Introduction of Environmental pollution

Perhaps the overriding theme of these definitions is the ability of the environment to absorb and adapt to changes brought about by human activities.

In one word, environmental pollution takes place when the environment cannot process and neutralize harmful by-products of human activities.

In fact, “the due course” itself may last many years during which the nature will attempt to decompose the pollutants; in one of the worst cases – that of radioactive pollutants – it may take as long as thousands of years for the decomposition of such pollutants to be completed.

Pollution occurs, on the one hand, because the natural environment does not know how to decompose the unnaturally generated elements. On the other, there is a lack of knowledge on the part of humans on how to decompose these pollutants artificially.

Although pollution had been known to exist for a very long time since people started using fire thousands of years ago, it had seen the growth of truly global proportions only since the onset of the industrial revolution during the 19th century.

Technological progress facilitated by super efficiency of capitalist business practices (division of labour – cheaper production costs – overproduction – overconsumption – overpollution) had probably become one of the main causes of serious deterioration of natural resources.The industrial revolution brought with it technological progress such as discovery of oil and its virtually universal use throughout different industries.

At the same time, of course, development of natural sciences led to the better understanding of negative effects produced by pollution on the environment.

Environmental pollution is a problem both in developed and developing place greater demands on the planet and stretch the use of natural resources to the maximum.

It has been argued that the carrying capacity of Earth is significantly smaller than the demands placed on it by large numbers of human populations. And overuse of natural resources often results in nature’s degradation.countries. Factors such as population growth and urbanization invariably 

Soil Pollution

Soil pollution comprises the pollution of soils with materials, mostly chemicals, that are out of place or are present at concentrations higher than normal which may have adverse effects on humans or other organisms. It is difficult to define soil pollution exactly because different opinions exist on how to characterize a pollutant; while some consider the use of pesticides acceptable if their effect does not exceed the intended result, others do not consider any use of pesticides or even chemical fertilizers acceptable. However, soil pollution is also caused by means other than the direct addition of xenobiotic (man-made) chemicals such as agricultural runoff waters, industrial waste materials, acidic precipitates, and radioactive fallout.

Both organic (those that contain carbon) and inorganic (those that don't) contaminants are important in soil. The most prominent chemical groups of organic contaminants are fuel hydrocarbons, polynuclear aromatic hydrocarbons ( PAHs ), polychlorinated

biphenyls ( PCBs ), chlorinated aromatic compounds, detergents, and pesticides. Inorganic species include nitrates, phosphates, and heavy metals such as cadmium, chromium and lead; inorganic acids; and radionuclides (radioactive substances). Among the sources of these contaminants are agricultural runoffs, acidic precipitates, industrial waste materials, and radioactive fallout.

Soil pollution can lead to water pollution if toxic chemicals leach into groundwater, or if contaminated runoff reaches streams, lakes, or oceans. Soil also naturally contributes to air pollution by releasing volatile compounds into the atmosphere. Nitrogen escapes through ammonia volatilization and denitrification . The decomposition of organic materials in soil can release sulfur dioxide and other sulfur compounds, causing acid rain. Heavy metals and other potentially toxic elements are the most serious soil pollutants in sewage. Sewage sludge contains heavy metals and, if applied repeatedly or in large amounts, the treated soil may accumulate heavy metals and consequently become unable to even support plant life.

In addition, chemicals that are not water soluble contaminate plants that grow on polluted soils, and they also tend to accumulate increasingly toward the top of the food chain. The banning of the pesticide DDT in the United States resulted from its tendency to become more and more concentrated as it moved from soil to worms or fish, and then to birds and their eggs. This occurred as creatures higher on the food chain ingested animals that were already contaminated with the pesticide from eating plants and other lower animals. Lake Michigan, as an example, has 2 parts per trillion (ppt) of DDT in the water, 14 parts per billion (ppb) in the bottom mud, 410 ppb in amphipods (tiny water fleas and similar creatures), 3 to 6 parts per million (ppm) in fish such as coho salmon and lake trout, and as much as 99 ppm in herring gulls at the top of the food chain.

The ever-increasing pollution of the environment has been one of the greatest concerns for science and the general public in the last fifty years. The rapid industrialization of agriculture, expansion of the chemical industry, and the need to generate cheap forms of energy has caused the continuous release of man-made organic chemicals into natural ecosystems. Consequently, the atmosphere, bodies of water, and many soil environments have become polluted by a large variety of toxic compounds. Many of these compounds at high concentrations or following prolonged exposure have the potential to produce adverse effects in humans and other organisms: These include the danger of acute toxicity, mutagenesis (genetic changes), carcinogenesis, and teratogenesis (birth defects) for humans and other organisms. Some of these man-made toxic compounds are also resistant to physical, chemical, or biological degradation and thus represent an environmental burden of considerable magnitude.
Numerous attempts are being made to decontaminate polluted soils, including an array of both in situ (on-site, in the soil) and off-site (removal of contaminated soil for treatment) techniques. None of these is ideal for remediating contaminated soils, and often, more than one of the techniques may be necessary to optimize the cleanup effort.
The most common decontamination method for polluted soils is to remove the soil and deposit it in landfills or to incinerate it. These methods, however, often exchange one problem for another: landfilling merely confines the polluted soil while doing little to decontaminate it, and incineration removes toxic organic chemicals from the soil, but subsequently releases them into the air, in the process causing air pollution.
For the removal and recovery of heavy metals various soil washing techniques have been developed including physical methods, such as attrition scrubbing and wet-screening, and chemical methods consisting of treatments with organic and inorganic acids, bases, salts and chelating agents. For example, chemicals used to extract radionuclides and toxic metals include hydrochloric, nitric, phosphoric and citric acids, sodium carbonate and sodium hydroxide and the chelating agents EDTA and DTPA. The problem with these methods, however, is again that they generate secondary waste products that may require additional hazardous waste treatments.

In contrast to the previously described methods, in situ methods are used directly at the contamination site. In this case, soil does not need to be excavated, and therefore the chance of causing further environmental harm is minimized. In situ biodegradation involves the enhancement of naturally occurring microorganisms by artificially stimulating their numbers and activity. The microorganisms then assist in degrading the soil contaminants. A number of environmental, chemical, and management factors affect the biodegradation of soil pollutants, including moisture content, pH, temperature, the microbial community that is present, and the availability of nutrients. Biodegradation is facilitated by aerobic soil conditions and soil pH in the neutral range (between pH 5.5 to 8.0), with an optimum reading occurring at approximately pH 7, and a temperature in the range of 20 to 30°C. These physical parameters can be influenced, thereby promoting the microorganisms' ability to degrade chemical contaminants. Of all the decontamination methods bioremediation appears to be the least damaging and most environmentally acceptable technique.

ways to prevent

Herbicide, Pesticide and Fertilizer

Herbicides are chemicals used to kill weeds and unwanted plants while pesticides are substances that kill unwanted insects and pests. Fertilizers supply nutrients to plants to help them grow but can contain heavy metals which can be harmful to the animals, including humans, that eat the plant say the Food and Fertilizer Technology Center. Reducing the use of or finding natural alternatives to toxic substances can help prevent soil pollution, according to the National Science Digital Library

Reuse and Recycle

Contribute less waste to help prevent soil pollution. Purchase glass and other reusable containers instead of throwing away plastic or paper regularly. Recycle paper and plastic through your local waste management company to reduce the amount of waste that is sent to a landfill. The National Science Digital Library, NSDL, reports that reusing and recycling products will help conserve natural resources and save more land from contamination.

Proper Solid Waste Treatment

Waste should be disposed of properly to avoid soil pollution. Lobby your community to adopt ways to treat waste before disposing it to prevent pollution. For example, the NSDL suggests that acidic and alkaline waste be neutralized before they are disposed of so they won’t contaminate the soil. Waste that is biodegradable should be broken down in a controlled environment before being disposed of because it is a much faster, resource-saving method.

Water Pollution

Water pollution is an undesirable change in the state of water, contaminated with harmful substances. It is the second most important environmental issue next toair pollution. Any change in the physical, chemical and biological properties of water that has a harmful effect on living things is water pollution. Water pollution effects all the major water bodies of the world such as lakes, rivers, oceans and groundwater. Polluted water is unfit for drinking and for other consumption processes. It is also not suitable for agricultural and industrial use. The effects of water pollution are harmful to human beings, plants, animals, fish and birds. Polluted water also contains viruses, bacteria, intestinal parasites and other harmful microorganisms, which can cause waterborne diseases such as diarrhea, dysentery, and typhoid. Due to water pollution, the entire ecosystem gets disturbed. 

Sources of water pollution
The important sources of water pollution are domestic wastes, industrial effluents and agricultural wastes. Other sources include oil spills, atmospheric deposition, marine dumping, radioactive waste, global warming and eutrophication. Among these, domestic waste (domestic sewage) and industrial waste are the most important sources contributing to water pollution. 

Domestic Sewage: Domestic sewage is wastewater generated from the household activities. It contains organic and inorganic materials such as phosphates and nitrates. Organic materials are food and vegetable waste, whereas inorganic materials come from soaps and detergents. Usually people dump the household wastes in the nearby water source, which leads to water pollution. The amount of organic wastes that can be degraded by the water bodies is measured in terms of Biological Oxygen Demand (BOD). BOD is the amount of oxygen needed by microorganisms to decompose the organic waste present in the sewage. The higher the amount of BOD, the more water is polluted with organic waste. Many people are not aware of the fact that soaps and detergents enrich the water bodies with phosphates. These phosphates often lead to algal bloom and eutrophication, which is is most common in stagnant water bodies such as ponds and lakes. Algal bloom and eutrophication lead to the suffocation of fish and other organism in a water body.

Industrial Effluents:Wastewater from the manufacturing and processing industries causes water pollution. The industrial effluents contain organic pollutants and other toxic chemicals. Some of the pollutants from industrial source include lead, mercury, asbestos, nitrates, phosphates, oils, etc. Wastewater from food and chemical processing industries contribute more to water pollution than the other industries such as distilleries, leather processing industries and thermal power plants. Also dye industries generate wastewater which changes the water quality especially water color. Since the water color is changed, there is alteration in the light penetration and hence it disturbs the aquatic plants and animals. Many of the big industries have come up with wastewater treatment plants. However, it is not the case with small-scale industries. It is very difficult to treat wastewater from the industries.

Let’s take the example of Minamata disease in which more than 1,784 people died and many more suffered due to consumption of fish, bioaccumulated with methyl mercury. It was caused by release of methyl mercury from Chisso Corporation’s chemical factory. The disease continued to affect animals and humans for over 30 years, from 1932 to 1968. 

Agricultural Waste: Agricultural waste include manure, slurries and runoffs. Most of the agricultural farms use chemical fertilizers and pesticides. The runoffs from these agricultural fields cause water pollution to the nearby water sources such as rivers, streams and lakes. The seepage of fertilizers and pesticides causes groundwater pollution, which is commonly known as leaching. Although the quantity of agricultural waste is low, the effects are highly significant. It causes nutrient and organic pollution to both water and soil. Nutrient pollution causes an increase in the nitrates and phosphates in the water bodies, which leads to eutrophication.

Depending upon the origin, sources of water pollution are classified as point source and non-point source and ground-water pollution. Point source pollution discharges the harmful waste directly into water bodies, for example, disposal through wastewater treatment plants. On the other hand, non-point source pollution delivers indirectly through other ways, for example, water pollution from acid rain.

How is Water Pollution Caused?

Although certain natural processes may cause some of the water pollution, however, human activity is the largest cause of our seas, rivers and lakes getting polluted. We need to use water everyday both in our industries as well as our homes. We get this water from groundwater sources, rivers, and lakes, and after using it, and often contaminating it, most of this water gets back into the rivers, lakes, and oceans.

The used water from agricultural and industrial practices, and household use create wastewater, also referred to as sewage. If this is allowed to flow back into water systems without being treated, it causes pollution, which results in harming both humans as well as animal life. Water also gets polluted when there is a runoff of rainwater from industrial, agricultural, and urban areas, which flow directly through stormwater drains into water systems without any treatment. 

The disposal of sewage is a major problem in developing countries where there isn’t adequate sanitation in large areas, thus carrying disease causing bacteria and viruses into sources of water. In countries that are developed, people often flush pharmaceutical and chemical products into their toilet.

Some of the other causes of pollution are oil spillages and dumping in oceans, dumping litter into streams, rivers, and oceans such as cardboard, newspaper, foam, Styrofoam, plastic packaging, aluminum, glass, and so on. Some of these take a very long time to degrade, e.g., plastic packaging can take 400 years, Styrofoam takes 80 years, foam takes 50 years, and aluminum takes 200 years. 

Nuclear waste, atmospheric deposition, and underground storage leakages are some of the other causes of water pollution.

What are the Ways to Prevent Water Pollution?

While we need to see to it that the government is stringent about seeing to it that there are adequate treatment plants to treat sewage, and seeing to it that industries have treatment plants and nuclear plants have proper waste storage systems for radioactive material, and so on, there are many things that we can do individually to prevent water pollution. Given below are a few ways to prevent water pollution:

• Toxic products like paints, automobile oil, polishes, and cleaning products should be stored and disposed off properly. As a matter of fact, it is better to use non-toxic, products for the house as far as possible. Also, never dispose off such products by throwing them into your toilet or sink.
• Dispose off your trash in a proper manner and try and incorporate the recycling habit as far as possible. Non-degradable products like tampons, sanitary napkins, and diapers should not be flushed down the toilet, for these can end up damaging the process of sewage treatment, and usually end up as litter on beaches.
• Refrain from throwing litter into streams, lakes, rivers, or seas. If you do spot litter on beaches or in water systems, after ascertaining that it is safe, collect them and dispose off them in any nearby waste disposal system.
• Try using environmentally friendly household products like toiletries, soap-based household cleaning material, and washing powder as far as possible.
• Try using natural fertilizers and pesticides as far as possible, or if not, do not overuse them or over-water gardens and lawns. This will help in reducing the pollutants that get into water systems due to runoffs.
• Automobile oil should be re-used as far as possible. Also, it is important to keep your automobile well maintained in order to prevent leakages of toxic fluids like antifreeze and oil.
• Also, actively conserve water by turning the tap off when you do not need running water, such as while brushing teeth. Apart from preventing water shortages, it lessens the amount of water that needs to be treated.

Air pollution

Air pollution is a change in the physical, chemical and biological characteristics of air that causes adverse effects on humans and other organisms. The ultimate result is a change in the natural environment and/or ecosystem. The substances that are responsible for causing air pollution are called air pollutants. These air pollutants can be either natural (e.g. wildfires) or synthetic (man-made); they may be in the form of gas, liquid or solid. 

Air pollutants are classified into two categories viz. primary and secondary. The former refers to air pollutants that are directly emitted from the source, for example, carbon monoxide gas from automobile exhaust. The secondary air pollutants, on the other hand, are the result of interaction of primary pollutants, for example, the ground level ozone, which is formed when sunlight hits fuel exhaust in the atmosphere. It is to be noted that some forms of air pollutants are both primary and secondary. Let's discuss in brief about the causes, effects and ways to prevent air pollution. 

Causes and Effects of Air Pollution

The major air pollutants are sulfur dioxides, carbon monoxides, carbon dioxides, nitrogen oxides and particulate matters. Among several different causes of air pollution, burning of fossil fuels, such as coal, petroleum and gasoline is the main source. Fossil fuels are used in all major industries, including the automobiles, jet planes, manufacturing industries, power plants, petroleum refineries etc. 

In the United States, automobile exhaust and power plants are responsible for more than 90 percent of air pollution. Carbon dioxide gas, which is used by the plants for photosynthesis, is identified as the major cause of global warming. Nitrogen oxide and sulfur dioxide, when dissolved in water, can cause acid rain, which in turn, leads to water pollution and and affects the aquatic life. 

Air pollutants, either present inside the house (indoor pollutants) or outside (outdoor pollutants), are hazardous to humans. The effects of air pollution on the human health are many; to mention a few, air pollution can cause respiratory diseases and irritation of eyes and throat. The common symptoms observed after exposure to a high level air pollution are chest tightness, burning eyes and cough. Those with certain medical conditions like heart disease and asthma are more susceptible to the hazards of air pollution than others. The effect of air pollution is more serious in case of children; prolonged exposure to air pollution can lead to earache, bronchitis and asthma in children.

Ways To Prevent Air Pollution

The fact is that human activities contribute the most to air pollution. Considering the harmful effects of air pollution, now it is very essential that everyone should contribute a bit to prevent air pollution. There are certain ways that one can help to reduce the emission of air pollutants in the atmosphere. Following are some tips for preventing air pollution:

Car Pool: Forming and implementing a car pool will reduce the number of cars, thereby, preventing air pollution by cutting down the use offossil fuels. This way, it will help in the sustainable use of fossil fuel and its conservation for the future generations.

Vehicle Care: Timely servicing of the car helps to keep it in a good condition and also minimizes fuel exhaust. Driving the car at an average speed and turning off in traffic is a key to save fuel. Make sure to use unleaded petrol and opt for regular pollution checking of your car. 

Public Transport: Whenever possible, try to travel by public transports. This helps in two ways; prevents air pollution and increases public income. If you are going to a nearby place, go by walking or use bicycle, instead of using your vehicle. The objective is to minimize the use of fuels, as far as possible. 

Alternative Energy Source: Another effective way to prevent air pollution is to use alternative energy sources such as solar energy, hydroelectric energy and wind energy. Nowadays, sophisticated technologies such as wind turbine, solar water heaters are introduced to generate electricity and other energy forms for the household use. 

Saving Energy: Saving energy will, of course, help to prevent air pollution. Switch off the lights, fans, air conditioners, televisions, and other appliances, when not in use. You can also share a room with others when the air conditioner or fan is on, instead of switching them on in every room. 

Minimize Air Pollutants: Always try to minimize smoke emission, as it can contribute to air pollution. One way is to compost dried leaves and kitchen waste, instead of burning them. Composting will also give you organic fertilizer for your garden. While buying the products, always choose air-friendly and recyclable products that will minimize the emission of pollutants. 

Social awareness about air pollution is the most essential step to be taken for the prevention of air pollution. Awareness programs and/or advertisements should be encouraged, so that people understand the potential health hazards of air pollution. Improvement of transport facilities and proper use of land for the sake of social benefits are equally important for controlling air pollution.