Air pollution is considered the emission of foreign materials into the air that can be gases, liquids or solids, which occurs both naturally and via man-made sources and are usually very concentrated in populated areas. It can also be considered a contaminated of the outdoor and indoor environment by any chemical, biological or physical agent that modifies the natural characteristics of the atmosphere.
Factory emitting harmful pollutants into the atmosphere
So what has brought about this in-dept concern in Air pollution, well simply industrialization as we you would have already known/notice is the major culprit of almost all major pollution on planet Earth.
Let discuss a little whats happening to us as a result of actions, now these undesirable compounds, biological pathogens or particulates are released into the atmosphere they result in serious health problems, hampering the well-being of any living thing that are exposed to them, hence the increasing importance of controlling and managing, since it is also considered a major problem to modern societies, and while air pollution is emitted more frequently in large cities, the pollutants contaminate air everywhere, harming human health and damaging the overall environment.
NATURAL SOURCES OF AIR POLLUTION
The atmosphere naturally consists of a number of gases in very precisely measured concentrations that ultimately contributes to the sustainability and proper functioning of the earth, when these gases exceeds their natural levels, the excess is considered pollutants. While many of these pollutants are given off into the air as a result of human behaviour. Pollution occurs on different levels naturally:
- Forest fires emit particulates, gases and VOCs;
- Soil erosion creates ultra-fine dust particles when water and weather loosen layers of soil increasing airborne particulate levels; and
- Volcanoes releases sulphur dioxide and large amounts of volcanic ash.
A naturally occurring volcanic activities this account for 50% of air pollution along with natural forest fires, wind erosion and seeds of plants, mushrooms and spores.
Volcano in Alaska – a major source of natural air pollution
ANTHROPOGENIC SOURCES OF AIR POLLUTION
While anthropogenic sources of air pollution occur in various ways and forms, rapidly increasing in today’s highly industrialized world plaguing the earth’s inhabitants as the major air pollutants, with countries around the world face with the tough decision of advancing their population by reducing poverty through manufacturing and technology advancement or protecting the environment.
Anthropogenic sources of air pollution can be emitted from:
- Stationary point sources – This is a single identifiable source of air pollution emission, this is usually single localized emitters of fossil fuel power plants, oil refineries, industrial process plants and other heavy industrialized sources. These can also be distinguished from mobile sources, such as automobiles, ships, aircrafts and other non-stationary sources. IEA survey claims that out of more than 14,000 identifiable sources, 7500 of the largest account for approximately 99% of the total emissions.
- Mobile Sources – This will include but not limited to the exhaust emissions from vehicles driven by fuel-burning engines, trucks, buses, trains, marine vessels and airplanes. This source contributes significantly to the cause of adverse health risk from breathing outdoor air toxics as a result of mobile point sources of air pollution. These are extremely harmful toxins according to the EPA, 2013 they are suspected to be related to the cause of cancers and other serious health or environmental effects of people living or working near major roads or spending a large amount of time in vehicles.
Mobile sources of air pollution affects a greater area and a large number of the population, it is worth noting that every individual reaction to pollutants vary resulting from irritation of the eyes to skin rashes etc and as far as affecting the respiratory systems of living organisms.
Industrialization is one of the main contributors to air pollution and all the adverse effects to the environment as a result these includes greenhouse gases that leads to global warming, acid rain and photochemical smog.
Air pollution – Vehicle emission in Beijing
IDENTIFICATION OF AIR POLLUTION POLLUTANTS
Management and control of air pollution is critical important for the simple fact that, everyday living results in creation of regular sources of air pollutants considered motor vehicles, household combustion devices, forest fires and industrial facilities.
All of which are of major public health concerns because of the carbon monoxide, nitrogen dioxide, ozone, particulate matter and sulphur dioxide overload to the environment, with both outdoor and indoor pollutants causing respiratory and other forms of diseases that may even be fatal.
In an effort of developing adequate management and control mechanisms it is critical to identify the major primary pollutants caused by human activities and their effects firstly.
PARTICULATE MATTER– These are naturally released into the air by volcanic activities, fires, dust storms and through living organisms in the form of pollen and spores and also through man’s activities which includes combustion of fossil fuels, burning of waste and grassland, industrial exhaust, extraction of ore, coal and quarry materials.
These includes all soil particulars found in suspended air and whether they remain in the air or settle on plant life they hamper the process of photosynthesis, by blocking the plants from absorbing sunlight. Particulate matters cause respiratory problems to animals.
NITROGEN OXIDES (NOX) – Nitrogen monoxide and dioxide are both produced as a result of combustion of fuels in vehicular use as well as in industry which are highly reactive gases. NO is easily oxidized to form NO2.
NO2 is characterized by a sharp odour and reddish-brown colour and contributes to the ozone formation and can have adverse effects on both terrestrial and aquatic ecosystems. Nitrogen oxides in the air can significantly contribute to a number of environmental effects including acid rain and Eutrophication in coastal waters. Eutrophication occurs when a body of water suffers from an increase in nutrients that leads to a reduction in the amount of oxygen in the water, which is extremely destructive to fish and marine life, while also contributing to the formation of ground-level ozone , and hence photochemical smog.
Alternatively, Nitrogen Dioxide can dissolve in water in the air to form nitric acid, in this way acting as a precursor to acid rain.
SULPHUR OXIDES (SOX) – Sulphur Dioxide is a colourless gas with a pungent, irritating odour and taste. It is highly soluble in water forming a weakly acidic sulphurous acid. When this is combined with oxygen in the air sulphur trioxide is slowly formed. Sulphur trioxide rapidly combines with water to produce sulphuric acid which is a pre-cursor for acid rain.
The lifespan of sulphur oxides in the atmosphere is from 4-10 days. Sulphur dioxide has a number of purposes in every-day life it is used in industrial process such as chemical preparation, refining, pulp-making, preparation and preservation of food since it prevents bacterial growth and the browning of fruit.
It is naturally present in the atmosphere from volcanoes and hot springs, while anthropogenically ,mainly in the combustion of coals ,petroleum products , smelter operations and industrial processes
CARBON MONOXIDE – This is emitted from the combustion process through the incomplete burning of natural gas and any other material containing carbon materials and is a poisonous, tasteless, odourless and colourless gas. The main source of CO in the atmosphere is are anthropogenic in nature, and its emission to ambient air comes from mobile sources. Carbon monoxide can cause harmful health effects by reducing oxygen delivery to the body’s organs such as the heart, brains and tissues, persons most at risk are welders, fire-fighters, taxi drivers, diesel mechanics etc.
CARBON DIOXIDE – CO2 is a colourless and odourless gas that is evolved naturally by living organisms through aerobic respiration, fermentation and volcanoes and is also evolved both naturally and anthropogenically through the burning of organic compounds, vehicular usage and in power plants burning of fuels, are the two major areas in which humans contribute to increased atmospheric levels of the gas.
Carbon dioxide also contributes to the acidification of rain by dissolving in water to form carbonic acid.
Carbon dioxide (CO2) is considered the primary greenhouse gas emitted through human activities causing global warming and ultimately changing the climate which adversely affects the health and well-being of all living thing on the planet Earth, although it is naturally present in the atmosphere as part of the Earth’s carbon cycle during the natural circulation of carbon among the atmosphere, oceans, soil, plants and animals. Global warming is essentially a problem of too much carbon dioxide (CO2) in the atmosphere, caused by carbon overload when fossil fuels such as coal, oil and gas or even deforestation.
VOLATILE ORGANIC COMPOUNDS (VOCs) – This group of compounds are characterized by having relatively low boiling points , allowing them easy transition to the gaseous phase by evaporation or sublimation, and as such are prone to being inhaled by living organisms. These compounds are more concentrated indoors than outdoors since they are widely used in a number of household products such as paints, vanishes, wax cosmetics, disinfecting, degreasing agents and hobby products, and released through natural means , such as production of methane by plants, wetlands and fermentation by bacteria.
Methane (CH4) on the other hand as a greenhouse gas is a naturally occurring, in-flammable gas, colourless and odourless gas that occurs abundantly in nature as the main component of natural gas and a common fuel source and is the second most prevalent greenhouse gas. Methane is also produced by geological coal formations and by the decomposition of organic matters under water, with the leading man-related sources of methane being landfills. VOCs also play a role in the formation of photochemical smog.
LEAD – This is found in every part of our environment in the air, soil, water and even inside our homes, Lead and Lead compounds have been used in a wide variety of products, this is a heavy metal originally used in gasoline in order to increase its octane rating for better performance. It was only later discovered that combustion of these fuels resulted in lead particles being released into the atmosphere, for inhalation by animals. The major sources of lead emissions to the air today are ore and metals processing and piston-engine aircraft operating on leaded aviation gasoline.
HEALTH EFFECTS OF VARIOUS AIR POLLUTANTS
An average adult breathes 2000 litres of air per day, along with the million tonnes of gases and harmful particles caused by the incomplete combustion of fossil fuel, causing harmful effect the overall health of all living things.
Many studies have shown direct links between air pollution and health effects, as it decreases lung function and an increase in heart attacks. According to EPA Air Quality Index high levels of air pollution adversely affects people with asthma and other types of lung or heart disease, with children and elder especially vulnerable to the effects of air pollution.
Humans breath in the pollutants present in the atmosphere, especially because most times they are not seen.
Effect of air pollution on human health
The level and type of risk, on an individual depends on several factors the amount of pollutant present in the air, the amount of air we breathe in a given time and our overall health.
|Carbon Monoxide||· Reduce visual acuity and sensory discrimination.
· Dizziness, fatigue , light headedness and in the case of long term exposure, death.
· Reduce respiratory function.
|· Traffic accidents.
· Asthma, bronchitis, aggravation of angima, arteriosclerotic disease.
|Sulfur Dioxide, Sulfates||· Irritation of respiratory system.
· Reduced respiratory function.
|· Excess mortality.
· Emphysema, bronchitis, other respiratory disease.
|Nitrogen||· Irritation or respiratory tract.
· Reduce respiratory function; reduced resistance to infection.
|· Bronchitis, other respiratory illness.
· Excess mortality, hypersensitive heart disease suspected.
|Hydrocarbons||· Some are irritating to eyes, respiratory tract.||· Cancer.|
|Oxidants||· Irritation of eyes, respiratory tract.||· Bronchitis, asthma, emphysema, difficulty in breathing.|
|Particulates||· Irritation of eyes, respiratory tract.||· Excess infant mortality, respiratory disease, some types of cancer.|
Air Pollution Symptoms associated with the air pollutants and their consequences.
|Total cancer; cancer of the respiratory
system; cancer of the digestive system
|Sulfur dioxide, sulfates, particulates, benzo(a)pyrene, asbestos, ambient air pollution; also numerous other agents whose incidence is localized, such as nickel,
|Respiratory disease mortality and morbidity||Particulates, sulfur dioxide, nitrogen dioxide, smoke, auto
|Bronchites||Particulates, sulfur dioxide, nitrogen dioxide, smoke, auto
|Pneumonia||Soot fall, smoke, sulfur dioxide, sulfates|
|Tuberculosis||Sulfur dioxide, particulates|
|Emphysema||Ambient air pollution, nitrogen oxides|
|Cardiovascular morbidity and mortality||Ambient air pollution, sulfur dioxide, sulfates,
Human Diseases associated with the air pollutants.
AIR POLLUTION MANAGEMENT AND CONTROL MEASURES
The dramatic effects of severe air pollution leading to acid rain, smog and greenhouse effect in cities around the world have alerted various government to the need for crisis procedures. All types are injurious to health and its prevention places an economic burden on the citizens and forcing governments to impose strict ambient quality levels to govern all from existing stationary sources.
Control measures can include, but it must be understood that there is no one way fits all, control measures will be required to take into consideration the uniqueness of a country and its population in the development of control measures policies to govern its citizens.
- Activated carbon is one of the most popular air pollution control mechanism, this involves the use of pollution filter, carbon to reduce the amount of pollutants are allowed to escape into the air.
- Bio-filtration – This is an innovation air pollution control technology for VOC emissions. This process involves the off-gases containing biodegradable volatile organic compounds or inorganic air toxics are vented through a biologically active material. Germany and the Netherlands have been using this technology at a full-scale level and as an application to control odours, VOCs and air toxic emission from a wide range of industrial and public sector sources. It reduces more than 90% of many common air pollutants, and due to its low operating cost bio-filtration can provide significant economic advantages over other technologies if applied to off-gases that contain readily biodegradable pollutants in low concentrations. This technology is most commonly used by food and waste plants, pharmaceutical companies and wastewater management facilities. The major downside of this technology is that it requires large spaces, many industries do not have the amount of space it requires so the method is commonly disregarded.
- Change in Fuel: This technique involves the use of less polluting fuel to reduce air pollution. Use of low sulphur fuel, the use of CNG is an great alternative and environmentally friendly, it emits fewer pollutants such as carbon monoxide, compared to gasoline and diesel, it also does not contain lead and benzene.
Other measures includes encouraging people to use public transport; walk or use a cycle as oppose to private vehicles; use unleaded petrol in vehicles; use fuels with low sulphur and ash content; reduce deforestation, plant more trees to encourage the natural removal of carbon dioxide from the atmosphere, implement zoning where industries and waste disposals sites are only allowed in areas outside the city preferably on the downwind of the city and finally use of catalytic converters to help in the control of emissions of carbon monoxide and hydrocarbons.
Catalytic reduction of exhaust gases are employed by industries to treat flue gases, reducing the harmful oxides to sulphur and Nitrogen gas. Catalytic converters are also employed in vehicles, to reduce emissions of VOC’s, carbon monoxide and nitrogen oxides . The catalyst , platinum and palladium, is coated onto a ceramic honeycomb or ceramic beads that are housed in a muffler-like package attached to the exhaust pipe. The catalyst helps to convert carbon monoxide into carbon dioxide. It converts the hydrocarbons into carbon dioxide and water. It also converts the nitrogen oxides back into nitrogen and oxygen. Control of nitrogen oxides and VOCs hence help manage the formation of ground level ozone.
The overall decision to ensure the air we breathe is as clean as possible are up to the citizenry, we have to determine how much we are willing to sacrifice our health for:
- Rapid industrialization
- Fast urbanization
- Rapid growth in population
- Growth of vehicles on the roads and
- Activities that disturbed the natural balance of the atmosphere.
Air pollution has been a nuisance in recent years posing serious threats to environmental and social wellbeing and rapidly increasing. Government, authorities and industry have been at the forefront to tackle air pollution with the help of policy reformation and technological innovation. Government need to develop appropriate policies to hold industries accountable for their actions imposing restricted permissible levels by industry, mandate that air pollution equipment be incorporated into the design and layout of every power plant and continuously measure and monitor to ensure compliance along with evaluating the environment to determine necessary policy improvements and reform.
The overall aim should be to understand the innovation activity in the technology domain and the different ways to observe patterns in relation to diffusion of innovation in different jurisdictions as mentioned before in order to bring about significant change the technology must be developed specifically for a country or region, taking into consideration all the local factors.
By NAZINA BELLE
Buzzle; 2015. Causes of Air Pollution.[Website] Available at< http://www.buzzle.com/articles/causes-of-air-pollution.html%5Baccessed on 16 February, 2015].
Chemistry Pre-Lab; 2015. Impact of Air Pollution on Human Health .[Website] Available at< http://njcmr.njit.edu/distils/lab/Air_html/impact.htm#envi> [accessed on 16 February, 2015].
Clean Air Strategic Alliance; 2015. Sulphuric Oxides .[Website] Availableat<http://dwb.unl.edu/teacher/nsf/c09/c09links/www.casahome.org/sulphur.htm> [accessed on 18 February, 2015].
Encyclopaedia Britannica; 2015. Methane [Website] Available at< http://www.britannica.com/EBchecked/topic/378264/methane> [accessed on 18 February, 2015].
NASA; 2015. Exploring the Carbon Cycle: Sources and Sinks [Website] Available at< http://ete.cet.edu/gcc/?/globaltemp_carbon_cycle/> [accessed on 19 February, 2015].
National Geosciences Data Base of Iran; 2015. Air Pollution.[Website] Available at< http://www.ngdir.ir/geolab/GeoLabExp.asp?PID=614 [accessed on 16 February, 2015].
OSHA; 2015. OSHA Factsheet Carbon Monoxide .[Website] Available at< https://www.osha.gov/OshDoc/data_General_Facts/carbonmonoxide-factsheet.pdf %5Baccessed on 16 February, 2015].
United States Environmental Protection Agency; 2012. Nitrogen Dioxide.[Website] Available at< http://www.epa.gov/airtrends/aqtrnd95/no2.html> [accessed on 18 February, 2015].
United States Environmental Protection Agency; 2012. Control Strategies.[Website] Available at<http://www.epa.gov/airquality/aqmportal/management/control_strategies.ht m> [accessed on 18 February, 2015].
Ying, L; 2011. Causes of Air Pollution in Singapore .[Website] Available at< http://filter-the-fumes.blogspot.com/2011/01/causes-of-air-pollution-in-singapore.html> [accessed on 16 February, 2015].