- Global Abatement of Air Pollution Through Green Technology Routes
- CLASSIFICATION OF AIR POLLUTANTS
- PRIMARY POLLUTANTS
- SECONDARY POLLUTANTS
- CONTRIBUTORS TO AIR POLLUTANTS
- ENVIRONMENT IMPACTS
- ACID RAIN
- INCORPORATION OF TOXINS INTO THE FOOD CHAIN
- OZONE HOLE
- MONTREAL PROTOCOL
- PLANT GROWTH AND CROP PRODUCTION
- ROAD SAFETY
- CLIMATE CHANGE
Global Abatement of Air Pollution Through Green Technology Routes
SIJO FRANCIS1*, REMYA VIJAYAN2, EBEY P. KOSHY3, and BEENA MATHEW4
department of Chemistry, St. Joseph's College, Moolamattom, India
- 2School of Chemical Sciences, Mahatma Gandhi University, Kottayam, India
- 3 Department of Chemistry, St. Joseph's College, Moolamattom, India
- 4School of Chemical Sciences, Mahatma Gandhi University, Kottayam, India
Air pollution seems to be the major unsolved problem of the modem era. This chapter deals with different causes of air pollutions and proposes some possible remedies. The green technological alternatives for the global abatement of air pollution are also suggested. The health problems associated with air contamination were also discussed.
Environment pollution is a fruit of industrialization which shaped the modem lifestyle with the so-called use and throw culture. Nowadays the technological progress without effecting pollution is a risky game. Pollutants are substances emitted by industrial structures and products which are harmful to human beings and animals in particular and the environment at large. The proper functioning of the whole ecosystem is hindered by air pollution because the distribution of air pollutants does not obey boundary conditions since pollutants can travel long distances without any obstruction. Thus, air pollution is a serious ecological issue of the modem world. Consequently, countries began to think to pass pollution prevention act. The United States passed the pollution prevention act in 1990 for preventing the generation of pollutants and then abatement. International bodies such as the World Health Organization and others monitor air pollutions on a global basis.
CLASSIFICATION OF AIR POLLUTANTS
Causes of air pollution may be natural or human-made. Based on the origin, air pollutants are classified into primaiy pollutants and secondary pollutants.
Primary pollutants are pollutants that are either directly emitted from natural sources or from anthropogenic activities. While natural activities such as volcanic eruptions, natural gas emissions, dust storms, seed germination, and marsh gas production are natural sources of primaiy pollutants; anthropogenic activities such as motor vehicle exhaust pipes and the outlet of factories contribute largely to the air pollution are manmade sources of air pollutants. Oxides of carbon (CO), oxides of sulfur (SOx), oxides of nitrogen (NOx), volatile organic compounds, and particulate matter are the main categories of primaiy pollutants.
They are generated by the reaction of primaiy pollutants with other compounds. Ozone, acid rain, hydrocarbons, etc. are examples of secondary pollutants. Ozone is formed in stratosphere when primaiy pollutants such as hydrocarbon, NOx, etc. react with atmospheric oxygen in the presence of sunlight.
CONTRIBUTORS TO AIR POLLUTANTS
Having seen different types of pollutants, let us see now what the contributors to air pollutants are. Modem means of transportation and automobiles are the mam sources of pollution. Coal-buming in automobiles, chimneys of factories, machinery in factories, power plants, cooking in kitchens, building constructions, waste incinerators, forest fires, etc. are also contributing to air pollution. Air may be contaminated by different CO emitted through either incomplete or complete burning of fossil fuels. Greenhouse gases were supplied to the atmosphere by automobile engines. Minerals extraction by using large machines increases the amount of pollutants in air. NO.. were formed in the atmosphere usually from combustion processes and photochemical reactions in the atmosphere. Combustion of sulfur-containing compounds, volcanic activities, smelting of sulfide ores, sulfuric acid manufacturing unit, etc., contribute SOx to the atmosphere. Bioaerosols are clouds of pollutants with the biological origin and are also a thread hr urban areas. Metal particulate matter contains toxic heavy metals like Ni, Fe, Cd, Cr, Pb, etc., which also contribute to air pollution.
Acid rain is one of the environmental impacts resulting from the emission of NO and SO when air is washed out with water. Main contents
of acid rain include sulfuric acid and nitric acid. Torres of agents of acid rain are expelled to air per year. Acid rain destroys monuments, buildings, marble statues, etc. Since, acid rain adversely affects the gr owth of plants and production of crops, the economy of the countries is largely affected by unexpected acid pouring. Besides vegetation and agro-industry, acid rain also affects fishery. Sulfuric acid content along with certain heavy metals destroys fish egg and thus offsprings of different kinds of fishes are destroyed in number and genus. This increases the acidic content in the river and ocean and thus the aquatic life is adversely affected. Acid rain is a great ecological threat that collapses the harmony of nature.
Eutrophication is the overabundance of plant nutrients especially in water bodies. It supports algae to bloom. Fertilizers washed away with soil erosion are mainly responsible for this phenomenon. NPK fertilizers mainly the nitrogenous fertilizers are responsible for this weed growth. Air-bome pollutants mainly sulfur and nitrogen-based pollutants contribute to dissolved nutrients for aquatic weeds. The dissolved oxygen content in water depletes seriously threatens aquatic life. Eutrophication is a natural process leading to aging of lakes. Human activities can greatly accelerate eutrophication in aquatic ecosystems. Emissions of nitrogen oxides from vehicles and other similar sources contribute to the amount of nitrogen entering aquatic ecosystems.1
INCORPORATION OF TOXINS INTO THE FOOD CHAIN
Biomagnification/bioamplification is the increase in the concentration of a toxin in the food chain from the tissues of tolerant organisms at a successively increasing level. For example, shellfish accumulate mercury in their body tissues and become a source of mercury contamination. Minamata accident is due to bioaccumulation of mercury in fish tissues. In the same way, airborne organic pollutants may also enter in multiple maimers into the food chain.
Ozone is 03 which occurs in the stratosphere of the upper atmosphere. It shields our earth from UV-rays emitted from the sun. Ultraviolet A is responsible for photoaging and ultraviolet В is responsible for sunburn. Increase in air pollutants affects human skin adversely. Ultraviolet radiation, polynuclear aromatic hydrocarbons, easily volatile organic compounds, particulate matter, ozone, etc. affect human skin adversely. Exposure to ultraviolet radiation leads to skin aging and skin cancers. UY radiation increases the risk of skin diseases, cataracts, metabolic disorders, and decreases reproduction rates. Skin infection is mainly caused by oxidative stress mechanisms by losing antioxidant defense property of skin. Prolonged exposure of organic air pollutants has profound harmful effects on the skin. Cigarette smoke is also responsible for skin cancers and allergic skin conditions.
Montreal Protocol is an international agreement made in 1987. This is a result of serious discussions made by 28 countries at the Vienna convention for the protection of ozone layer. This protocol controls the production of chemicals that depletes ozone concentration in the atmosphere. Chloro- fluorocarbons from refrigerators, coolants, aerosol sprays produce chlorine atoms that are the major ozone-depleting gases. This treaty entreats countries to reduce the production of ozone-depleting gases.
PLANT GROWTH AND CROP PRODUCTION
Air pollutants like SOx, NOx, particulates, ozone, etc. have toxic effects on vegetation. The retardation of plant growth is caused by air pollution. The ozone exposure increased plant susceptibility to disease, pests, and environmental stresses. The crop and forest damage can also be caused by UY radiation resulted by ozone depletion. UV-rays damage wheat, cotton, soybean, and com. These crops show reduced yields under exposure to ozone and thus reduce the crop production. Soil fertility and water level of soil are affected seriously by air pollution. Plant leaves are scavenged by airborne pollutants.2
Recent studies show that the air quality substantially also affects road safety. Road accidents cause material damages, bodily harm, and even to the loss of life. Air pollution may distract safe driving because many pollutants responsible involved in air pollution cause various harm to the driver, including the affecting the visibility of driving during the drive. The road vehicles themselves are the major source of air pollutants responsible for road accidents. Besides, the volume of vehicles on roads and road accidents rate are interrelated.
The sky darkening and redaction in visibility are the after-effects of smog and fog in industrial areas. Smog is a type of air pollution. Smog is formed in a wanner climate where the presence of UY radiation is high. Photochemical smog originates from vehicle exhausts mainly from nitric oxide and hydrocarbons as well as from other industrial sources. This also affects road safety. Haze, which constitutes a part of air pollution, is also a threat to road safety. Haze is produced by NOx and SOx combined with smoke from industries/wildfires. Haze-causing particles can be carried by the wind to a large distance. Thick blanket of haze particles affects photosynthesis by diminishing the availability of sunlight essential for it and reduce road safety. Thus, we can say that air quality is of at most importance in road safety. Reducing air pollution levels will decrease the rate of road accidents.3
Air pollutants such as greenhouse gases adversely affect the climatic conditions of the globe. Major greenhouse gases are carbon dioxide (CO,) and methane (CH4). CO,possesses the first position among the greenhouse effect. To control drastic climate change, greenhouse-gas emissions must be reduced. Reduction of fossil-fuel use is of the highest priority. CO, shoots up the atmospheric temperature. Increase in temperature which results in rising sea levels, extreme weather, and the increase of infectious and heat-related diseases are the main after-effects of global warming Air pollution increases the risk for environmental catastrophes. It is seen that most of the flooded regions are rich in aerosols. The particulates, dust, and soot can produce intense rain, severe storms, and snowfall. According to the study by United States government, the particulate matter and the tiny solid pollutants coming from power plants can cause wildfires.