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AIR POLLUTION The major pollution caused by factories or industrials’ activities is air pollution. According to the Engineers’ Joint Council “Air Pollution and Its Control”, air pollution means the presence in the outdoor atmosphere of one or more contaminants, such as dust, fumes, gas, mist, odour, smoke or vapour in quantities of characteristics and of duration, such as to be injurious to human, plant or animal life or to property or which unreasonably interfaces with the comfortable enjoyment of life and property.
On the other way, air pollution also can be defined as the chemicals, particulate matters or biological materials that cause harm or discomfort to humans or other living organisms, or damages the natural environment, into the atmosphere. The rapid growth of industries has now spread to a number of developing counties of the Third World including Malaysia. Although the sizes of industrial plants in these countries are comparatively small by Western standards, it is important that the planner be aware of the cumulative effect of these many small industrial sources of pollution.
In Malaysia, 39 percent of the total pollution is contributed by industries. Of this industrial pollution, more than 27 percent comes from wood-based industries. It has been estimated that only 20 percent of this wood waste was usefully recovered as fuel for boilers and kilns. There are many different chemical substances emit by industrial activities that contribute to air pollution. These chemicals come from a variety of sources. Among the many types of air pollutants are nitrogen oxides, carbon monoxides, and organic compounds that can evaporate and enter the atmosphere.
Air pollutants have sources that are both natural and human. Now, humans contribute substantially more to the air pollution problem. The effects of air pollution are diverse and numerous. Air pollution can have serious consequences for the health of human beings, and also severely affects natural ecosystems. Because it is located in the atmosphere, air pollution is able to travel easily. As a result, air pollution is a global problem and has been the subject of global cooperation and conflict. Some areas now suffer more than others from air pollution.
Cities with large numbers of factories or those that use great quantities of coal often suffer most severely from problems of air pollution. SOURCES OF AIR POLLUTION Different industries activities emit different pollutants. For example, the chemical industry releases emissions that contain many nitrogen and sulphur compounds while refineries discharge sulphur dioxide and hydrocarbons. The metal working industry is partially responsible for the emissions of sulphur dioxide and large amounts of toxic dust. Text: ‘Clean Air For Our Cities, 2006, by DOE Malaysia & German Technical Co-operation) In addition, power plants represent the next large source of air pollutant emissions. In many countries power supply is obtained very largely from fuel oil and in some instances coal. All our large power plants in Malaysia are using fossil fuels. Because sulphur is one of the major ingredients of these fuels, power plants are the greatest contributors of sulphur dioxide pollution. Of the total sulphur dioxide emission in Peninsular Malaysia, over 50 percent is produced by power plants. Air Pollutants
An air pollutant is known as a substance in the air that can cause harm to humans and the environment. Pollutants can be in many forms which may be natural or man-made. It can in the form of solid particles, liquid droplets, or gases. Carbon dioxide is one of the major industrial pollutants in the atmosphere. Major sources of CO2 are fossil fuels burning and deforestation which implicated by the development of the industry sector. The concentrations of CO2 in the air around 1860 before the effects of industrialization were felt, is assumed to have been about 290 parts per million (ppm).
In the hundred years and more since then, the concentration has increased by about 30 to 35 ppm that is by 10 percent. CO2 is a good transmitter of sunlight, but partially restricts infrared radiation going back from the earth into space. This produces the so-called greenhouse effect that prevents a drastic cooling of the Earth during the night. Increasing the amount of CO2 in the atmosphere reinforces this effect and is expected to result in a warming of the Earth’s surface. Currently carbon dioxide is responsible for 57% of the global warming trend.
Another type of air pollutant is carbon monoxide, which is a colourless, odourless, non-irritating but very poisonous gas. It is a product by incomplete combustion of fuel such as natural gas, coal or wood. Vehicular exhaust is a major source of carbon monoxide. Nitrogen oxides such as nitric oxide (NO3) or nitrogen dioxide (NO2) also contribute most of the atmospheric contaminants. They are natural component of the Earth’s atmosphere which comes from the burning of biomass and fossil fuels. The industrial activities produced 30 to 50 million tons per year.
They cause the formation of both acid precipitation and photochemical smog (ozone), and causes nitrogen loading which can reduce the stratospheric ozone. Another type of nitrogen oxide is nitrous oxide (N2O). N2O comes from nitrogen based fertilizers, deforestation, and biomass burning. The human inputs 6 million tons of N2O per year. It can cause the greenhouse effect and causes nitrogen loading. Sulphur dioxide is produced by combustion of sulphur-containing fuels, such as coal and fuel oils. Sulphur oxides can injure man, plants and materials.
At sufficiently high concentrations, sulphur dioxide irritates the upper respiratory tract of human beings because potential effect of sulphur dioxide is to make breathing more difficult by causing the finer air tubes of the lung to constrict. “Power plants and factories emit 90% to 95% of the sulphur dioxide (SO2) and 57% of the nitrogen oxides in the United States. Almost 60% of the SO2 emissions are released by tall smoke stakes, enabling the emissions to travel long distances”. As emissions of SO2 and nitric oxide from stationary sources are transported long distances by winds, they form econdary pollutants such as nitrogen dioxide, nitric acid vapour, and droplets containing solutions of sulphuric acid, sulphate, and nitrate salts. These chemicals descend to the earth’s surface in wet form as rain or snow and in dry form as a gases fog, dew, or solid particles. This is known as acid deposition or acid rain. Chlorofluorocarbons, also known as Freon, are greenhouse gases that contribute to global warming. CFCs are lowering the average concentration of ozone in the stratosphere. “Since 1978 the use of CFCs in aerosol cans has been banned in the United States, Canada, and most Scandinavian countries.
Aerosols are still the largest use, accounting for 25% of global CFC use”. Spray cans, discarded or leaking refrigeration and air conditioning equipment, and the burning plastic foam products release the CFCs into the atmosphere. Depending on the type, CFCs stay in the atmosphere from 22 to 111 years. Chlorofluorocarbons move up to the stratosphere gradually over several decades. Under high energy ultra violet (UV) radiation, they break down and release chlorine atoms, which speed up the breakdown of ozone (O3) into oxygen gas (O2). Besides that, volatile organic compounds (VOCs) are also an important outdoor air pollutant.
They are often divided into two categories which are methane (CH4) and non-methane. Methane is an extremely efficient greenhouse gas which contributes to enhance global warming. Other hydrocarbon VOCs are also significant greenhouse gases via their role in creating ozone and in prolonging the life of methane in the atmosphere, although the effect varies depending on local air quality. Within the non-methane, the aromatic compounds benzene, toluene and xylene are suspected carcinogens and may lead to leukaemia through prolonged exposure. 1,3-butadiene is another dangerous compound which is often associated with industrial uses.
On the other hand, ammonia, which is emitted from agricultural processes is normally encountered as a gas with a characteristic pungent odor. Ammonia contributes significantly to the nutritional needs of terrestrial organisms by serving as a precursor to foodstuffs and fertilizers. Ammonia, either directly or indirectly, is also a building block for the synthesis of many pharmaceuticals. Although in wide use, ammonia is both caustic and hazardous. Nevertheless, smog is created by burning coal and heavy oil that contain sulphur impurities in power plants, industrial plants, etc.
The smog consists mostly of a mixture of sulphur dioxide and fog. Suspended droplets of sulphuric acid are formed from some of the sulphur dioxide, and a variety of suspended solid particles. Smog’s unpleasant properties result from the irradiation by sunlight of hydrocarbons caused primarily by unburned gasoline emitted by automobiles and other combustion sources. The products of photochemical reactions include organic particles, ozone, aldehydes, ketones, organic acids, and other oxidants. Ozone is a gas created by nitrogen dioxide or nitric oxide when exposed to sunlight.
Ozone causes eye irritation, impaired lung function, and damage to trees and crops. IMPACT OF AIR POLLUTION Air pollution is responsible for major health effects. Every year, the health of countless people is ruined or endangered by air pollution. The World Health Organization states that 2. 4 million people die each year from causes directly attributable to air pollution. There are also studies have estimated that the number of people killed annually in the US alone could be over 50,000. Older people are highly vulnerable to diseases induced by air pollution.
Those with heart or lung disorders are under additional risk. Children and infants are also at serious risk. Because people are exposed to so many potentially dangerous pollutants, it is often hard to know exactly which pollutants are responsible for causing sickness. Also, because a mixture of different pollutants can intensify sickness, it is often difficult to isolate those pollutants that are at fault. The health effects caused by air pollutants may range from subtle biochemical and physiological changes to difficulty in breathing, wheezing, oughing, bronchitis and aggravation of existing respiratory and cardiac conditions such as lung cancer. These effects can result in increased medication use, increased doctor or emergency room visits, more hospital admissions and premature death. Another air pollution impact is greenhouse effect that is a phenomenon where by greenhouse gases create a condition in the upper atmosphere causing a trapping of heat and leading to increased surface and lower troposphere temperatures. It shares this property with many other gases, the largest overall forcing on Earth coming from water vapor.
Other greenhouse gases include methane, hydro fluorocarbons, per fluorocarbons, chlorofluorocarbons, and ozone. Many greenhouse gas, contain carbon, and some of that from fossil fuels. Currently, scientists are studying the role of changes in composition of greenhouse gases from natural and anthropogenic sources for the effect on climate change. Urban air pollution effects upon precipitation have been noted for a number of decades but were difficult to verity by statistical taste due to the high variability of rainfall amount and the inadequacies of the ordinary rain gauge as a sampling device.
These are known as weather and climate effect. The effects of pollution modifying climate are less obvious on a global scale. Such modifications are being attributed largely to an increase in the emission of carbon dioxide and dust into atmosphere. Part of the carbon dioxide from combustion is consumed in plant photosynthesis, which restores the oxygen to the air. Another portion of the carbon dioxide is absorbed into the ocean and precipitated as carbonate solids. However, the large-scale burning of oil, coal and gas has emitted so much carbon dioxide that a residual increase has occurred.
This steadily growing concentration may change the light-absorbing properties of the atmosphere. Besides that, cities around the world with high exposure to air pollutants has the possibility of children living within them to develop asthma, pneumonia and other lower respiratory infections as well as a low initial birth rate. Protective measures to ensure the youth’s health are being taken in cities such as New Delhi, India where buses now use compressed natural gas to help eliminate the “pea-soup” smog.
Research by the World Health Organization shows there is the greatest concentration of particulate matter particles in countries with low economic world power and high poverty and population rates. Examples of these countries include Egypt, Sudan, Mongolia, and Indonesia. The Clean Air Act was passed in 1970; however in 2002 at least 146 million Americans were living in areas that did not meet at least one of the “criteria pollutants” laid out in the 1997 National Ambient Air Quality Standards. Those pollutants included: ozone, particulate matter, sulfur dioxide, nitrogen dioxide, carbon monoxide, and lead.
Because children are outdoors more and have higher minute ventilation they are more susceptible to the dangers of air pollution. REDUCTION EFFORTS There are various air pollution control technologies and land use planning strategies available to reduce air pollution. At its most basic level land use planning is likely to involve zoning and transport infrastructure planning. In most developed countries, land use planning is an important part of social policy, ensuring that land is used efficiently for the benefit of the wider economy and population as well as to protect the environment.
Efforts to reduce pollution from mobile sources includes primary regulation (many developing countries have permissive regulations),[ expanding regulation to new sources (such as cruise and transport ships, farm equipment, and small gas-powered equipment such as lawn trimmers, chainsaws, and snowmobiles), increased fuel efficiency (such as through the use of hybrid vehicles), conversion to cleaner fuels (such as bioethanol, biodiesel, or conversion to electric vehicles).