Unit IV. The Problems of Soil Pollution. Noise Pollution.

“We must try to live without causing unnecessary harm, not just to fellow humans but to all beings. We must try not to be stingy, or to exploit others. There will be enough pain in the world as it is.”

Gary Snyder, Poet

Before you read Text 1

• How do you understand the statement given in the quotation of this unit?

• What do you think soil pollution is?

• Do you think this problem concerns you directly? In what way?

Text 1. Soil Pollution.

Major Pollutants and Their Sources.

Soil pollution is defined as the build-up in soils of persistent toxic compounds, chemicals, salts, radioactive materials, or disease causing agents, which have adverse effects on plant growth and animal health.

Until the 1970s, there was little talk of soil pollution and its devastating effects. In the 1980s, the U.S. Superfund was created to set guidelines for the handling of hazardous material and soil contamination cleanup. Today there are more than 200,000 sites awaiting EPA (Environmental Protection Agency) soil cleanup, which is very expensive and labor-intensive work. Even a small cleanup project can cost $10,000, while larger areas require millions of dollars to clean it up for future use.

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.

Past and present economic activities have often resulted in the pollution of the underlying soil where these activities take place. Industry is to blame for some of the biggest soil-pollution disasters. Heavy metals come from iron, steel, power and chemical manufacturing plants that recklessly use the Earth as a dumping ground for their refuse. Plants that burn their waste on-site are guilty of releasing heavy metals into the atmosphere, which come to settle in the soil, thus leaving behind lasting effects for years to come. Even companies that try to dispose of their waste properly contribute to the problem when faulty landfills and bursting underground bins leach undesirable toxins into the soil.

Mining leaves a tremendous impact on the surrounding communities. The 2001 West Virginia Geological and Economic Survey found that people living near mines have a 70 percent higher risk of kidney disease, 64 percent higher risk for chronic obstructive pulmonary disease and a 30 percent higher risk of high blood pressure.

The most common toxic soil pollutants include metals and their compounds, organic chemicals, oils and tars, pesticides, explosive and toxic gases, radioactive materials, biologically active materials, combustible materials, asbestos and other hazardous materials. These substances commonly arise from the disposal of industrial and domestic waste products in designated landfills or uncontrolled dumps.

Heavy metals. Soil contamination by heavy metals, such as cadmium, lead, chromium, copper, zinc, mercury and arsenic, is a matter of great concern. Heavy metals are present naturally in the soil, but their levels are increased by:

• industry (non-ferrous industries, power plants, iron, steel and chemical industries);

• agriculture (irrigation with polluted water, use of mineral fertilisers)

• waste incineration;

• combustion of fossil fuels;

• road traffic.

Pollution of agricultural soils by heavy metals may lead to reduced yields and elevated levels of these elements in agricultural products, and thus to their introduction into the food chain. Heavy metal deposits on grassland soils remain predominantly in the top few centimetres and are directly ingested with soil by grazing animals. Heavy metals are toxic and inhibit the soil's microorganic activity. Their concentration in the soil can remain for decades or even centuries.

Reduction of heavy metal emissions is the most direct way to decrease the atmospheric deposition of these elements and their build-up in the soil. Despite the great increase in traffic, for example, a reduction in lead emissions has been achieved through incentives to use unleaded petrol.

Implementing complex measures that reduce soil acidification could more efficiently reduce heavy metals. On agricultural land, heavy metal quantities can be decreased by using low-metal content resources for fertilisers, replacing inorganic pesticides with organic products, and other similar methods.

Organic pollutants. Pesticides pollute the soil directly by affecting the organisms that reside in it. Soil, however, can act as a vector for the pollution of surface water and groundwater. Organic pollutants enter the soil via atmospheric deposition, direct spreading onto land, contamination by wastewater and waste disposal.

In addition to pesticides, organic contaminants include many other components, such as oils, tars, chlorinated hydrocarbons, PCBs and dioxins. There is such a wide variety of organic substances that their detection and monitoring in the soil is practically impossible. Pesticides (mainly fungicides, herbicides and insecticides) are used in agriculture to protect crops and to ensure a quality harvest. Persistent or mobile pesticides are especially dangerous, as are those that affect non-targeted organisms.

The use of pesticides may lead to:

• destruction of the soil's micro-flora and fauna, leading to both physical and chemical deterioration;

• severe yield reduction in crops;

• leaching of toxic chemicals into groundwater and potentially threatening drinking water resources.

Some improvements in application and legislation may reduce the side effects of pesticides, such as:

• banning broad-spectrum and highly mobile pesticides;

• employing integrated pest-management;

• enforcing biological control; and

• developing biotechnologies.

Nitrates and phosphorus. Nitrogen and phosphorus are elements essential to all forms of life and are therefore relevant to soil systems and food crops. Although they are important plant nutrients, excessive application may lead to nitrogen or phosphate saturation in the soil, and eventual contamination of the groundwater. The amount of leaching depends on the soil, the local climate and the style of crop management.

Phosphorus accumulates in the upper layer of soil in regions with high livestock densities. In soils saturated with phosphorus, especially those with shallow groundwater, high phosphorus concentration occurs in the upper groundwater layer and in surface water, resulting in eutrophication.

The problem of nitrate pollution is recognised internationally and is usually associated with intensive agriculture practices. Good agricultural practices that alleviate the problem are:

• the selection of crops that require fewer nutrients;

• a timely application of fertiliser (in the growing season);

• improved methods of manure application;

• shortening the length of the grazing season; and

• reducing the intensity of grassland use (by lowering cattle density).

Artificial radionuclides. Contamination of soil with artificial radionuclides (cesium-137, strontium-90 and some plutonium isotopes) has given rise to increased public concern since the Chernobyl accident.

Radionuclides in the upper layers of soil may expose plants and animals to radiation and, in extreme cases, present a threat to humans in the form of direct ionising radiation. Radionuclides can enter the food chain through the soil, leading to intake by humans and animals through ingestion, while wind-blown contaminated soil particles could lead to exposure through inhalation.

The existence of unauthorised dumps is one of the environmental problems in Europe that deserves utmost attention. The remediation costs of polluted areas in Europe are roughly estimated at more than EUR 100 billion.

After you read Text 1. Look at the texts and try to find:

1. The definition of soil pollution.

2. The main causes of soil pollution.

3. The main types of pollutants and their sources.

4. Some effects of organic pollutants use.

5. Artificial radio-nuclides and their affects.

6. Heavy metals contamination affects.

As you read Texts 2

• Which paragraphs contain the following information? Prove the statements with the text.

A The effects of soil pollution which potentially can happen .

B Encouraging recycling programs and educating consumers about the dangers of littering.

C Soil chemistry changes can manifest in the alteration of metabolism of endemic microorganisms.

D Some strategies for treatment.

E The traditional methods of soil pollution treatment.

Text 2. Ecosystem effects.

Treatment of Soil Pollution.

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 and arthropods resident in a 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 potential extinction of species.

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.

Soil pollution at both former and present industrial sites represents a serious potential threat to human health, ecosystems and the economy. Because of the wide variety of soil pollutants and concentrations, impacts are imprecisely known. The potential effects of soil pollution are:

• release of contaminants to the land surface, groundwater or surface water;

• uptake of contaminants by plants;

• direct contact by humans with contaminated soil;

• inhalation of dust particles or volatile substances;

• fire or explosion of landfill gases;

• corrosion of underground pipelines and other building components;

• generation of hazardous, secondary waste streams;

• conflict with proposed land use.

The conventional methods of soil pollution are very time-consuming and very costly. EPA (Environmental Protection Agency) officials excavate the soil to dispose of it elsewhere – a band-aid for the problem, no doubt, but essential for toxic disasters in highly populated places. Soils can be aerated, heated up in a process called thermal remediation, contained with pavement or caps, extracted with an active electromechanical system or propagating the soil with microbes that will digest organic pollutants.

New processes are being developed to combat the problem in a natural, less laborious way. By studying plants that grew naturally in toxic mines, scientist Chen Tongbin discovered that certain plants loved to eat heavy metals like arsenic, bronze, lead, zinc, cobalt and cadmium. The contaminants can then be retrieved from the plant's leaves and used in industrial materials. This safe and effective method isn't perfect, but it's a start.

Prevention of Soil Pollution. Naturally, prevention is the best cure for soil pollution. Most states have enacted tougher legislation to stop illegal dumping. For instance, one can expect five years in jail and a fine of $100,000 for soil pollution in Texas. Educating consumers about the dangers of littering, while encouraging recycling programs, is a good way to ensure everyone does their part to keep debris where it belongs. Consumers can also make a concerted effort to buy organic foods to demand that chemical pesticides aren't used on their foods.

People who grow their own food can keep excess nitrogen and phosphorus out of the soil by choosing crops that do not need as many nutrients from the soil, by applying fertilizer during the growing season to replenish the soil, by shortening the grazing season / cattle density, by using organic compost, by keeping the surface moist and mulched, and by choosing fruiting crops like tomatoes, squash, peas and corn. Gardens should be situated away from old painted buildings and roadways. Outer leaves of lettuce should be discarded and all vegetables should be washed before eating.

Over the years, stronger and more indestructible bins were created to store hazardous materials. Researchers will continue to look for ways to improve manufacturing and agricultural processes to avoid the need for toxic byproducts. Business leaders, miners and community officials will work together to reduce wastefulness and contaminants to keep the world a clean place for future generations.

Cleanup options. Cleanup or remediation is analyzed by environmental scientists who utilize field measurement of soil chemicals and also apply computer models for analyzing transport 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-DSPtm.

• 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).

Before you read Texts 3 and 4

• What are the noise pollution effects you feel almost every day?

• What do you think is necessary to do to reduce noise pollution?

• What are the most common sources of noise pollution?

Text 3. Noise Pollution.

The Causes and Sources.

The word noise is derived from the Latin term nausea meaning seasickness. Noise is defined as unwanted sound, a potential hazard to health and communication dumped into the environment with regard to the adverse effect it may have on unwilling ears. Sound, which pleases the listeners, is music and that which causes pain and annoyance is noise. At times, what is music for some can be noise for others. Noise pollution (or environmental noise) is displeasing human-, animal- or machine-created sound that disrupts the activity or balance of human or animal life.

Noise pollution is a type of energy pollution in which distracting, irritating, or damaging sounds are freely audible. As with other forms of energy pollution (such as heat and light pollution), noise pollution contaminants are not physical particles, but rather waves that interfere with naturally-occurring waves of a similar type in the same environment. Thus, the definition of noise pollution is open to debate, and there is no clear border as to which sounds may constitute noise pollution. In the most narrow sense, sounds are considered noise pollution if they adversely affect wildlife, human activity, or are capable of damaging physical structures on a regular, repeating basis. In the broadest sense of the term, a sound may be considered noise pollution if it disturbs any natural process or causes human harm, even if the sound does not occur on a regular basis.

Decibel is the standard unit for measurement of sound. Usually 80 db (decibel) is the level at which sound becomes physically painful. And can be termed as noise. Humans, animals, plants and even inert objects like buildings and bridges have been victims of the increasing noise pollution caused in the world. Be it human or machine-created, noise disrupts the activity and balance of life. While traffic dons the cap of being the largest noise maker throughout the world, there are many others that add to it, making our globe susceptible to its effects. The effect of noise pollution is multi-faceted and inter-related.

Causes and Sources of noise Pollution. Noise can arise from several sources: domestic noise (loud music, barking dogs); commercial or industrial premises (pubs, clubs, factories); noisy equipment (alarms, ventilation fans, refrigeration units); outdoor events; vehicles (car alarms, ice cream chimes); construction work (from DIY to major projects).

The source of most outdoor noise worldwide is transportation systems, including motor vehicle noise, aircraft noise and rail noise. Traffic noise is the main source of noise pollution caused in urban areas. With the ever-increasing number of vehicles on road, the sound caused by the cars and exhaust system of autos, trucks, buses and motorcycles is the chief reason for noise pollution. Poor urban planning may give rise to noise pollution, since side-by-side industrial and residential buildings can result in noise pollution in the residential area.

With the low flying military aircrafts soaring over the national parks, wasteland and other vacant areas, the level of noise pollution has drastically increased in these previously unaffected zones. People living beside railway stations put up with a lot of noise from locomotive engines, horns and whistles and switching and shunting operation in rail yards. This is one of the major sources of noise pollution.

To meet the demands of the basic necessity of living, the construction of buildings, highways and city streets causes a lot of noise. Pneumatic hammers, air compressors, bulldozers, loaders, dump trucks and pavement breakers are the major sources of noise pollution in construction sites.

Though not a prime reason, industrial noise adds to the noise pollution. Machinery, motors and compressors used in the industries create a lot of noise which adds to the already detrimental state of noise pollution. Plumbing, boilers, generators, air conditioners and fans create a lot of noise in the buildings and add to the prevailing noise pollution.

Household equipments, such as vacuum cleaners, mixers and some kitchen appliances are noisemakers of the house. Though they do not cause too much of problem, their effect cannot be neglected. Other sources of indoor and outdoor noise pollution are car alarms, emergency service sirens, office equipment, factory machinery, construction work, groundskeeping equipment, barking dogs, appliances, power tools, lighting hum, audio entertainment systems, loudspeakers, and noisy people.

Text 4. Effects of Noise Pollution

Human health effects. Noise health effects are both health and behavioural in nature. The unwanted sound is called noise. This unwanted sound can damage physiological and psychological health. Noise pollution can cause annoyance and aggression, hypertension, high stress levels, tinnitus, hearing loss, sleep disturbances, and other harmful effects. Furthermore, stress and hypertension are the leading causes to health problems, whereas tinnitus can lead to forgetfulness, severe depression and at times panic attacks.

Hearing Problems. Exposure to noise can damage one of the most vital organs of the body, the ear. Hearing impairment due to noise pollution can either be temporary or permanent. When the sound level crosses the 70dB mark, it becomes noise for the ear. Noise levels above 80 decibels produce damaging effects to the ear. When ear is exposed to extreme loud noise (above 100 decibels) for a considerable period of time, it can cause irreparable damage and lead to permanent hearing loss.

Chronic exposure to noise may cause noise-induced hearing loss. Older males exposed to significant occupational noise demonstrate significantly reduced hearing sensitivity than their non-exposed peers, though differences in hearing sensitivity decrease with time and the two groups are indistinguishable by age 79. A comparison of Maaban tribesmen, who were insignificantly exposed to transportation or industrial noise, to a typical U.S. population showed that chronic exposure to moderately high levels of environmental noise contributes to hearing loss.

Cardiovascular Issues. A noisy environment can be a source of heart related problems. Studies have shown that high intensity sound cause a dramatic rise in blood pressure as noise levels constrict the arteries, disrupting the blood flow. High noise levels can contribute to cardiovascular effects and exposure to moderately high levels during a single eight hour period causes a statistical rise in blood pressure of five to ten points and an increase in stress and vasoconstriction leading to the increased blood pressure noted above as well as to increased incidence of coronary artery disease.

The heart rate (the number of heartbeats per minute) also increase. These sudden abnormal changes in the blood increase the likelihood of cardiovascular diseases in the long run.

Noise pollution is also a cause of annoyance. A 2005 study by Spanish researchers found that in urban areas households are willing to pay approximately four Euros per decibel per year for noise reduction.

Sleep Disturbances. This is one of the noise pollution effects that can deter your overall well being. Noise can interrupt a good night's sleep, and when this occurs, the person feels extremely annoyed and uncomfortable. People deprived of uninterrupted sleep show a sharp dip in their energy levels which often results into extreme fatigue. This can considerably decrease a person's ability to work efficiently.

Interference in Verbal Communication. A noisy environment that produces more than 50-60 decibels simply does not allow 2 people to communicate properly. Interpreting the speech of a second person becomes quite difficult and may lead to misunderstandings.

Mental Health Problems. Exposure to loud sound can lead to elevated stress levels as well as stimulate violent behavior. A constant noise in the vicinity can also trigger headaches, make people tense and anxious, and disturb emotional balance.

Environmental effects. Noise pollution effects on the environment have also been studied. Man made noise pollution has made the Earth an uncomfortable place to stay for animals as well. Hearing loss and rapid increase in heart rate are some of the ill-effects of noise pollution on animals. High intensity sound induces fear, forcing them to abandon their habitat. Noise can have a detrimental effect on animals by causing stress, increasing risk of death by changing the delicate balance in predator/prey detection and avoidance, and by interfering with their use of sounds in communication especially in relation to reproduction and in navigation. Acoustic overexposure can lead to temporary or permanent loss of hearing.

An impact of noise on animal life is the reduction of usable habitat that noisy areas may cause, which in the case of endangered species may be part of the path to extinction. One of the best known cases of damage caused by noise pollution is the death of certain species of beached whales, brought on by the loud sound of military sonar.

Noise also makes species communicate louder, which is called Lombard vocal response. Scientists and researchers have conducted experiments that show whales' song length is longer when submarine-detectors are on. If creatures don't "speak" loud enough, their voice will be masked by anthropogenic sounds. These unheard voices might be warnings, finding of prey, or preparations of net-bubbling. When one species begins speaking louder, it will mask other species' voice, causing the whole ecosystem to eventually speak louder.

European Robins living in urban environments are more likely to sing at night in places with high levels of noise pollution during the day, suggesting that they sing at night because it is quieter, and their message can propagate through the environment more clearly. Interestingly, the same study showed that daytime noise was a stronger predictor of nocturnal singing than night-time Light pollution, to which the phenomenon is often attributed.

Zebra finches become less faithful to their partners when exposed to traffic noise. This could alter a population's evolutionary trajectory by selecting traits, sapping resources normally devoted to other activities and thus lead to profound genetic and evolutionary consequences.

Noise pollution indirectly affects the vegetation. Plants require cool & peaceful environment to grow. Noise pollution causes poor quality of crops.

Noise indirectly weakens the edifice of buildings, bridges and monuments. It creates waves, which can be very dangerous and harmful and put the building in danger condition.

After you read Text 3 and 4. Answer these questions:

1. What is the origin of the word noise?

2. Why is the definition of noise pollution open to debate?

3. What is the standard unit for measurement of sound?

4. What sources can noise arise from?

5. What is the difference between outdoor and indoor noise?

6. What is the noise level which produce damaging effects to the ear?

7. Why is noise considered to be harmful also for environment?

8. What are health problems caused by noise pollution?

9. What can you personally do to reduce noise pollution?

Text 5. Noise Pollution Control.

Like water and air pollution, noise pollution too needs to be controlled. To bring down noise levels, one has to first identify the sources of noise. Considering the ill effects of noise, some preventive steps need to be taken to reduce noise levels at the source. Here are some tips to limit the noise:

• People living in the heart of city or near the airport, often have to bear the brunt of high noise levels. To decrease noise, one can install dual-paned windows. Offices, too can use windows to curb noise levels. Soundproofing is another alternative that can be looked at to reduce excessive sound levels.

• Use of music systems and television sets with high volumes can cause noise pollution at home. Instead, using these appliances with the volume kept at a moderate level is a better option.

• An effective way to manage noise would be to wear ear protection while working in noisy conditions. Animals should be moved to some other place, away from the noise source, thereby decreasing their noise exposure time.

• Vehicles and factory machines need to be maintained properly and checked from time to time. Lack of maintenance will not only increase noise levels, but also decrease the efficiency of these machines.

Technology to mitigate or remove noise can be applied as follows:

There are a variety of strategies for mitigating roadway noise including: use of noise barriers, limitation of vehicle speeds, alteration of roadway surface texture, limitation of heavy vehicles, use of traffic controls that smooth vehicle flow to reduce braking and acceleration, and tire design. An important factor in applying these strategies is a computer model for roadway noise, that is capable of addressing local topography, meteorology, traffic operations and hypothetical mitigation. Costs of building-in mitigation can be modest, provided these solutions are sought in the planning stage of a roadway project.

Aircraft noise can be reduced to some extent by design of quieter jet engines, which was pursued vigorously in the 1970s and 1980s. This strategy has brought limited but noticeable reduction of urban sound levels. Reconsideration of operations, such as altering flight paths and time of day runway use, have demonstrated benefits for residential populations near airports. FAA sponsored residential retrofit (insulation) programs initiated in the 1970s has also enjoyed success in reducing interior residential noise in thousands of residences across the United States.

Exposure of workers to Industrial noise has been addressed since the 1930s. Changes include redesign of industrial equipment, shock mounting assemblies and physical barriers in the workplace.

Although most developed nations have government agencies responsible for the protection of the environment, no nation has a single body that regulates noise pollution. In the United States, regulation of noise pollution was stripped from the federal Environmental Protection Agency (EPA) and passed on the individual states in the early 1980's. Although two noise-control bills passed by the EPA are still in effect, the agency can no longer form relevant legislation. In the United States, Canada, Europe, and most other developed parts of the world, different types of noise are managed by agencies responsible for the source of the noise. Transportation noise is usually regulated by the relevant transportation ministry, health-related work noise is often regulated by health ministries and worker's unions, and entertainment noise such as loud music is a criminal offense in many areas. As the bodies responsible for noise pollution reduction usually view noise as an annoyance rather than a problem, and reducing that noise often hurts the industry financially, little is currently being done to reduce noise pollution in developed countries.

If you can’t eliminate noise from your environment, you can actually create a healthier environment by replacing stress-inducing environmental sounds with more pleasing ones. For example, you can reduce the impact of airport or city noise with a white noise machine or ‘sound spa’. They play sounds ranging from waterfalls to rain to babbling brooks to basic static, and these sounds mask the more jarring environmental noises that can distract you or negatively affect your sleep. They can also make it easier to meditate or practice visualization techniques.

Additionally, you can drown out distracting sounds from a noisy office environment or neighborhood with music from your iPod or stereo and enjoy the stress management and health benefits of music while lessening the impact of the other noise. This can also improve your mood, boost your immunity, calm your physiology, or energize you. While you’re really trading some sounds for others, the sounds of nature or music can be more soothing and better for your health.

After you read Text 5. Answer these questions:

1. What are the tips to limit the noise given in the text?

2. What are the strategies for reducing roadway and aircraft noise?

3. Whom are the noise pollution problems regulated by?

4. How can you reduce the impact of airport or city noise?

5. Can you give some more ideas to solve the problem?

Fast Facts

Pesticides:

• In the US, pesticides poison 110,000 people each year. More than one-third of calls to animal poison control centers result from pets exposed to pesticides.

• The volatile organic compounds (including pesticides) found indoors are believe to cause 3,000 cases of cancer a year in the US.

• According to the New York State Attorney General’s office, 95 percent of the pesticides used on residential lawns are considered probable carcinogens by the EPA.

• 2,4-D—a component of Agent Orange—is used in about 1,500 lawn care products.

Quantifying noise pollution:

• Noise intensity is measured in decibel units. The decibel scale is logarithmic; each 10-decibel increase represents a tenfold increase in noise intensity. Human perception of loudness also conforms to a logarithmic scale; a 10-decibel increase is perceived as roughly a doubling of loudness.

• Above 45 decibels of noise, the average person cannot sleep.

• Above 66 decibels of noise, we are above the threshold deemed safe by the EPA for the workplace or home-life. Some of the health effects include irritability, heartburn, indigestion, ulcers, high blood pressure, and possibly heart disease.

• At 85 decibels we are at risk for hearing loss. (Continuous exposure at lower levels can also lead to hearing loss).

• One burst of noise, as from a passing truck, is known to alter endocrine, neurological, and cardiovascular functions in many individuals.

• Prolonged or frequent exposure to such noise contributes to noise-induced stress and potential mental illness.

• Environmental Protection Agency studies show that sound barriers can cut highway noise levels in half. A reduction in 10 decibels, commonly achieved with sound barriers, has the effect of reducing 50% of unwanted noise.

• Benefits include lessened sleep disturbance, improved ability to enjoy outdoor life, reduced speech interference, stress reduction, reduced risk of hearing impairment and reduction in blood pressure (improved cardiovascular health).

• human-created noise harmful to health or welfare. Transportation vehicles are the worst offenders, with aircraft, railroad stock, trucks, buses, automobiles, and motorcycles all producing excessive noise. Construction equipment, e.g., jackhammers and bulldozers, also produce substantial noise pollution.

• Subjected to 45 decibels of noise, the average person cannot sleep. At 120 decibels the ear registers pain, but hearing damage begins at a much lower level, about 85 decibels. The duration of the exposure is also important. There is evidence that among young Americans hearing sensitivity is decreasing year by year because of exposure to noise, including excessively amplified music.

• Biomusic is a form of experimental music which deals with sounds created or performed by living things. The definition is also sometimes extended to included sounds made by humans in a directly biological way. For instance, music that is created by the brain waves of the composer can also be called biomusic as can music created by the human body without the use of tools or instruments that are not part of the body (singing or vocalizing is usually excluded from this definition).

• Biomusic can be divided into two basic categories: music that is created solely by the animal (or in some cases plant), and music which is based upon animal noises but which is arranged by a human composer.

• Biomusic can take many other forms. These can include the simple amplification of animal sounds, or the creation of music through the fluctuation of electric current in plants. More unusual still is the use of animal notation: music scores created by animals, often in the form of paw prints. Biomusic can also take the form of animals trained to perform specific behaviors as part of a musical performance (birds trained to sing for instance).

• Acoustic ecology, or soundscape ecology, is the relationship, mediated through sound, between living beings and their environment. Acoustic ecology studies started in the late 1960s with R. Murray Schafer and his team at Simon Fraser University (Vancouver, Canada) as part of the World Soundscape Project.