Plastic

Plastic

Plastics are a subspecies of a class of materials known as polymers. These are composed of large molecules, formed by joining many, often thousands, of smaller molecules (monomers) together. Other kinds of polymers are fibers, films, elastomers (rubbers), and biopolymers (i.e., cellulose, proteins, and nucleic acids).

Plastics are made from low-molecular-weight monomer precursors, organic materials, which are mostly derived from petroleum, that are joined together by a process called “polymerization.” Plastics owe their name to their most important property, the ability to be shaped to almost any form to produce articles of practical value.

Plastics can be stiff and hard or flexible and soft. Because of their light weight, low cost, and desirable properties, their use has rapidly increased and they have replaced other materials such as metals and glass. They are used in millions of items, including cars, bullet-proof vests, toys, hospital equipment, and food containers.


More than a hundred billion pounds of plastic were produced in 2000. Their increased use has resulted in concern with:

1. The consumption of natural resources such as oil, 
2. The toxicity associated with their manufacture and use, and 
3. The environmental impact arising from discarded plastics.

Pollution Problems

Industrial practices in plastic manufacture can lead to polluting effluents and the use of toxic intermediates, the exposure to which can be hazardous. Better industrial practices have led to minimizing exposure of plant workers to harmful fumes; for example, there have been problems in the past resulting from workers being exposed to toxic vinyl chloride vapor during the production of polyvinyl chloride.

Much progress has been made in developing “green processes” that avoid the use of detrimental substances. For example, phosgene, a toxic “war gas,” was formerly used in the manufacture of polycarbonates.

New processes, now almost universally employed, eliminate its use. Also, the “just in time” approach to manufacture has been made possible by computer-controlled processes, whereby no significant amounts of intermediates are stored, but just generated as needed. In addition, efforts are ongoing to employ “friendly” processes involving enzyme-catalyzed low-temperature methods akin to biological reactions to replace more polluting high-temperature processes involving operations like distillation.

Spillage of plastic pellets that find their way into sewage systems, and eventually to the sea, has hurt wildlife that may mistake the pellets for food. Better “housekeeping” of plastic molding facilities is being enforced in an attempt to address this problem.

Most plastics are relatively inert biologically, and they have been employed in medical devices such as prosthetics, artery replacements, and “soft” and interocular lenses. Problems with their use largely result from the presence of trace amounts of nonplastic components such as monomers and plasticizers.

This has led to restrictions on the use of some plastics for food applications, but improved technology has led to a reduction in the content of such undesirable components. For example, the use of polyacrylonitrile for beverage bottles was banned at one time because the traces of its monomer, acrylonitrile, were a possible carcinogen.


However, current practices render it acceptable today. There has been concern about endocrine disruption from phthalate-containing plasticizers used for plastics such as polyvinyl chloride (PVC). The subject of this possible side effect is controversial, but caution in use is warranted pending further study.

Plastics may also result in problems resulting from their improper use, and there is need of better education concerning limitations of use, for example, precautions that should be taken with items such as frying pan coatings and microwavable containers. When exposed to high temperatures, some plastics decompose or oxidize and produce low molecular weight products that may be toxic.

Reduced Use and Recycling

There is growing concern about the excess use of plastics, particularly in packaging. This has been done, in part, to avoid the theft of small objects. The use of plastics can be reduced through a better choice of container sizes and through the distribution of liquid products in more concentrated form. A concern is the proper disposal of waste plastics. Litter results from careless disposal, and decomposition rates in landfills can be extremely long.

Consumers should be persuaded or required to divert these for recycling or other environmentally acceptable procedures. Marine pollution arising from disposal of plastics from ships or flow from storm sewers must be avoided. Disposal at sea is prohibited by federal regulation.

Recycling of plastics is desirable because it avoids their accumulation in landfills. While plastics constitute only about 8 percent by weight or 20 percent by volume of municipal solid waste, their low density and slowness to decompose makes them a visible pollutant of public concern. It is evident that the success of recycling is limited by the development of successful strategies for collection and separation.

Recycling of scrap plastics by manufacturers has been highly successful and has proven economical, but recovering discarded plastics from consumers is more difficult. It is well recognized that separated plastics can be recycled to yield more superior products than possible for mixed ones.

Labeling plastic items with symbols has been employed, which enables consumers to identify them easily for placement in separate containers for curbside pickup. However, success depends on how conscientious consumers are in employing such standards and the ability of collectors to keep various types of plastic separate.

Even a small amount of a foreign plastic in recycling feedstock can lead to the appreciable deterioration of properties, and it is difficult to achieve a high degree of purity. Manual sorting at recycling centers helps, but even trained sorters have difficulty identifying recyclables.

Furthermore, manual sorting is an unattractive task and retaining labor willing to be trained for this is problematic. Automatic sorting techniques have been developed that depend on various physical, optical, or electronic properties of plastics for identification. Such methods prove difficult because of the variety of sizes, shapes, and colors of plastic objects that are encountered.

Although in principle it is possible to create devices that can separate plastics with varying degrees of success, the equipment generally becomes more expensive with increasing efficiency. Technology for this continues to improve, and it is becoming possible to successfully separate mixed plastics derived from curbside pickup using such equipment.

To separate plastics, it is first necessary to identify the different types as indicated in the table. One must also distinguish between thermoplastics and thermosets. The latter, as found in tires and melamine dishes, has molecules that are interconnected by “crosslinks” and cannot be readily melted for recycling unless they are chemically reduced to low-molecular-weight species. For tires, recycling has not proved economical so disposal has involved grinding them up as asphalt additives for roads or burning in cement kilns.

Over 1.5 million pounds of plastic bottles were recycled in 2000, representing a four-fold increase in the amount of plastic recycled the previous decade. Nonetheless, the capacity to recycle bottles appreciably exceeds their supply by about 40 percent, so local governments and environmental groups need to encourage greater participation in this practice among consumers.

Profitable operations are currently in place for recycling polyethylene terephthalate (PET) from bottle sources and converting it into products such as fibers. One persistent problem, though, is obtaining clean enough feed-stock to avoid the clogging of orifices in spinnerets by foreign particles.

This has limited the ability to produce fine denier fibers from such sources. PET recycling is also constrained by regulations limiting its use to produce items in contact with food because there had been concern about contamination in consideration of improved recycling techniques.

A leading candidate for recycle feedstock is carpets because replacement carpets are usually installed by professionals able to identify recyclables and who serve as a ready source for recycling operations. They face the problem, however, of separating the recyclable carpet components from other parts such as jute backing and dirt. Such recycling operations have been only marginally profitable.

Polystyrene (PS) is another potentially recyclable polymer, but identifying a readily collectable source is problematic. One had been the Styrofoam “clamshells” fast-food chains use to package hamburgers. Recyclers were able to profitably collect polystyrene from such sources and produce salable products. However, largely because of public pressure, this use of polystyrene has declined, so related recycling practices have largely disappeared too.

Cafeteria items from school lunchrooms are another potential, but the collection of such objects involves the development of an infrastructure, often not in place. In these cases, it is necessary to separate the polystyrene from paper and food waste, but washing and flotation techniques have been developed for this purpose.

Increasing amounts of plastic components appear in automobiles, and their recovery from junked cars is a possibility. Its success depends on the ability of a prospective “junker” to identify and separate the plastic items. Three efforts may aid in this accomplishment:

1. The establishment of databases to enable junkers to learn what kinds of plastic are used in what parts of what model cars.
2. A reduction in the number of different plastics used for car construction.
3. The design of cars such that plastic parts may be removed easily (this would require special types of fasteners).

This illustrates a general need—the design of plastic-containing products with the ability to recycle in mind. As a consequence of public concern about the environmental problems arising from plastic use, industry is responding to these needs. The effort continues to use fewer different kinds of plastics and to adopt designs that allow for easier recycling but still retain desirable properties.

There are, however, some worthwhile products that can be produced from mixed plastic, such as “plastic lumber” used for picnic benches and marine applications such as docks and bulkheads that successfully replace wooden lumber which often contains toxic preservatives and arsenic. But, the market for such a product is limited, so efforts to obtain separated plastics are preferred.

Degradable Plastics

Discarded plastics are hard to eliminate from the environment because they do not degrade and have been designed to last a long time. It is possible to design polymers containing monomer species that may be attacked by chemical, biological, or photochemical action so that degradation by such means will occur over a predetermined period of time.

Such polymers can be made by chemical synthesis (as with polylactic acid) or through bacterial or agricultural processes (as with the polyalkonates). Although such processes are often more expensive than conventional ones, cost would undoubtedly drop with increased production volume. One success story was the introduction of carbonyl groups into polyethylene by mixing carbon monoxide with ethylene during synthesis.

These carbonyl groups are chomophores that lead to chain breaking upon the absorption of ultraviolet light. The polymer is then broken down into small enough units that are subject to bacterial attack. This approach has been successful, for example, in promoting the disappearance of rings from beverage cans, which are potentially harmful to wildlife.

A problem with the degradation of plastics is that it is probably undesirable in landfills because of the leachants produced that may contaminate water supplies. It is better in these instances to ship the plastics to composting facilities.

This requires the separation of degradable plastics from other materials and the availability of such facilities. In most cases, the infrastructure needed for such an approach is not in place. This has discouraged its use for disposable diapers that are said to constitute 1 to 2 percent of landfill volume.

Degradable polymers may have limited use in the reduction of litter and production of flushable plastics, for example, feminine hygiene products, but it seems unlikely that the use of such materials will be a viable means of disposal for large amounts of plastic products. Degradation leads to the loss of most of the potential energy content of plastics that might be recovered by trash-to-energy procedures.

Trash to Energy

A method of plastic disposal with more positive environmental implications is burning and recovering the energy for power generation or heating. Plastics contain much of the energy potential of the petroleum from which they are made, and they, in a sense, are just borrowing this energy that may be recovered when the plastic is burned. Environmentalists and the public have objected to this procedure, leading to legislative restrictions.

This has arisen, in part, because of the image of “old-fashioned” incinerators polluting the air with toxic fumes and ash. However, it is possible to construct a “high-tech” incinerator designed to operate at appropriate temperatures and with sufficient air supply that these problems are minimized.

Remaining toxic substances in fumes may be removed by scrubbing, and studies have shown that no significant air pollution results. Toxic ash, for the most part, does not arise from the polymer components of the feedstock, but rather from other materials mixed with the polymers as well as from fillers, catalyst content, and pigments associated with the polymers.

Proper design of the polymers and crude separation of the incinerator feedstock can reduce this problem. Furthermore, if the feedstock was not incinerated but placed in landfills, contaminants would ultimately enter the environment in an uncontrolled way.

Incineration reduces the volume, so that the ash, which may contain them, can be disposed of under more controlled conditions. Also, it is possible to insolublize the ash by converting it into a cementlike material that will not readily dissolve.

Facilities for converting trash to energy in an environmentally acceptable way are expensive and at present not cost-effective when considering short-range funding. However, in the long run, they are environmentally desirable and reduce the need for alternative means for plastic waste disposal. It is imperative that legislators and taxpayers soon adopt this long-range perspective.

Point Source

Point source pollution

Point source pollution is contamination that enters the environment through any discernible, confined, and discrete conveyance, such as a smokestack, pipe, ditch, tunnel, or conduit. Point source pollution remains a major cause of pollution to both air and water.

Point sources are differentiated from non-point sources, which are those that spread out over a large area and have no specific outlet or discharge point. Point source pollution in the United States is regulated by the Environmental Protection Agency (EPA).

Point Sources of Water Pollution

Point sources of water pollution include municipal sewage treatment plant discharges and industrial plant discharges. Municipal sewage treatment plant point sources can contribute pollution in the form of oxygen-depleting nutrients and in the form of pathogens that cause serious health hazards in drinking water and swimming areas.


Industrial point sources can contribute pollution in the form of toxic chemicals and heavy metals. Examples of non-point source water pollution include agricultural and urban runoff, and runoff from mining, and construction sites.

The Clean Water Act (CWA), passed by Congress in 1972, provides the basic structure for regulating the discharge of pollutants from point sources to waters of the United States. The CWA gives the EPA the authority to establish effluent limits. Effluent is the outflow from a municipal or industrial treatment plant. The CWA also requires the acquisition of a National Pollution Discharge Elimination System (NPDES) permit prior to the discharge of pollutants. States may be authorized to implement CWA programs, but the EPA retains oversight responsibilities.

The EPA manages effluent limits for point sources in two ways: through technology-based controls and through water quality-based controls. Industry-wide effluent limits are established on a technology basis. These are minimum standards based on available treatment technology and pollution prevention measures.

Effluent limits are also established on a water-quality basis. Water quality-based criteria are scientifically defensible standards that ensure protection of designated uses of a receiving water. Either standard may be superceded by the more stringent standard, as determined by the control authority.

Municipal point sources are the result of community sewage treatment systems. At the sewage treatment plant, wastewater is treated to remove solid and organic matter, disinfected to kill bacteria and viruses, and then often discharged to a surface water. Not all solids and organic matter are removed during treatment, resulting in degraded receiving water quality, due to a reduction in dissolved oxygen.

Nutrients such as phosphorus that are not removed during treatment can cause overgrowth of algae and other organisms, also leading to lower dissolved oxygen. Many toxic substances can pass through conventional municipal treatment systems. Improperly treated sewage can be released as a result of upsets to the treatment process or as a result of operator error.

During heavy rain, discharges from sewage treatment systems can be a serious problem. In many municipalities, storm-water runoff is combined with municipal sewage in a common system. The increased water volume leads to reduced treatment. Combined sewer overflows occur when water flow exceeds treatment plant capacity, resulting in untreated sewage being discharged directly to rivers, lakes, or the ocean.

Industrial point sources are the result of industries using water in their production processes, and then treating the water prior to discharge. Some of the industries requiring process waters include pulp and paper mills, food processors, electronic equipment manufacturers, rare metal manufacturers, textile manufacturers, pharmaceutical manufacturers, forest product producers, leather tanners, and chemical manufacturers.

The National Pretreatment Program is charged with controlling the 126 priority pollutants from industries that discharge into sewer systems. These pollutants fall into two categories: metals and toxic organics. The metals include lead, mercury, chromium, and cadmium. The toxic organics include solvents, pesticides, dioxins, and polychlorinated biphenyls (PCBs).

Unlike municipal treatment methods, which are similar across the country, industrial treatment methods are industry-specific. For example, electroplating wastewater may require cyanide removal through oxidization. In general, physical processes may be used to remove solids and biological processes to remove organics. Chemical treatment, such as precipitation and neutralization, is also widely used.

The National Water Quality Inventory: 2000 Report is compiled based on the water quality reports required to be submitted to the EPA by states every two years. The report identifies “impaired” waters: water that cannot support its designated use, such as fishing or swimming, due to contamination.

According to the report, municipal point sources contributed to 37 percent and industrial discharges contributed to 26 percent of reported water-quality problems in the impaired portion of estuaries. Municipal point sources were the leading cause of contamination in 21 percent of the impaired ocean shorelines, and industrial discharges were the leading cause in 17 percent.

Municipal point sources were a leading source of contamination in 10 percent of the impaired river miles and 12 percent of the impaired lake acres. These figures are improved over the percentages recorded in the 1992 Report when municipal point sources were a leading contamination source in 15 percent of the impaired river miles and 21 percent of the impaired lake acres.

The NPDES permit program can be credited with achieving significant improvements to the water quality of the United States. Immediately following passage of the CWA, efforts focused mainly on regulating traditional point sources, such as municipal sewage plants and industrial facilities. In the late 1980s, efforts to address “wet weather point sources,” such as urban storm sewer systems, began.

Currently, there is a greater focus on nonpoint source pollution. The EPA is moving away from a source-by-source and pollutant-by-pollutant approach to a watershed-based approach. A watershed, or “place-based,” approach is a process that emphasizes addressing all stressors within a hydrologically defined boundary or drainage basin. Equal emphasis is placed on protecting healthy waters and restoring impaired waters.

Point Sources of Air Pollution

Point sources of air pollution

Point sources of air pollution include stationary sources such as power plants, smelters, industrial and commercial boilers, wood and pulp processors, paper mills, industrial surface coating facilities, refinery and chemical processing operations, and petroleum storage tanks.

Examples of nonpoint sources of air pollution include: on-road mobile sources such as cars and trucks; nonroad mobile sources such as construction and recreation equipment engines; and natural sources such as windstorms and fires. Exposure to air pollution is associated with adverse effects on human health including respiratory problems and lung diseases. Air pollution can also significantly affect ecosystems.

The Clean Air Act (CAA) was passed by Congress in 1970 and amended in 1990. Under the CAA, EPA sets limits on how much of a pollutant is allowed in the air anywhere in the United States. Each state is required to develop a state implementation plan (SIP) to explain how it will do its job under the CAA. A permit must be obtained for large sources that release pollutants into the air. The permits require information on which pollutants are being released, how much pollutant is released, what steps are being taking to reduce pollution, and plans for monitoring.


The EPA has set national air quality standards for six principal air pollutants (also known as criteria pollutants): carbon monoxide (CO), lead (Pb), nitrogen dioxide (NO2), ozone (O3), particulate matter (PM), and sulfur dioxide (SO2). CO, Pb, NO2, and SO2 result from direct emissions from a variety of sources, including point sources. PM can result from direct emissions or can form when emissions and other gases react in the atmosphere.

Ozone is not emitted directly, but forms when nitrogen oxides (NOx) and volatile organic compounds (VOCs) react in the presence of sunlight. The EPA refers to chemicals that cause serious health and environmental impacts as hazardous air pollutants (HAPs) or air toxics. Currently, 189 air toxics have been identified, including chemicals such as benzene, chloroform, and mercury.

The EPA tracks air pollution in two ways: (1) emissions form all sources going back thirty years and (2) air quality measured from monitoring stations around the country going back twenty years. The EPA summarizes its most recent evaluations in the report Latest Findings on National Air Quality: 2000 Status and Trends.

Since 1970, the total emissions for the six criteria pollutants
have been reduced 29 percent. National air quality levels measured at monitoring stations across the country have also shown improvements over the past twenty years for all six criteria pollutants. Over 160 million tons of pollution (from both point sources and non-point sources) are emitted into the air each year in the United States.

In 2000 Status and Trends, the EPA reports an increasing focus on tracking and controlling ground-level ozone and fine particles, key components of smog and haze. Progress has been slowest for ground-level ozone.

In some regions of the United States, ozone levels have actually increased in the past ten years. The ozone increase correlates to the increase in NOx emissions from power plants and other sources. NOx emissions also contribute to acid rain, haze and particulate matter.

Sulfates, formed mainly from coal-fired power plant emissions, are the main source of particles in the eastern United States. The emissions also contribute to the formation of acid rain. The EPA’s emissions trading program successfully reduced these air pollutants, resulting in improved visibility in the eastern United States.

While point source pollution is declining in the United States, it remains a global environmental concern. According to the UN report Global Environment Outlook 2000, rapid urbanization and industrialization in many developing countries is creating high levels of air and water pollution.

Population

Population

Throughout most of human history, the world’s population has grown gradually. It took thousands of years for the global population to reach one billion people (around 1800). Then, in a little more than a century, the population jumped to two billion (by 1960), and to three billion by 1980. In just twenty years—between 1980 and 2000—the world’s human population doubled from three billion to six billion people.

The human population explosion during the past century was the result of several factors. Fertility rates remained high, while medical and agricultural advances such as antibiotics, immunizations, clean water, and improved food availability reduced mortality rates—especially among infants and children.

It is difficult to predict how rapidly the human population will continue to increase, due to the many factors that affect population growth. Another important question that scholars ask is “How many people can the earth support?” While the human population grows, the earth’s size and resources remain the same.


Technology can increase the amount of food that can be produced on a piece of land, but it cannot increase the amount of land and water on the planet. Many people regard population growth as the single most serious global issue, because population size is closely linked to environmental and human health conditions.

Environmental problems are aggravated by population explosions. More people means more resources and energy are consumed and more pollution is created and more waste is sent to landfills. More land is needed to grow crops and build houses. More trees are cut down for new homes.

More cars are built, more fossil fuels are used, and more gases are released into the environment. More natural wilderness areas or beautiful landscapes are destroyed to provide resources and cropland. In short, population growth makes other environmental problems harder to solve.

Projecting Population Change

Population change

Scholars have spent centuries trying to find reliable ways to predict population change. One of the most famous population researchers was Thomas Malthus, a British clergyman who studied population growth in the 1770s.

In his famous 1798 Essay on the Principle of Population, Malthus argued that human populations tend to grow exponentially, while food production is limited by land available for agriculture. In short, human populations tend to increase faster than food supply, leading to an imbalance.

Malthus projected that population increases in England would quickly outstrip the available food supplies, leading to famine and misery. Malthus’s predictions for England never occurred in his lifetime. England’s population did increase, but advances in science and technology enhanced food production.

Malthus’s theory also failed to take into account colonial growth as a result of other factors. Still, scholars use Malthus’s concepts of geometric population growth today, though new models of population change are far more complex.


Researchers who study population change consider many factors for each country. Population change for any group of people is determined by fertility, mortality, and migration rates. What is the average number of children per family? What is the life expectancy? Are people migrating into or out of a country? Each of these is, in turn, affected by other factors.

It is important to remember that population projections are just estimates based on past information; they do not account for unknowns such as future wars, epidemics, or the effects of climate change. However, the scholars who make the projections attempt to improve their accuracy by revising projections as new information is collected.

The United Nations Population Division is one of the organizations responsible for making population projections. After considering the potential impact of the current AIDS epidemic, the United Nations recently lowered its population projection for 2050 by more than one billion people.

United Nations Projections

At the beginning of the twenty-first century, the world population is still growing at a rate of 1.2 percent annually. This is the same as adding 77 million people (roughly the population of France) to the world each year. A world population projection published by the United Nations in 2002 estimates that the world’s human population will reach 8.9 billion by 2050.

This population increase is not expected to occur evenly across the globe. The populations of some nations are shrinking while those of other nations are swelling. During the past few decades, reproduction rates have decreased in countries where the standard of living has improved; these improved living standards are generally associated with higher education levels across a population and access to birth control.

Today, as many as thirty-three countries are witnessing population declines due to lower birthrates. Japan, Bulgaria, Italy, Bulgaria, Estonia, and the Russian Federation are among the countries that have achieved negative population growth.

Population explosions tend to occur in regions already struggling with hunger. Africa is expected to undergo the most rapid growth, increasing from 784 million people in 2000 to nearly 1.8 billion in 2050. Eight countries India, Pakistan, Nigeria, the United States, China, Bangladesh, Ethiopia, and the Democratic Republic of Congo—are expected to account for half of the world’s population increase during the next fifty years.

India may overtake China as the most populous country, rising from just over one billion to more than 1.5 billion between 2000 and 2050. Birthrates are not the only reason for the anticipated rises. The United States has a low birthrate, but a high immigration rate.

How Many People Can the Earth Support?

Overload

Is there a limit to the number of people the world can support? Some people contend that new technologies will make it possible for the earth to support ever-larger human populations. They describe the earth’s resources as virtually inexhaustible, due to the potential of technology. They point to the scientific advances that helped increase crop yields across India and China as an example of the human ability to adapt through technology.

Other scholars believe that there are limits to how much technology can accomplish. They argue that the earth’s capacity to support human population growth is finite—because natural resources can be damaged or depleted. For example, India’s increased crop production has not keep pace with its growing population. India’s per-person food production is actually dropping as the food supply is shared among more and more people.

Water shortages may be the most insurmountable obstacles for human survival, as populations continue to grow. On every continent (including North America), rising demands for water are already causing water tables to drop to dangerously low levels, depleting future water supplies. Several of the world’s major rivers are being drained dry before running their courses. Most of this water is used for irrigation (to grow food); less is used for industry and domestic use.

Water scarcity is already a serious survival problem for people living in the more populous and arid regions of the world. Scholars predict that most of the world will face water scarcity as human demands on the earth’s resources continue to rise. Despite hope for technologies such as desalinization to solve the world’s water shortages, the prospects to solve global problems are unlikely. So far, desalinization is too expensive for most nations.

A second challenge the world faces is food production. There is hope that breakthroughs in plant genetics and other sciences will continue to improve food production. Yet many scholars argue that even the most remarkable advances in agricultural technology, aquaculture, and ranching could not raise food production enough to meet the world’s growing needs. Food production is also limited by the availability of fresh water and land that can be farmed—two finite resources.

Malnutrition is already a growing problem in many regions that depend on grains. Likewise, countries that depend on fish as a primary protein source are also faced with shrinking food supplies as the world’s fish populations are further depleted.


Impact on Human Health and the Environment

Population growth affects almost every element of human health and the environment by exacerbating preexisting problems. For example, if a nation is already struggling to provide food, education, and healthcare to its people, the needs of an even larger population may exhaust the nation’s ability to provide for anyone. As a result, the rate of poverty, homelessness, and disease are likely to rise. In most cases, rapid population growth results in a decline in human living standards.

The impact of human population on the environment is complex. A popular theory is that the degree of human impact on the environment is determined by three factors: population size, how much each person consumes, and how much waste each person produces.

India may have a much larger population than the United States, but people in United States tend to consume and waste far more goods than people in any other part of the world. According to this theory, a rise in the U.S. population would have a greater impact on the environment than would a similar increase in India’s population.

What Is Being Done?

There are many views on what to do about global population growth. Several advocacy groups, such as Negative Population Growth, Zero Population Growth, Planned Parenthood, and the Carrying Capacity Network, focus on raising public awareness about birth control and the need to lower fertility rates. At least one group (Negative Population Growth) advocates that the U.S. government should provide incentives for smaller families and should limit immigration in the United States.

The world’s most populous country, China, has been exploring a variety of laws and incentives to limit urban families to one child per family, with the goal of reversing the country’s unsustainable population growth. However, due to the government’s inability to restrict family size in rural areas, where the overwhelming majority of China’s population lives, and other factors, China’s population growth is not expected to turn around until at least 2020.

Slowing population growth is also a priority for many environmental organizations, including the National Audubon Society, the Sierra Club, the Wilderness Society, the National Wildlife Federation, and the Environmental Defense Fund. Most of these groups have policy statements and/or education programs that deal with population issues.

Poverty

Poverty

Continuing industrialization and technological advances benefit many (though not all) of the people in the developed countries, but the gap between the rich and poor countries is significant and increasing.

In general, poverty deprives people of adequate education, health care, and of life’s most basic necessities—safe living conditions (including clean air and clean drinking water) and an adequate food supply.

The developed (industrialized) countries today account for roughly 20 percent of the world’s population but control about 80 percent of the world’s wealth. Poverty and pollution seem to operate in a vicious cycle that, so far, has been hard to break. Even in the developed nations, the gap between the rich and the poor is evident in their respective social and environmental conditions.


Poverty, the Environment, and Pollution

Regardless of the reason or the area of the world in which a poor population lives, certain reciprocal elements will act on the population and its environment. Lack of education, oppression, lack of appropriate infrastructure — from watertreatment facilities to better roads and communication — all exacerbate the twin problems of poverty and environmental degradation.

One cannot ask people to heal the environment, or even just mind it, if they can barely sustain themselves. For example, tropical fish are considered to be either delicacies or exotic pets by people who can pay for them and people in tropical regions can earn good money for catching these fish.

But to catch the fish more easily they use cyanide or dynamite to stun the fish. The former pollutes (and moves up the food chain) and the latter destroys the reef environment. Agricultural practices that tax the soil lead to soil erosion, which lowers crop yields and pollutes rivers and streams with silt.

Poor fisherman

The accumulation of the silt—from the loose eroded soil—kills the fish in the river and streams. Another cause of soil erosion is the cutting down of trees, in massive numbers, either for use as firewood (because the winters are harsh and there is no other way to stay warm) or to sell for much needed cash.

Eventually, not only will the soil erode to a point where it can no longer sustain agriculture, but the trees would be gone too. The above examples show that practices that fail to consider environmental health perpetuate the poverty cycle, thereby further destroying the environment.

The environment as a whole tends to be jeopardized more in the poorer areas. In the United States, Louisiana is a poor state in which there is an area known as “Cancer Alley.” It is a stretch on the lower Mississippi River that is home to 125 companies, many of which manufacture products that result in highly hazardous waste.


Cancer rates in the area are higher than the national average, and respiratory illnesses, as well as incidents of liver and kidney toxicity, are rampant. In one typical area, Ascension Parish, environmental justice activist Robert Bullard points out, “eighteen petrochemical plants are crammed into a nine and a half square mile area” (Bullard, p. 106).

Poor people tend to be less well educated (because they do not have the time and resources to obtain an education), and less politically powerful. Many people in Louisiana’s Cancer Alley were never aware of the dangers of hazardous waste as industries started moving in.

Many of them, after years of discrimination, are distrustful of politicians and public officials. Their land is cheap, and Louisiana provides the big industries with tax breaks, which appeal to companies looking at the bottom line.

Globally, the large industries find the same advantage in poor nations. Pollution controls and hazardous-waste-disposal regulations are stricter, and more expensive, in the developed nations. Many companies find it cheaper to export their waste to the developing countries, which are starving for cash.

Waste and poverty

The hazardous waste disposal in those countries is unsafe and dangerously polluting. The people handling the waste are poorly educated, and therefore may suffer severe health consequences as a result of their work. However, if they are paid a salary they are better off than many others.

In addition, the developing countries themselves, eager to grow economically, may develop heavy industry but not the controls or infrastructure necessary to contain the pollution. It is easy to see, therefore, that there is a huge divide, economically and ideologically, between the developed and developing countries.

The North–South Divide

Economists talk about the North–South divide when referring to the economic growth and development of nations. The developed, or industrialized, countries, most of which are in the northern hemisphere, are referred to as the North. The developing countries, which are economically underdeveloped to varying degrees, are referred to as the South. When it comes to pollution and environmental preservation, the North and South have different priorities that seem to put them at odds with each other.

The concept of sustainable development is crucial to understanding the conflict between the North and South. The United Nations, in a 1987 report of its World Commission on Environment and Development, defines sustainable development as the ability to grow economically and improve quality of life in such a way that “meets the needs of the present without compromising the ability of future generations to meet their own needs.” (Nebel, p. 16)

Poverty area

As mentioned above, the most pressing priority for the southern hemisphere nations is economic growth: the poverty rate in the developing countries can reach 90 percent (by comparison, the North has a poverty rate, on average, of 15 percent). Environmental conservation and pollution control are far less a priority in the South.

The priority in the North is sustainable development—the ability to continue on the course of consumption and energy use while ensuring a healthy environment. The developing countries feel this attitude is elitist, even racist (most poor nations or groups are not white). They contend that the developed countries’ demands for environmental regulations place an undue burden on the developing nations.

Worse yet, the largest polluters are the developed countries, which also consume the most global resources. Many of the problems of environmental destruction in the poor countries are a direct result of consumption levels in the developed countries (poaching for ivory in Africa is but one example, albeit extreme).

Historically, European colonization disrupted those societies that normally lived in balance with their environment. Mostly hunting, agricultural, or fishing in nature, the people grew or consumed enough to sustain themselves, never taking more than they needed.

The European settlers diverted the native agriculture to grow certain target crops (sugarcane and tobacco, for example) that were valuable in Europe. Not rotating the crops depleted the soil and reduced crop yields. It also made the colonized countries’ economies wholly dependent on the fluctuations in cash-crop prices. The settlers also mined and deforested the environment, causing heavy damage.

To this day, developing nations are in the ironic position of exporting a big percentage of their agricultural yield, while having to import food. Even after gaining their independence, many of these countries were unable to build an economy independent of European and U.S. consumption patterns.

The developing nations are heavily in debt to the developed countries, and their cash crops and other commodities (such as diamonds in Africa) are controlled by international corporations. The entire set of circumstances creates severe tension between the North and the South and is getting renewed attention with the emphasis now being given to environmental justice.

Environmental Equity

In 1997 a study by the Harvard Center for Population and Development Studies found that life expectancy for people living in poor communities in the United States was markedly lower than life expectancy for people living in wealthier communities, sometimes by as much as fifteen years. While many factors contribute to this alarming discrepancy, it has become clearer since the 1980s that poor communities, which are also predominantly non-white, bear the brunt of adverse pollution affects.

In 1983, for example, a U.S. General Accounting Office report found that in eight southeastern states that were studied, “Blacks make up the majority of the population in three out of four communities where landfills are located.” (U.S. GAO, p. 1) Worldwide, the trend is similar. Big corporations find it easier and cheaper to export trash and to build polluting factories in poor developing nations.

Environmental justice is, to use the U.S. Department of Energy’s definition, “the fair treatment and meaningful involvement of all people regardless of race, color, national origin, or income with respect to the development, implementation, and enforcement of environmental laws, regulations, and policies” (http://www.epa.gov/compliance/environmentaljustice/index.html). In the United States, the 1980s saw the beginning of an environmental justice movement that started focusing attention on the undue burdens placed on poor communities when it comes to living in a polluted environment.

Fighting what some refer to as environmental racism, the grassroots environmental justice movements at times clashed with older environmental groups, who formed around the idea of conservation, and whose concern for the natural environment seemed elitist.

There was a perception that organizations such as the Sierra Club concerned themselves with the conservation of the natural environment but did not care about pollution in inner cities and poor rural communities. Much more research is being done on the connection between hazardous living conditions and poverty not only on the effects, but also on the causes.

Among the environmental justice group’s many victories was Executive Order 12898, signed by President Bill Clinton on February 11, 1994, directing federal agencies to correct the “disproportionately high and adverse human health or environmental effects” that their operations have on the minorities and low-income populations.