Unit – 5

ENVIRONMENTAL POLLUTION

QUESTION BANK

1. What is Environmental Pollution?

ANS:- Environmental Pollution can be defined as any undesirable change in physical, chemical, or biological characteristics of any component of the environment i.e. air, water, soil which can cause harmful effects on various forms of life or property. The term pollution can be defined as influence of any substance causing nuisance, harmful effects, and uneasiness to the organisms. Any substance causing Nuisance or harmful effects or uneasiness to the organisms, then that particular substance may be called as the pollutant.

2.     Define Air Pollution?  What are Types, Causes ,Effects and Controls of Air Pollution?

ANS:-

Air Pollution

Air pollution refers to any physical, chemical or biological change in the air. It is the contamination of air by harmful gases, dust and smoke which affects the plants, animals, and humans drastically.

There is a certain percentage of gases present in the atmosphere. An increase or decrease in the composition of these gases is harmful to survival. This imbalance in the gaseous composition has resulted in an increase in earth’s temperature, which is known as global warming.

Types of Air Pollution

1. Primary Pollutants

The pollutants that directly cause air pollution are known as primary pollutants. Sulphur-dioxide emitted from factories is a primary pollutant.

2.     Secondary Pollutants

The pollutants formed by the intermingling and reaction of primary pollutants are known as secondary pollutants. Smog, formed by the intermingling of smoke and fog, is a secondary pollutant.

Causes of Air Pollution

Following are the important causes of air pollution:

The combustion of fossil fuels emits a large amount of sulphur dioxide. Carbon monoxide released by incomplete combustion of fossil fuels also results in air pollution.

The gases emitted from vehicles such as jeeps, trucks, cars, buses, etc. pollute the environment. These are the major sources of greenhouse gases and also result in diseases among individuals.

Ammonia is one of the most hazardous gases emitted during agricultural activities. The insecticides, pesticides and fertilizers emit harmful chemicals in the atmosphere and contaminate it.

Factories and industries are the main source of carbon monoxide, organic compounds, hydrocarbons, and chemicals. These are released into the air, degrading its quality.

In the mining process, the minerals below the earth are extracted using large pieces of equipment. The dust and chemicals released during the process not only pollute the air, but also deteriorate the health of the workers and people living in the nearby areas.

The household cleaning products and paints contain toxic chemicals that are released in the air. The smell from the newly painted walls is the smell of the chemicals present in the paints. It not only pollutes the air but also affects breathing.

Effects of Air Pollution

The hazardous effects of air pollution on the environment include:

Air pollution has resulted in several respiratory disorders and heart diseases among humans. The cases of lung cancer have increased in the last few decades. Children living near polluted areas are more prone to pneumonia and asthma. Many people die every year due to the direct or indirect effects of air pollution.

Due to the emission of greenhouse gases, there is an imbalance in the gaseous composition of the air. This has led to an increase in the temperature of the earth. This increase in earth’s temperature is known as global warming. This has resulted in the melting of glaciers and an increase in sea levels. Many areas are submerged underwater.

The burning of fossil fuels releases harmful gases such as nitrogen oxides and sulphur oxides in the air. The water droplets combine with these pollutants, become acidic, and fall as acid rain which damages human, animal and plant life.

The release of chlorofluorocarbons, halons, and hydro chlorofluorocarbons in the atmosphere is the major cause of depletion of the ozone layer. The depleting ozone layer does not prevent the harmful ultraviolet rays coming from the sun and causes skin diseases and eye problems among individuals.

The air pollutants suspend on the water bodies and affect the aquatic life. Pollution also compels the animals to leave their habitat and shift to a new place. This renders them stray and has also led to the extinction of a large number of animal species.

Control Measures

Following are the measures one should adopt, to control air pollution:

People should avoid using vehicles for shorter distances. Rather, they should prefer public modes of transport to travel from one place to another. This not only prevents pollution, but also conserves energy.

A large number of fossil fuels are burnt to generate electricity. Therefore, do not forget to switch off the electrical appliances when not in use. Thus, you can save the environment at the individual level. Use of energy-efficient devices such CFLs also controls pollution to a greater level.

3.     Define Water Pollution?  What are Types , Causes ,Effects and Controls of Water Pollution?

ANS:-

Water Pollution

Water pollution can be defined as the contamination of water bodies. Water pollution is caused when water bodies such as rivers, lakes, oceans, groundwater, and aquifers get contaminated with industrial and agricultural effluents.

When water gets polluted, it adversely affects all life forms that directly or indirectly depend on this source. The effects of water contamination can be felt for years to come.

Types of Water Pollution

1. Chemical pollution: The most common type of water pollution, chemicals can infiltrate both underground water sources and those sitting on the Earth's surface.
2. Groundwater pollution: agriculture is a key source of water pollution, especially for groundwater. Fertilisers and pesticides applied to crops can seep into the ground and contaminate underwater rivers and waterbeds, thus compromising the quality of wells, boreholes and other places from which groundwater is extracted for human use.
3. Microbiological pollution: Unlike most others on this list, microbiological pollution is a naturally occurring form of water contamination. Microorganisms such as bacteria, protozoa and viruses can infiltrate water supplies, causing diseases such as bilharzia and cholera. Humans are most susceptible to this kind of pollution in places where adequate water treatment systems are not yet in place.
4. Nutrient pollution : While they’re vital for underwater flora and fauna to flourish, an excess of nutrients can upset the delicate imbalance of water-based ecosystems. Fertilisers contain a high concentration of nutrients which, if they contaminate rivers, lakes and coastal areas, can cause algal blooming that can block out sunlight and inhibit the growth of other organisms.
5. Oxygen-depletion pollution: Another consequence of algal blooms is their consumption of oxygen supplies. This means that those species which depend upon oxygen to survive are killed off, while anaerobic ones thrive. Some anaerobic microorganisms are capable of producing ammonia, sulphides and other harmful toxins, which can make the water even more dangerous to animals (and humans, too).
6. Surface water pollution: which can lead to poor water quality, while accidental oil spills and negligent industries emptying waste into water bodies are also key contributors. Suspended matter, Improperly discarded waste, such as fragments of plastic, rubber or other manmade materials, can find themselves into water sources and persist for a long time. Because they are too robust to dissolve in the water and too big to mix effectively with the molecules, they simply float on its surface and prevent oxygen and sunlight from penetrating below.

Causes of Water Pollution

The main causes of water pollution are attributed to

• Industrial activities
• Urbanization
• Religious and social practices
• Agricultural runoff
• Accidents (such as oil spills, nuclear fallouts etc)

Effects of Water Pollution

The effect of water pollution depends upon the type of pollutants and its concentration. Also, the location of water bodies is an important factor to determine the levels of pollution.

• Water bodies in the vicinity of urban areas are extremely polluted. This is the result of dumping garbage and toxic chemicals by industrial and commercial establishments.
• Water pollution drastically affects aquatic life. It affects their metabolism, behaviour, causes illness and eventual death. Dioxin is a chemical that causes a lot of problems from reproduction to uncontrolled cell growth or cancer. This chemical is bio accumulated in fish, chicken and meat. Chemicals such as this travel up the food chain before entering the human body.
• The effect of water pollution can have a huge impact on the food chain. It disrupts the food-chain. Cadmium and lead are some toxic substances, these pollutants upon entering the food chain through animals (fish when consumed by animals, humans) can continue to disrupt at higher levels.
• Humans are affected by pollution and can contract diseases such as hepatitis through faecal matter in water sources. Poor drinking water treatment and unfit water can always cause an outbreak of infectious diseases such as cholera etc.
• The ecosystem can be critically affected, modified and destructured because of water pollution

Control Measures

Water pollution, to a larger extent, can be controlled by a variety of methods. Rather than releasing sewage waste into water bodies, it is better to treat them before discharge. Practising this can reduce the initial toxicity and the remaining substances can be degraded and rendered harmless by the water body itself. If the secondary treatment of water has been carried out, then this can be reused in sanitary systems and agricultural fields.

A very special plant, the Water Hyacinth can absorb dissolved toxic chemicals such as cadmium and other such elements. Establishing these in regions prone to such kinds of pollutants will reduce the adverse effects to a large extent.

Some chemical methods that help in the control of water pollution are precipitation, the ion exchange process, reverse osmosis, and coagulation. As an  individual, reusing, reducing, and recycling wherever possible will advance a long way in overcoming the effects of water pollution.

ANS:- Soil pollution refers to the contamination of soil with anomalous concentrations of toxic substances. It is a serious environmental concern since it harbours many health hazards. For example, exposure to soil containing high concentrations of benzene increases the risk of contracting leukaemia. An image detailing the discolouration of soil due to soil pollution is provided below.

Types of Soil Pollution

Soil pollution mainly occurs due to the following:

1. Industrial wastes

2. Urban wastes

3. Agricultural practices

4. Radioactive pollutants

5. Biological agents

Causes of Soil Pollution

Some common causes of soil pollution are listed below,

• Improper disposal of industrial waste: industries are believed to be one of the leading causes of soil pollution due to improper management and disposal of the toxic wastes generated during industrial activities.
• Excessive and inefficient usage of pesticides and fertilizers: the agriculture industry makes extensive use of chemical fertilizers and pesticides for the growth and maintenance of crops. However, excessive and inefficient use of these toxic chemicals can seriously contaminate the soil.
• Petroleum or diesel spills: leaks in fuel transportation pipes can cause fuel spills. These fuels are known to contain toxic hydrocarbons which can cause soil contamination.

Effects of Air Pollution

Soil contaminants can exist in all three phases (solid, liquid, and gaseous). Therefore, these contaminants can find their way into the human body via several channels such as direct contact with the skin or through the inhalation of contaminated soil dust.

The short term effects of human exposure to polluted soil include:

• Headaches, nausea, and vomiting.
• Coughing, pain in the chest, and wheezing.
• Irritation of the skin and the eyes.
• Fatigue and weakness.

A variety of long-term ailments have been linked to soil pollution. Some such diseases are listed below.

• Exposure to high levels of lead can result in permanent damage to the nervous system. Children are particularly vulnerable to lead.
• Depression of the CNS (Central Nervous System).
• Damage to vital organs such as the kidney and the liver.
• Higher risk of developing cancer.

It can be noted that many soil pollutants such as petroleum hydrocarbons and industrial solvents have been linked to congenital disorders in humans. Thus, soil pollution can have several negative effects on human health.

Since soil pollution is often accompanied by a decrease in the availability of nutrients, plant life ceases to thrive in such soils. Soils contaminated with inorganic aluminium can prove toxic to plants. Also, this type of pollution often increases the salinity of the soil, making it inhospitable for the growth of plant life.

Plants that are grown in polluted soil may accumulate high concentrations of soil pollutants through a process known as bioaccumulation. When these plants are consumed by herbivores, all the accumulated pollutants are passed up the food chain. This can result in the loss/extinction of many desirable animal species. Also, these pollutants can eventually make their way to the top of the food chain and manifest as diseases in human beings.

• Since the volatile contaminants in the soil can be carried away into the atmosphere by winds or can seep into underground water reserves, soil pollution can be a direct contributor to air and water pollution.
• It can also contribute towards acid rain (by releasing huge quantities of ammonia into the atmosphere).
• Acidic soils are in hospitable to several microorganisms that improve soil texture and help in the decomposition of organic matter. Thus, the negative effects of soil pollution also impact soil quality and texture.

Control Measures

Several technologies have been developed to tackle soil remediation. Some important strategies followed for the decontamination of polluted soil are listed below.

• Excavation and subsequent transportation of polluted soils to remote, uninhabited locations.
• Extraction of pollutants via thermal remediation – the temperature is raised in order to force the contaminants into the vapour phase, after which they can be collected through vapour extraction.
• My core mediation involves the use of fungi for the accumulation of heavy metal contaminants.

ANS:-

Noise Pollution

Noise is the unpleasant and undesirable sound which leads to discomfort to human beings. The intensity of sound is measured in decibels (dB). The faintest sound which can be heard by the Human ear is 1 Db. Due to increasing noise around the civilizations; noise pollution has become a matter of concern. Some of its major causes are vehicles, aircraft, industrial machines, loudspeakers, crackers, etc. Some other appliances also contribute to noise pollution like television, transistor, radio, etc. when used at high volume.

Types of Noise Pollution

Following are the three types of pollution:

It mainly consists of traffic noise which has increased in recent years with the increase in the number of vehicles. The increase in noise pollution leads to deafening of older people, headache, hypertension, etc.

The  noise from gadgets, household utensils etc. Some of the main sources are musical instruments, transistors, loudspeakers etc.

It is the high-intensity sound which is caused by heavy industrial machines. According to many researches industrial noise pollution damages the hearing ability to around 20%.

Causes of Noise Pollution

Following are the causes and sources of noise pollution:

• Industrialization: Industrialization has led to an increase in noise pollution as the use of heavy machinery such as generators, mills, huge exhaust fans, etc are used resulting in the production of unwanted noise.
• Vehicles: Increased number of vehicles on the roads are the second reason for noise pollution.
• Events: Weddings, public gatherings involve loudspeakers to play music resulting in the production of unwanted noise in the neighbourhood.
• Construction sites: Mining, construction of buildings, etc add to the noise pollution.

Effects of Noise Pollution

Noise pollution can be hazardous to human health in the following ways:

• Hypertension: It is a direct result of noise pollution which is caused due to elevated blood levels for a longer duration.
• Hearing loss: Constant exposure of human ears to loud noise that are beyond the range of sound that human ears can withstand damages the eardrums resulting in loss of hearing.
• Sleeping disorders: Lack of sleep might result in fatigue and low energy level throughout day affecting everyday activities. Noise pollution hampers the sleep cycles leading to irritation and uncomfortable state of mind.
• Cardiovascular issues: Heart related problems such as blood pressure level, stress, and cardiovascular diseases might come up in a normal person and person suffering from any of these diseases might feel the sudden shoot up in the level.

Control Measures

Some noise pollution preventive measures are provided in the points below.

• Honking in public places like teaching institutes, hospital, etc. should be banned.
• In commercial, hospital, and industrial buildings adequate soundproof systems should be installed.
• Musical instruments sound should be controlled to desirable limits.
• Dense tree cover is useful in noise pollution prevention.
• Explosives should be not used in forest, mountainous, and mining areas.

ANS:- According to International Atomic Energy Agency (IAEA), a nuclear and radiation accidents/ hazards is an event that has led to significant consequences to people, the environment or the facility.  Nuclear hazards. Risk or danger to human health or the environment exposed by the radiation emanating from the atomic nuclei is called as nuclear hazard. Nuclear hazard is an actual or potential release of radioactive material at a commercial nuclear power plant or a transportation accident.

  Nuclear power plant accidents:

• The SL-1 accident(1961)
• The Three Mile Island Accident(1979)
• Chernobyl Disaster (1986)
• Fukushima Daiichi nuclear disaster(2011)

7.     What are the effects of Nuclear Hazzard on  Human Health?

ANS:-

Human Health Risks

• Studies shown that the health effects due to radiation are dependent on the level of dose, kind of radiation, duration of exposure and types of cells irradiated. Radiation effects can be somatic or genetic.
• Radioactive iodine and caesium are being released into the environment from the malfunctioning nuclear reactors in Japan.
• As radioactive material decays, or breaks down, the energy released into the environment has two ways of harming a body that is exposed to it.
• It can directly kill cells, or it can cause mutations to DNA. If those mutations are not repaired, the cell may turn cancerous.
• Children are most at risk for thyroid cancer, since their thyroid glands are 10 times smaller than those of adults as the radioactive iodine would be more concentrated in them. The Chernobyl accident released a plume of radioactive materials into the atmosphere in a fraction of a second. In the following years, the incidence of thyroid cancer among those exposed as children increased in Ukraine and nearby countries.

ANS:-

• Laboratory generated nuclear wastes should be disposed off safely and scientifically.
• Nuclear power plants should be located in areas after careful study of the geology of the area, tectonic activity and meeting other established conditions.
• Appropriate protection against occupational exposure
• Leakage of radioactive elements from nuclear reactors, careless use of radioactive elements as fuel and careless handling of radioactive isotopes must be prevented.
• Safety measure against accidental release of radioactive elements must be ensured in nuclear plants.
• Unless absolutely necessary, one should not frequently go for diagnosis by x-rays.
• Regular monitoring of the presence of radioactive substance in high risk area should be ensured.

ANS:- An integrated waste management strategy includes three main components

1. Source reduction

2. Recycling

3. Disposal

Source reduction is one of the fundamental ways to reduce waste. This can be done by using less material when making a product, reuse of products on site, designing products or packaging to reduce their quantity. On an individual level we can reduce the use of unnecessary items while shopping, buy items with minimal packaging, avoid buying disposable items and also avoid asking for plastic carry bags.

Recycling is reusing some components of the waste that may have some economic value. Recycling has readily visible benefits such as conservation of resources reduction in energy used during manufacture and reducing pollution levels. Some materials such as aluminum and steel can be recycled many times. Metal, paper, glass and plastics are recyclable. Mining of new aluminum is expensive and hence recycled aluminum has a strong market and plays a significant role in the aluminum industry. Paper recycling can also help preserve forests as it takes about 17 trees to make one ton of paper. Crushed glass (cullet) reduces the energy required to manufacture new glass by 50 percent. Cullet lowers the temperature requirement of the glassmaking process thus conserving energy and reducing air pollution.

10.   Explain Pollution - Case Studies?

ANS:-

1. Taj Trapezium case

Taj Mahal The “Taj Mahal” is the “King of Emperor” amongst world wonder. It is one of the most priceless national monuments and also a glorious reputation to the men’s achievements in architecture. He chemical industries and refinery at Mathura are source of damage “Taj Mahal”. SO3 came from the industry react with moisture in atmosphere and form the “Acid Rain”. This will make corroding effect on clean white marble. The judgment vigorously applied the “precautionary principle” and in May 1999,the Central Government constituted the Taj Trapezium Pollution Authority.

The world’s worst industrial accident occurred in Bhopal city, M.P. On midnight of 3 Dec 1984. Who manufactures some carbonate pesticides, using Methyl isocyanate(MIC). The reactor exploded due to the failure of the cooling system .

Effects

• Lower amount of MIC it affects lungs, eyes and cause irritation on skin.
• Higher amount of MIC cause O2 remove from lungs and cause death .
• 5000 persons were killedMIC spread over 40 sq.km area  .
• 65000 people suffer from eye & reparatory disorder and 1000 person became blind .