Air Pollution: Air is the ocean we breathe. Air supplies us with oxygen which is essential for our bodies to live. Air is 99.9% nitrogen, oxygen, water vapor and inert gases. Human activities can release substances into the air, some of which can cause problems for humans, plants, and animals. Air quality is important simply because we can’t avoid breathing in the air around us. The average adult breathes in about 20 cubic meters, or 20,000 liters of air a day. Air pollutants can cause a variety of health problems - including breathing problems; asthma; reduced lung function; lung damage; bronchitis; cancer; and brain and nervous system damage. Air pollution can also irritate the eyes, nose and throat, and reduce resistance to colds and other illnesses. Air pollution can be especially harmful to the very young, the very old, and those with certain preexisting medical conditions. Small portions of air pollution and greenhouse gas emissions comes from natural sources, such as forest fires, bogs and volcanic activity. Human activities, such as burning fossil fuels, using chemicals and industrial processes are the source of most air pollution. Air pollution and greenhouse gases are the cause of smog, climate change and land and water contamination when pollutants fall in rain or snow. Air pollution is the human introduction into the atmosphere of chemicals, particulate matter, or biological materials that cause harm or discomfort to humans or other living organisms, or damages the natural environment. Air pollutants fall into four main categories: criteria air contaminants, persistent organic pollutants, heavy metals and toxics. Individual pollutants differ from one another in their chemical composition, reactions with other chemicals, sources, persistence, ability to travel through the atmosphere, and impacts. Air pollution is often identified with major stationary sources, but the greatest source of emissions is mobile sources, mainly automobiles. Gases such as carbon dioxide, which contribute to global warming, have recently gained recognition as pollutants by climate scientists, while they also recognize that carbon dioxide is essential for plant life through photosynthesis. There are several main types of pollution and well-known effects of pollution which are commonly discussed. These include smog, acid rain, the greenhouse effect, and "holes" in the ozone layer. Each of these problems has serious implications for our health and well-being as well as for the whole environment. The exhaust from burning fuels in automobiles, homes, and industries is a major source of pollution in the air. Some authorities believe that even the burning of wood and charcoal in fireplaces and barbeques can release significant quantities of soot into the air. Another type of pollution is the release of noxious gases, such as sulfur dioxide, carbon monoxide, nitrogen oxides, and chemical vapors. These can take part in further chemical reactions once they are in the atmosphere, forming smog and acid rain. The Greenhouse Effect, also referred to as global warming, is generally believed to come from the build up of carbon dioxide gas in the atmosphere. Carbon dioxide is produced when fuels are burned. Plants convert carbon dioxide back to oxygen, but the release of carbon dioxide from human activities is higher than the world's plants can process. The situation is made worse since many of the earth's forests are being removed, and plant life is being damaged by acid rain. Thus, the amount of carbon dioxide in the air is continuing to increase. This buildup acts like a blanket and traps heat close to the surface of our earth. Changes of even a few degrees will affect us all through changes in the climate. Refining oil is a dirty procedure that contributes to pollution and global warming. Refineries that keep cars and trucks running also contribute to global warming. Fuel must be burned to make gasoline from oil, generating carbon-dioxide pollution. Oil refineries pollute our air, water, and land. Oil refineries are one of the largest sources of air pollution in the North America. Refineries are the single largest stationary source of various organic chemical compounds, the primary source of urban smog. Refineries are also one of the largest industrial source of toxic emissions and the single largest industrial source of benzene emissions. Our air is polluted by up to one hundred pollutants emitted from the stacks and leaking equipment at refineries. Chemicals emitted from oil refineries include metals like lead, and small dust particles called PM10, which get deep into our lungs and harm our ability to breathe. Finally, refineries emit many gases like sulphur dioxide (SO2), nitrogen oxide (NO2), carbon dioxide, carbon monoxide, methane, dioxins, hydrogen fluoride, chlorine, benzene and others. Many of the gases emitted by refineries are harmful to humans, and can cause permanent damage and even death. They can cause respiratory problems such as asthma, coughing, chest pain, choking, and bronchitis. Oil refinery emissions also can lead to skin irritations, nausea, eye problems, headaches, birth defects, leukemia, and cancers Air pollution also can exist inside homes and other buildings. It can, and every year, the health of many people is affected by chemical substances present in the air within buildings. There are many sources of indoor air pollution. Tobacco smoke, cooking and heating appliances, and vapors from building materials, paints, furniture, etc. cause pollution inside buildings. Radon is a natural radioactive gas released from the earth, and it can be found concentrated in basements Carbon monoxide (CO) is a gas that forms whenever you burn fuel like propane, natural gas, gasoline, oil, coal and wood. Because it is colourless, odourless and tasteless, it is hard to detect without a carbon monoxide detector. Carbon monoxide can cause health problems before and even death. Fuel-burning appliances such as furnaces, fireplaces, gas stoves and water heaters (especially those that are not properly vented or maintained) or when chimneys are blocked or dirty; Idling vehicles in garages that are attached to homes or buildings; Barbecues, grills, space heaters and other non-vented fuel-burning appliances that are designed for outdoor use; and tobacco smoke. The growing use of synthetic materials, modern office equipment (photocopiers, laser printers, and computers), cleaning products, and outdoor air pollution also contribute to indoor air contamination The most harmful and widespread contaminant of indoor air is tobacco smoke. Mould and dampness, improperly maintained combustion appliances, off-gassing from domestic chemicals and dust mites and their byproducts in the indoor environment can also cause a number of health problems. Mould growing in your home can release mould spores, toxins from mould and moldy odours. Harmful chemicals can be released from synthetic fabrics, furnishings and household products. Other sources of indoor air pollutants are burning candles, or improperly maintained or vented combustion devices, such as gas or propane cooking stoves, furnaces, water heaters, wood stoves and fireplaces.Smoking tobacco is the main source of indoor air pollution in the developed world. Tobacco smoke contains about 4,000 chemicals, including 50 that are known to cause cancer Air pollution has resulted in the increase of ailments related to respiratory infections such as bronchitis, lung diseases, acute respiratory distress syndrome and respiratory allergies, including attacks of severe asthma. Increased air pollution has also caused cases of middle ear infections which lead to various degrees of hearing impairment. Secondhand smoke, also known as environmental tobacco smoke, is the single largest contributor to indoor air pollution when a smoker is present. . Second-hand smoke can drift under doors, through open windows, vents and even electrical outlets. Drifting tobacco smoke is a problem for many people who live in multi-unit buildings as renters or as owners Studies of secondhand smoke indicate that air pollution in general can affect the heart and circulatory system. Fortunately in many countries laws are becoming much stricter regarding smoking in public places. For example in some provinces in Canada, smoking is not permitted in restaurants, shopping malls, public buildings and even licensed bars. From growing tobacco plants to disposal of butts and packaging, the life cycle of a cigarette creates a lot of pollution. Tobacco causes environmental damage where it is used as well as where it is produced Tobacco cultivation involves a great deal of pesticides, which are used in the early stages of tobacco growth. Pesticides, herbicides and fertilizers poison farm workers, seep into the soil and pollute waterways and ecological systems, and poison livestock and food crops In many countries in the world, steps are being taken to stop the damage to our environment from air pollution. Scientific groups study the damaging effects on plant, animal and human life. Legislative bodies write laws to control emissions. Educators in schools and universities are teaching students about the effects of air pollution. Many countries have set legislations on pollution emissions for transportation vehicles and industry. This is usually done to through a variety of coordinating agencies which monitor the air and the environment. In addition, it is possible to prevent many types of air pollution that are not regulated through personal, careful attention to our interactions with the environment. Only through the efforts of scientists, business leaders, legislators, and individuals can we reduce the amount of air pollution on the planet. This challenge must be met by all of us in order to assure that a healthy environment will exist for ourselves and our children.