CURRENT TOPICS IN ENVIRONMENTAL SCIENCE
Preparing and presenting a topic on some popular subjects for studious purposes before a serious audience calls for some meticulous efforts. Recently I was offered an opportunity of that sort by the
It’s as part of a UGC sponsored refresher course for college teachers of the University.
The event was conducted at Dr. John Mathai Centre of
I was asked to go and make the presentation on 18th September 2009.
The topic chosen was “Current Topics in Environmental Science”.
What I could do was to accept the offer without thinking of anything else, because I consider it as reward on its own.
Whenever we are entrusted with task of giving a detailed presentation on any topic we have to ponder over the subject for some time seriously and conscientiously.
The first thing we have to do is to sum up all the information we have, write(type) it down and read it to form an idea about the level to which we are informed about the subject.
After this locate some authentic sources of information, either in print or over the internet. Short list some individuals who are subject experts in that particular subject.
Consult with everyone possible and refer every source of information accessible from your level and within the time available.
Once again go back to the old initial note you have prepared on the subject and read it.
While reading, incorporate the new information gathered to make it updated. Read the whole thing after you finish. Think of any other reference source to make it really authentic, consult with someone if possible to ensure the final authenticity.
Now you can, prepare the material. Once you are thorough with the topic make note of the important points and make a list and arrange the cues in order. Write it down on a pad or a small flip chart so that glancing at it whenever required you can do a lively presentation.
If you are using a computer go for presentation tools like Powerpoint
It’s good that you read some books on effective presentation modalities and practice the presentation before you actually make it.
Now let me give you a brief description about the presentation I made at the Dr. John Mathai Ctntre,
Under the Heading “Current Topics in Environmental Science” I choose three topics.
Air Pollution, Acid Rain and Asbestosis.
1. Air Pollution.
It’s now a global concern. Because of rapid industrialization and increased human activities the air we breathe in is becoming polluted every moment. It’s figuratively said that if a housefly which lived about 100 years from now is transported to the present time and let loose to live in the present day air the fly will die in that instant of breathing poison. Whether it’s right or wrong it makes clear to us the dangerous levels at which pollution is increasing.
The presentation centered on the theme of decreased plundering of the nature and advocated the theory of taking the bare essentials from the nature during the life. Eat, drink, travel and enjoy things at the expense of natural resources the minimum. Leave a less plundered world to your posterity. Consider other animals and plants as fellow inhabitants who have an equal right on the natural resources as Homo sapiens.
More plants, plants of any sort, means lesser pollution and a better world to live in. So cut as much less trees as possible.
The main air pollutants are dusts, pollen grains, hazardous gases etc. Increased human activity and an alarming over population is the difficult to remove causes of the pollution.
Air Pollution though a global phenomenon the magnitudes of it in
Industrial emissions and burning of fossil fuels are cited to be major causes. Deforestation and forest fires are also matters of great concern in this regard.
If the present trend goes like this by 2025, three times as many people in
The accelerated industrialization and the increase in human activities precipitated as a consequence, which is multiplied by an increased human population is making the universe untidier than ever.
Causes of Air Pollution
Burning of fossil fuels, coal, petroleum products, natural gas and biomass are the main causes. The burning of these substances releases harmful chemicals like sulfur, Carbon dioxide etc to the air. Tiny particulates of the unburned fuel are also pollutants.
In
Air pollution once was considered to be an urbane phenomenon, where as even remote villages now are no exemption.
Air pollution can cause a lot of unhealthy conditions in human beings and other living things. In human beings they are mostly affecting the Respiratory tract. Bronchitis, Bronchial Asthma, Lung Cancer etc are some well known diseases caused by air pollution. It can increase the infant mortality rates considerably. More than everything it can help precipitating the malaise of unhealthy living surroundings, which is hard to remove.
Air pollution not only affects human beings. It destroys everything, it damages the environment altogether. Many beautiful locations on the face of earth has been damaged by air pollution and its after effects. Gulin in
Biomass combustion and forest fires also are causes of large scale air pollution. This releases harmful substances like tar, carbon, ash to the atmosphere. Perhaps we may not be aware of the fact that half of
Controlling Air Pollution
Reduced uses of fossil fuels is the most effective way to control air pollution. Usage of cleaner fuels is another method. Adopting more efficient fuel usage modalities is another suggestion. Modification of the fuels is yet another modality to render the fuels less polluting. The biogas digesters used in Biomass burning is an example. Thus it can be turned to cleaner burning fuels. Sometimes the biomass is converted to briquettes to make it more effective as a fuel and to render it less polluting. Using electricity or natural gases also can be an effective alternative sometimes. Uses of low sulfur coals and choosing the best form of the available fuels also helps to combat the problem of air pollution.
Educating the laymen on the hazards of air pollution and the ways to overcome it is very important. The masses should be given apt information of these subjects and their cooperation ensured.
We should arrive at a global consensus, national priorities should be set. A global governing body should be formed and all nations must readily cooperate with its directives. Research and development initiatives should be set up under the governance of this body and an international fund should be raised to support this kind of endeavours at different parts of the world.
We will now move on to the second topic.
2. Acid Rain
Acid Rain was the next topic selected. Before going any further let’s understand what is meant by the term Environmental Science. It’s the scientific study of the ways in which the biological, physical and chemical components of the environment interact with and it also deals with the relation that exists between them. The term Ecology is sometimes used as a substitute of the term, but there exists a subtle difference between the two.
Ecology is the study of interactions of living organisms with their environment and with other living organisms.
Yet another term with which we should get familiarized with is “Environmental Technology”. It’s defined as the application of environmental science and theories of sustainable development for the purpose of environmental conservation by curbing negative impacts of human-environment interaction and thus protecting the natural environment.
With this introduction let’s move onto our subject “Acid Rain”
What is Acid Rain
Any form of heaven to earth precipitation of water which is acidic in nature is called acid rain. Sulfur and Nitrogen in industrial emissions and automobile exhausts combines with other substances in the atmosphere to turn the rain acidic.
Acid Rain is detrimental to plants and animals and on infrastructure naturally existing or built by men.
See what havoc acid rain has wrought on a tree
In its purest form rain water is just like distilled water; as pure as it can be; neutral in pH; no carbon dioxide dissolved and almost colourless and odourless. When rain water fall through atmosphere many particles gets suspended or dissolved in it. Dust particles, pollen grains, carbon dioxide etc are some of them. This process can alter the pH of the rain water. Lightning and Volcanic eruptions also can alter the pH of rain water.
Carbon dioxide present or precipitated into the atmosphere combines with water to form carbonic acid (H2CO3).
The chemical reaction can be represented like this:
H2O(l) + CO2(g) -> H2CO3(aq)
Carbonic acid is a weak acid and the reaction is a reversible one.
Carbonic acid in water ionizes to form low concentration of carbonate and hydronium ions.
The reaction is represented as:
2H2O(l) + H2CO3(aq) = CO32-(aq) + 2H30+(aq)
Thus the pH of the rain water becomes something between 6 and 5.2, and this level of acidity is considered to be not dangerous.
Let’s have a clearer idea about the pH factor.
The normal rain water in its pure form will have a pH of 7. The sea water is a bit alkaline in nature and will have a pH around 8. Rain water which is having a pH between 7 and 5.6 is considered to be normal. The rain is termed acidic when the pH reaches between 5.2 and 3. Sometimes acid rains with a pH of 2 also are reported in some parts of the world. The battery acid is having a pH of 2 to 1.
Let us see when and how rain water attains dangerous pH levels. If the pH of rain water is above 5.2 it’s considered to be dangerous.
Gaseous oxides of Sulfur and Nitrogen, phosphoric acid or hydrochloric acid mists present in the air, etc renders the rain water highly acidic. Nitrogen is the major component of atmospheric air. So a precipitation of acidic water in the atmosphere by the dissolution of acids formed, and its downward pour is called acid rain
It’s precipitated on to earth in the form of rain, fog, snow, sleet, hailstorm, freezing rain and dew.
Chemistry of Acid Rain
Sulfuric acid and Nitric acid are the main constituents of acid rain. Let’s now see how sulfuric acid is formed in the atmosphere.
n Sulfur released into the atmosphere combines with atmospheric oxygen to form sulfur dioxide (SO2)
n Sulfur dioxide reacts with atmospheric water to form sulfurous acid - SO2(g) + H20(l) = H2SO3(aq)
n Sulfurous acid is also present in acid rain.
n Sulfur dioxide gradually oxidizes to form sulfur trioxide (SO3) - 2SO2(g) + O2(g) = 2SO3(g)
n Sulfur trioxide reacts with water to form Sulfuric acid (H2SO4) - SO3(g) + H20(l) = H2SO4(aq)
Now we can see how nitric acid is formed in the atmosphere:
n Nitrogen combines with atmospheric oxygen to form nitrogen dioxide (NO2)
n Nitrogen dioxide reacts with water to form nitrous acid (HNO2) and nitric acid (HNO3) – 2NO2(l) + H2O(l) = HNO2(aq) + HNO3(aq)
Adverse Effects:
On Infrastructures:
Acid rain destroys buildings and monuments by its corrosive effect. The façade of buildings gets corroded and damaged. Monuments gets destroyed, the beauty marred.
Acid rain reacts with the calcium carbonate (CaCo3) to form soluble calcium hydrogen carbonate or calcium bicarbonate, Ca(HCO3)2 - CaCO3 + Acid rain = Ca(HCO3)2(aq)
Calcium carbonate being water soluble gets washed off along with water.
Many buildings and monuments of the world have been affected by the adverse effects of acid rain. Taj Mahal of
Glass window panes on exposure to acid rain gets damaged, crusts gets formed on it and acid also damages or defaces steel monuments, railway lines, bridges and decorative banisters. The painted exteriors of the buildings get totally defaced. Acid weakens leather too.
On Trees and Plants:
Important minerals are washed off by acid rain from the surface of leaves. This causes under nutrition and retarded growth of trees and plants. It damages the bark of trees and exposes the core. So the tree becomes prone to bacterial, fungal and insect attacks more. Acid rain also blocks the micro pores on the leaf surface thus thwarting the uptake of carbon dioxide. This may block the process of photosynthesis completely. It affects the whole food synthesis for the whole living world. Eventually the tree gets totally destroyed.
On Soil
The soil contains a lot of minerals and metals. Absorption of some ingredients may be harmful to the life forms. Alluminium, Mercury, Lead etc a few examples for this. This metals since not soluble in water, are not absorbed by the plants, normally. Thus nature prevents the plants from being poisoned by harmful metals. Acid exposure makes these metals getting converted to water soluble salts of these metals. Thus plants absorb them and cause alluminium, mercury, or lead poisoning. Once it’s being absorbed by the plants it gets into various levels of the food chain. It affects the whole food chain.
These soluble salts along with rain water flows into the rivers and other resources of the water, polluting the whole water body. It can also cause depletion of oxygen from water. The fish can’t respire properly; causes malnutrition and heavy metal poisoning. This paves the way for the entry of these poisonous metals to the other land animals and birds living on the land. Poisonous substances get accumulated in the systems of birds and animals. Levels of poisoning as it goes up in the food chain increase in a geometrical proportion. The concentration of harmful chemicals introduced shows an increasing trend as it goes up in levels of food chain. This increased accumulation of poisonous substances in various levels the food chain are termed biomagnification.
On Human Health
This in turn reaches human systems and produces a lot of harm to the human beings.
Many diseases are caused by the acid rain phenomenon. Lead poisoning, Mercurial poisoning and Alluminium poisoning are caused by acid rain. Acid vapour inhalation cause many respiratory tract diseases. Acid is corrosive and carcinogenic.
Acid rain is potent enough to destroy life on earth. It destroys everything that comes into contact with it. Water bodies of earth, soil, all living beings and the infrastructures are affected by it. It produces ill health to all.
Solutions Suggested:
Reduced use of fossil fuels is the main remedy being suggested. To achieve this we have to practice walking for most of our purposes. We should make it habit to walk whenever we can. Walk for more than one purpose combined. Please don’t go for a walk, you will be taken for a ride. Use share cars or public transport systems whenever you can. Alternative sources of energy must be utilized as much as possible. Energy from geothermals, water, wind and sun must be trapped at a higher percentage. Use of hybrid cars or any equipment which runs on renewable energy have to be used whenever possible. Plant and foster trees at every plausible place.
All individuals must be ready to adapt to the changed situations. They must be educated about the need of adopting conservational measures themselves. Flu gas desulfurizers, wet scrubbers installed in the smoke stacks etc are some measures to better the industrial emissions. Industrial entrepreneurs must be informed about the most prompt conservational modalities from time to time, and cooperation ensured.
Now we will move on to the third topic:
3. Asbestosis:
Asbestosis is a chronic inflammatory disease of the lung. It’s caused by asbestos inhalation. Inhaled asbestos fibers get stuck on the alveolar walls of the lung and cause dyspnea and even lung cancer. Breathing microscopic asbestos fibers over a period of time lodge these fibers firmly into the lungs, leading to lung scarring and a drastic reduction in breathing capacity
It’s very hard to diagnose since the symptoms appear many years after inhalation of asbestos. The disease can turn out to be fatal too.
What is asbestos:
Asbestosis is a naturally occurring mineral in fiber form. There are two types of this mineral: Amphibole and Chrysotile. Amphibole is straight elongated fibers and consists of actinolyte, anthophylite, amosite, corcidolite and tremolite. Chrysotile is the most widely used variety of asbestos. The properties of asbestos include excellent heat resistance, excellent fire resistance, chemical resistance, and it’s excellent non conductor of electricity too. These properties makes it a most preferred insulating material. Asbestos has been mined out since 1800s. Even though the usage was all the more widespread during 1940 through 1980, and a ban on its usage came in 1980 due to the increased incidence of untoward effects.
It was used widely in floor Tiles, roofing, insulation material, pop ceilings, switch boards, paints, insulation for ship boilers and hot water pipes, in clutch and brake-liners of all vehicles, and in a host of other applications
Even when man knew the dangers involved in asbestos usage they continued the usage and a ban was imposed in 1980.
The main problem caused by asbestos exposure is ASBESTOSIS. Mine workers and nearby dwellers of asbestos mines, factory workers, Workers of Shipyards, Construction, Automobile mechanics or any one who frequently handle asbestos products run a high risk of contacting the disease.
Today asbestos is banned in almost all products and handling of old asbestos is regulated. Even with all precautions taken, persons even today are at risk while renovating their homes that contain asbestos in the flooring, roofing, and insulation
After a confirmed asbestos exposure it will take 20 to 40 years for the cardinal signs of the disease to face up. The early symptoms resemble the symptoms of simple bronchial asthma and treatment will be restricted to bronchodilators and steroidal anti-inflammatory drugs.
The symptom complex may include:
n Difficulty in breathing, with the condition getting worse over a period of time
n Constant dry, crackling sound while breathing
n Getting tired after doing very little physical work
n Constant mild to severe pain in the chest
Late detection of the condition makes the treatment difficult and it may affect other parts of the body too. Other complications include Lung cancer, Increased blood-pressure within the lungs, Cardiac complications, Mesothelioma etc. Smokers are more likely to develop lung cancer and mesothelioma.
The scars caused by asbestosis may compress the blood vessels in the alveolar region and cause pulmonary hypertension. This increased blood pressure or hypertension can cause cardiac problems at a later stage.
Mesothelioma:
The Asbestos fibers get into the inner lining of the pleura and may trigger off an unwanted cell growth precipitating a malignant condition called mesothelioma.
Treatment:
The lungs is already in a bad shape. So other respiratory tract infections like Flu, common cold etc can affect the patient more easily. So a vaccination against the commonly encountered bacterial and viral infection will be ideal and form the essential ingredient of the asbestosis management.
Medication include anti hypertensives, bronchodilators, platelet activation inhibitors (blood thinners) etc. Immediate cessation of smoking g is advised if he is a smoker.
PLEASE DON’T GIVE UP SMOKING
For a grave reason like Asbestosis. Give it up for some simpler reasons, for the pleasure that’s life. Quit smoking for others around you.
Before I stop this presentation Let me place some food for thought. Please ideate on the following topics and mail it to me. I would like to open a discussion forum on these topics.
Food for Thought:
1. According to you which is the most suitable Funeral Modality? Why?
2. Construction of Roads is a perennial denial of the right to live?
3.The overhead electrical lines is an Ecological Problem?
WISHING YOU ALL A HAPPIER, HEALTHIER LIFE.
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