Environmental Pollution - Class IX

Greenhouse gases trap heat and make the planet warmer causes global warming. Human activities are responsible for almost all of the increase in greenhouse gases in the atmosphere over the last 150 years and USA is responsible for releasing largest amount of greenhouse gases. The primary sources of greenhouse gases in USA are electricity production (31%), transportation (27%), industry (21%), commercial and residential (12%) etc.

There are five major types of pollution:
1. Air pollution

Geochemical cycle refers to the chemical interactions in surface reservoirs such as the atmosphere, hydrosphere, lithosphere, and biosphere. Pollution is any undesirable change in physical, chemical or biological characteristics of air, land, water or soil. Agents that bring about such an undesirable change are called as pollutants. Local flora and fauna is also affected by the pollutant. Balance of nature also gets disturbed as pollutant affects the living organism and composition of gases in the atmosphere.

Pollutant is a substance which when introduced into the environment has undesired effects. Pollutant causes long- or short-term damage by changing the environmental factors. Some pollutants are biodegradable and therefore do not persist in the environment in the long term. However, the degradation products of some pollutants are themselves polluting such as the products DDE and DDD produced from degradation of DDT.

• Pollution is the introduction of contaminants into the natural environment that causes adverse change. 
• Pollution can take the form of chemical substances or energy, such as noise, heat or light. Pollutants, the components of pollution, can be either foreign substances/energies or naturally occurring contaminants. 
• Hence, Introduction of contaminants into an environment that causes instability, disorder, harm or discomfort to the ecosystem i.e, physical systems or living organisms, is called Pollution.
• So, the correct answer is 'Pollution'.

Fuel-powered ecosystems (industrialized systems) rely on fossil fuels, which generate significant economic output but are also the primary source of environmental pollution.

Carbon monoxide (CO) is a major byproduct of incomplete combustion in internal combustion engines, making it the most significant pollutant from automobile exhausts.

Non- biodegradable compounds such as DDT and mercury accumulate in the tissues of organisms that consume them since they do not break down easily. As a result, when they, in turn, are consumed by secondary organisms their amount magnifies. This is known as biomagnification. Hence, such non-biodegradable compounds affect the organisms of higher trophic level more. So, the correct option is 'heavy metal salts and non-biodegradable phenolic compounds'.

Detergents often contain phosphates (which cause eutrophication), surfactants like sulphonated hydrocarbons, and other organic additives, all of which contribute to water pollution.

Atmospheric pollutants have a negative effect on the plants; they can have direct toxic effects, or indirectly by changing soil pH followed by solubilization of toxic salts of metals like aluminium. The particulate matters have a negative mechanical effect. They cover the leaf blade reducing light penetration and blocking the opening of stomata. These influence strongly the process of photosynthesis whose rate declines sharply. Also, the leaves of the trees have an important role in the retention of the particulate matters; they are mostly affected when the wet and dry atmospheric deposition increase.

Dry deposition refers to the process where fine dust particles, aerosols, and gases settle out of the atmosphere onto surfaces without the presence of precipitation.

Environmental pollution is defined as the introduction of harmful materials or unfavorable alterations into the environment that cause adverse effects on living organisms.

Temperature inversion traps pollutants near the ground by preventing vertical mixing, which leads to a buildup and maximization of pollutant concentrations in the lower atmosphere.

PM10 and PM2.5 refer to particulate matter with diameters of 10 micrometers or less and 2.5 micrometers or less, respectively, which are standard metrics for measuring air pollution.

Fly ash is produced due to the incomplete burning or combustion of the fossil fuels. The ash contains the carbon particles or flecks which are suspended in the air. The pollutants which are released from the exhaust of the motor vehicle are particulate matter, SO$ _2$, NO$ _x$, CO, etc. 

Pollution disrupts the natural equilibrium of ecosystems, affecting the interactions between biotic and abiotic components before specific impacts on climate or fauna are observed.

Lichens are well-known bioindicators sensitive to SO2, CO is a toxic pollutant, and not all pollutants are waste (some are useful substances in the wrong place).

Asbestos is widely used in shipbuilding, commercial product manufacturing, power plants, and construction. It causes air pollution. Asbestos fibers are easily inhaled because they are microscopic. Once inhaled, the fibers cling to the respiratory system, including the lining of the lungs and inner cavity tissue. Asbestos fibers are rigid hence they become lodged in the soft internal tissue of the respiratory system. They cannot be easily expelled or broken down by the body thus damaging the lungs. Thus the correct answer is option A.

Bronchitis is caused due to infection and swollening of the bronchial tubes which carries air to the lungs. It is of two types i.e., acute and chronic. The acute is of mild type and caused by virus, even by bacteria and also exposure to substances that irritate the lungs, such as tobacco smoke, dust, fumes, vapors, and air pollution.

Fluoride toxicity in plants typically manifests as necrosis (tissue death) and chlorosis (yellowing) starting at the leaf margins and tips, where fluoride accumulates due to transpiration.

The pollution indicators are the agents which determine the presence of the pollutant. There is a change in the structure of the pollution indicators when there is pollutant present in the environment. The indicators are sensitive to pollution. The plants which are used as the pollution indicators show bleaching, stunting or death due to the presence of the pollutant.

The labours who are working in the cement factories suffer from respiratory disorders. Cement contains silica and the cement is present in the powdered form which readily gets into the atmosphere. The cement particles when inhaled results in cytosilicosis. This is a disease in which there is an accumulation of silica in the cells of the body. 

Sulphur dioxide form a a very harmful gas. It is also responsible for the formation of acid rain and a potent atmospheric pollutant. People with asthma and similar bronchial conditions are at a greater risk through sulphur dioxide poisoning. It is also linked with cardio vascular diseases.

Aerosols are minute organic or inorganic particles suspended in the atmosphere. These are the colloids of solid and liquids suspended in air. Their scattering of sunlight can reduce visibility.

Epiphytic lichens lack roots and absorb nutrients and water directly from the air, making them highly sensitive to air pollutants like SO2, which damages their chlorophyll.

Heat in the form of thermal waste waters flowing out of electricity-generating units, e.g., thermal power plants, constitute important category of pollutants. Thermal waste water eliminates or reduces the number of organisms sensitive to high temperature, and may damage the indigenous flora and fauna. Noise is an unwanted sound, or sound which produces unpleasant effects and discomfort on the ears and reduces the quality of life. Radiation, that is given off by nuclear waste is extremely damaging to organisms, because it causes mutations at a very high rate. At high doses, nuclear radiation is lethal but at lower doses, it creates various disorders, the most frequent of all being cancer. All the three are pollutants but does not have any physical weight.  

Particulate matter is the small and fine solid particles present in the atmosphere. These suspended particles may be due to aerosols, dust particles, particles of carbon or other elements, etc. When the amount of these particles and the pollutants in the atmosphere are higher, there is a reduction in the intensity of the sunlight reaching this region. Due to the air pollution in the cities, there is less intensity of the light which is received compared to the villages. 

Primary pollutants are emitted directly from sources, while secondary pollutants like ozone are formed in the atmosphere through chemical reactions between primary pollutants (like NOx and VOCs) and sunlight.

Carbon dioxide is described as pollutant or not a pollutant depending on the source of emission. The carbon dioxide which is released from the plants and animals as the end product of the respiration is not considered as a pollutant. The carbon dioxide gas which is released as the exhausts and emissions from the industries causes pollution and are referred as a pollutant. The main role of the gas is in increasing the temperature of Earth and so these are not pollutants

Industries are the chief cases of water, soil and air pollution. All the major cities of India are situated on the banks of some river or the others. Some of the commonly produced industrial waste are boiled ash, metal scraps etc. 

Ozone is formed through reactions between the primary nitrogen oxides and hydrocarbons in the presence of sunlight. It is a gaseous pollutant. Particulate matter consists of soot, flash, dust of various types, fur, hair, spores etc. They are classified into settleable and suspended particulate matter. Thus, the correct answer is option B.

There are five major types of pollution
1.air pollution
2.water pollution
3.soil pollution
4.radiation
5.noise

Pollution is the addition of any such constituent to air,water or land which deteriorate the natural quity of the environment. And Pollutant is any such constituent which causes pollutant.

The air pollution is basically of two types:
1) Gaseous pollution: harmful gases given out from a variety of sources.
2) Particulate pollution: particles such as those of dust, smoke, mining, stone drilling, wearing of rubber types of motor vehicles.

Pollution is the addition of any such constituent to air, water or land which deteriorates the natural equality of the environment.Pollutant is any such constituent which causes pollution. It degrades the quality of the environment.

Pollutant is the addition of any such constituent to air,water or land which deteriorate the natural quality of the environment.

Environment is said to be contaminated when there is introduction of some unwanted contaminant in the natural environment. There are certain limitations to the presence of these contaminant upto to which it is considered to be safe. Increase in the level of these would be considered to be polluted.

Natural pollution comes from natural sources like release of methane by cattle and paddy fields, carbon dioxide from plants and animals, dust storms, nitrogen oxides, ozone, volcanic eruptions, emission of natural gas, sol erosion, ultraviolet rays,etc. Mercury is not a cause of natural pollution.

Primary pollutants persist in the form they are released in the environment. Secondary pollutants are formed by reaction amongst the primary pollutants. Secondary pollutant are more toxic than primary pollutants. DDT is a primary pollutant.

Benzopyrene is a polycyclic aromatic hydrocarbon found in smoke and soot; it is a well-documented carcinogen and is considered an environmental effluent.

Biomagnification refers to the increasing concentration of a substance in the tissues of organisms at successively higher levels in a food chain. Mercury (Hg) compounds are classic examples of persistent pollutants that biomagnify.

The environment is our surrounding. This includes living and non-living things around us. The non-living components of the environment are land, water and air. The living components are plants and animals. All plants and animals adjust to the environment in which they are born and live. A change in any component of the environment may cause discomfort and affect normal life. Any unfavourable change or degradation in the environment is known as environmental pollution. Thus, the correct answer is option B.

In the modern world, to save resources for the next generation it is very important to reuse the goods available. Plastic, paper and water are the easiest substances that could be reused rather than dumping them out.

Carbon monoxide binds to hemoglobin with a much higher affinity than oxygen, forming carboxyhemoglobin, which prevents the blood from transporting oxygen to tissues.

The best known example of heavy metal pollution in the oceans took place when Japanese factory discharged a significant amount of mercury metal into Minamata Bay, contaminating the fish stocks there. By that time, many local people had eaten the fish and around 2000 were poisoned. Hundreds of people were left dead or disabled.

Introduction of an undesired component in the natural ecosystem is called as pollution. The undesired component is called as pollutant.

The release of waste products into the nearby lake caused various problems which led to the failure of the embryo development. This can happen because of the following reasons:

• The chemicals released from the factory caused some mutations in the embryos which led to the failure in development.
  
• The birds might not have taken care of the eggs and they might have failed to exhibit proper nesting behavior.
  
• The chemicals in the contaminated lake water might have affected the development of the birds.
  
• The chemicals from the lake might have affected the sperms of the males and so they were unable to fertilize the eggs. Thus, the correct answer is option E.
  

The producer is required initially for the availability of organic food. The consumer will consume the organic food prepared by the producer and will also make an equilibrium in the environment by being a part of the nutrient cycle. A decomposer will breakdown the dead organic from the dead bodies of producer and consumer. So, these are required in a functional ecosystem. The presence of polluter is undesirable as it would distort the environment, making it difficult for the biotic and abiotic components to keep their sustenance.

Anthropogenic air pollutants are man-made pollutants like emissions, burning of fossil fuels, mining, etc. Sulpur dioxide is produced in large quantities during the smelting of metallic ores and the burning of petroleum and coal in industries and by motor vehicles. It is cause of acid rain