Pollution

POLLUTION

Pollution is the introduction of contaminants into the natural environment that cause adverse change. Pollution can take the form of chemical substances or energy, such as noise, heat or light. Pollutants i.e., the components of pollution, can be either foreign substances/energies or naturally occurring contaminants. Pollution is often classed as point source or non-point source pollution. Air pollution has always accompanied civilizations. Pollution started from the prehistoric times when man created the first fires. According to a 1983 article in the journal Science, "soot found on ceilings of prehistoric caves provides ample evidence of the high levels of pollution that was associated with inadequate ventilation of open fires." The forging of metals appears to be a key turning point in the creation of significant air pollution levels outside the home. Core samples of glaciers in Greenland indicate increases in pollution associated with Greek, Roman and Chinese metal production, [but at that time the pollution was comparatively less and could be handled by nature. It was the industrial revolution that gave birth to environmental pollution as we know it today. The emergence of great factories and consumption of immense quantities of coal and other fossil fuels gave rise to unprecedented air pollution and the large volume of industrial chemical discharges added to the growing load of untreated human waste.

Forms of pollution

The major forms of pollution are listed below along with the particular contaminant 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:- the criminal throwing of inappropriate man-made objects, unremoved, onto public and private properties.

Noise pollution:- which encompasses roadway noise, aircraft noise, industrial noise as well as high-intensity sonar.

Soil contamination occurs when chemicals are released by spill or underground leakage. Among the most significant soil contaminants are hydrocarbons, heavy metals, 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, municipal solid waste or space debris.

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 produced by ships may alter clouds, affecting global temperatures.

Air pollution comes from both natural and human-made (anthropogenic) sources. However, globally human-made pollutants from combustion, construction, mining, agriculture and warfare are increasingly significant in the air pollution equation.

Motor vehicle emissions are one of the leading causes of air pollution. China, United States, Russia, India, Mexico, and Japan are the world leaders in air pollution emissions. Principal stationary pollution sources include chemical plants, coal-fired power plants, oil refineries, 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.

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), zinc, arsenic and benzene.

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

Overview of main health effects on humans from some common types of pollution:

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.

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.

Regulation and monitoring

To protect the environment from the adverse effects of pollution, many nations worldwide have enacted legislation to regulate various types of pollution as well as to mitigate the adverse effects of pollution.

Pollution control

Pollution control is a term used in environmental management. It means the control of emissions and effluents into air, water or soil. Without pollution control, the waste products from consumption, heating, agriculture, mining, manufacturing, transportation and other human activities, whether they accumulate or disperse, will degrade the environment. In the hierarchy of controls, pollution prevention and waste minimization are more desirable than pollution control. In the field of land development, low impact development is a similar technique for the prevention of urban runoff.

Practices

• Recycling
• Reusing
• Waste minimisation
• Mitigating
• Preventing
• Compost

Perspectives

The earliest precursor of pollution generated by life forms would have been a natural function of their existence. The attendant consequences on viability and population levels fell within the sphere of natural selection. These would have included the demise of a population locally or ultimately, species extinction. Processes that were untenable would have resulted in a new balance brought about by changes and adaptations. At the extremes, for any form of life, consideration of pollution is superseded by that of survival.

For humankind, the factor of technology is a distinguishing and critical consideration, both as an enabler and an additional source of byproducts. Short of survival, human concerns include the range from quality of life to health hazards. Since science holds experimental demonstration to be definitive, modern treatment of toxicity or environmental harm involves defining a level at which an effect is observable.

"The solution to pollution is dilution", is a dictum which summarizes a traditional approach to pollution management whereby sufficiently diluted pollution is not harmful. It is well-suited to some other modern, locally scoped applications such as laboratory safety procedure and hazardous material release emergency management. But it assumes that the dilutant is in virtually unlimited supply for the application or that resulting dilutions are acceptable in all cases. Such simple treatment for environmental pollution on a wider scale might have had greater merit in earlier centuries when physical survival was often the highest imperative, human population and densities were lower, technologies were simpler and their byproducts more benign. But these are often no longer the case. Furthermore, advances have enabled measurement of concentrations not possible before. The use of statistical methods in evaluating outcomes has given currency to the principle of probable harm in cases where assessment is warranted but resorting to deterministic models is impractical or infeasible. In addition, consideration of the environment beyond direct impact on human beings has gained prominence.

Yet in the absence of a superseding principle, this older approach predominates practices throughout the world. It is the basis by which to gauge concentrations of effluent for legal release, exceeding which penalties are assessed or restrictions applied. One such superseding principle is contained in modern hazardous waste laws in developed countries, as the process of diluting hazardous waste to make it non-hazardous is usually a regulated treatment process. Migration from pollution dilution to elimination in many cases can be confronted by challenging economic and technological barriers.

Greenhouse gases and global warming

Carbon dioxide, while vital for photosynthesis, is sometimes referred to as pollution, because raised levels of the gas in the atmosphere are affecting the Earth's climate. Disruption of the environment can also highlight the connection between areas of pollution that would normally be classified separately, such as those of water and air. Recent studies have investigated the potential for long-term rising levels of atmospheric carbon dioxide to cause slight but critical increases in the acidity of ocean waters, and the possible effects of this on marine ecosystems.

Most polluted places in the developing world

The Blacksmith Institute, an international non-for-profit organization dedicated to eliminating life-threatening pollution in the developing world, issues an annual list of some of the world's worst polluted places. In the 2007 issues the ten top nominees, already industrialized countries excluded, are located in Azerbaijan, China, India, Peru, Russia, Ukraine and Zambia.

Industrial Pollution

The wastes from industries are directly dumped into surrounding water bodies and open lands which causes various types of pollution. This is known as industrial pollution. The pollutants include grit, asbestos, phosphates and nitrates, mercury, lead, caustic soda and other sodium compounds, sulfur and sulfuric acid, oils, and petrochemicals.

In addition, numerous manufacturing plants pour off undiluted corrosives, poisons, and other noxious byproducts. The construction industry discharges slurries of gypsum, cement, abrasives, metals, and poisonous solvents. Another pervasive group of contaminants entering food chains is the polychlorinated biphenyl (PCB) compounds, components of lubricants, plastic wrappers, and adhesives. In yet another instance of pollution, hot water discharged by factories and power plants causes so-called thermal pollution by increasing water temperatures. Such increases change the level of oxygen dissolved in a body of water, thereby disrupting the water's ecological balance, killing off some plant and animal species while encouraging the overgrowth of others.

The impact of pollution on the population varied according to prevailing methods of waste disposal, the shifting geography of manufacturing, changes in the city's economic base, and specific political initiatives designed to reduce human exposure. In addition, planing mills and sawmills sprayed copious amounts of wood dust into the air.

Reducing Pollution:

There are two approaches through which pollution can be reduced:

• Reducing consumption or usage of a polluting product.
• Treatment of wastes, discharges and disposals of a pollutant.

Yet waste treatment can only be effective if pollution is coming from a defined and accessible source (point source).

Many countries, including the E.U., Switzerland, Canada and the U.S., have effectively implemented systems that treat waste water for most chemicals, yet significant improvement in methods are possible. In such improvements, priority should be given to considering the use of microbes or fungi for cleanup of heavy metals and organic compounds that are hard to degrade because of their high efficiency relative to chemical or physical methods. Most developing and threshold countries lack treatment facilities, meaning waste waters in these countries are significantly more toxic per unit mass then waste water in developed countries, which is also a result of companies shifting pollution-intensive production to countries with fewer environmental restrictions. This is especially observed in the mining industry, where treatment of waste is often very expensive and pollutants are very toxic.

It is often assumed that governmental restrictions or strong consumer pressure are necessary to cause significant reduction in the production of polluting goods, because there is usually no short-term internal benefit to reducing pollution for corporations. The reasons corporations reduce their pollution are based on consumer preference for low-pollution goods and the high cost of noncompliance with environmental regulations. But reducing pollution does not only mean treating waste or paying for waste removal, which only raises costs.

Consumers and governments need to do their part to push companies to decrease pollution. Although pollution prevention can provide a financial incentive for private corporations, consumer pressure is still necessary to develop company awareness of pollution issues. To implement standards throughout a pollution-intensive industry, a government agency must implement environmental regulations. Regulations could include a levy or tax plan which would make polluters pay a fixed amount of money for pollution, a cap-and-trade system which would fix the amount of emissions, prescription of maximum releases, or minimum waste reduction techniques. Such regulations might come with a high cost to production if no comparable alternatives are available and efficiency measures are already exploited. The potential for development of efficiency has resulted in a small industry of efficiency counseling, which could be helpful in eliminating unnecessary pollution from industrial processes. In general, government regulations need to be stronger in order to eliminate such industrial overuse of pollutants and provide incentives for research and implementation of more efficient techniques. The exact guidelines must be determined by case, as different pollutants have different effects and can be reduced by different measures, which warrants different approaches.

A long-term solution that could reduce pollution from agricultural chemicals is research into more sustainable methods of farming large amounts of food, such as ecosystem engineering or biomimicry. This research focus is necessary for an eventual transition to non-polluting agriculture, which is not feasible now because current methods don't work. However, non-polluting agriculture will eventually become necessary, because all pesticides are by definition poisons; indefinitely relying on them is not a solution that will generate integrated ecosystems, which are necessary to eventually increase biodiversity while keeping high yields.

Other organic materials are often not quite as toxic as pesticides, yet studies have found that degraded forms of dichlophenac, a common painkiller, have caused the loss of kites, a carrion-eating bird, in Pakistan and India. Organic solvents can also have high toxicity values, making them ecologically significant as well. Unlike agrochemical pollution, which occupies too much area and includes too many possibilities for runoffs to be modeled as a point source, most other organic chemicals released to the environment are gathered in waste disposals of urban or industrial sewage systems and can theoretically be treated. For effective treatment, the proper degrading microbes as well as enough time are necessary, which means that extensive treatment plants should be developed for many countries. This treatment could take the form of microbial degradation plants commonly used in industrialized countries or, if sufficient space were available, constructing degrading wetlands could be a cost-effective alternative.

Degrading Toxicants

In the case of pollution leading to buildup of toxic material, reduction of availability to the environment must be ensured to rebuild ecosystem services in a polluted area. Although physical or chemical methods such as change in acidity or absorption into the soil can help decrease the availability of chemicals, additional monitoring and securing is necessary to make sure that the pollutant is not brought back into the environment. Ideally, the system should be able to degrade the pollutant by microbes or fungi, as this will irreversibly destroy the toxicant.

Many inorganic materials take a long time to biodegrade, which means that their buildup rate is almost proportional to the total rate of pollution at any given time. These are also often some of the most potent and generally poisonous materials and thus strongly toxic even in low concentrations. Influential inorganic pollutants include non-metals like ammonia and cyanide and heavy metals such as Cu, Hg, Cd among others, which are all toxic in various degrees. Many inorganic discharges are point sources, so proper treatment of material is generally possible through biological degradation with microbes and fungi or electrokinetic treatment (the use of electricity to reduce heavy metal ions and turn them into elemental precipitates). Also, most heavy metals are much less toxic in alkaline environments, a fact that can be used in treatment plans. Some combination of these three techniques should be established to lower emissions for point source metal pollution.

Recolonization

After a site has been rid of its toxicity and offers a space in which normal, pollution-intolerant organisms can live, recolonization and reconstruction of the ecosystem need to occur. This recolonization depends on the availability of organisms to refill the parts of the ecosystem that have been destroyed. If a distinct and isolated environment were destroyed, such as pond ecosystem, not all species may be available in close proximity.

Macroorganisms, like mammals, amphibians, or fish, often have their own mechanisms of travel, yet even many of them need connected biomes. On the other hand, many smaller organisms that are essential to the ecosystem, such as small insects or microbes, cannot travel on their own and rely on wind, rain, drift, or transportation by other organisms to change places. Macroorganism travel may be significantly impaired by habitat fragmentation through urbanization, pollution of river biomes all the way to their sources, or an extinction or large reduction in numbers of transporting species such as waterfowl. These obstacles are also often directly correlated to the pollution or the cause of pollution. For instance, strong industrial presence can pollute environments, but will also lead to urbanization and habitat fragmentation due to workers living nearby. If there are no colonies preserved from pre-pollution eras and classical mechanisms of transport have been destroyed for organisms occupying important niches in the ecosystems, careful human intervention may be needed to introduce necessary species.

Action Plan

Any action plan to reduce industrial pollution will need to be tailored toward specific pollutants to work well and not pose undue risks on either the economy or the environment. A slightly generalized plan based on the different kinds of solutions available can be proposed for the different pollutants.

Reduction of Pollution:

Toxic metals should have a restriction on maximum environmental release based on relative toxicity levels and accumulation rates in ecosystems. If it is inevitable that heavy metals will be released in waste, treatment is necessary before the waste is released into the environment. In a series of steps, electrolysis should be used to reduce precious metals (Cu, Ag), which can then be refined and sold. Then, biological processing with the appropriate microbes should be used to reduce toxicity of very reactive ions (Hg, Cd, Mn). Last, the waste solution should be made slightly alkaline to precipitate as much metal hydroxides as possible before release into the environment.

Toxic organic compound emissions that are not pesticide applications should be reduced by setting a fixed standard of emissions and ecotoxicity in a cap-and-trade system which can gradually be lowered. Ideally, this would eventually lead to zero emissions, as most organic compounds can be degraded by microbes and thus treated effectively. If compounds are found to be excessively toxic, a blanket ban should be introduced.

Agrochemicals should be subject to a taxation system in which the ecotoxicity of the compound determines the levy. However, some dangerous pesticides such as atrazine should be incorporated in a cap-and-trade system of dangerous agrochemicals that would gradually be lowered to allow time for transition to less dangerous chemicals. Again, excessively toxic compounds will need to be removed from the market by a blanket ban.

Detoxification and Recolonization:

Strongly polluted sites should be cleaned up through progams such as the U.S. Superfund, though bioremediation and in-site cleanup should be the preferential treatment options.

Physical and chemical reductions to bioavailability will need to be secured additionally, preferably by an irreversible degradation, so that pollutants cannot be released again.

Once a site has been detoxified, appropriate measures should be taken to ensure that all important positions of the biome can be fulfilled.

Research is necessary for more advanced treatment plans, systems of production that do not use polluting agents and remediation technology. Research should be influenced by key concepts such as integration of ecosystems and biomimicry