Natural power's losing their Abilities

Seas Losing Ability To Absorb CO2

Do you all know that Earth's Environment itself saves it from the Environment Pollution? All natural things like rocks,seas,oceans etc. prevent our nature by their various different phenomenons. If the whole world plays their role in just balancing the Environment Balance that is balanced by nature itself, then we can think about prevention of Earth's Environment.

Emissions from the fossil fuels began soaring in the 1950s, and oceans largely kept up.

But the growth in the intake rate has slowed since the 1980s.

The Earth's oceans, which have absorbed carbon dioxide from emissions since the dawn of the industrial era, have recently grown less efficient at sopping it up, new research suggests.

Emissions from the burning of fossil fuels began soaring in the 1950s, and oceans largely kept up, scientists say. But the growth in the intake rate has slowed since the 1980s, and markedly so since 2ooo, the authors of a study write in a report in issue of nature. The research suggests that the seas cannot indefinitely be considered a reliable "carbon sink" as humans gases linked to global warming.

The slowdown in the rise of the absorption rate resulted from a gradual change in the oceans' chemistry, the study found . '' The more carbon dioxide the ocean absorbs,the more acidic it becomes and the less carbon dioxide it can absorb, " said the study's lead author, Samar Khatiwala, a research scientist at the Lamont-Doherty Earth observatory of Columbia University and a professor at the Georgia Institute of Tecchnology.

" It's a small change in absolute terms, '' Khatiwala said. ''What I think is fairly clear and important in the long term is the trend toward lower values, which implies that more of the the emissions will remain in the atmosphere.''

To calculate the slow-down , Khatiwala created a mathematical model using measurements of seawater collected over the past 20 years. Even as human-generated eissions of carbon dioxide increase, the oceans' uptake rate growth appears to have dropped by 10 % from 2000 to 2007, he said.

The last major research effort to measure industrial carbon uptake in the oceans was published in a 2004 Science study led by christopher sabine. His methodology was different but arrived at similar conclusions.

Sabine used CO2 measurements taken by more than 100 ships to come up with a single figure: the oceans' total industrial carbon uptake until 1994. Khatiwala 's proach provides ocean carbon storage estimates from 1765 to 2008.

Thus, at last we all can say that nature itself plays a important role for protecting our Environment from Pollution.

Look at dangerous effects of global warming ?

Global Warming & Its Effect on Icy Habitats

When you visit a doctor, he records your temperature. And if it is higher than the normal body temperature of 98.6°F (degrees Fahrenheit) or 37°C (degrees Celsius) , it means that your are not well. Similarly, when the temperature of our planet increase, it means that our planet is ill too! The rise in your body temperature is called fever; when the same happens to the Earth's atmosphere and oceans it is called global warming.

Thermometer with Fahrenheit units on the outer scale and Celsius units on the inner scale



Every day , when the sun's rays reach earth , a group of gases called greenhouse gases absorb heat from the sun's rays & make our planet warm enough for us to survive.But if the levels of these gases in the atmosphere increases , they will absorb more heat , making Earth too hot for us to live ! Because of pollution , cutting down of trees & forests , burning fossil fuels like coal & petrol , the level of green house gases in the atmosphere is increasing , thus causing global warming.

Since 1880 the average temperature of our planet has risen by 1.4°F(0.8°C ). Though that doesn't sound like much , the results are alarming! The ice in polar regions has already started melting , resulting in floods , rising sea levels , submergence of low lying islands & coastal areas. Warmer temperature have also triggered climate changes & the extinction of animal & plant species.

Global warming is not having the same impact on all parts of the world. Some areas of our planet are warming faster than other. The polar regions are warming twice as fast as other parts of the world , thus making the wild life at the poles most vulnerable to rising temperatures. One such animal is the polar bear.

Polar bears depend completely on sea ice for hunting.But because of the rising temperatures , the sea is melting , thus making hunting extremely difficult for polar bears.Global warming has also resulted in a decline in the population of seals. Declining seal population means that polar bears are running out of food. it is a pity to see an animal so extraordinarily adapted to survive at below freezing temperature , perish because of the lack of the food.

TO Find Out What You Can Do To Help

* Using an air conditioner ( 2.5 ton ) for an hour generates 3 kg of CO2

If you decide to go without AC for an hour a day,

you can stop the release of 3 × 365 = 1095 kg of CO2 into the atmosphere per year.

* Using a geyser for an hour generates = 3.3 kg of CO2

If you cut down on your use of the geyser by just one hour a day,

you can stop the release of 3.3 × 365 = 1204.5 kg of CO2 into the atmosphere per year.

* One dripping tap in a house = wastage of 13 litres of water in a single day

Wastage in a year = 13 litres × 365 = 4745 litres of water

* On an average , each person who runs the tap while brushing

waste about 2 × 3.5 = 7 litres of water

If 1.13 billion Indians ( estimated population as on March 2008 )

simply change the way they brush their teeth , we could save

1.13 billion × 7 litres = 7.91 billion litres of water - in just a day!!

* The estimated population of India on March 2008 was 1.13 billion .

A single tree absorbs one ton of carbon dioxide (CO2) during its lifetime.

Even if each of us plant just one tree in our lifetime ,

we can eliminate 1.13 billion ton of CO2 from the atmosphere.

The Difference We All Can Make

* Simply switching off DVD player , stereo & computer when you are not using them will stop the release of thousand of pounds of carbon dioxide a year.

* Do you know , if the temperature of our Earth ,almost 7 million in India people will have to move their homes , because the sea will rise & cover some parts of Chennai & Mumbai ?

* Making cans from recycled aluminium uses 90% less energy than making cans from scratch. We can watch T.V. for 3 hours from the energy saved from recycling one can!

* Take shorter hot water showers. Heating water uses energy.

* The glacial lake in Southern Chile was sighted in March ,but two months laters it had completely disappeared!

The culprit : global warming

* It is true - the oceans are turning to acid! Ocean absorb CO2 which , when mixed with sea water , turns to a weak carbonic acid.

* Louisiana , a state in USA about size of Orissa ,is losing an acre of its land , to the rising sea levels , every 24 minutes!

* Between 1961 & 1997 , the world's glaciers lost 890 cubic miles of ice.

* Warmer temperatures are killing eucalyptus trees , the main food source for koalas. It is that because of this koalas could become extinct in the next few decades!

* Global warming means bad news for baseball lovers! Ash tree from which all baseball bats are made , is in the danger of disappearing because of warmer temperatures.

* As rising ocean temperatues are killing off their food supply , more number of gray whales are being washed up on beaches after starving to death.

Ozone Hole Is also Polluting Our Environment

Ozone layer

The ozone layer is the part of the Earth's atmosphere which contains relatively high concentrations of ozone (O3).

Although the concentration of ozone in the ozone layer is very small, it is vitally important to life because it absorbs biologically harmful ultraviolet (UV) radiation from the Sun.

" Changes In Earth's Ozone Layer Predicted To Increase UV Radiation In World "

Physicists have discovered that changes in the Earth’s ozone layer due to climate change will reduce the amount of ultraviolet (UV) radiation in northern high latitude regions. Other regions of the Earth, such as the tropics and Antarctica, will instead face increasing levels of UV radiation.


According to my views - “Climate change is an established fact, but scientists are only just beginning to understand its regional manifestations.”


21st-century climate change will alter atmospheric circulation, increasing the flux of ozone from the upper to the lower atmosphere and shifting the distribution of ozone within the upper atmosphere. The result will be a change in the amount of UV radiation reaching the Earth’s surface which varies dramatically between regions: e.g. up to a 20 per cent increase in UV radiation over southern high latitudes during spring and summer, and a 9 per cent decrease in UV radiation over northern high latitudes, by the end of the century.

Ozone Depletion Reduces Ocean Carbon Uptake

The Southern Ocean plays an important role in mitigating climate change because it acts as a sink of atmospheric carbon dioxide. Most current models predict that the strength of the Southern Ocean carbon dioxide sink should increase as atmospheric carbon dioxide rises, but observations show that this has not been the case.

Consider the effects of stratospheric ozone depletion, which most previous studies had not included. They compare coupled carbon-climate models with and without ozone depletion and find that including ozone depletion produced a significant reduction in Southern Ocean carbon uptake, in good agreement with observed trends.

Ozone depletion, combined with increased atmospheric greenhouse gas concentration, drives stronger winds above the Southern Ocean. These stronger winds bring more carbon-rich deep water to the surface, which reduces the ocean's ability to absorb more carbon dioxide from the atmosphere.

While the effects of increased UV have been widely studied because of the problem of ozone depletion, decreased UV could have adverse effects too, e.g. on vitamin D production for people in regions with limited sunlight such as the northern high latitudes.

“Both human and ecosystem health are affected by air quality and by UV radiation." While there has been much research on the impact of climate change on air quality, our work shows that this research needs to include the effect of changes in stratospheric ozone. And while there has been much research on the impact of ozone depletion on UV radiation and its impacts on human and ecosystem health, the notion that climate change could also affect UV radiation has not previously been considered.

Light Pollution

Light pollution, also known as photopollution or luminous pollution, is excessive or obtrusive artificial light. Light pollution is defined as:

“

Any adverse effect of artificial light including sky glow, glare, light trespass, light clutter, decreased visibility at night, and energy waste.

”

It obscures the stars in the night sky for city dwellers, interferes with astronomical observatories, and, like any other form of pollution, disrupts ecosystems and has adverse health effects. Light pollution can be divided into two main types: 1) annoying light that intrudes on an otherwise natural or low-light setting and 2) excessive light (generally indoors) that leads to discomfort and adverse health effects. Since the early 1980s, a global dark-sky movement has emerged, with concerned people campaigning to reduce the amount of light pollution.

Light pollution

Light pollution is a side effect of industrial civilization. Its sources include building exterior and interior lighting, advertising, commercial properties, offices, factories, streetlights, and illuminated sporting venues. It is most severe in highly industrialized, densely populated areas of North America, Europe, and Japan and in major cities in the Middle East and North Africa like Cairo, but even relatively small amounts of light can be noticed and create problems. Like other forms of pollution (such as air, water, and noise pollution) light pollution causes damage to the environment.

Impact on Energy Usage

Energy conservation advocates contend that light pollution must be addressed by changing the habits of society, so that lighting is used more efficiently, with less waste and less creation of unwanted or unneeded illumination. The case against light pollution is strengthened by a range of studies on health effects, suggesting that excess light may induce loss in visual acuity, hypertension, headaches and increased incidence of carcinoma. Several industry groups also recognize light pollution as an important issue.

one form of light pollution.

Information about light pollution, the problems it causes, and how to reduce its impact.

Since not everyone is irritated by the same lighting sources, it is common for one person's light "pollution" to be light that is desirable for another. One example of this is found in advertising, when an advertiser wishes for particular lights to be bright and visible, even though others find them annoying. Other types of light pollution are more certain. For instance, light that accidentally crosses a property boundary and annoys a neighbor is generally wasted and pollutive light.

Types

Light pollution is a broad term that refers to multiple problems, all of which are caused by inefficient, unappealing, or (arguably) unnecessary use of artificial light. Specific categories of light pollution include light trespass, over-illumination,light clutter, and sky glow.


Light trespass

Light pollution source using a broad spectrum metal halide lamp pointing upward.

Light trespass occurs when unwanted light enters one's property, for instance, by shining over a neighbor's fence. A common light trespass problem occurs when a strong light enters the window of one's home from the outside, causing problems such as sleep deprivation or the blocking of an evening view.

Over-illumination

Over-illumination is the excessive use of light.Office building illuminated by high pressure sodium (HPS) lamps shining upward, of which much light goes into the sky and neighboring apartment blocks and causes light pollution

Over-illumination stems from several factors:

• Not using timers, occupancy sensors or other controls to extinguish lighting when not needed
• Improper design, especially of workplace spaces, by specifying higher levels of light than needed for a given task
• Incorrect choice of fixtures or light bulbs, which do not direct light into areas as needed
• Improper selection of hardware to utilize more energy than needed to accomplish the lighting task
• Incomplete training of building managers and occupants to use lighting systems efficiently
• Inadequate lighting maintenance resulting in increased stray light and energy costs
• "Daylight lighting" can be required by citizens to reduce crime or by shop owners to attract customers, so over-illumination can be a design choice, not a fault. In both cases target achievement is questionable.
• Substitution of old mercury lamps with more efficient sodium or metal halide lamps using the same electrical power
• Indirect lighting techniques, such as lighting a vertical wall to bounce photons on the ground.

Comparison of the view the night sky from a small rural town (top) and a metropolitan areastars.Light pollution vastly reduces the visibility of stars.

Light clutter

Las Vegas displays excessive groupings of colorful lights. This is a classic example of light clutter.

Light clutter refers to excessive groupings of lights. Groupings of lights may generate confusion, distract from obstacles (including those that they may be intended to illuminate), and potentially cause accidents. Clutter is particularly noticeable on roads where the street lights are badly designed, or where brightly lit advertising surrounds the roadways. Depending on the motives of the person or organization who installed the lights, their placement and design may even be intended to distract drivers, and can contribute to accidents.

Skyglow

Mexico City at night, with a brightly illuminated sky.

Skyglow refers to the "glow" effect that can be seen over populated areas. It is the combination of all light reflected from what it has illuminated escaping up into the sky and from all of the badly directed light in that area that also escapes into the sky, being scattered by the atmosphere back toward the ground. This scattering is very strongly related to the wavelength of the light when the air is very clear (with very little aerosols). Rayleigh scattering dominates in such clear air, making the sky appear blue in the daytime. When there is significant aerosol (typical of most modern polluted conditions), the scattered light has less dependence on wavelength, making a whiter daytime sky. Because of this Rayleigh effect, and because of the eye's increased sensitivity to white or blue-rich light sources when adapted to very low light levels, white or blue-rich light contributes significantly more to sky-glow than an equal amount of yellow light. Sky glow is of particular irritation to astronomers, because it reduces contrast in the night sky to the extent where it may even become impossible to see any but the brightest stars.

Measurement and Global Effects

False colors show various intensities of radiation — both direct and indirect — from artificial light sources that reach space (Image credit: P. Cinzano)

Measuring the effect of sky glow on a global scale is a complex procedure. The natural atmosphere is not completely dark, even in the absence of terrestrial sources of light. This is caused by two main sources: airglow and scattered light.

At high altitudes, primarily above the mesosphere, UV radiation from the sun is so intense that ionization occurs. When these ions collide with electrically neutral particles they recombine and emit photons in the process, causing airglow. The degree of ionization is sufficiently large to allow a constant emission of radiation even during the night when the upper atmosphere is in the Earth's shadow.

Apart from emitting light, the sky also scatters incoming light, primarily from distant stars and the Milky Way, but also sunlight that is reflected and backscattered from interplanetary dust particles (the so-called Zodiacal light).

Consequences

Energy waste

Lighting is responsible for one-fourth of all energy consumption worldwide and case studies have shown that several forms of over-illumination constitute energy wastage, including non-beneficial upward direction of night-time lighting. In 2007, a saving of 645.2 million kWh in electricity consumption during the daylight saving period from April to October report comes out. It attributes this saving to the delayed need for artificial lighting during the evenings.

Effects on human health and psychology

Medical research on the effects of excessive light on the human body suggests that a variety of adverse health effects may be caused by light pollution or excessive light exposure, and some lighting design textbooks use human health as an explicit criterion for proper interior lighting. Health effects of over-illumination or improper spectral composition of light may include: increased headache incidence, worker fatigue, medically defined stress, decrease in sexual function and increase in anxiety.

Common levels of fluorescent lighting in offices are sufficient to elevate blood pressure by about eight points. There is some evidence that lengthy daily exposure to moderately high lighting leads to diminished sexual performance. Specifically within the USA, there is evidence that levels of light in most office environments lead to increased stress as well as increased worker errors.

Disruption of ecosystems

Light pollution poses a serious threat to wildlife, having negative impacts on plant and animal physiology. Light pollution can confuse animal navigation, alter competitive interactions, change predator-prey relations, and cause physiological harm.The rhthym of life is orchestrated by the natural diurnal patterns of light and dark, so disruption to these patterns impacts the ecolgical dynamics.

Migrating birds can be disoriented by lights on tall structures.

Night blooming flowers that depend on moths for pollination may be affected by night lighting, as there is no replacement pollinator that would not be affected by the artificial light.

Effect on astronomy

The constellation Orion, imaged at left from dark skies, and at right from within the Provo/Orem, Utah metropolitan area.

Skyglow reduces the contrast between stars and galaxies in the sky and the sky itself, making it more difficult to detect fainter objects. This is one factor that has caused newer telescopes to be built in increasingly remote areas. Some astronomers use narrow-band "nebula filters" which only allow specific wavelengths of light commonly seen in nebulae, or broad-band "light pollution filters" which are designed to reduce the effects of light pollution by filtering out spectral lines commonly emitted by sodium- and mercury-vapor lamps, thus enhancing contrast and improving the view of dim objects such as galaxies and nebulae. Unfortunately this affects color perception, so these filters cannot be used to visually estimate variable star brightness, and no filter can match the effectiveness of a dark sky for visual or photographic purposes. Due to low surface brightness, the visibility of diffuse sky objects such as nebulae and galaxies is affected by light pollution more than are stars. A simple method for estimating the darkness of a location is to look for the Milky Way.

Reduction

This kind of LED droplight could reduce unnecessary light pollution in building interiors

Reducing light pollution implies many things, such as reducing sky glow, reducing glare, reducing light trespass, and reducing clutter. The method for best reducing light pollution, therefore, depends on exactly what the problem is in any given instance. Possible solutions include:

• Utilizing light sources of minimum intensity necessary to accomplish the light's purpose.
• Turning lights off using a timer or occupancy sensor or manually when not needed.
• Improving lighting fixtures, so that they direct their light more accurately towards where it is needed, and with less side effects.
• Adjusting the type of lights used, so that the light waves emitted are those that are less likely to cause severe light pollution problems.
• Evaluating existing lighting plans, and re-designing some or all of the plans depending on whether existing light is actually needed.

• some or all of the plans depending on whether existing light is actually needed.

Adjusting types of light sources

Several different types of light sources exist, each having different properties that affect their appropriateness for certain tasks, particularly efficiency and spectral power distribution. It is often the case that inappropriate light sources have been selected for a task, either due to ignorance or because more sophisticated light sources were unavailable at the time of installation. Therefore, badly chosen light sources often contribute unnecessarily to light pollution and energy waste. By re-assessing and changing the light sources used, it is often possible to reduce energy use and pollutive effects while simultaneously greatly improving efficiency and visibility.

Some types of light sources, in order of energy efficiency, are:

Type of light source	Color	Luminous effectiveness in lumens per watt
Low Pressure Sodium (LPS/SOX)	yellow/amber	80 - 200
High Pressure Sodium (HPS/SON)	pink/amber-white	90 - 130
Metal Halide	bluish-white/white	60 -120
Mercury-Vapour	blue-greenish white	13 - 48
Incandescent	yellow/white	8 - 25

Pollution is geting more and more harmful

7 MOST DANGEROUS TYPES OF POLLUTION

1. Smog

There are many types of environmental pollution, and one of the most dangerous of these is pollution that affects the ozone layer, and results in smog. Cities like Los Angeles are the most at risk, where the smog blocks the atmosphere and creates serious health risks that can be deadly. This pollution can lead to lung cancer, asthma attacks which can be fatal, and many other medical problems. Smog can combine with other types of air pollution, such as particle pollution, to increase the health and safety risks. This environmental pollution type is one of the most serious, and affects many areas around the globe.

2. Particle Air Contamination

One of the types of environmental pollution that must be stopped because of the fatal consequences that can result is particle air contamination. This occurs when particles of liquids and solids are released and mix with the air. These particles can consist of many different things, including metals, exhaust fumes, chemicals, ash, and other components. This type of air contamination can be caused by exhaust, burning wood, industrial pollution, and many other sources.

3. Greenhouse Gas Emissions

Greenhouse gas emissions are one of the types of environmental pollution that must be prevented, because of the effect it has on the entire earth. This pollution thins out the ozone layer, and increases the global warming effects that are being seen. Temperature fluctuations and changes, and other effects are being seen because of greenhouse gas emissions. These emissions may also contribute to smog, because they pollute and damage the ozone layer.

4. Nuclear Power Plants And Radioactive Waste

Environmental damage from radioactive waste and nuclear material is a very large concern in the modern world. This source of pollution can be deadly, and can have consequences which can last generations, and thousands of years for some waste types. Radioactive waste can alter genetic material, resulting in gene and chromosome changes which can be passed on to future generations. Cancers and radiation sickness can also result from being exposed to this source of pollution.

5. Heavy Metal Use And Disposal

Heavy metal pollution can occur from many things, including mining and other extraction and industrial procedures. Heavy metals may be used to leach gold and other ores from the earth, leaving behind destruction. The heavy metals may lay on any groundwater or puddles, and poison birds and other wildlife in the area as well as any people.

6. Pollution From Coal Power Plants

Coal power plants have the distinction of being one of the most deadly types of environmental pollution. These plants release tons of particle pollution and greenhouse gas emissions, as well as encouraging mining to recover coal. There are polluting byproducts created when the coal is burn, and the ashes and leftover waste can be very toxic to the environment and life in the area. These hazardous wastes must be disposed of, and this is usually done by dumping them in nearby lakes and in pits dug for this purpose. This disposal contaminates the land and water surrounding the plants, creating significant environmental pollution and harm to the ecosystem.

7. Chemicals

One of the types of environmental pollution that is the most dangerous is the use of chemicals. Chemicals, like pesticides and those used in manufacturing and other industrial applications, can be a very dangerous source of pollution to the environment. Chemicals can seep into the ground, rivers and lakes, and have devastating effects to everything in the area. Plants, fish, and wildlife, as well as humans in the area, may be poisoned quickly or the effects may be slow and take months or years for medical symptoms to show. Many chemicals are considered carcinogens and are known to cause cancers in animals and humans.

Soil Pollution

Excavation showing soil contamination at a disused gasworks.

Soil pollution is caused by the presence of man-made chemicals

or other alteration in the natural soil environment.This type of contamination typically arises from the rupture of underground storage tanks,application of pesticides,percolation of contaminated surface water to subsurface strata,oil and fuel dumping,leaching of wastes from landfills or direct discharge of industrial wastes to the soil.The most common chemicals involved are petroleum hydrocarbons,

solvents,pesticides,lead and other heavy metals.This occurrence of this phenomenon is correlated with the degree of industrializations and intensities of chemical usage.

The concern over soil contamination stems primarily from health risks,both of direct contact and from secondary contamination of water supplies.Mapping of contaminated soil sites and the resulting cleanup are time consuming and expensive tasks,requiring extensive amounts of geology,hydrology,chemistry and computer modeling skills.

It is in North America and Western Europe that the extent of contaminated land is most well known,with many of countries in these areas having a legal framework to identify and deal with this environmental problem;this however may well be just the tip of the iceberg with developing countries very likely to be the next generation of new soil contamination cases.

The immense and sustained growth of the People's Republic of China since the 1970s has exacted a price from the land in increased soil pollution.The State Environmental Protection Administration believes it to be a threat to the environment,to food safety and to sustainable agriculture.According to a scientific sampling,150 million mi (100,000 square kilometres) of China’s cultivated land have been polluted,with contaminated water being used to irrigate a further 32.5 million mi (21,670 square kilometres) and another 2 million mi (1,300 square kilometres) covered or destroyed by solid waste.In total,the area accounts for one-tenth of

China’s cultivatable land,and is mostly in economically developed areas.An estimated 12 million tonnes of grain are contaminated by heavy metals every year,causing direct losses of 20 billion yuan (US$2.57 billion).

The United States,while having some of the most widespread soil contamination,has actually been a leader in defining and implementing standards for cleanup.Other industrialized countries have a large number of contaminated sites,but lag the U.S. in executing remediation.Developing countries may be leading in the next generation of new soil contamination cases.

Each year in the U.S., thousands of sites complete soil contamination cleanup,some by using microbes that “eat up” toxic chemicals in soil,many others by simple excavation and others by more expensive high-tech soil vapor extraction or air stripping.Efforts proceed worldwide to identify new sites of soil contamination.

Ecosystem Effects

Not unexpectedly, soil contaminants can have significant deleterious consequences for ecosystems.There are radical soil chemistry changes which can arise from the presence of many hazardous chemicals even at low concentration of the contaminant species.These changes can manifest in the alteration of metabolism of endemic microorganisms and arthropods resident ina given soil environment.The result can be virtual eradication of some of the primary food chain, which in turn have major consequences for predator or consumer species.Even if the chemical effect on lower life forms is small, the lower pyramid levels of the food chain may ingest alien chemicals,which normally become more concentrated for each consuming rung of the food chain. Many of these effects are now well known, such as the concentration of persistent DDT materials for avian consumers,leading to weakening of egg shells,increased chick mortality and potentially species extinction.

Effects occur to agricultural lands which have certain types of soil contamination.Contaminants typically alter plant metabolism, most commonly to reduce crop yields.This has a secondary effect upon soil conservation,since the languishing crops cannot shield the Earth's soil mantle from erosion phenomena.Some of these chemical contaminants have long half-lives and in other cases derivative chemicals are formed from decay of primary soil contaminants.

Cleanup Options

Microbes can be used in soil cleanup

Cleanup or remediation is analyzed by environmental scientists who utilize field measurement of soil chemicals and also apply computer models for analyzing tra

nsport and fate of soil chemicals. Thousands of soil contamination cases are currently in active cleanup across the U.S. as of 2006. There are several principal strategies for remediation:

• Excavate soil and take it to a disposal site away from ready pathways for human or sensitive ecosystem contact. This technique also applies to dredging of bay muds containing toxins.
• Aeration of soils at the contaminated site (with attendant risk of creating air pollution)
• Thermal remediation by introduction of heat to raise subsurface temperatures sufficiently high to volatize chemical contaminants out of the soil for vapour extraction.Technologies include ISTD,electrical resistance heating (ERH), and ET-DSP^tm.
• Bioremediation,involving microbial digestion of certain organic chemicals.Techniques used in bioremediation include landfarming,biostimulation and bioaugmentating soil biota with commercially available microflora.
• Extraction of groundwater or soil vapor with an active electromechanical system,with subsequent stripping of the contaminants from the extract.
• Containment of the soil contaminants (such as by capping or paving over in place).

Types of soil pollution control

Body movement causes contamination and protective clothing such as hats, cleanroom suits and face masks are basic forms of contamination control. Apart from people, the other common way for contamination to enter is on the wheels of trolleys used to transport equipment.

To prevent airborne contamination, high efficiency particulate air (HEPA) filters, airlocks and cleanroom suits are used.HEPA filtration systems used in the medical sector incorporate high-energy ultra-violet light units to kill off the live bacteria and viruses trapped by the filter media.These measures restrict the number of particulates within the atmosphere, and inhibit growth in those that are viable.

Studies by 3M show that over 80% of contamination enters the cleanroom through entrances and exits, mostly at or near floor level.To combat this suitable flooring systems are used that effectively attract, retain and inhibit growth of viable organisms.Studies show that the most effective type of flooring system is one of polymer composition.

Polymer mats are particularly effective due to their suppleness as they allow for more contact with serration on shoes and wheels and can accommodate for more particles whilst remaining effective.An electrostatic potential adds to the effectiveness of this type of contamination control as it holds particles until being cleaned.This method of attracting and retaining particles is more effective than mats with an active adhesive coating which needs to be peeled and is often not as supple. As long as the tack level of the mat is greater than the donor (foot or wheel), the contamination touching the surface will be removed.Very high tack surfaces pose a contamination threat because they are prone to pulling off over-shoe protection.Polymeric flooring is produced to ensure a higher level of tackiness than the surfaces it comes into contact with, without causing discomfort and potentially damaging ‘stickiness’.

Heating too produce a lot of Pollution

Thermal Pollution

INTRODUCTION

Thermal pollution is the degradation of water quality by any process that changes ambient water temperature. A common cause of thermal pollution is the use of water as a coolant by power plants and industrial manufacturers. When water used as a coolant is returned to the natural environment at a higher temperature, the change in temperature impacts organisms by decreasing oxygen supply and affecting ecosystem composition. Urban runoff--stormwater discharged to surface waters from roads and parking lots--can also be a source of elevated water temperatures.

When a power plant first opens or shuts down for repair, fish and other organisms adapted to particular temperature range can be killed by the abrupt rise in water temperature known as 'thermal shock'.

Thermal pollution can also be caused by the release of very cold water from the base of reservoirs into warmer rivers. This affects fish (particularly their eggs and larvae), macroinvertebrates and river productivity.

Ecological effects — warm water

Elevated temperature typically decreases the level of dissolved oxygen in water. The decrease in levels of DO can harm aquatic animals such as fish, amphibians and copepods. Thermal pollution may also increase the metabolic rate of aquatic animals, as enzyme activity, resulting in these organisms consuming more food in a shorter time than if their environment were not changed. An increased metabolic rate may result in food source shortages, causing a sharp decrease in a population. Changes in the environment may also result in a migration of organisms to another, more suitable environment, and to in-migration of fishes that normally only live in warmer waters elsewhere. This leads to competition for fewer resources; the more adapted organisms moving in may have an advantage over organisms that are not used to the warmer temperature. As a result one has the problem of compromising food chains of the old and new environments. Biodiversity can be decreased as a result.

It is known that temperature changes of even one to two degrees Celsius can cause significant changes in organism metabolism and other adverse cellular biology effects. Principal adverse changes can include rendering cell walls less permeable to necessary osmosis, coagulation of cell proteins, and alteration of enzyme metabolism. These cellular level effects can adversely affect mortality and reproduction.

Primary producers are affected by warm water because higher water temperature increases plant growth rates, resulting in a shorter lifespan and species overpopulation. This can cause an algae bloom which reduces the oxygen levels in the water. The higher plant density leads to an increased plant respiration rate because the reduced light intensity decreases photosynthesis. This is similar to the eutrophication that occurs when watercourses are polluted with leached agricultural inorganic fertilizers.

A large increase in temperature can lead to the denaturing of life-supporting enzymes by breaking down hydrogen- and disulphide bonds within the quaternary structure of the enzymes. Decreased enzyme activity in aquatic organisms can cause problems such as the inability to break down lipids, which leads to malnutrition.

In limited cases, warm water has little deleterious effect and may even lead to improved function of the receiving aquatic ecosystem. This phenomenon is seen especially in seasonal waters and is known as thermal enrichment. An extreme case is derived from the aggregational habits of the manatee, which often uses power plant discharge sites during winter. Projections suggest that manatee populations would decline upon the removal of these discharges.

The temperature can be as high as 70° Fahrenheit for freshwater, 80° F for saltwater, and 85° F for tropical fish.

Ecological effects — cold water

Releases of unnaturally cold water from reservoirs can dramatically change the fish and macroinvertebrate fauna of rivers, and reduce river productivity. In Australia, where many rivers have warmer temperature regimes, native fish species have been eliminated, and macroinvertebrate fauna have been drastically altered and impoverished. The temperatures for freshwater fish can be as low as 50° F, saltwater 75° F, and tropical 80° F.

Urban runoff
During warm weather, urban runoff can have significant thermal impacts on small streams, as stormwater passes over hot parking lots, roads and sidewalks. Stormwater management facilities that absorb runoff or direct it into groundwater, such as bioretention systems and infiltration basins, can reduce these thermal effects. Retention basins tend to be less effective at reducing temperature, as the water may be heated by the sun before being discharged to a receiving stream.

Control of thermal pollution

Cooling tower at Gustav Knepper Power Station, Dortmund, Germany

Industrial wastewater
In the United States, thermal pollution from industrial sources is generated mostly by power plants, petroleum refineries, pulp and paper mills, chemical plants, steel mills and smelters. Heated water from these sources may be controlled with:

• cooling ponds, man-made bodies of water designed for cooling by evaporation, convection, and radiation
• cooling towers, which transfer waste heat to the atmosphere through evaporation and/or heat transfer
• cogeneration, a process where waste heat is recycled for domestic and/or industrial heating purposes.

Some facilities use once-through cooling which do not reduce temperature as effectively as the above systems. For example, the Potrero Generating Station in San Francisco, which uses once-through cooling, discharges water to San Francisco Bay approximately 10° C (20° F) above the ambient bay temperature.

Save Water

Water Pollution

Water pollution is the contamination of water bodies such as lakes, rivers, oceans, and groundwater. All water pollution affects organisms and plants that live in these water bodies and in almost all cases the effect is damaging either to individual species and populations but also to the natural biological communities. It occurs when pollutants are discharged directly or indirectly into water bodies without adequate treatment to remove harmful constituents.

Introduction

Water pollution is a major problem in the global context. It has been suggested that it is the leading worldwide cause of deaths and diseases and that it accounts for the deaths of more than 14,000 people daily. In addition to the acute problems of water pollution in developing countries, industrialized countries continue to struggle with pollution problems as well. In the most recent national report on water quality in the United States, 45 percent of assessed stream miles, 47 percent of assessed lake acres, and 32 percent of assessed bay and estuarine square miles were classified as polluted.

Water is typically referred to as polluted when it is impaired by anthropogenic contaminants and either does not support a human use, like serving as drinking water, and/or undergoes a marked shift in its ability to support its constituent biotic communities, such as fish. Natural phenomena such as volcanoes, algae blooms, storms, and earthquakes also cause major changes in water quality and the ecological status of water. Water pollution has many causes and characteristics.

Point source pollution

Point source pollution refers to contaminants that enter a waterway through a discrete conveyance, such as a pipe or ditch. Examples of sources in this category include discharges from a sewage treatment plant, a factory, or a city storm drain. The U.S. Clean Water Act (CWA) defines point source for regulatory enforcement purposes.

Non-point source pollution

Non-point source (NPS) pollution refers to diffuse contamination that does not originate from a single discrete source. NPS pollution is often acumulative effect of small amounts of contaminants gathered from a large area. Nutrient runoff in stormwater from "sheet flow" over an agricultural field or a forest are sometimes cited as examples of NPS pollution. Contaminated stormwater washed off of parking lots, roads and highways, called urban runoff, is sometimes included under the category of NPS pollution.

However, this runoff is typically channeled into storm drain systems and discharged through pipes to local surface waters, and is a point source. The CWA definition of point source was amended in 1987 to include municipal storm sewer systems, as well as industrial stormwater, such as from construction sites.

Groundwater pollution

Interactions between groundwater and surface water are complex. Consequently, groundwater pollution, sometimes referred to as groundwater contamination, is not as easily classified as surface water pollution.By its very nature, groundwater aquifers are susceptible to contamination from sources that may not directly affect surface water bodies, and the distinction of point vs. nonpoint source may be irrelevant. A spill of a chemical contaminant on soil, located away from a surface water body, may not necessarily create point source or non-point source pollution, but nonetheless may contaminate the aquifer below. Analysis of groundwater contamination may focus on soil characteristics and hydrology, as well as the nature of the contaminant itself.

Causes of water pollution

The specific contaminants leading to pollution in water include a wide spectrum of chemicals, pathogens, and physical or sensory changes such as elevated temperature and discoloration. While many of the chemicals and substances that are regulated may be naturally occurring (calcium, sodium, iron, manganese, etc.) the concentration is often the key in determining what is a natural component of water, and what is a contaminant.

Oxygen-depleting substances may be natural materials, suc

h as plant matter (e.g. leaves and grass) as well as man-made chemicals. Other natural and anthropogenic substances may cause turbidity (cloudiness) which blocks light and disrupts plant growth, and clogs the gills of some fish species.

Many of the chemical substances are toxic. Pathogens can produce waterborne diseases in either human or animal hosts. Alteration of water's physical chemistry include acidity (change in pH), electrical conductivity, temperature, and eutrophication. Eutrophication is the fertilization of surface water by nutrients that were previously scarce.

Chemical and other contaminants

Muddy river polluted by sediment. Photo courtesy of United States Geological Survey.

Contaminants may include organic and inorganic substances.

Organic water pollutants include:

• Detergents
• Disinfection by-products found in chemically disinfected drinking water, such as chloroform
• Food processing waste, which can include oxygen-demanding substances, fats and grease
• Insecticides and herbicides, a huge range of organohalides and other chemical compounds
• Petroleum hydrocarbons, including fuels (gasoline, diesel fuel, jet fuels, and fuel oil) and lubricants (motor oil), and fuel combustion byproducts, from stormwater runoff^[12]
• Tree and bush debris from logging operations
• Volatile organic compounds (VOCs), such as industrial solvents, from improper storage. Chlorinated solvents, which are dense non-aqueous phase liquids (DNAPLs), may fall to the bottom of reservoirs, since they don't mix well with water and are denser.
• Various chemical compounds found in personal hygiene and cosmetic products.

Inorganic water pollutants include:

• Acidity caused by industrial discharges (especially sulfur dioxide from power plants)
• Ammonia from food processing waste
• Chemical waste as industrial by-products
• Fertilizers containing nutrients--nitrates and phosphates--which are found in stormwater runoff from agriculture, as well as commercial and residential use^[12]
• Heavy metals from motor vehicles (via urban stormwater runoff)^[12][13] and acid mine drainage
• Silt (sediment) in runoff from construction sites, logging, slash and burn practices or land clearing sites

Macroscopic pollution—large visible items polluting the water—may be termed "floatables" in an urban stormwater context, or marine debris when found on the open seas, and can include such items as:

• Trash (e.g. paper, plastic, or food waste) discarded by people on the ground, and that are washed by rainfall into storm drains and eventually discharged into surface waters
• Nurdles, small ubiquitous waterborne plastic pellets
• Shipwrecks, large derelict ships

Transport and chemical reactions of water pollutants

Most water pollutants are eventually carried by rivers into the oceans. In some areas of the world the influence can be traced hundred miles from the mouth by studies using hydrology transport models. Advanced computer models such as SWMM or the DSSAM Model have been used in many locations worldwide to examine the fate of pollutants in aquatic systems.

Indicator filter feeding species such as copepods have also been used to study pollutant fates in the New York Bight, for example. The highest toxin loads are not directly at the mouth of the Hudson River, but 100 kilometers south, since several days are required for incorporation into planktonic tissue. The Hudson discharge flows south along the coast due to coriolis force. Further south then are areas of oxygen depletion, caused by chemicals using up oxygen and by algae blooms, caused by excess nutrients from algal cell death and decomposition. Fish and shellfish kills have been reported, because toxins climb the food chain after small fish consume copepods, then large fish eat smaller fish, etc. Each successive step up the food chain causes a stepwise concentration of pollutants such as heavy metals (e.g. mercury) and persistent organic pollutants such as DDT. This is known as biomagnification, which is occasionally used interchangeably with bioaccumulation.

Large gyres (vortexes) in the oceans trap floating plastic debris. The North Pacific Gyre for example has collected the so-called "Great Pacific Garbage Patch" that is now estimated at 100 times the size of Texas. Many of these long-lasting pieces wind up in the stomachs of marine birds and animals. This results in obstruction of digestive pathways which leads to reduced appetite or even starvation.

Many chemicals undergo reactive decay or chemically change especially over long periods of time in groundwater reservoirs. A noteworthy class of such chemicals is the chlorinated hydrocarbons such as trichloroethylene (used in industrial metal degreasing and electronics manufacturing) and tetrachloroethylene used in the dry cleaning industry (note latest advances in liquid carbon dioxide in dry cleaning that avoids all use of chemicals). Both of these chemicals, which are carcinogens themselves, undergo partial decomposition reactions, leading to new hazardous chemicals (including dichloroethylene and vinyl chloride).

Groundwater pollution is much more difficult to abate than surface pollution because groundwater can move great distances through unseen aquifers. Non-porous aquifers such as clays partially purify water of bacteria by simple filtration (adsorption and absorption), dilution, and, in some cases, chemical reactions and biological activity: however, in some cases, the pollutants merely transform to soil contaminants. Groundwater that moves through cracks and caverns is not filtered and can be transported as easily as surface water. In fact, this can be aggravated by the human tendency to use natural sinkholes as dumps in areas of Karst topography.

There are a variety of secondary effects stemming not from the original pollutant, but a derivative condition. An example is silt-bearing surface runoff, which can inhibit the penetration of sunlight through the water column, hampering photosynthesis in aquatic plants.

Control of water pollution

Domestic sewage

Deer Island Waste Water Treatment Plant serving Boston, Massachusetts and vicinity.

In urban areas, domestic sewage is typically treated by centralized sewage treatment plants. I

n the U.S., most of these plants are operated by local government agencies. Municipal treatment plants are designed to control conventional pollutants: BOD and suspended solids. Well-designed and operated systems (i.e., secondary treatment or better) can remove 90 percent or more of these pollutants. Some plants have additional sub-systems to treat nutrients and pathogens. Most municipal plants are not designed to treat toxic pollutants found in industrial wastewater.

Cities with sanitary sewer overflows or combined sewer overflows employ one or more engineering approaches to reduce discharges of untreated sewage, including:

• utilizing a green infrastructure approach to improve stormwater management capacity throughout the system

  

• repair and replacement of leaking and malfunctioning equipment
• increasing overall hydraulic capacity of the sewage collection system (often a very expensive option).

A household or business not served by a municipal treatment plant may have an individual septic tank, which treats the wastewater on site and discharges into the soil. Alternatively, domestic wastewater may be sent to a nearby privately-owned treatment system (e.g. in a rural community).

Industrial wastewater

Dissolved air flotation system for treating industrial wastewater.

Some industrial facilities generate ordinary domestic sewage that can be treated by municipal facilities. Industries that generate wastewater with high concentrations of conventional pollutants (e.g. oil and grease), toxic pollutants (e.g. heavy metals, volatile organic compounds) or other nonconventional pollutants such as ammonia, need specialized treatment systems. Some of these facilities can install a pre-treatment system to remove the toxic components, and then send the partially-treated wastewater to the municipal system. Industries generating large volumes of wastewater typically operate their own complete on-site treatment systems.

Some industries have been successful at redesigning their manufacturing processes to reduce or eliminate pollutants, through a process called pollution prevention.

Heated water generated by power plants or manufacturing plants may be controlled with:

• cooling ponds, man-made bodies of water designed for cooling by evaporation, convection, and radiation
• cooling towers, which transfer waste heat to the atmosphere through evaporation and/or heat transfer
• cogeneration, a process where waste heat is recycled for domestic and/or industrial heating purposes.

Agricultural wastewater

Riparian buffer lining a creek in Iowa

Nonpoint source controls
Sediment (loose soil) washed off fields is the largest source of agricultural pollution in the United States.Farmers may utilize erosion controls to reduce runoff flows and retain soil on their fields. Common techniques include contour plowing, crop mulching, crop rotation, planting perennial crops and installing riparian buffers.

Nutrients (nitrogen and phosphorus) are typically applied to farmland as commercial fertilizer; animal manure; or spraying of municipal or industrial wastewater (effluent) or sludge. Nutrients may also enter runoff from crop residues, irrigation water, wildlife, and atmospheric deposition. Farmers can develop and implement nutrient management plans to reduce excess application of nutrients.

To minimize pesticide impacts, farmers may use Integrated Pest Management (IPM) techniques (which can include biological pest control) to maintain control over pests, reduce reliance on chemical pesticides, and protect water quality.

Confined Animal Feeding Operation in the United States

Point source wastewater treatment
Farms with large livestock and poultry operations, such as factory farms, are called concentrated animal feeding operations or confined animal feeding operations in the U.S. and are being subject to increasing government regulation.Animal slurries are usually treated by containment in lagoons before disposal by spray or trickle application to grassland. Constructed wetlands are sometimes used to facilitate treatment of animal wastes, as are anaerobic lagoons. Some animal slurries are treated by mixing with straw and composted at high temperature to produce a bacteriologically sterile and friable manure for