AIOU Course Code 1422-2 Solved Assignments Spring 2022

Course: Environmental Pollution (1422)     

Level: BA (General) (Renamed as Associate Degree)              Semester: Spring, 2022

Assignment no 2



How the ozone layer can depleted? Describe the effect of ozone depletion on vegetation and other living environment.

Ultraviolet (UV) radiation is divided into three categories of increasing energy: UV-A, UV-B and UV-C. UV-A is a low energy form of UV and has only minimal biological effects. UV-B, a higher energy form, causes the most damage to living organisms and materials. UV-C is absorbed by the oxygen in the atmosphere and never reaches us.

Effects on the environment

Ultraviolet radiation not only affects humans, but wildlife as well. Excessive UV-B inhibits the growth processes of almost all green plants. There is concern that ozone depletion may lead to a loss of plant species and reduce global food supply. Any change in the balance of plant species can have serious effects, since all life is interconnected. Plants form the basis of the food web, prevent soil erosion and water loss, and are the primary producers of oxygen and a primary sink (storage site) for carbon dioxide.

Picture of the sun through flowers

UV-B causes cancer in domestic animals similar to those observed in humans. Although most animals have greater protection from UV-B because of their heavy coats and skin pigmentation, they cannot be artificially protected from UV-B on a large scale. Eyes and exposed parts of the body are most at risk.The ozone layer acts as a natural filter, absorbing most of the sun’s burning ultraviolet (UV) rays. Stratospheric ozone depletion leads to an increase in UV-B that reach the earth’s surface, where it can disrupt biological processes and damage a number of materials.

The fact that UV-B can cause biological effects is well demonstrated by the familiar sunburn that follows overexposure to the sun. However the health impacts of excessive exposure to UV-B go beyond just getting burned. Exposure to UV radiation has been linked to many human health problems, including skin cancer. Scientists also indicate that increased exposure to UV-B rays affects the human immune system and causes premature aging of the skin.

It is important to note, however, that UV-B radiation has always had these effects on humans. In recent years these effects have become more prevalent because Canadians are spending more time in the sun and are exposing more of their skin in the process. An increase in the levels of UV-B reaching the Earth as a result of ozone depletion may compound the effects that sun worshipping habits have already created.

Effects on the skin

Although fair-skinned, fair-haired individuals are at highest risk for skin cancer, the risk for all skin types increases with exposure to UV-B radiation. The effects of UV-B on the human immune system have been observed in people with all types of skin. There are three main types of skin cancer, basal cell carcinoma, squamous cell carcinoma, and malignant melanoma. Most cases of skin cancer in Canada are either basal or squamous cell carcinoma. Basal and squamous cell carcinomas progress slowly and rarely cause death because they usually don’t spread to other parts of the body. These cancers are easily removed by surgery. Melanoma is the most serious and fortunately the least common form of skin cancer. Scientists strongly suspect that malignant melanoma, which can be fatal, is caused by exposure to UV light.

Scientists have confirmed that non-melanoma skin cancer is caused by UV-B radiation, and further believe that a sustained 10% depletion of the ozone layer would lead to a 26% percent increase in non-melanoma skin cancer. Effects on the eyes

UV-B causes cancer in domestic animals similar to those observed in humans. Although most animals have greater protection from UV-B because of their heavy coats and skin pigmentation, they cannot be artificially protected from UV-B on a large scale. Eyes and exposed parts of the body are most at risk.8



Discuss the various types and effects of water pollution on environment, birds, fish and other lining things.

It is the contamination of water bodies such as oceans, seas, lakes, rivers, groundwater, and aquifers by pollutants. The contaminants can end up in the water by the direct or indirect application. It is the second most prevalent type of environmental pollution, after air pollution. Below is an insight into the different types of water pollution and its effects.


Water contamination is categorised based on the source or the nature of the water body it affects. Some of the most common pollution types are:


Surface water includes water that is found naturally on the earth’s surface. They include lagoons, rivers, oceans, and lakes. Contamination of such water features results from the dissolving or mixing of the water with pollutants. It can be accidental, such as oil spills in the ocean or intentional, like industries eliminating their wastes into rivers or sea.


It occurs when the hazardous chemicals and particles applied on the surface by humans seep into the ground by rainwater. The contaminants pollute underground water features such as underground rivers and waterbeds. As a result, wells and boreholes might become contaminated. The most common cause of this type of pollution is the use of pesticides and fertiliser on farms.


Chemicals are the most common type of water contaminants. They affect both surface and underground water bodies. Industries and farming activities are the leading cause Solvents and metals used in industries can pollute rivers and lakes. Weed, insects, and fungi control in farms using pesticides is the other cause of soil contamination. Chemical contamination also results from petroleum spills.


Even though nutrients are essential for plant and aquatic life, an excess of it is dangerous. Wastewater and fertilisers have a high content of nutrients required for plant growth. Consequently, they cause rapid and uncontrolled growth of vegetation and algae on the water surface when they end up in the water.It leads to clogging of water filters and contamination of drinking water. It also uses up all the oxygen leading to the destruction of marine life.


Aquatic microorganisms thrive on biodegradable substances. When many of these materials get into the water, the number of microorganisms increases. They use up all the oxygen in the water. The depletion of oxygen leads to the death of aerobic microorganisms but promotes the thriving of anaerobic organisms.Certain anaerobic microorganisms contaminate the water by producing toxins such as sulphides and ammonia. All these are harmful to humans and aquatic life.


It is a natural type of contamination of water, as it results from natural existing microorganisms such as protozoa, viruses, and bacteria. Water containing some of these microorganisms can cause diseases such as cholera and bilharzia. The effects of microbiological pollution are common in areas where people drink untreated water.


Some contaminants do not dissolve in water and are too large to mix with water molecules. They include can, straws, and other large objects. When suspended, they form a layer on the surface of the water, preventing oxygen penetration leading to oxygen depletion pollution.Some of the particulate matter may settle at the bottom of the lake, ocean, or river, affecting the life on the floor of the river, lake, or ocean. In some cases, the material can comprise of harmful toxins.


Pollution of water affects both humans and aquatic life. Most water sources close to cities and urban centres are polluted by garbage and dumping of chemicals, legally or illegally. Below are some of the common as well as adverse effects of polluting water bodies.


Life is a cycle, and humanity’s irresponsible behaviour often comes back to haunt it. Adding contaminants to water bodies has affected the human family in several ways. According to a 2017 WHO report, 2.1 billion people do not have access to safe water. In 2019, it stated that 785 million people lack access to essential drinking water.One of the main effects of this is diseases. World Health Organisation notes that there are about 120,000 cholera-related deaths annually. Also, the Fukushima tragedy, for example, increased the prevalence of thyroid cancer in exposed infants by 70%.


Animals and plants that depend on water for life are the most affected by polluted water. Statistics from the Centre for Biological Diversity on the effects of the Deep Horizon spill provides a useful glimpse of the impact of pollution on aquatic life. In the report, the 2010 spill on the Gulf of Mexico harmed over 82,000 birds, 25,900 marine animals, 6165 sea turtles, and an unknown number of fish and invertebrates.


Pollution disrupts the food chain by moving the toxins from one level in the chain to higher levels. In some cases, pollution can wipe out an entire part of the food chain. Such affect the other organisms by either causing excessive growth, in case the predator dies or death (if it wipes out the prey).


The introduction or elimination of certain microorganisms distorts the ecosystem. Nutrient pollution, for example, leads to an increase in algae, which depletes the water of oxygen, thereby leading to the death of fish and other aquatic life.


Managing and restoring polluted water bodies is expensive. For example, Japan declared in 2019 that it is running out of space to contain the contaminated water after the Fukushima disaster. It currently has over a million tons of contaminated water stored in tanks. Research shows that it will cost at least $660 billion to clean up the effects of the disaster. In normal conditions, it costs more to purify drinking water, not to mention the health cost of treating diseases resulting from contaminated water.

Question 3

Define the terms soil erosion and desertification; discuss the causes and  effects of soil erosion and desertification in your own words.

Soil erosion is a gradual process that occurs when the impact of water or wind detaches and removes soil particles, causing the soil to deteriorate. Soil deterioration and low water quality due to erosion and surface runoff have become severe problems worldwide. The problem may become so severe that the land can no longer be cultivated and must be abandoned. Many agricultural civilizations have declined due to land and natural resource mismanagement, and the history of such civilizations is a good reminder to protect our natural resources.Erosion is a serious problem for productive agricultural land and for water quality concerns. Controlling the sediment must be an integral part of any soil management system to improve water and soil quality. Eroded topsoil can be transported by wind or water into streams and other waterways. Sediment is a product of land erosion and derives largely from sheet and rill erosion from upland areas, and to a lesser degree, from cyclic erosion activity in gullies and drainageways. The impact of soil erosion on water quality becomes significant, particularly as soil surface runoff. Sediment production and soil erosion are closely related. Therefore, the most effective way to minimize sediment production is the stabilization of the sediment source by controlling erosion. Several conservation practices can be used to control erosion but first you need to understand the factors affecting soil erosion. Soil erosion is the detachment and movement of soil particles from the point of origination through the action of water or wind. Thus, minimizing the impact of water or wind forces is the main objective for erosion control. Water erosion is the most pertinent erosion problem in Iowa.Soil erosion by water occurs when bare-sloped soil surface is exposed to rainfall, and the rainfall intensity exceeds the rate of soil intake, or infiltration rate, leading to soil-surface runoff.


Desertification is defined as a process of land degradation in arid, semi-arid and sub-humid areas due to various factors including climatic variations and human activities. Or, to put it in another way, desertification results in persistent degradation of dryland and fragile ecosystems due to man-made activities and variations in climate. Desertification, in short, is when land that was of another type of biome turns into a desert biome because of changes of all sorts. A huge issue that many countries have is the fact that there are large pockets of land that are going through a process that is known as desertification

Soil erosion can occur in two stages:

1) detachment of soil particles by raindrop impact, splash, or flowing water; and

2) transport of detached particles by splash or flowing water.

. Therefore, soil erosion is a physical process requiring energy, and its control requires certain measures to dissipate this energy. The hydrologic processes of rainfall and runoff play an essential role in water erosion. The amount and rate of surface runoff can affect erosion and sediment transport. Thus, soil conservation practices are important in reducing soil erosion. Improving the soil infiltration rate, resulting in less surface runoff, can lead to reduction of soil erosion. Agronomic, cultural, or structural practices are available for controlling soil erosion. Structural practices involve physical changes in the shape and topography of the land. All these practices are not mutually exclusive. Some situations may require both management and structural changes, where the topography is highly complex. In other situations, erosion control can be achieved by implementing a single practice, where the erosion is minimum, such as the establishment of grassed waterways.

Types of Erosion

Sheet erosion (water) is almost invisible. Lighter colored soils are a sign that over the years erosion has taken its toll.

Wind erosion is highly visible. Although it is a problem, water erosion is generally much more severe.

Rill erosion occurs during heavy rains, when small rills form over an entire hillside, making farming difficult.

Gully erosion makes gullies, some of them huge, impossible to cross with farm machinery.

Ephemeral erosion occurs in natural depressions. It differs from gully erosion in that the area can be crossed by farm equipment.

Question 4.

Explain the concept of noise pollution and identify the sources of noise pollution.

The present generation and the coming generations have to solve three grave problems, namely, population poverty and pollution if they have to survive. Pollution being the most dangerous problem likes cancer in which death is sure but slow. Environment pollution is assuming dangerous proportions all through the globe and India is not free from this poisonous disease. This is the gift of modern living, industrialization and urbanization. Unless timely action is taken we have a forbid and bleak future for the world. The word noise is derived from the Latin term nausea. It has been defined as unwanted sound, a potential hazard to health and communication dumped into the environment with regard to the adverse effect it may have on unwilling ears. Noise- a sound; a harsh disagreeable sound, or such sound; a din. Pollution- an excessive or annoying degree of noise in a particular area, e.g. from traffic or aero plane engines. Pollution is a noise derived from the verb pollute. Section 2 (c ) of the Environment (Protection ) Act, 1986 defines environmental pollution to mean the presence in the environment of any environmental pollutant. Section 2 (b) of the said Act defines environmental pollutant to means any solid, liquid or gaseous substance present in such concentration as may be ,or tends to be injurious to environment.

Sources of Noise Pollution

Noise pollution like other pollutants is also a by- product of industrialization, urbanizations and modern civilization. Broadly speaking , the noise pollution has two sources, i.e. industrial and non- industrial. The industrial source includes the noise from various industries and big machines working at a very high speed and high noise intensity. Non- industrial source of noise includes the noise created by transport/vehicular traffic and the neighborhood noise generated by various noise pollution can also be divided in the categories , namely, natural and manmade. Most leading noise sources will fall into the following categories: roads traffic, aircraft, railroads, construction, industry, noise in buildings, and consumer products.

  1. Road Traffic Noise:

In the city, the main sources of traffic noise are the motors and exhaust system of autos , smaller trucks, buses, and motorcycles.

This type of noise can be augmented by narrow streets and tall buildings, which produce a canyon in which traffic noise reverberates.

  1. Air Craft Noise: Now-a-days , the problem of low flying military aircraft has added a new dimension to community annoyance, as the nation seeks to improve its nap-of the- earth aircraft operations over national parks, wilderness areas , and other areas previously unaffected by aircraft noise has claimed national attention over recent years.
  2. Noise from railroads:

The noise from locomotive engines, horns and whistles, and switching and shunting operation in rail yards can impact neighboring communities and railroad workers. For example, rail car retarders can produce a high frequency, high level screech that can reach peak levels of 120 dB at a distance of 100 feet, which translates to levels as high as 138, or 140 dB at the railroad worker’s ear.

  1. Construction Noise:

The noise from the construction of highways , city streets , and buildings is a major contributor to the urban scene . Construction noise sources include pneumatic hammers, air compressors, bulldozers, loaders, dump trucks (and their back-up signals), and pavement breakers.

  1. Noise in Industry:

Although industrial noise is one of the less prevalent community noise problems, neighbors of noisy manufacturing plants can be disturbed by sources such as fans, motors, and compressors mounted on the outside of buildings Interior noise can also be transmitted to the community through open windows and doors, and even through building walls. These interior noise sources have significant impacts on industrial workers, among whom noise- induced hearing loss is unfortunately common.

  1. Noise in building:

Apartment dwellers are often annoyed by noise in their homes, especially when the building is not well designed and constructed. In this case, internal building noise from plumbing, boilers, generators, air conditioners, and fans, can be audible and annoying. Improperly insulated walls and ceilings can reveal the soundof-amplified music, voices, footfalls and noisy activities from neighboring units. External noise from emergency vehicles, traffic, refuse collection, and other city noises can be a problem for urban residents, especially when windows are open or insufficiently glazed.

  1. Noise from Consumer products:

Certain household equipment, such as vacuum cleaners and some kitchen appliances have been and continue to be noisemakers, although their contribution to the daily noise dose is usually not very large.

4 Harmful Effects:

On Human Being, Animal and Property: Noise has always been with the human civilization but it was never so obvious, so intense, so varied & so pervasive as it is seen in the last of this century. Noise pollution makes men more irritable. The effect of noise pollution is multifaceted & inter related. The effects of Noise Pollution on Human Being, Animal and property are as follows:

I It decreases the efficiency of a man:- Regarding the impact of noise on human efficiency there are number of experiments which print out the fact that human efficiency increases with noise reduction. A study by Sinha & Sinha in India suggested that reducing industrial booths could improve the quality of their work. Thus human efficiency is related with noise.

II Lack of concentration:- For better quality of work there should be concentration , Noise causes lack of concentration. In big cities , mostly all the offices are on main road. The noise of traffic or the loud speakers of different types of horns divert the attention of the people working in offices.

III Fatigue:- Because of Noise Pollution, people cannot concentrate on their work. Thus they have to give their more time for completing the work and they feel tiring.

IV Abortion is caused: – There should be cool and calm atmosphere during the pregnancy. Unpleasant sounds make a lady of irriative nature. Sudden Noise causes abortion in females.

V It causes Blood Pressure: – Noise Pollution causes certain diseases in human. It attacks on the person’s peace of mind. The noises are recognized as major contributing factors in accelerating the already existing tensions of modern living. These tensions result in certain disease like blood pressure or mental illness etc.

VI Temporary of permanent Deafness:- The effect of nose on audition is well recognized. Mechanics , locomotive drivers, telephone operators etc. All have their hearing . Impairment as a result of noise at the place of work. Physictist, physicians & psychologists are of the view that continued exposure to noise level above. 80 to 100 db is unsafe, Loud noise causes temporary or permanent deafness.

Question 5.

Briefly explain the following terms in your own words:

 Soil structure and function

Natural aggregates that can be clearly seen in the field are called peds. Clods, on the other hand, are aggregates that are broken into shape by artificial actions such as tillage. The surfaces of peds persist through cycles of wetting and drying in place. Commonly, the surface of the ped and its interior differ as to composition or organization, or both, because of soil development. Earthy clods and fragments stand in contrast to peds, for which soil forming processes exert weak or no control on the boundaries. Structure is very important since (along with soil texture) it affects the porosity of the soil. A dense structure will greatly reduce the amount of air and water than can move freely through the soil. Also, it will affect the plant’s ability to propagate roots through the soil.Soil is the topmost weathering layer of the Earth’s crust. It consists of mineral particles, humus, water, air and living organisms. Healthy soil has a well-defined structure. Soil particles are arranged in such a way that large enough spaces, known as pores, form between them. These pores store water and allow air to circulate. They can account for up to 50 percent of the total soil volume. The soil regulates the natural cycles of water, air, and organic and mineral matter. It filters and purifies water, stores and breaks down substances and is therefore a vital link in the constant flow of energy and matter throughout the Earth’s entire ecosystem. A significant share of this valuable work is performed by billions of organisms that live in the soil. These are mostly inconspicuous plants and animals that are viewed with contempt rather than appreciation. Some of these include bacteria, algae, fungi, worms, springtails, and woodlice, etc. The most obvious example is probably the earthworm. Soil biota are responsible for new soil formation. The soil’s surface and substance also make it a resource for food and fodder production, a source of energy and raw materials, a basis for protection forests and a site for settlements and transport and utility infrastructure. Furthermore, it performs ideal functions as a component of nature and landscapes, as a cultural and geohistorical archive, as a religious site and as a research object. However, soil can only fulfil most of its ecological and economic functions if its moisture regime and aeration are not disrupted, plants have enough room for their roots, nutrients and soil biota types and quantities are in balance and pollution levels are within tolerable limits for plants and soil organisms


There are five major classes of structure seen in soils: platy, prismatic, columnar, granular, and blocky. There are also structureless conditions. Some soils have simple structure, each unit being an entity without component smaller units. Others have compound structure, in which large units are composed of smaller units separated by persistent planes of weakness.


In platy structure, the units are flat and platelike. They are generally oriented horizontally. A special form, lenticular platy structure, is recognized for plates that are thickest in the middle and thin toward the edges. Platy structure is usually found in subsurface soils that have been subject to leaching or compaction by animals or machinery. The plates can be separated with a little effort by prying the horizontal layers with a pen knife. Platy structure tends to impede the downward movement of water and plant roots through the soil.


In prismatic structure, the individual units are bounded by flat to rounded vertical faces. Units are distinctly longer vertically, and the faces are typically casts or molds of adjoining units. Vertices are angular or subrounded; the tops of the prisms are somewhat indistinct and normally flat. Prismatic structures are characteristic of the B horizons or subsoils. The vertical cracks result from freezing and thawing and wetting and drying as well as the downward movement of water and roots.


In columnar structure, the units are similar to prisms and are bounded by flat or slightly rounded vertical faces. The tops of columns, in contrast to those of prisms, are very distinct and normally rounded. Columnar structure is common in the subsoil of sodium affected soils. Columnar structure is very dense and it is very difficult for plant roots to penetrate these layers. Techniques such as deep plowing have help to restore some degree of fertility to these soils.


In blocky structure, the structural units are blocklike or polyhedral. They are bounded by flat or slightly rounded surfaces that are casts of the faces of surrounding peds. Typically, blocky structural units are nearly equidimensional but grade to prisms and to plates. The structure is described as angular blocky if the faces intersect at relatively sharp angles; as subangular blocky if the faces are a mixture of rounded and plane faces and the corners are mostly rounded. Blocky structures are common in subsoil but also occur in surface soils that have a high clay content. The strongest blocky structure is formed as a result of swelling and shrinking of the clay minerals which produce cracks. Sometimes the surface of dried-up sloughs and ponds shows characteristic cracking and peeling due to clays.


In granular structure, the structural units are approximately spherical or polyhedral and are bounded by curved or very irregular faces that are not casts of adjoining peds. In other words, they look like cookie crumbs. Granular structure is common in the surface soils of rich grasslands and highly amended garden soils with high organic matter content. Soil mineral particles are both separated and bridged by organic matter breakdown products, and soil biota exudates, making the soil easy to work. Cultivation, earthworms, frost action and rodents mix the soil and decreases the size of the peds. This structure allows for good porosity and easy movement of air and water. This combination of ease in tillage, good moisture and air handling capabilities, and good structure for planting and germination, are definitive of the phrase good tilth.


  1. Effects of noise pollution

Noise pollution is the spread of unwanted sounds into the environment.

Noise is almost always around us, whether natural, such as birdsong, or from human activity, such as vehicle traffic. However, noise build-up can have a significant impactTrusted Source on the well-being of humans and animals. Noise pollution occurs when unwanted sounds enter the environment. The potential health effects of noise pollution include increased stress levels, sleep disturbance, or hearing damage.

Some examples of noise pollution sources

  • construction
  • motorized vehicles
  • crowds
  • concerts
  • aircraft
  1. Enlist factors responsible for soil erosion

Factors such as rainfall, runoff, wind soil, slope, plant cover and presence or absence of conservation measures are responsible for soil erosion. But mainly three following factors affect the erosion.

  1. Energy:

It include The potential ability of rainfall, runoff and wind to course erosion and other factor which affects the power of erosive agents such as reduction in length of runoff or wind blow through construction of terrace, bunds etc. in case of water erosion and wind breaks or shelter belts incase of wind erosion.

  1. Resistance:

It is referred to that factors which affect soil erodibility and soil erosion. Mechanical and chemical properties of soil are responsible for infiltration rate of soil which reduces runoff and decreases soil erodibility. Cultivation decreases the erodibility of clay but increases erodibility of sandy soils.

  1. Protection:

It refers to plant covers which intercept the raindrop falling on ground surface reducing their impact on soil. Plant cover also reduces the runoff and wind velocity, there by soil erosion. Different plant cover offers different protection so suitable cover can be developed to control erosion.

  1. D) Particular matter

The aerodynamic properties of particles determine how they are transported in air and how they can be removed from it. These properties also govern how far they get into the air passages of the respiratory system. Additionally, they provide information on the chemical composition and the sources of particles. Particles have irregular shapes and their aerodynamic behaviour is expressed in terms of the diameter of an idealised sphere. The sampling and description of particles is based on this aerodynamic diameter, which is usually simply referred to as ‘particle size’. Particles having the same aerodynamic diameter may have different dimensions and shapes. Some airborne particles are over 10,000 times bigger than others in terms of aerodynamic diameter.

Based on size, particulate matter is often divided into two main groups:

The coarse fraction contains the larger particles with a size ranging from 2.5 to 10 µm (PM10 – PM2.5).

The fine fraction contains the smaller ones with a size up to 2.5 µm (PM2.5). The particles in the fine fraction which are smaller than 0.1 µm are called ultrafine particles. Most of the total mass of airborne particulate matter is usually made up of fine particles ranging from 0.1 to 2.5 µm. Ultrafine particles often contribute only a few percent to the total mass, though they are the most numerous, representing over 90% of the number of particles

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