The University of LahoreDepartment of Civil Engineering

Course Title: Environmental Engineering -I Course Code: CE 3602Credit Hours: 4 (3 hrs of lecture and 3 hrs of lab/design )Pre-Requisite: Fluid MechanicsCourse Instructor: Prof. Dr Muhammad Zulfiqar Ali KhanRoom: to be allotted

Instructor Office Hours

Days Time Time Tel. Ext. No. EmailMonday 9am 4pm 1800Tuesday 9am 4pm 1800Wednesday 9am 4pm 1800Thursday 9am 4pm 1800Friday 9am 4pm 1800

Course Objectives / Description:

Objective:• To learn principles of environmental engineering and inculcate abilities for design and

implementation of water supply schemes.

Course Contents:

Introduction to Environmental Engineering

Water Pollution: Water chemistry and characteristics, Introduction to sources of pollution, Effects on water quality, Control parameters.

Water Demand and Supply: Population Forecast; Water uses & consumption; Types and variations in demand; Maximum demand & fire demand.

Water Quality: Water impurities & their health significance; Water quality guidelines / standards (U.S. & WHO, etc); water quality monitoring.

Water Sampling and Testing: Sampling techniques and examination of water (physical, chemical and microbiological parameters), Water borne diseases.

Water Treatment: Treatment of surface & ground water, screening, sedimentation, coagulation, Filtration, design aspects of slow sand and rapid sand filters; and their operations, Pressure filters

Miscellaneous Water Treatment Techniques: Fluoridation, Iron & Manganese removal; Water softening methods; Water disinfection and chemicals; Chlorination; Emergency treatment methods.

Water Distribution: Layout and design of water transmission works and distribution networks, service reservoirs, Fixtures and their installation; Tapping of water mains, Urban and Rural Water Supply.

Introduction to Air & Noise PollutionRecommended Text Book : 1. Terence J. McGhee, Water Supply and Sewerage, 6thPP edition, McGraw Hill

Additional Books Recommended2. Mackenzie L. Davis, David A. Cornwell, Introduction to Environmental Engineering,

McGraw-Hill, 3. Howard S. Peavy, D.R. Rowe, George Tchobanoglous, Environmental Engineering

McGraw-Hill Publishing Co.; 7th Rev Ed edition 4. Warren Viessman,Jr., and Mark Hammer , water Supply and Pollution Control, Fourth

Edition, Harper and Row, Publishers, New York.

Week Wise Topics (Syllabus break down in weeks)

Weeks

Topics Assignments

Quizzes

1,2,3 Introduction to Environmental Engineering: Definition of environment, factors affecting environment; environmental engineering;sources of environmental pollution ( water, air, soil) ; impact on health; global,regional and national environmental problems. FIRST ONE HOUR QUIZZ x

4,5 Water Pollution: Water chemistry and characteristics, Introduction to sources of pollution, Effects on water quality, Control parameters.

6,7 Water Demand and Supply: Population Forecast; Water uses & consumption; Types and variations in demand; Maximum demand & fire demand.FIRST ASSIGNMENT x

8,9 Water Quality: Water impurities & their health significance; Water quality guidelines / standards (U.S. & WHO, etc); water quality monitoring.MID TERM EXAM

10,11 Water Sampling and Testing: Sampling techniques and examination of water (physical, chemical and microbiological parameters), Water borne diseases.

12,13 Water Treatment: Treatment of surface & ground water, screening, sedimentation, coagulation, Filtration, design aspects of slow sand and rapid sand filters; and their operations, Pressure filtersSECOND ONE HOUR QUIZZ x

14,15 Miscellaneous Water Treatment Techniques: Fluoridation, Iron & Manganese removal; Water softening methods; Water disinfection and chemicals; Chlorination; Emergency treatment methods.SECOND ASSIGNMENT x

16,17 Water Distribution: Layout and design of water transmission works and distribution networks, service reservoirs, Fixtures and their installation; Tapping of water mains, Urban and Rural Water Supply.

18 Introduction to Air & Noise PollutionReview SessionFINAL EXAM

+++++Overhead projector and multi-media equipment are needed for the theory lectures as well as lab. experiments/ design problems..

Grading Policy:

Assignments 10%

Quizzes 10%

Lab Work/Design 20%

Mid-Term 20%

Final-Term 40%

The student must obtain 50% or higher scores in both the Lab . as well as Theory in order to get a final passing grade

++++ computer Lab. may be needed for training/ application of relevant software to the students.

Attendance Policy:

All students must have minimum of 75 % attendance to be eligible to appear in the final exam.

Introduction to Environmental Egineering ( weeks 1,2, and 3)

Environment

the place or surroundings in which people are born, live, play, study and work, including all the

physical conditions that affect them. For Example

We need to create a safe working environment for all employees.

He grew up in a harsh urban environment.

A dirty environment is a breeding ground for germs.

Health

is a state of complete physical, mental, and social well-being and not merely the absence of disease or infirmity ( WHO Definition of Health)

Water Cycle

Water is life .Earth is the water planet with more than two-thirds of its surface covered by water. Most of life on Earth is also primarily composed of water; our cells, and those of plants and animals are composed of approximately 70 percent water. Vast quantities of water also cycle through the Earth's atmosphere, oceans, land, and biosphere over both short and long time scales. This grand cycling of water is called the hydrologic cycle. The cycling of water shapes our weather and climate, supports plant growth, and makes life itself possible. The water cycle is dominated by the oceans, where 96 percent of the water on Earth is found and where 86 percent of global evaporation occurs.

When rain and other precipitation falls on land, some of it runs off into surface waters such as lakes and streams. Much of it, however, seeps into the ground. This process ? the movement of water into and through the soil and rocks ? is called infiltration. How water behaves once it is in the ground, the speed and character of infiltration, is determined by the type of soil or rock through which the water moves. It is primarily during this stage of the hydrologic cycle that water is purified. The extent to which the water is ?cleaned? depends on the state of the environment and the amount of pollution in the water. Passing through layers of sediment and rock helps to filter pollutants out, allowing the pure water to pass through. Generally, the deeper groundwater is found, the cleaner it will be.

Water that is not absorbed into the soil flows across the landscape to rivers, lakes, streams, and eventually to the oceans, as runoff. While some runoff waters originate from precipitation, others stem from melting snow or ice, and are called melt water runoff. The area where precipitation that reaches the land drains into a common body of water is called a ?watershed,? and can range in size from a few acres to many square miles. As communities strive to improve the quality of their watersheds, education in this area continues to expand.

Rather than seep into the soil or run off into surface waters, some water returns to the air in gaseous form (water vapor) through evaporation. However, of all water that returns to the atmosphere through evaporation, ocean evaporation is the most prevalent, consisting of about 80 percent of total global evaporation. For land-based evaporation, roughly half occurs on the surface area of plants and is called transpiration. These processes ? evaporation and transpiration ? are sometimes given a single term: evapotranspiration.

Another form of evaporation is sublimation, by which water molecules become gaseous directly from ice without first becoming liquid water. Sublimation accounts for the slow mid-winter disappearance of ice and snow at temperatures too low to cause melting.

The process in which water vapor is converted back into liquid is called condensation. A familiar type of condensation is the formation of dew drops on blades of grass or on the outside of a cold glass. A more important type of condensation within the hydrologic cycle takes place in the atmosphere. As water vapor moves upward in the atmosphere it cools. This process ? the loss of heat through vertical movement ? is called convection. The droplets formed from atmospheric condensation gather together as a result of their gravitation pull to form clouds. Depending on the temperature of the surrounding air, this cloud moisture will take either frozen or liquid form.

Water in the atmosphere, after condensing and forming into clouds, returns to Earth through precipitation, which can take many forms. Although some water is transmitted directly to Earth through the condensation of ambient water vapor, it is primarily through precipitation that water moves from the atmosphere to the Earth.

Natural water storage. Water is stored for periods of time in various types of reservoirs. The primary reservoirs are (in order of size) the oceans, polar ice and glaciers, the atmosphere, groundwater, lakes, soils, atmosphere, rivers and streams, and the biosphere (plants and animals). There is about 50 times as much water stored in the oceans than in the next largest water reservoir, polar ice and glaciers. The amount of time that water stays in the reservoirs varies: deep groundwater can be held for up to 10,000 years, while glaciers retain their water for an average of about 40 years. At the other end of the spectrum, the retention time for rivers, soil moisture, and seasonal snow cover is typically less than 6 months.

Reservoirs (a)

Reservoir Size (volume of water in cubic km x 10,000,000)

Percent of Water in Hydrologic Cycle

Oceans 1370 97 Polar Ice and Glaciers 29 2 Groundwater 9.5 0.7 Lakes 0.125 0.01 Soils 0.065 0.005 Atmosphere 0.013 0.001 Rivers and Streams 0.0017 0.0001 Biosphere 0.0006 0.00004

Built Environment. The term built environment refers to the structures, and infrastructure, that are made by man. This can include everything from simple housing to entire cities, and even man-made outdoor environments. Built environments provide the basic necessities for human life as we know it, and therefore must be functional and healthy for all. Finding this balance is a complicated and challenging process, and one that is consistently being refined.

A built environment includes all structures created by people, including infrastructure elements like streets, sidewalks, water and sewer lines, and electric and other utilities. Human behavior experts and city planners work to discover the most positive use of space for people. A single building can also be studied for its effectiveness. Commercial building designs are constantly changing layouts to better accommodate the business that takes place within the walls.There are serious concerns about the health impact that a built environment has on people. Studies have shown that people, particularly those in low income areas, can be negatively influenced by their built environment. Advocates of healthy living point to the lack of adequate exercise space and healthy eating facilities as some of the key reasons why those in low-income areas have poor health. Independent civic groups often study particular areas and implement changes to the environment to encourage a more well-rounded communityA built environment can also be an outdoor space that has been manipulated by man. Community parks and other engineered open space areas are examples of outdoor places that are considered built environments. There is a challenging balance between preserving space and making it usable for the people, particularly for tourists at large national parks. Some naturalists wish to keep land as it is, without adding additional walking trails or other elements to the areas. The overall outcome is that most large parks have designated spots for tourism, while other areas remain untouched.Sustainability is one of the most recent concerns when planning a new environment, or upgrades to an old one. Green energy sources and building materials are being used more than ever. An example of this is the town of Greensburg, Kansas, which was destroyed by a tornado in 2007. The town was rebuilt using sustainable materials and energy-conserving power sources. It has gone on to be known as the "Greenest town in

America." Communities that undergo greening such as this serve as social experiments into positively-functioning built environments

Environmental management: is the process by which environmental health is regulated. It does not involve managing the environment itself, but it is the process of taking steps and behaviors to have a positive effect on the environment. Environmental management involves the wise use of activity and resources to have an impact on the world . Many organizations develop a management plan or system to implement, manage and maintain environmental goals. Management plans for the environment are constructed by many companies and organizations, as taking care of the planet is the responsibility of everybody in every type of profession. The most successful plans are built on a Plan , Do, Check, Act model. The first step, planning, involves defining specific goals for that organization to accomplish regarding the environment. Next, the company needs to take whatever steps are necessary to implement the processes laid out in the planning stage. Checking involves monitoring the environmental management plan, evaluating its effects and adjusting the procedures as necessary. Finally, acting involves reviewing the plan after it is complete and looking at reports from activities conducted or talking to those who were directly involved to get feedback and adjust the plan according

Employees at a company, or members of an organization that has chosen to implement an environmental management plan must be given the proper environmental training. While goals such as conservation and better methods of waste disposal are solid ideals to strive for, many of these techniques have been tried before. If everyone at the organization is not on board and using the same methods, the plan will serve no ultimate good. If an environmental management plan is properly enforced, however, the company will see benefits both to its business and to the environment.Environmental management does not come without costs. These include the investment of resources such as time and money, the cost of training the employees, the cost of hiring consultants or other professionals and the cost of technical resources for studying the environment and its impacts. It is widely believed, however, that the benefits of an environmental management plan far outweigh the costs. These include the prevention of pollution a nd the conservation of natural resources, increased energy efficiency, stronger environmental performance and an attention to and responsibility for taking care of the earth. Following a management plan for the environment is a great way to build strong employee relationships and foster company support around one goal.

Environmental sustainability applies ecological science to the design of man-made artifacts and the management of human changes to the environment. This is done for the purpose of sustaining life-supporting biological, meteorological, geological and hydrological systems. A sustainable system is one in which a balance of diverse plant and animal life, and hydrological cycles continue on in a stable manner, thereby supporting abundant biological diversity. If environmental damage has already occurred, sustainability may also be a proactive endeavor that restores the integrity of these systems. Environmental science is applied to both the proactive and restorative aspects of environmental sustainability.Features of natural environmental systems includes hydrology, and indigenous plant and animal life. Activities that ensure or restore sustainability in natural systems also affect human social activities such as recreation, industry, and agricultural production. In designing and implementing sustainable practices, the impact of people on ecological systems and vice versa is also considered part of environmental sustainability. This practice is often referred to as the triple bottom line, or "people, planet, profit." The triple-bottom-line theory advocates the inclusion of economic factors in the design and implementation of sustainable ecological solutions. It is an approach that is gaining support, as it attempts to ameliorate the opposition sometimes mounted by economic interests of those concerned about the impact of eco-friendly practices on local economiesHydrological systems are of major concern in environmental sustainability. These systems are impacted by weather patterns, and man-made developments such as highways, or construction of buildings in agricultural areas, as well as erosion caused by human changes to water sheds. Pollution or changes in water flow in hydrological systems can degrade many aspects of the surrounding ecological system.Environmental management of biodiversity involves restoring a natural balance between human, animal and botanical species. The spread of an invasive species may be a sign of environmental degradation. For example, Reed Canary Grass may populate a river bank in which the natural hydrology cycles have been disrupted. The biodiversity of native plants that may provide food and shelter for native animals is gradually replaced by a much less desirable species. As a result, a decrease in the environmental sustainability of the hydrological system will eventually occur. Sustainable practices may by implemented at the neighborhood level, all the way up to attempts to restore planetary environmental sustainability. An example of the former would be restoring a creek that has been degraded through pollution caused by runoff. An example of

the latter would involve geopolitical actions to ascertain and reach sustainable levels of carbon released into the atmosphere.While political discussions have resulted in divergent opinions on some issues regarding environmental sustainability, consumer sentiment impacts this area. More businesses are responding to marketplace trends that show an increasing public awareness of the dangers of unsustainable practices. Consumers who desire eco-friendly practices in architecture and construction are also part of the environmental sustainability movement

Environmental management policy is a set of laws, restrictions, or standards designed to protect and conserve environmental resources. Many large industries and federal governments put policies into place to regulate pollution, waste dumping, and other activities that could result in negative impacts on the environment. An effective environmental management policy clearly outlines rules and expectations for people to follow and includes the reasons why conservation is important. When forming an environmental management policy, authorities usually rely on information provided by environmental scientists, geologists, and conservation biologists. Through careful observation and experimentation, scientists gather data about the environmental impacts of people and businesses. They analyze soil, water, and air samples, observe changes in ecosystems, and predict future outcomes if policies are not put into place. Scientists create detailed reports and submit them to companies or governments, highlighting their expert opinions on the best ways to limit environmental risks.A government environmental management policy is designed to regulate the activity of industries. Based on statistics and recommendations from conservation scientists, policymakers pass laws that clearly define acceptable and unacceptable practices. Laws are set in place to cap emissions and pollution, mitigate the use of dangerous chemicals, In addition to regulating industrial practices, government environmental management policies are frequently extended to include the activity of all individuals within a society. Common environmental management policy items include regulations on vehicle emissions, littering, and landfill use. Local governments often staff specially-trained officers to enforce environmental policies, such as fish and game wardens. The goal of an environmental management policy is to educate and motivate citizens to be more aware of their surroundings. People can come to understand the potential impacts they can have in protecting the environment for future generations.Many businesses create their own environmental management policies that go beyond legal restrictions. Companies often try to promote

environmentally-friendly practices, such as reducing pollution and emissions by employing alternative fuel sources. Some businesses take the practice farther by encouraging employees to aid in cleanup efforts, like picking up litter or carpooling to work. An environmentally-conscious business owner might create his or her own policy, or bring in private consultants to determine the most effective means of setting standards and educating employees and enforce appropriate waste disposal procedures. Governments often regulate the amount and type of pesticides that can be used in agriculture, and place strict limits on forestry and fishing companies. By imposing strict laws and standards, a government promotes new innovations in cleaner fuels and industrial practices

Healthy Environment : The term "healthy environment" is a huge one, encompassing many different meanings. To complicate the matter, environments that are healthy for one population aren’t always healthy for another. This makes it hard to agree upon what is needed in order to create a healthy environment, and to determine what has priority in this environment, such as humans, other animals, insects or plants. Usually, when people use this term, they refer to a human environment that would pose few risks for disease or health hazards.

Dictionaries may speak of environment as the sum total of all surrounding living conditions. This would mean all physical things, all growing things, all structures, all objects, and all chemicals. There’s also a sharing aspect to this. People are not only surrounded by their environment but constantly contribute to it with every behavior, including breathing. A person cannot have a smoke, clean a rug, take out the trash, do the dishes, or drive a car without having some effect on the environmentIn a sense, part of achieving a healthy environment is to determine how to live in total surrounding conditions with minimal or improving effects upon it. Obviously smoking improves nothing, threatening the physical health of the smoker and anyone who inhales the smoke. Cleaning the rug may be a bit more complicated. Will rug chemicals have cumulative effects on the health of an environment or will getting rid of dust mites be healthier for asthma sufferers in the home? There’s a growing market for a variety of products that are judged environmentally friendly, but many of these are still sold in plastic bottles, and the manufacture of these can give out chemicals that reduce environmental health.

The issue of a healthy environment goes deeper than this and it’s often pointed out that people forget the structures in which they live and which surround them. Houses, buildings and highways are taken for granted. In creating a healthy environment, though, these cannot simply be ignored while people try to change behavior. Years of research have pointed out problems with things like lead paint in homes or with asbestos, but there are other features in structures that may prove as problematic. For instance, where a structure is built can have a total effect on environment. Schools built near highways could be subject to much higher levels of pollution that contribute to poor human health and higher development of disease. It’s common to think that simply urban environments are the problem. Studies of farm workers in many parts of the world show this not to be the case. Those who live in areas where pesticides are used frequently may have greater risk of respiratory diseases and development of cancer.Large structures anywhere tend to affect environment adversely, and they may rely on consumption of fossil fuels, which create greater pollution. They may also, while sheltering people, decimate populations of animals that protect people. There is often much fuss when a protected species is found near a planned building site, and some feel this is overrated. Yet, when that protected species has some positive effect on the human population (the consumption of disease-bearing mosquitoes, for example), effects of removing it could be devastating and hurt people.Given the complication of trying to create a healthy environment, it would seem almost futile to try. Many argue that this isn’t the case. Studying the environment helps people understand which issues may be causing the greatest problems. Certainly, understanding that lead paint could harm kids, or that DDT was creating high risk of disease were important findings which have helped eliminate these environmental hazards in certain parts of the world.Many people devote their lives to finding ways to create a healthy environment for all residents of the planet, and they may focus in different areas. They can examine human behaviors that risk things like lung cancer, diabetes, or perpetuation of abuse. Others study the effects of chemicals, gases, changes in climate, or changes to the total environment. Thus the answer of how to create a healthy environment is not likely to come from a single source, but instead it comes to humans in bits and pieces, like a puzzle. Each human then has the responsibility of deciding how to fit those pieces together to create a healthier world.

Environmental health is a wide branch of study and theory focused on illness and conditions caused by the world around human beings. Rather than looking at health issues caused by the body, environmental health looks for causes and potential problems in the humans native environment. The study of environmental health usually covers the physical aspect of both the natural world and human-built surroundings. Air and water quality, climate, ultra-violet radiation, and human-created toxins are all issues carefully studied with the goal of improving environmental health.

Water and air quality are major considerations of environmental health efforts. Human beings need to hydrate and breathe simply to survive; if their air or water is polluted, it increases the risks to public health . Water and air can be polluted by a variety of factors both human and natural. Chemical runoff from factories can easily lower air quality, but the sniffling and sneezing of millions each spring shows that pollen can harm human health as well. By encouraging efforts to clean up water and air and warning the public about potentially harmful airborne or waterborne particles, public health officials can shield or at least prepare humans in harmful conditionsOne of the biggest concerns in the study of environmental health is the effects of radiation on the population. Although it may seem that radiation is usually human-created, it is easy to forget that the sun is an intense radio-active body that most humans expose themselves to daily. With the thinning of the ozone layer allowing more ultraviolet rays to penetrate the atmosphere, many experts believe that high-levels of sun exposure can be a factor in many cancers, particularly skin-related cancers. The enormous explosion in radiation-emitting electronic devices is also of concern to environmental health experts, as even small increases in human exposure to radiation can have serious or dangerous results. Another major area of concern for environmental health experts is global change to human living environments. Climate change, global warming, and loss of species diversity all can do serious harm to the living conditions of humans. By working closely with scientists who study all aspects of the environment, from biologists working with endangered species re-population efforts, to meteorologists studying weather changes due to global warming, public health officials can help provide services and information about global impact on the human environment.Public health organizations such as the World Health Organization (WHO) devote much effort to understanding and improving environmental health. In daily life, humans tend to be exposed to a variety of natural and man-made

features that can be dangerous to overall health. By providing information, public health officials can help to create an informed public that is capable of reducing health risks caused by environmental problems. If a “wear sunscreen” ad pops up, a billboard urges water conservation, or a sewer sign reads “no dumping- drains to ocean,” it is likely that public health officials concerned with environmental factors have been involved

Environment Pollution

As the sciences have evolved, so has environmental engineering; today, environmental engineers work in a wide variety of settings to improve the condition of the environment. Preventative measures include things like waste management, pollution controls, and resource allocations which are designed to ensure that supplies of clean water endure.

Environmental issues were first pushed to the forefront of the collective consciousness in the late 1900s, when people realized that their activities were having a negative impact on the environment. Pollution, rampant use of natural resources, and other activities were questioned in light of information about how these activities hurt the environment, and people began to look into more eco-friendly ways of living and doing business.

What is Environmental Pollution?

The environment is made up of systems, cycles, and specialized relationships between living and non-living elements. When everything’s working the way it should be, all the living organisms within the environment, including humans, are healthy and thriving.

But when something harmful is introduced to the cycle, or part of the cycle is disrupted somehow, it can cause a chain reaction of problems right through the rest of the system. These changes can really hurt the health and well being of living organisms. One of these negative changes is pollution, which is the result of unnatural elements entering the environment. Unfortunately, humans are usually at fault.

Anything that’s harmful to the environment is pollution. Litter, car exhaust, motor oil, used tires, smoke, chemicals – all of these can have an instant or a gradual impact on the health of our earth.

But even though there’s been a lot of damage done to the environment by pollutants, that doesn’t mean it’s “game over” for Earth. There are two ways to tackle the problem. First, clean up what we can. And second, take action to prevent further pollution.

Land Pollution:Most of the pollution on land comes from litter. People toss away garbage instead of disposing of it properly, which clogs up the land, attracts pests such as insects and rodents, and even harms the soil and the critters that live there if it contains chemicals. If garbage kills the plants in an area by covering them up, it affects the food chain, since green plants are the start of every chain. It also affects the air quality, since plants help clean the air.

Air Pollution:Some pollutants that enter the air come from natural sources. For example, When a volcano erupts, volcanic ash blasts into the air and can remain there for years. Other natural sources of air pollution include smoke from forest fires, and dust and sand from storms.

While there are some natural sources of air pollution, the majority of air pollutants come from things we do ourselves—or things people have invented, such as the combustion engine.

Airborne pollutants make it tough to breathe and can even cause diseases like cancer . One problem is the way winds criss-cross the globe, picking up pollutants and carrying them all over the world. This is how areas far away from where the actual pollution is created can become affected, too. Air pollution is not just a local concern.

Water Pollution:

When sewage, oil, chemicals, and other pollutants enter the water cycle, it can be devastating and even deadly. Sediments that collect in the water from trash or chemicals in the water prevent fishes from filtering oxygen through their gills, and they can suffocate. When the dissolved oxygen in the water drops below a certain level (two to five parts per million gallons of water), many types of fish and aquatic animals can’t survive. Aquatic plants also are “choked” and die, disrupting the food chains.

Water Pollutants can come from various sources

Sewage and farm waste can introduce harmful bacteria.

Herbicides, pesticides, and fertilizers from agriculture can wash into the water.

Beach-goers and boaters often leave their trash behind

Silt from construction or land clearing sites can enter the water through runoff.

Water Pollution

Water pollution refers to the changes in the physical, biological, and chemical conditions of any body of water which detrimentally disrupts the balance of the ecosystem.

Like any type of pollution, water pollution results when an overpowering amount of waste coming from different sources of pollutants can no longer be accommodated by the natural ecosystem. Consequently, when the wastes are non ruined as fast as they are produced, they make it unfavorable to humans and many other organisms. But that’s not all. Learn more about what causes water pollution.

There are really many particular reasons behind what causes water pollution. However, it is important to acquaint yourself with the two main categories of water pollution. Some pollution comes directly from one’s particular location. This type of pollution is called point source pollution such as sewerage pipes that empty polluted water into the river and farmland. Meanwhile, non-point source pollution is pollution that comes from large areas like gasoline and other dirt from highways that go into the lakes and rivers.

What are the causes water pollution? Who are the culprits who should be responsible for the harm brought by their pollutants? How do these sources of pollution foul dissimilar bodies of water?

One major cause of water pollution that has caused serious environmental and wellness problems are the pollutants coming from chemical and industrial processes. When factories and manufacturers pour their chemicals and stock wastes directly into streams and rivers, the water becomes poisonous and oxygen levels are low causation many aquatic organisms to die. These wastes include solvents and toxic substances. Most of the wastes are non biodegradable. Power plants, paper mills, refineries, automobile factories dispose waste into the rivers.

The heated water from the power plants is called thermal pollution. This kills aquatic animals and plants by reducing the oxygen content of the water. Power plants use water to cool their machineries, thus changing the temperature of the water.

Aside from thermal pollution, there are also organic and inorganic pollutants. The organic wastes admit refuse from slaughter houses, fish and meat canning factories, and leather tanning companies, manufacturing plants, pesticides and crude oil companies. Since organic wastes are decomposed by microorganisms, much of the dissolved o in water is used up and the waster begins to stink.

Inorganic wastes admit toxic and corrosive substances like acids, heavy metals, mercury, cadmium and lead which can impair the normal body processes. Battery manufacturers, mining, paper mills increase the concentration of mercury making the water dangerous and poisonous for most living things.

Another cause of water pollution is from pesticides. Farm pesticides poison aquatic plants and animals. Animal manure, chemical fertilizers, orthophosphate detergent foul water by provision excess nutrients. This pollution is known as eutrophication. This greatly increases the growth of algae in water thereby decreasing the amount of oxygen level in water causation the death of many aquatic organisms.

Water is also being polluted by garbage specifically plastics and other plastic-like substances. Some plastic like nylon can entangle fishes and other marine animals. Plastics that have broken down into tiny pieces can be eaten by sea creatures which may cause their death. Since plastic is non-biodegradable, it will continue to kill more fishes.

One more cause of water pollution is sewage coming from households. Since no one wants to live in a contaminated area, near a dumpsite or landfill, the wastewater and untreated sewage are carried away from the home polluting unlike bodies of water. Most development countries practice this type of sewage disposal. Even modern countries carry poorly treated sewerage to canals leading to major bodies of water. The peril is when the sewage pipes gets broken and waste contaminates the drinking water. When this happens, the break will open a wide array of water borne diseases that will surely pose peril to consumers.

Last among the causes of water pollution are personal care and household products. Shampoo, lotion, moisturizer, hair dye, bleach, laundry detergent, fabric softener, and many others contribute to water pollution. Human waste is not the only thing that goes to sewage. These products also join the wastewater to contaminate the streams, rivers, and lakes.

Although the world abounds with water, only three percent of it is potable. Included in the 3% source of potable water are the streams, spring, rivers, lakes, and waterfalls that are continuously being threatened and contaminated by the unlike factors that cause of water pollution. If the sources of water pollution are not controlled, this basic necessity will eventually become a rare good only a few can afford to have

Water Pollution(continued)

Today, the world is facing one of the most serious problems of humanity and other forms of life, pollution. It is a known fact that pollution is very rampant(ip) all over the globe. Just look around and you will see rivers, lakes, beaches that are murky, stinky, and lifeless. Plastic, empty cans, bottles, and other trash have replaced the fishes and other wonderful marine creatures that used to reside under water. Yet, when scarceness arises and when epidemics occur many point their fingers to others and turn their backs from the responsibility. But in fact there is no one else to blame but the people. Man is the main cause of water pollution.

People foul the water with chemicals and other wild materials. People have no regard to water – their source of life. They do not realize that this once abundant resourcefulness is rapidly being contaminated due to their negligence and carelessness.

Waste disposal has always been an inveterate problem, none only because of the amount of wastes, but because of its kind and the inadequate provision for a good system and technology to address the problem. There are many sources of water pollution but it is non the source that is really causation the problem but the improper disposal of the pollutants. People resort to regardless disposal because it is cheaper, more advantageous, or simply commodious to them.

When you are taking a bath using your favorite shampoo or whenever you wash your laundry using no other than the best detersive in town, it is certain that before buying those products you really ne’er consider request yourself whether their contents can harm the environment or not. What mattered more was the scent and softness of your hair and the clean comfort of your clothes. Instead of finding an environmental friendly product, you simply chose convenience and your satisfaction of meeting your interests. However, if you will support environmental favorable products and become more conscientious of how you can avoid contributing to water pollution, then the world has gotten disembarrass of one polluter.

In the same way, if chemic factories are only equipped with better facilities that can release treated wastewater, there will be no harm through to the lakes or rivers where they dump their by products. If home owners associations will work to build and provide their subdivisions with sewage treatment facilities, eutrophication can be controlled and dying bodies of water will be spared. But as mentioned, polluters choose the easier way where they can save on operation costs and where they can free themselves of the hassles of responsibility. Anyway, they are not affected by the effects of their misdeeds.

Aside from improper and regardless waste disposal, another main cause of water pollution is toxic substances coming from industrial, farming(a) and domestic use. Trace elements of lead, cadmium mercury, dioxins ar detected in different water sources which sometimes accumulate in the water supply causing health problems. These toxic substances come from industries such mining, power plants, automobile manufacturers and others that produce toxic substances leading to bodies of water. Apart from these industries, these toxic materials contaminate the water through accidents like chemic or oil spills.

One more main cause of water pollution is the presence of excessive nutrients in the water. Nitrogen and phosphorous compounds that generally come from sewage, fertilizers, and animal manure ar good food sources of algae. Excess nutrients in water also result to excessive growth

of algae that deprive aquatic plants and animals adequate levels of oxygen to survive. Because of this many aquatic organisms die and decay which aggravates the problem.

Lastly, another considerable main cause of water pollution is sedimentation. Although it is hard to imagine how soil particles can contribute to water pollution, but it does. When huge amount of solid particles accumulate in water, whether due to deforestation, farming, or soil erosion, the sediments cloud the spawning grounds of fishes leading to their gradual extinction.

Humans greatly affect the environment. People will either be heroes or villains of Mother Nature. Toxic substances, algal bloom, deposit are all end results of human activities. These pollutants are not the real evils of water pollution but the people behind every wrong disposal and negligence. Unless man realizes that it is non the prohibition of pollutants nor banning industrial productions that should be changed but the behavior and attitude he possesses towards his environment, the rivers, lakes, and other water systems have no hope to be saved.

Water Pollution Cycles

Mankind moldiness continually look into his rearview mirror when it comes to the environment, and in doing so helium moldiness understand his history accurately and with a clear view supported by empiric data. When it comes to pollution we need to separate out the various types of pollution, and as you know some pollution occurs naturally and is very much part of the standard cycles.

Consider if you will the pollution caused by a volcano erupting, methane burp in the ocean, or erosion causing mineral deposits to leach corrupting what would normally be fresh water, then flowing to the ocean effecting ocean life, delta regions, and changing the distribution and chemic balance of the water. When it comes to water pollution caused by mankind there ar several serious challenges.

The first comes from nitrates from agriculture which run-off into fresh surface water, underground aquifers, and into the oceans. There are many dead zones off the coasts from these activities. Dead zones ar areas where the o has been low in the water, therefore nothing grows, little or no fish or aquatic life – this is a stain on mankind’s stewardship indeed.

Another big cause of pollution in water is the acidification caused by man-made emissions and chemicals into the air. Still, Mother Nature is also a big contributor in this case as well – volcanoes for instance. But that still doesn’t make it okay for humans to unnecessarily contaminate the air causing acid rain, and run-off into the water.

Then of course, there is human waste, trash and garbage, as well as discharges from non-treated biological waste. Sewer treatment plants overflow too often, but then many areas do non have

sewer treatment plants at all. There ar also overflows from animal waste and livestock, and these too can be quite damaging to the environment.

Industrial waste, household waste, and polluted urban run-off ar all serious. Taken individually, it’s really nothing the water cannot handle, but cumulatively, it’s a real challenge, and the results are in folks, we haven’t done such a hot job, we need to do better – that means everyone.

We also have all heard about oil spills and what have you, but we should realize that crude oil spills are not as bad for the environment as refined petroleum products. It’s non that crude oil doesn’t make a mess or cause problems, it surely does, but crude oil also leaks out into rivers and oceans and has for millions of years in various places, and that’s nothing new. It is part of the cycle of geological eras.

Yes, mankind needs to do a better job policing itself when it comes to pollution, after all we have to drink the water, and we also eat fish. So the Planet’s water is the last thing we need to be polluting if we wish to survive, that is to say; if we want to live long and prosper. Indeed, I hope you will delight consider all this.

Environmental Engineering

is the application of science and engineering principles to improve the natural environment (air, water, and/or land resources), to provide healthy water, air, and land for human habitation (house or home) and for other organisms, and to remediate polluted sites. It involves waste water management and air pollution control, recycling, waste disposal, radiation protection, industrial hygiene, environmental sustainability, and public health issues as well as a knowledge of environmental engineering law. It also includes studies on the environmental impact of proposed construction projects.

1. Environmental engineers conduct hazardous-waste management studies to evaluate the significance of such hazards, advise on treatment and containment, and develop regulations to prevent mishaps. Environmental engineers also design municipal water supply and industrial wastewater treatment systems[1][2] as well as address local and worldwide environmental issues such as the effects of acid rain, global warming, ozone depletion, water pollution and air pollution from automobile exhausts and industrial sources.[3][4][5][6] At many universities, Environmental Engineering programs follow either the Department of Civil Engineering or The Department of Chemical Engineering at Engineering faculties.

Environmental "civil" engineers focus on hydrology, water resources management, bioremediation, and water treatment plant design. Environmental "chemical" engineers, on the other hand, focus on environmental chemistry, advanced air and water treatment technologies and separation processes.

Additionally, engineers are more frequently obtaining specialized training in law (J.D.) and are utilizing their technical expertise in the practices of Environmental engineering law.[citation needed]. About four percent of environmental engineers go on to obtain Board Certification in their specialty area(s) of environmental engineering (Board Certified Environmental Engineer or BCEE) {http://www.aaee.net].

Most jurisdictions also impose licensing and registration requirements.

Development of environmental engineering

Ever since people first recognized that their health and well-being were related to the quality of their environment, they have applied thoughtful principles to attempt to improve the quality of their environment. The ancient Harappan civilization utilized early sewers in some cities. The Romans constructed aqueducts to prevent drought and to create a clean, healthful water supply for the metropolis of Rome. In the 15th century, Bavaria created laws restricting the development and degradation of alpine country that constituted the region's water supply.

The field emerged as a separate environmental discipline during the middle third of the 20th century in response to widespread public concern about water and pollution and increasingly extensive environmental quality degradation. However, its roots extend back to early efforts in public health engineering.[7] Modern environmental engineering began in London in the mid-19th century when Joseph Bazalgette designed the first major sewerage system that reduced the incidence of waterborne diseases such as cholera. The introduction of drinking water treatment and sewage treatment in industrialized countries reduced waterborne diseases from leading causes of death to rarities.[8]

In many cases, as societies grew, actions that were intended to achieve benefits for those societies had longer-term impacts which reduced other environmental qualities. One example is the widespread application of DDT to control agricultural pests in the years following World War II. While the agricultural benefits were outstanding and crop yields increased dramatically, thus reducing world hunger substantially, and malaria was controlled better than it ever had been, numerous species were brought to the verge of extinction due to the impact of the DDT on their reproductive cycles. The story of DDT as vividly told in Rachel Carson's "Silent Spring" is considered to be the birth of the modern environmental movement and the development of the modern field of "environmental engineering."[9]

Conservation movements and laws restricting public actions that would harm the environment have been developed by various societies for millennia. Notable examples are the laws decreeing the construction of sewers in London and Paris in the 19th century and the creation of the U.S. national park system in the early 20th century.

Scope of Environmental Engineering

Briefly speaking, the main task of environmental engineers is to protect public health by protecting (from further degradation), preserving (the present condition of), and enhancing the environment. Environmental engineering is the application of science and engineering principles to the environment. Some consider environmental engineering to include the development of sustainable processes. There are several divisions of the field of environmental engineering.

Environmental impact assessment and mitigation

In this division, engineers and scientists use a systemic identification and evaluation process to assess the potential impacts of a proposed project , plans, programs, policies, or legislative actions upon the physical-chemical, biological, cultural, and socioeconomic components on environmental conditions.[10] They apply scientific and engineering principles to evaluate if there are likely to be any adverse impacts to water quality, air quality, habitat quality, flora and fauna, agricultural capacity, traffic impacts, social impacts, ecological impacts, noise impacts, visual (landscape) impacts, etc. If impacts are expected, they then develop mitigation measures to limit or prevent such impacts. An example of a mitigation measure would be the creation of wetlands in a nearby location to mitigate the filling in of wetlands necessary for a road development if it is not possible to reroute the road.

The practice of environmental assessment was intitiated on January 1, 1970, the effective date of the National Environmental Policy Act (NEPA) in the United States. Since that time, more than 100 developing and developed nations either have planned specific analogous laws or have adopted procedure used elsewhere. NEPA is applicable to all federal agencies in the United States.[10]

Water supply and treatment

Engineers and scientists work to secure water supplies for potable and agricultural use. They evaluate the water balance within a watershed and determine the available water supply, the water needed for various needs in that watershed, the seasonal cycles of water movement through the watershed and they develop systems to store, treat, and convey water for various uses. Water is treated to achieve water quality objectives for the end uses. In the case of potable water supply, water is treated to minimize the risk of infectious disease transmission, the risk of non-infectious illness, and to create a palatable water flavor. Water distribution systems are designed and built to provide adequate water pressure and flow rates to meet various end-user needs such as domestic use, fire suppression, and irrigation.

Wastewater conveyance and treatment

Wastewater Treatment

Most urban and many rural areas no longer discharge human waste directly to the land through outhouse, septic, and/or honey bucket systems, but rather deposit such waste into water and convey it from households via sewer systems. Engineers and scientists develop collection and treatment systems to carry this waste material away from where people live and produce the waste and discharge it into the environment. In developed countries, substantial resources are applied to the treatment and detoxification of this waste before it is discharged into a river, lake, or ocean system. Developing nations are striving to obtain the resources to develop such systems so that they can improve water quality in their surface waters and reduce the risk of water-borne infectious disease.

Sewage treatment plant, Australia.

There are numerous wastewater treatment technologies. A wastewater treatment train can consist of a primary clarifier system to remove solid and floating materials, a secondary treatment system consisting of an aeration basin followed by flocculation and sedimentation or an activated sludge system and a secondary clarifier, a tertiary biological nitrogen removal system, and a final disinfection process. The aeration basin/activated sludge system removes organic material by growing bacteria (activated sludge). The secondary clarifier removes the activated sludge from the water. The tertiary system, although not always included due to costs, is becoming more prevalent to remove nitrogen and phosphorus and to disinfect the water before discharge to a surface water stream or ocean outfall.[11]

Air quality management

Engineers apply scientific and engineering principles to the design of manufacturing and combustion processes to reduce air pollutant emissionsto acceptable levels. Scrubbers, electrostatic precipitators, catalytic converters, and various other processes are utilized to remove particulate matter, nitrogen oxides, sulfur oxides, volatile organic compounds (VOC), reactive organic gases (ROG) and other air pollutants from flue gases and other sources prior to allowing their emission to the atmosphere.

Scientists have developed air pollution dispersion models to evaluate the concentration of a pollutant at a receptor or the impact on overall air quality from vehicle exhausts and industrial flue gas stack emissions. To some extent, this field overlaps the desire to decrease carbon dioxide and other greenhouse gas emissions from combustion processes.

Environmental Problems

A variety of environmental problems now affect our entire world. As globalization continues and the earth's natural processes transform local problems into international issues, few societies are being left untouched by major environmental problems.

Some of the largest problems now affecting the world are Acid Rain, Air Pollution, Global Warming, Hazardous Waste, Ozone Depletion, Smog, Water Pollution, Overpopulation, and Rain Forest Destruction

Pollution is the introduction of contaminants into a natural environment that causes instability, disorder, harm or discomfort to the ecosystem i.e. physical systems or living organisms.[1] Pollution can take the form of chemical substances or energy, such as noise, heat, or light. Pollutants, the elements of pollution, can be foreign substances or energies, or naturally occurring; when naturally occurring, they are considered contaminants when they exceed natural levels. Pollution is often classed as point source or nonpoint source pollution. The Blacksmith Institute issues an annual list of the world's worst polluted places. In the 2007 issues the ten top nominees are located in Azerbaijan, China, India, Peru, Russia, Ukraine, and Zambia.[2]

Forms of pollution

The Lachine Canal in Montreal Canada, is polluted.

The major forms of pollution are listed below along with the particular pollutants relevant to each of them:

Air pollution , the release of chemicals and particulates into the atmosphere. Common gaseous pollutants include carbon monoxide, sulfur dioxide, chlorofluorocarbons (CFCs) and nitrogen oxides produced by industry and motor vehicles. Photochemical ozone and smog are created as nitrogen oxides and hydrocarbons react to sunlight. Particulate matter, or fine dust is characterized by their micrometre size PM10 to PM2.5.

Light pollution , includes light trespass, over-illumination and astronomical interference. Littering Noise pollution , which encompasses roadway noise, aircraft noise, industrial noise as well as

high-intensity sonar. Soil contamination occurs when chemicals are released intentionally, by spill or underground

leakage. Among the most significant soil contaminants are hydrocarbons, heavy metals, MTBE,[9] herbicides, pesticides and chlorinated hydrocarbons.

Radioactive contamination , resulting from 20th century activities in atomic physics, such as nuclear power generation and nuclear weapons research, manufacture and deployment. (See alpha emitters and actinides in the environment.)

Thermal pollution , is a temperature change in natural water bodies caused by human influence, such as use of water as coolant in a power plant.

Visual pollution , which can refer to the presence of overhead power lines, motorway billboards, scarred landforms (as from strip mining), open storage of trash or municipal solid waste.

Water pollution , by the discharge of wastewater from commercial and industrial waste (intentionally or through spills) into surface waters; discharges of untreated domestic sewage, and chemical contaminants, such as chlorine, from treated sewage; release of waste and contaminants into surface runoff flowing to surface waters (including urban runoff and

agricultural runoff, which may contain chemical fertilizers and pesticides); waste disposal and leaching into groundwater; eutrophication and littering.

Pollutants :A pollutant is a waste material that pollutes air, water or soil. Three factors determine the severity of a pollutant: its chemical nature, the concentration and the persistence.

Sources and causes

Air pollution comes from both natural and man made sources. Though globally man made pollutants from combustion, construction, mining, agriculture and warfare are increasingly significant in the air pollution equation.[10]

Motor vehicle emissions are one of the leading causes of air pollution.[11][12][13] China, United States, Russia, Mexico, and Japan are the world leaders in air pollution emissions. Principal stationary pollution sources include chemical plants, coal-fired power plants, oil refineries,[14] petrochemical plants, nuclear waste disposal activity, incinerators, large livestock farms (dairy cows, pigs, poultry, etc.), PVC factories, metals production factories, plastics factories, and other heavy industry. Agricultural air pollution comes from contemporary practices which include clear felling and burning of natural vegetation as well as spraying of pesticides and herbicides[15]

About 400 million metric tons of hazardous wastes are generated each year.[16] The United States alone produces about 250 million metric tons.[17] Americans constitute less than 5% of the world's population, but produce roughly 25% of the world’s CO2,[18] and generate approximately 30% of world’s waste.[19][20] In 2007, China has overtaken the United States as the world's biggest producer of CO2,[21] while still far behind based on per capita pollution - ranked 78th among the world's nation. [22]

In February 2007, a report by the Intergovernmental Panel on Climate Change (IPCC), representing the work of 2,500 scientists, economists, and policymakers from more than 120 countries, said that humans have been the primary cause of global warming since 1950. Humans have ways to cut greenhouse gas emissions and avoid the consequences of global warming, a major climate report concluded. But in order to change the climate, the transition from fossil fuels like coal and oil needs to occur within decades, according to the final report this year from the UN's Intergovernmental Panel on Climate Change (IPCC).[23]

Some of the more common soil contaminants are chlorinated hydrocarbons (CFH), heavy metals (such as chromium, cadmium–found in rechargeable batteries, and lead–found in lead paint, aviation fuel and still in some countries, gasoline), MTBE, zinc, arsenic and benzene. In 2001 a series of press reports culminating in a book called Fateful Harvest unveiled a widespread practice of recycling industrial byproducts into fertilizer, resulting in the contamination of the soil with various metals. Ordinary municipal landfills are the source of many chemical substances entering the soil environment (and often groundwater), emanating from the wide variety of refuse accepted, especially substances illegally discarded there, or from pre-1970 landfills that may have been subject to little control in the U.S. or EU. There have also been

some unusual releases of polychlorinated dibenzodioxins, commonly called dioxins for simplicity, such as TCDD.[24]

Pollution can also be the consequence of a natural disaster. For example, hurricanes often involve water contamination from sewage, and petrochemical spills from ruptured boats or automobiles. Larger scale and environmental damage is not uncommon when coastal oil rigs or refineries are involved. Some sources of pollution, such as nuclear power plants or oil tankers, can produce widespread and potentially hazardous releases when accidents occur.

In the case of noise pollution the dominant source class is the motor vehicle, producing about ninety percent of all unwanted noise worldwide.

Effects

Human health

Overview of main health effects on humans from some common types of pollution.[25][26][27]

Adverse air quality can kill many organisms including humans. Ozone pollution can cause respiratory disease, cardiovascular disease, throat inflammation, chest pain, and congestion. Water pollution causes approximately 14,000 deaths per day, mostly due to contamination of drinking water by untreated sewage in developing countries. An estimated 700 million Indians have no access to a proper toilet, and 1,000 Indian children die of diarrhoeal sickness every day.[28] Nearly 500 million Chinese lack access to safe drinking water.[29] 656,000 people die prematurely each year in China because of air pollution. In India, air pollution is believed to cause 527,700 fatalities a year.[30] Studies have estimated that the number of people killed annually in the US could be over 50,000.[31]

Oil spills can cause skin irritations and rashes. Noise pollution induces hearing loss, high blood pressure, stress, and sleep disturbance. Mercury has been linked to developmental deficits in children and neurologic symptoms. Older people are majorly exposed to diseases induced by air pollution. Those with heart or lung disorders are under additional risk. Children and infants are

also at serious risk. Lead and other heavy metals have been shown to cause neurological problems. Chemical and radioactive substances can cause cancer and as well as birth defects.

Environment

Pollution has been found to be present widely in the environment. There are a number of effects of this:

Biomagnification describes situations where toxins (such as heavy metals) may pass through trophic levels, becoming exponentially more concentrated in the process.

Carbon dioxide emissions cause ocean acidification, the ongoing decrease in the pH of the Earth's oceans as CO2 becomes dissolved.

The emission of greenhouse gases leads to global warming which affects ecosystems in many ways.

Invasive species can out compete native species and reduce biodiversity. Invasive plants can contribute debris and biomolecules (allelopathy) that can alter soil and chemical compositions of an environment, often reducing native species competitiveness.

Nitrogen oxides are removed from the air by rain and fertilise land which can change the species composition of ecosystems.

Smog and haze can reduce the amount of sunlight received by plants to carry out photosynthesis and leads to the production of tropospheric ozone which damages plants.

Soil can become infertile and unsuitable for plants. This will affect other organisms in the food web.

Sulphur dioxide and nitrogen oxides can cause acid rain which lowers the pH value of soil.

Noise, by definition, is unwanted sound. What is pleasant to some ears may be extremely unpleasant to others, depending on a number of factors. The natural environment contains many sources of noise - wind, volcanoes, oceans, and animal sounds are all familiar intrusions accepted at various levels. Man-made noises - from machines, automobiles, trains, planes, explosives and firecrackers, etc. - are more contentious. Both kinds of noise affect sleep, hearing, communication, as well as mental and physical health.

Pollution is a noun derived from the verb pollute, meaning: to foul. It is now increasingly understood that pollution from noise is an important component of air pollution, which was previously understood as being limited to material pollution. Noise is an inescapable by-product of the industrial environment, which is increasing with advances in industrialization and urbanization. Even in non-industrial areas, noise from such activities as printing, auto-repair, grinding, affects those living in the immediate surroundings. Noise not only causes irritation or annoyance but also constricts the arteries, and increases the flow of adrenaline and forces the heart to work faster. Continuous noise causes an increase in the cholesterol level resulting in permanent constriction of blood vessels, making one prone to heart attacks and strokes. Health experts are of the opinion that excessive noise can also lead to neurosis and nervous breakdown.

Noise travels through air and hence it is measured in ambient air quality level. Noise is measured in decibels. Experts believe that continuous noise levels in excess of 90 decibels can cause loss of

hearing and irreversible changes in nervous systems. The World Health Organization [WHO] has fixed 45 decibels as the safe noise level for a city. Metropolitan areas in India usually register an average more than 90 decibels; Mumbai is rated the third noisiest city in the world, with New Delhi following closely.

Waste and Water Pollution

When toxic substances enter lakes, streams, rivers, oceans, and other water bodies, they get dissolved or lie suspended in water or get deposited on the bed. This results in the pollution of water whereby the quality of the water deteriorates, affecting aquatic ecosystems. Pollutants can also seep down and affect the groundwater deposits.

Today, many people dump their garbage into streams, lakes, rivers, and seas, thus making water bodies the final resting place of cans, bottles, plastics, and other household products. The various substances that we use for keeping our houses clean add to water pollution as they contain harmful chemicals. In the past, people mostly used soaps made from animal and vegetable fat for all types of washing. But most of today’s cleaning products are synthetic detergents and come from the petrochemical industry. Most detergents and washing powders contain phosphates, which are used to soften the water among other things. These and other chemicals contained in washing powders affect the health of all forms of life in the water.

The effects of water pollution are not only devastating to people but also to animals, fish, and birds. Polluted water is unsuitable for drinking, recreation, agriculture, and industry. It diminishes the aesthetic quality of lakes and rivers. More seriously, contaminated water destroys aquatic life and reduces its reproductive ability. Eventually, it is a hazard to human health. Nobody can escape the effects of water pollution

Air Pollution

One of the formal definitions of air pollution is as follows – ‘The presence in the atmosphere of one or more contaminants in such quality and for such duration as is injurious, or tends to be injurious, to human health or welfare, animal or plant life.’ It is the contamination of air by the discharge of harmful substances. Air pollution can cause health problems and it can also damage the environment and property. It has caused thinning of the protective ozone layer of the atmosphere, which is leading to climate change.

Modernisation and progress have led to air getting more and more polluted over the years. Industries, vehicles, increase in the population, and urbanization are some of the major factors responsible for air pollution. The following industries are among those that emit a great deal of pollutants into the air: thermal power plants, cement, steel, refineries, petro chemicals, and mines.

Air pollution results from a variety of causes, not all of which are within human control. Dust storms in desert areas and smoke from forest fires and grass fires contribute to chemical and particulate pollution of the air. The source of pollution may be in one country but the impact of pollution may be felt elsewhere. The discovery of pesticides in Antarctica, where they have never been used, suggests the extent to which aerial transport can carry pollutants from one place to another.

Listed below are the major air pollutants and their sources.

Carbon monoxide (CO) is a colourless, odourless gas that is produced by the incomplete burning of carbon-based fuels including petrol, diesel, and wood. It is also produced from the combustion of natural and synthetic products such as cigarettes. It lowers the amount of oxygen that enters our blood . It can slow our reflexes and make us confused and sleepy

Carbon dioxide (CO2) is the principle greenhouse gas emitted as a result of human activities such as the burning of coal, oil, and natural gases.

Chloroflorocarbons (CFC) are gases that are released mainly from air-conditioning systems and refrigeration. When released into the air, CFCs rise to the stratosphere, where they come in contact with few other gases, which leads to a reduction of the ozone layer that protects the earth from the harmful ultraviolet rays of the sun.

Lead is present in petrol, diesel, lead batteries, paints, hair dye products, etc. Lead affects children in particular. It can cause nervous system damage and digestive problems and, in some cases, cause cancer.

Ozone occur naturally in the upper layers of the atmosphere. This important gas shields the earth from the harmful ultraviolet rays of the sun. However, at the ground level, it is a pollutant with highly toxic effects. Vehicles and industries are the major source of ground-level ozone emissions. Ozone makes our eyes itch, burn, and water. It lowers our resistance to colds and pneumonia

Nitrogen oxide (Nox) causes smog and acid rain. It is produced from burning fuels including petrol, diesel, and coal. Nitrogen oxides can make children susceptible to respiratory diseases in winters.

Suspended particulate matter (SPM) consists of solids in the air in the form of smoke, dust, and vapour that can remain suspended for extended periods and is also the main source of haze which reduces visibility. The finer of these particles, when breathed in can lodge in our lungs and cause lung damage and respiratory problems.

Sulphur dioxide (SO2) is a gas produced from burning coal, mainly in thermal power plants. Some industrial processes, such as production of paper and smelting of metals, produce sulphur dioxide. It is a major contributor to smog and acid rain. Sulfur dioxide can lead to lung diseases.

Chemical Pollution

In some parts of the world, the bodies of whales and dolphins washing ashore are so highly contaminated that they qualify as toxic waste and have to be specially disposed of. There are many different sources of chemical pollution, including:

domestic sewage industrial discharges seepage from waste sites atmospheric fallout domestic run-off accidents and spills at sea operational discharges from oil rigs mining discharges and agricultural run-off.

However, the chemicals that are probably of most concern for everyone are the persistent pollutants: those substances that enter marine food chains and are eventually passed along the chain to the marine top predators in increasing amounts.Persistent pollutants include pesticides, such as DDT, and industrial chemicals, most famously the PCBs.