ENVIRONMENTAL POLLUTION: ECOLOGICAL IMBALANCE AND RELATED HEALTH HAZARDS
Environment in its widest sense is called: Biosphere which consists of earth’s crust, the surrounding Atmosphere and various forms of life that exist in the zone 600 meters above and 10,000 meters below the sea level. The Biosphere is too large and so complex that it is divided into smaller units of Ecosystem.
Ecosystem is defined as the plants, animals and the microorganisms that live in a defined zone and the physical factors present i.e. soil water and air. Within an ecosystem, there exist a dynamic interrelationship between the living forms and their physical environment. The balanced operation of natural cycles and the ecosystem contribute to the stability of whole biosphere, which is fundamental to the continued co-existence and development of life on earth. The general impact of Pollution within an Ecosystem is the disturbance/alteration in the prevailing congenial balance of natural cycles which operate in atmosphere on the land and in water.
Various natural cycles that operate in the Environment are as follows:
Water cycle (Hydrological cycle): Water as the vital ingredient of life support system in nature is balanced by continuing processes of evaporation, transpiration, precipitation, surface runoff & ground water movements.
Nitrogen Cycle: Nitrogen is an essential element of most biological components. It is largely required in Protein Synthesis. By nitrogen uptake from the air, plants produces protein by the nitrogen fixation microbial. The nitrogen chain thus maintains nitrogen in the Environment.
Phospahate Cycle: Organophosphates are essential for the cell division involving the production of DNA & RNA. Phosphates are required for the growth and maintenance of animal bones and teeth. Plant and animal nutrition involve energy metabolic pathways with chemical reaction involving utilization of ATP. The natural phosphate cycles can be substantially affected by the Pollution. The agriculture industry using heavy amount of phosphate fertilizers causes large scale contamination in the sewage and on surface. Excessive phosphate discharge may cause growth of algae in lakes and in stagnant water which in turn deplete the water oxygen content; thus disrupting the whole natural chains.
Sulphur Chain: Plants and animals require continuous supply of sulphur and its compounds for the synthesis of certain amino acids and proteins. Exchange of sulphur takes place within the ecosystem through additives of so-called sulphur bacteria which converts sulphites into sulphate for the use in another protein synthesis. In polluted water there may be anaerobic conditions with no dissolved oxygen present and thus bacteria decay action produces obnoxious H2S and deposits of FeS.
Oxygen Cycle: Oxygen being the major component of all living organisms; adequate supply of oxygen, therefore is quite necessary for the continued life cycle on the biosphere. Oxygen is required by plants, animals and human beings for aerobic respiration & enzyme oxidation of the organic foodstuffs for sustenance of growth and general metabolism. There is continuous exchange of oxygen between atmosphere (20.9%) and all areas of water and earth. The total amount of oxygen in biosphere is thus kept constant by such oxygen cycle. Pollution effects may cause deficiency of oxygen in localized aquatic environs.
Food Chains and Webs: In an ecosystem, groups of organisms and microorganisms of plants and animals are interdependent in respect of food and energy. Someone’s fruits or excreta may be other’s food and vice versa. In an aquatic ecosystem, food chain is affected by changes in the environment such as variations in water, temp & oxygen content as well as the nutrient supply which can alter population of link species. Both the foods and web can be affected by pollution which cause changes in the ecological balance of ecosystem. The presence of toxicological wastes such as pesticides can reduce or completely eliminate the population of some link species and thus severely disrupt the food web. In fresh water, the presence of polluted organic matter as sewage or silage effluent reduce the dissolved oxygen content of water which reduces or eliminate those link species which require aerobic conditions and can promote the increase of those link species which do not require highly oxygenated water.
Environment is a question of our survival and continued coexistence on this planet. Environment knows only the geographical not the political boundaries. Noted environmentalist Re Dubos: think globally act locally. Unscientific, unforeseen, and careless urbanization, industrialization, agricultural advancements are major threats to the stability of Biosphere. Thus the principle causes of environmental degradation had been the need of poor, greed of rich and careless application of technology. Pollution is therefore, a manmade component of our natural environment. Thus the four primary consumptive uses namely, irrigation, power production, domestic and industrial, contribute such problem.
Pollution: A substance or effect which adversely alters the environment by changing the growth rate of species, interferes with food chains, is toxic or interfere with health, comfort or property values of the people. Thus pollution causes degradation or damage to the natural functions of the Biosphere.
Hazardous Substances: Any substance which can adversely affect the health and wellbeing of mankind and his environment either by improper handling or by natural contact. Such substances can be chemicals, microorganisms (microbes or pathogens). Hazardous chemicals cover a broad range of groups e.g. poisons or toxic agents, corrosive chemicals, flammable materials & materials in which dangerous heat buildup occurs on storage.
The importance & existence of pollution in the environment as a national and or global problem was not generally recognized until 1960s. Major Indian environmental problems include denundation of forests, overgrazing, sewage pollution and communicable diseases etc. Nothing has ever focused the attention of mankind so clearly & deeply as the environmental crisis. The life support system for man and other living things are being threatened by the ongoing environmental degradation at an alarming pace.
Since our societies mainly depend on chemicals, there are more than five million chemical substances with an average increase of one thousand new more chemicals annually in order to meet the challenging needs of the present day heavily industrialized society. There are now around 25,000 occupational chemicals with potential mutagenic character in the list of around 10,000 potentially toxic chemicals and substances causing ecological disruption & effects on health. Hence, we re regularly being faced with the environmental degradation problems such as Acid Rain, extensive contamination of surface and ground water, severe air pollution, uncontrolled hazardous waste sites, long range transport of deadly pesticides, estuarine and coastal water pollution, radioactive radiation hazards, occupational hazards, and largely growing problems of Green house effect, Global Warming and threat to protective stratospheric ozone layer are the major global environmental concerns.
Air pollution: More than 300 m tones of pollutants are emitted annually, whereas India alone contributes to more than 10 m tones in the form of particulates such as CO, SO2, hydrocarbons etc. Combustion of fuel is the largest single category of air pollution sources. High emissions, stagnant weather patterns and topography like valleys can cause rapid buildup of air pollutants with severe tragedy. The most ubiquitous air pollutants include SO2, NOX, CO, CxHy, Lead,O3. Particulates of So2 and NOx are the principal precursors of acid deposition/acid rain. As a matter of fact, whatever we take daily, 80% of it is air and we breathe up to nearly 22,000 times inhaling about 16 kg of such polluted air into the body.
Air pollution causes mainly the respiratory and cardiovascular diseases including lung cancer and increased susceptibility to infectious diseases. Some particulates are of a size which may be breathed deep into lungs, some may be lodged in the alveoli – the terminal sacs of respiratory tract as interfaces through which gases are exchanged between air and blood. These particulates may consist of soot permeated with organic inhalation of acid aerosols. Ozone and associated air pollutants may cause adverse effects on health particularly to sensitive population like children, the elderly people with chronic respiratory illness.
In the air pollutants, there are some chemicals including polycyclic aromatic hydrocarbons which are proven carcinogenic in human being. A group of chemicals in diesel exhaust such as nitropyrenes account for up to 30% of mutagenic activity. Studies revealed that it may take up to 20 yrs of exposure or more for a truck, bus or railway engine driver to develop the cancer. The gasoline (petrol) with tetraethyl lead has now been fully replaced by lead free ingredient.
In addition to human health problems, damage to forest and agriculture crop is largely due to air pollution. Combination of air pollutants including acid deposition, SO2,NOx, O3 and heavy metal particulates are joint factors for denundation of forests. NOx besides forming acid rain also produces O3 in biosphere, the known plant pathogen. Peroxyacetyl Nitrate (PAN) causes chlorosis and brown necrosis in the leaf of groundnut. Fluorosis causes necrosis in the grapes crop. Acid rain a consequence of air pollution can leach lead, copper and asbestos from distribution system pipes. Toxic heavy metals e.g. Hg and Pb can be mobilized from soils into underground drinking water supplies or surface reservoir. SO2 and acid precipitation corrosion of metals and react with lime stone, marble and exterior coatings to erode surface. Even a small quantity of SO2 gas is enough to corrode i.e. there is no safe limit for SO2 to sensitive plant parts and buildings.
Forestry and the Environment
There are 12 Indian Biosphere reserves, above 45,000 plant species and 65,000 animal species in India which include 50,000 species of insects and 2,000 species of birds. For a healthy and balanced environment, the survival and maintenance of such living forms is a vital necessity. Trees not only serve as support system to mankind and other animals, but keep environment balanced for the sustenance of life on earth. Saptashati of the Purana predicted: so long as this earth has forests, gardens, lakes, and great mountains, you and your children will survive. Trees soak polluted air and releases carbohydrates and oxygen. Forests also balance rains, moderate weather and conserve soil and water, help prevent floods and droughts and provide shelter to wildlife; wood, timber and food to mankind.
Deforestation as a cause of ecological degradation (as environmental problem) since past two decades has received maximum public attention. The destruction of forest started since 2nd world war. More than 50% of the forests had already been wiped out, mainly in Asian continent. India is the world’s worst hit country in deforestation. Besides more than 15% as country’s share of global population, India has hardly 1% of the global forest area. National Remote Sensing Agency (NRSA) is closely monitoring the forest status.
The valuable assets of a tree (plant) are shown as follows:
A 50 yr old tree serves the mankind by worth over Rs 2 million,
A peepal tree replaces approx. 2,252 kg polluted air through 1713 kg oxygen
during its lifetime, sufficient enough for as many as 6 lakh people,
One hectare of forest consumes 3 metric tones of polluted air and provide 2
million tones of oxygen,
One medium sized tree can take CO2 given out by 2 families and provide
oxygen for them,
Towns without avenue trees have 4 to 5 times more dust particles in the
atmosphere than the towns having avenue trees.
Deforestation causes degradation of land making unsuitable for cultivation. Excessive soil erosion forms ravines, water becomes polluted and scarce. Timber need, paper industry, and cutting trees for construction of dams, plants and heavy projects are key factors of deforestation. The opencast mining of Kudremukh in western ghats resulted in the removal of top soil and large scale of deforestation. The process of deforestation is also brought about by Laterisation (due to heavy rainfall and high temperature, most of the organic matters get breakdown and leached out of the top soil). Thus, due to laterisation, Ca, Mg and silica are leached out and the oxides of Al and Fe increases on soil and so soil becomes acidic in nature.
In India, out of about 15,000 species of higher plants,1500-2000 are either under threat or rare occurrence. Plants are very good indicators ofair pollution. Foliage of trees and plants exhibit the most obvious effect of air pollution. Injury to plants, bleaching of green parts (chlorosis), death of circumscribed tissues are visible symptoms on plants exposed to pollutants. Among the plants that exhibit such characteristics are – siser, cassia, guava, jamun, vegetables like cucumber, brinials, castor, wild apple, wolnut, acracia. Tamarind and margosa plants are also capable of absorbing dust and gaseous particles from the polluted air. The green belt thus acts as sanitary protection to reduce pollution level particularly of the particulates in the air. Special emphasis therefore, should be laid on the plantation of such trees on railway track, roadside and in the industrial belts.
Following major incidents had been noticed as a result of environmental pollution:
1. Mustard gas (bis-2-chloroethylsulphide) was used in the 1st world war for poisoning soldiers. Such gas was latter reported to be carcinogenic to lab animals. Hence, its exposure was possible cause of human cancer;
2. Explosion in West Germany (Opal) in sept 1921 killed 570 people in a chemical plant;
3. A coal dust explosion at Hon Keiko colliery in China in April 1942 killed 1500 people;
4. The tragic fog incident in Dec 1952 in London - a dense fog settled over the city for a week (due to deadlocked volume of air, the city’s furnaces, factories and automobiles pored tones of smoke dust and chemical fumes) turning the fog brown and thin black, visibility fell to a few inches leading to lot of accidents. Millions went through the city with smarting eyes, coughs, nausea and vomiting. Some suffered prolonged illness;
5. In Yokkaichi city of Japan in 1970, 44 people died and more than thousand citizens suffered from lung cancer or from the famous Yokkaichi asthma because of the discharged sulphurous acid;
6. On Dec 27, 1975 an explosion occurred in Chasnala (India) mining killing 430 people;
7. In 1976, an explosion sent highly toxic dioxin over Northern Italian City (Seveso) forcing evacuation of residents, killing over 100 animals, and causing skin cancer to nearly 200 people;
8. In 1979, an estimated 300 people died from Anthak after accident at the chemical and Biological warfare plant in Novosibirsk (USSR);
9. On midnight of Dec 3, 1984 the deadly methylisocyanate (MIC) gas leaked from the storage tank of Union Carbide factory in Bhopal (M.P.) which took life of about 3000 people, leaving thousands permanently damaged with long term health hazards including genetic malfunctioning;
10 On April 26, 1986 a major accident occurred at the reactor of Chernobyl (USSR) Nuclear Power station– the largest ever reported accidental release of radioactive material. It resulted into contamination of most agriculture and animal products.
11. Mercury poisoning of fish & its subsequent consumption in Japan caused famed Minamata disease killing hundreds of people;
12. International Development Research Centre (I.D.R.C.) Ottawa claims that more than 10,000 people die of pesticide poisoning every year in the developing countries. In Kerala, 106 deaths occurred by consumption of wheat flour and sugar contaminated with pesticide (folidol). In Udaipur (Rajasthan), aluminium poisoning caused 28 deaths by mistaken consumption;
13. Monkey diseases epidemic in Balthangadi Taluka of S.Canara Distt(Karnataka) in early eighty was due to felling of trees in large areas of virgin forests in Western ghats. Virologists called it Kyasanur Forest Disease (KFD) which killed about 100 people;
14. Oleum gas leakage at Sri Ram Food & Fertilizers factory in Delhi caused nausea and other serious ailments;
15. In the British Agriculture industry, there happened huge loss of life in the Piper Alpha disaster in North Sea;
16. SO2 emissions from coal powered plants in industrial belt and NOx emissions from automobile exhausts have widely destroyed life in lakes in North East and in Canada;
17. The mental development of children in London is reportedly threatened by the widespread poisonous exhaust fumes of motor vehicles;
18. Reportedly, every Bombay citizen spends at least 5 yrs of his life in coughing or suffering from asthma, bronchitis, burning eyes, coarse skin, stiff hair or cold due to acute pollution in winter;
19. Release of organophosphates, pesticides and organomercurial compounds to the Rhine river at Basel (Switzerland) caused by a fire at a chemical warehouse resulted into 10-30 m tones of contaminants washed into river by fighting runoff due to which fish kill extended over 250 km;
20.Acid rain in Bombay (early 80s) caused skin rashes, burning of eyes and faster ageing;
21. Ozone pollution on surface mostly from motor vehicles has destroyed thousands of Pine trees in mountains east of Los Angeles;
22. Tokyo, Los Angeles and Sydney are the world’s smoggiest cities.
23. In a recent survey it has been found that about 800 people in 2 Chinese villages are suffering due to airborne waste from a nearby Pb factory.
Followings are the possible hazardous happenings due to fast degrading ecological balance due to chemical race:
Suspected levels of radio nuclides in foods as fall out of nuclear tests;
Release of many volatile chemicals into ambient environment, many of which are implicated in depletion of stratospheric protective ozone layer. Some of such compounds are suspected cause of human cancer. Decrease of ozone layer due to use of CFCs, nuclear weapons, nuclear and atomic explosions and supersonic jets and increase of CO2 and CH4 in atmosphere greatly affects earth’s biota. Green house effect is suspected to cause Global Warming, drought and weather changes;
There published reports of elevated Pb level in soil and biota near major roadways and industrial complexes;
Common symptoms of exposure to pesticides, heavy metals and solvents include inability to concentrate, loss of memory, depression, anxiety, restlessness, confusion, sleep disturbances from insomnia to somnambulism, irritability, headaches and weakness;
High incidence of neuropsychiatric disability to workers in printing industry due to exposure of organic solvents;
Risk of cancer from the use of Tar Bitumen in road works mainly to its workers;
W.H.O. in a Bombay study reported that motorists are more prone to cancer and other lung diseases;
Lung cancer is possibly related to various jobs in Rubber industry;
Occurrence of pancreatic cancer to machining/grinding & metal industry workers;
Coronary heart diseases to workers exposed to CS2 in the manufacture of Rayon;
Radon, a naturally occurring radioactive gas through normal decay of Uranium and Thorium found in rocks and soil is the second leading cause of lung cancer;
Risk of lung cancer to asbestos and cement manufacture workers;
Male exposure to heat and female to noise, textile dyes, lead, mercury and cadmium are associated with infertility;
USEPA warned that due to CO2 buildup in the atmosphere, an estimated global temp to 2 C by 2040 and up to 5 C by 2100 could rise;
Ever increasing fleet of super thermal power plants will add substantial amount of acidic gases in atmosphere, so low ash content coal should be used as it contains least amount of dust particles;
Accumulation of potentially toxic elements like Zn and Al weakens the population of beneficial link species like earthworms;
Due to acid rain, deforestation has long been associated with tropical forests in third world countries, but now temperate forests are also found to be victims, thus a heavy loss of timber is speculated;
Excessive manufacture of paper causes heavy destruction of forests;
Chinese Scientists discovered that people living in forest areas have a greater chance of centenarians than others;
Due to highly polluted water (both chemically and bacterial), heavy incidence of epidemiological cases are suspected globally. As per W.H.O. report, bout 90% of diseases are due to water borne;
The unabated race of chemical and nuclear weapons, space shuttles, nuclear and atomic explosions pose much more serious threat to environment & the mankind;
Use of potentially harmful chemicals in furnished goods of routine use, poor hygienic and occupational work conditions and malnutrition adversely affect the health and wellbeing of general public;
Some of the least harmful substances like dyes and dye ingredients of some vital drugs, cosmetics, toiletteries etc may cause severe skin problems on the exposure to sunlight or artificial light due to their photosensitizing potential;
More and more agricultural, Industrial and human wastes produced due to incredible growth of human population pollutes the environment at all levels creating large scale ecological imbalance.
Thus ecological imbalance being caused by both the chemical race (pollution) and deforestation is affecting mankind to the threat of extinction of plant and animal species by human interference, nearly one specie is becoming extinct daily. Mankind is exclusively dependent on 30 plant and 6 animal species. Biosphere poisoning due to man’s economic activity or more correctly due to his bid to conquer is already causing a fast disappearance of innumerable species.
The problem of pollution, like other problems including over population, food scarcity, arms race etc is a problem affecting the whole mankind in general and oppressed in particular. Environmental pollution merely does not lead to diseases and disasters but can upset the hereditary factors e.g. the birth of maimed off springs. Nuclear radiations not only increase the number of cancer, but produce mutagenic effects in chromosomes which lead to hereditary disorders.
Measures to combat such menace:
Some vehicles offer a unique advantage of monitoring changes on earth, ocean & its atmosphere. Satellites have helped weather forecasting and also in monitoring deforestation, desertification, volcanic activity etc. The state of sea surface, oceanic currents, abundance/occurrence of trace gases in upper atmosphere and situation of depletion of stratospheric ozone layer. Space shuttles could be modified by lower combustion temperature engines to avoid reaction of atmospheric NO and O2, which ultimately destroys the ozone layer. Levels of NOx produced in the burning of coal and heavy oil can be substantially lowered by the selective reducing agents and modified combustions at low temperature.
Likewise, other forms of management e.g. Banking, Industrial, Finance, Manpower etc, it is highly desired to establish a mission of Environmental Management at all levels of human activities. The academic institutions should recognize the plight of precious environment with active participation in interdisciplinary manner. There should be a full fledged faculty of Environmental management at the University level. It should aim to reduce or minimize the impact of human activities on physical and ecological environment. It should be an endeavor to avoid overuse, misuse or abuse of environmental resources. It should work for to conserve what needs to be conserved/ protected and regulate utilization of natural resources to acceptable limits.
Therefore, for the safe environment for today and tomorrow’s generation, environmental education is to be largely imparted a movement of the people, by the people and for the people with following strong message:
Population control and health care;
Water pollution control in lakes, rivers, oceanic systems;
Air pollution control in industrial belts;
Integrated land use planning and watershed management: revegitation of the marginal lands for fodder, firewood, and long term environmental safety;
Development of reliable, nonpolluting renewable energy sources;
Solid waste utilization by recycling as today’s waste is tomorrow’s raw material;
Conservation of Biological Diversity in its totality;
Development of new types of human settlements without congestion and above all affecting the slum conditions;
Radical changes in national/global policies regarding nuclear & chemical warfare and limiting unnecessary explosions, expeditions, and other experiments;
Environmental education and awareness at all levels of society.