particulate by careful land-excavating activities.
AIR POLLUTION IN DEVELOPING COUNTRIES
MEXICO CITY
When looking at the developing countries that have air pollution, I would like to focus on Mexico City, because of how severe the pollution is. Mexico City is the world's fourth largest city. It has the most polluted air of any metropolitan area in the world. The reasons for this are because of its great population growth in the past 40 years and in part to the city's location. The city has almost 3 million motor vehicles, 360 gasoline stations, and about 30,000 businesses, which the Mexican government says spew 3.94 million metric tons of pollutants into the air each year. Also, liquefied petroleum gas, which is the major source of energy for cooking and heating in Mexico City, leaks in unburned form into the atmosphere, releasing hydrocarbons that contribute significantly to the city's air pollution.
In the 1990's, Mexico embarked on a plan to improve air quality by gradually replacing old buses, taxis, delivery trucks, and cars with "cleaner" vehicles and switching to unleaded gasoline.
FOLLOW -UP
Mexico City's air pollution plan has not been totally effective. The city's government does not have the political will to enforce air pollution control measures. Air quality was worse in 1996 than it was in 1986. In 1995, ozone levels exceeded Mexico City's standards of acceptability on 324 days.
The images I'm going to show you, shows the change in visibility from Mexico City, depending on the pollution level.
DAY WITH NO POLLUTION
LOWLY POLLUTED DAY
HIGHLY POLLUTED DAY
AIR POLLUTION AND HUMAN HEALTH
Every year, some 64,000 people may die from cardiopulmonary cause linked to particulate air pollution, according to an analysis conducted by NRDC. In the most polluted cities, lives are shortened by one to two years. Los Angeles tops the list with an estimated 5,873 deaths, followed by New York (4,024), Chicago (3,479), Philadelphia (2,599) and Detroit (2,123).
Both Sulfur dioxide and particulate irritate the respiratory tract and, because they cause the airways to constrict, actually impair the lungs' ability to exchange gases. People suffering from asthma and emphysema are very sensitive t sulfur dioxide and particulate pollution. Nitrogen dioxide also cause airway constriction and, in people suffering asthma. Carbon monoxide combines with the bloods' hemoglobin, reducing its ability to transport oxygen. At medium concentrations, carbon monoxide causes headaches and fatigue. A high level of carbon monoxide causes death. People at greatest risk from carbon monoxide include pregnant women, infants, and those with heart or respiratory diseases.
CHILDREN AND AIR POLLUTION
Click here on picture to see more!
Air Pollution is a greater health threat to children than it is to adults. The lungs continue to develop throughout childhood, and air pollution can restrict lung development. In addition, a child has a higher metabolic rate than an adult and therefore needs more oxygen. To obtain this oxygen, a child breathes more air about two times as much air per pound of body weight compared to an adult. This means that a child also breathes more air pollutants into the lungs. In a 1990 study, autopsies were preformed on 100 Los Angeles children who died for unrelated reasons found that more than 80 percent had subclinical lung damage, which is lung disease in its early stages, before clinical symptoms appear. A long-term study is underway to determine the effects on children's developing lungs of chronic exposure to air pollution.
INDOOR AIR POLLUTION
Welcome to my website on Air Pollution. We all need to understand how important air pollution really is. All of us face a variety of risks to our health as we go about our day-to-day lives. Driving cars, flying planes, engaging in recreational activities, and being exposed to environmental pollutants all pose-varying degrees of risks. Some risks are simply unavoidable. Some we choose to accept because to do otherwise would restrict our ability to lead our lives the way we want. Some are risks we might decide to avoid if we had the opportunity to make informed choices. Indoor air pollution is one risk that you can do something about. In the last several years, a growing body of scientific evidence has indicated that the air within homes and other buildings can be more seriously polluted than the outdoor air. In addition, people who may be exposed to indoor air pollutants for long periods of time, are often those most susceptible to the effects of indoor air pollution. We look further into indoor air pollution as we go through some important issues first. 
Air pollution consists of gases, liquids, or solids present in the atmosphere in high levels. It can harm humans and other organisms or materials. Human activities make a major contribution to global air pollution. Air Pollution is often divided into two catorgies, primary and secondary.(11) 
If too little outdoor air enters a home pollutants can accumulate to levels that can pose health and comfort problems. Unless they are built with special mechanical means of ventilation, homes that are designed and constructed to minimize the amount of outdoor air that can leak into and out of the home may have higher pollutant levels than other homes. However, because some weather conditions can drastically reduce the amount of outdoor air that enters a home, pollutants can build up even in homes that are normally considered "leaky". Now I'm going to discuss several indoor air pollutants to you. 
The most serious indoor air pollutant is likely to be radon. Radon is a colorless, tasteless radioactive gas produced naturally during the radioactive decay of uranium in the Earth's crust. Indoor radon is uranium in the soil or rocks on which your homes are built on. As uranium naturally breaks down, it releases radioactive gases. Radon enters the home through dirt floors, cracks in walls and floors, floor drains and sumps. 
Nonsmall cells carcinoma--Doctors group several types of lung cancer together and calls them Nonsmall cell lung cancer. 
Do not smoke in your home or permit others to do so. 
If you think your home may have asbestos, don't panic! 
Unusual and noticeable odors 
It was shown in a study done by NASA, each plant was placed and sealed and injected with chemicals. Philodendron, spider plants and the golden pathos were labeled the most effective in removing formaldehyde molecule. This molecule comes from pressed wood products that are used in office furniture. It's also in grocery bags, waxed papers, facial tissues and paper towels. Other sources of this molecule include heating and cooking fuels and cigarette smoking. Flowering plants such as a daisy were superior when removing benzene from the chamber atmosphere. The plants take substances out of the air through the tiny opening in their leaves. NASA research has consistently shown that living, green and flowering plants can remove several toxic chemicals from the air in building interiors. You can use plants in your home to improve the air quality. 
LINKS