Exposures To Residential Electric And Magnetic Fields example essay topic

The Effects of Living Under Electro Magnetic Fields Power Lines Electric power is a fact of life in America in the world today. Ever since electric power was introduced society has thought nothing of the harmful effects of electromagnetic fields or electricity as long as they had it at their disposal. I will not be able to answer the question for you about how harmful it is but I will be able to enlighten you with information to help you decide how harmful it really is. For many years there have been studies to see if electromagnetic fields are the cause of many some cancers and other health issues.

There are many questions that people have about power lines. People often wonder if they are safe to live near powerlines Scientists all over the world have been tackling these questions as far back as the 1960's. Recently, a new question has emerged about the electric power we all depend on: Does it have anything to do with cancer or brain tumors Some epidemiological studies have suggested that a link may exist between exposure to power-frequency electric and magnetic fields (also known as EMF's) and certain types of cancer, primarily leukemia and brain cancer. Other studies have found no such link. Laboratory researchers are studying how such an association is biologically possible.

At this point, there is no scientific knowledge about the EMF issue-except a general agreement that better information is needed. A national EMF research effort is under way, and major study results are expected in the next few years... (web) In order for you to fully understand what I am talking about I will inform you about power lines or else known as transmission lines and explain to you what they look like and how they work. There are two basic types of power lines there are transmission lines and distribution lines. Transmission lines are high-voltage power lines. The high voltage allows electric power to be carried efficiently over long distances from electrical generation facilities to substations near urban areas.

In the United States, most transmission lines use alternating current (AC) and operate at voltages between 50 and 765 kV... (web) Transmission lines end at transformer substations where the voltage is increased or decreased as required for further transmission. Transmission lines are made up of metallic conductors, each is designed to carry specific electrical voltages. The structures that support the conductors are made from single or double wooden poles, or lattice steel. A single circuit transmission line consists of a set of three metallic conductors to create a complete electrical circuit. A double circuit towers carry two sets of conductors. The conductor must clear the ground at the low point between the towers by at least seven meters, height may vary according to different CSA standards.

A lighting guard is or called sky wire is installed at the high point of the tower to avoid lighting outages. (Fur, 2). Then we have distribution lines which, utilities use that are lower-voltage to bring power from substations to businesses and homes. Distribution lines operate at voltages below 50 kV. (web) Before I inform you about the effects of electromagnetic radiation, here is some information to give you an idea what I am talking about. Electromagnetic Radiation Electromagnetic radiation is defined as the emission and transmission of energy in the form of electromagnetic waves (Chang, pp. 246). An electromagnetic wave consists of two waves at perpendicular planes, on representing the electrical field while the other represents the magnetic field.

This spectrum is split up into about 81 octaves, much like the octaves of sound, which scientists have categorized in order to depict the usefulness of the different properties. Theoretically electromagnetic waves can be as long as the expansive width of the universe in one wave, to a wavelength the size of a quanta (the smallest amount of energy that can be transmitted). That, however, is at this point in time negligible because we either cannot detect wavelengths so extremely large or infinitesimally small. So generally the spectrum is regarded to be set between 30,000,000 km and. 0001 angstroms (1 km is equal to 1 X 10^13 angstroms). The longest and least energetic of the accepted wavelengths are radio waves.

Their wavelengths range from 300,000 km to 30 cm and a frequency of 30 kHz to 3,000,000 kHz. The waves are used in the transmission of radio and television signals. AM and FM radio signals fall in the long-wave radio range, while TV signals use the short-wave radio range, somewhere in the 3 m wavelength. Radio waves take up about 30 of the 81 octaves. The next slightly more energetic and shorter wavelength is microwaves.

Obviously, most are familiar with microwaves since they are always being used to cook food, but microwaves are also used in radio telescopes and radar, even the radiation from a neutral hydrogen atom falls in this range. Microwave range extends from wavelengths of 30 cm to. 3 cm and frequencies of 1-100 billion cycles per second. This corresponds to 6 1/2 octaves. Then comes the infrared range. While much of the radio spectrum passes easily through our atmosphere, infrared is almost completely blocked off due to absorption by gaseous molecules that reside there.

Infrared waves are present during the transmission of heat. It's wavelengths range from. 3 cm to. 000076 cm with frequencies from 100 billion (10^11) to almost 10^14 cycles per second.

12 octaves are part of the infrared spectrum. The visible spectrum with its single octave is the part of the spectrum that only the blind are denied. The atmosphere is highly transparent to the visible spectrum, and is one reason why biologists believe it is the only part of the spectrum our eyes are sensitive to. Our sun produces intense amounts of visible light, which also explains why we don t perceive the much less abundant radio wavelengths that are also impervious to our atmosphere. The visible wavelengths range from. 76 microns (7600 angstroms) to.

38 microns (3800 angstroms) with frequencies of slightly less than a quadrillion (10^15). They all behave as waves and particles, and all travel at the unerring speed of light, 300,000 Km per second. So we see not only could these electromagnetic fields cause cancer or brain tumors they could also affect eyesight thought UV rays produced by the sun. One of the major health issues that is being studied is cancer. Scientists as well as society are pondering if there is a link between electromagnetic fields and cancer The electrical charges produce Electric and magnetic fields (EMFs). Devices that produce or use electrical power, like power lines and power transformers, give off EMFs.

Common household appliances that use electricity give off EMF's such as like electric clocks, shavers, computers, televisions, and microwave ovens. Cancer I would say is the biggest concern that they are dealing with in this topic especially cancer in children and breast cancer in adult women. But the part of the electromagnetic field that is believed to cause the cancer is known as Carcinogen. In industry, there are many potential exposures to carcinogens. ( web). According to the Webster's Dictionary Carcinogens are substances or agents that produce or incite cancer. Generally, workplace exposures are considered to be at higher levels than for public exposures.

Experts believe that children are getting leukemia and brain tumors because of these electromagnetic fields. According to British Journal of Cancer, it is shown that radiation fields produce changes in the makeup of the cells and some of the damage was passed on to the next generation of mice. The risk of developing leukemia was nearly doubled in the PPI mice. Leukemia is A disorder affects the soft inner portion (marrow) of some of your bones. web It is assumed that it slows down the production of normal bone marrow and blood cells.

The damage in the bone marrow cells alone was not enough to cause the leukemia, but it increased vulnerability to the disease. Leukemia developed earlier and more frequently in the cells when they were exposed to a powerful cancer-causing chemical. (web). But A 1996 review by a prominent group of scientists at the U.S. National Academy of Science concluded that: "No conclusive and consistent evidence shows that exposures to residential electric and magnetic fields produce cancer, adverse neuro behavioral effects, or reproductive and developmental effects". (Q 27 E).

I will go over some studies from around the world that I found in my research. Let me remind you that there are literally thousands of studies out there that on this topic so I will give you a few that can give you different views on the subject. Now that we are in the year 2001 most people are using cellular phones and other technological advancements. Could these increase the cause of disease Right now most people in society are carrying around cell hones or other technological advancements that give off these radiation fields as well...

Numerous studies in recent years have suggested cell phones and the low levels of radiation they emit may be responsible for everything from anxiety to concentration lapses to long-term memory loss. Through studies of animals there has been a suggested theory that it causes brain cancer. The bottom line, experts say, is that no one yet knows if cell phones pose a health risk - if any at all. A series of comprehensive studies under way should provide much-needed answers.

"If you ask the question - 'Is there a link between cell phone use and brain tumors' - we don't know", says Henry Lai, research professor in the bio electromagnetics research laboratory at the University of Washington. Lai has done extensive research into low-level radiation similar to that produced by cell phones. (web). One of the health effects that I had come across form my research was about pacemakers and other implantable medical devices. This was an actual court case dated in June 2000. The Plaintiff was with the Power Line Task Force and the Defendants were the State of Minnesota, County of Hennepin. A women by the name of Heidi Benedict that works at Northern Power Company as an analyst responsible for monitoring developments in research regarding electric and magnetic fields including health effects, testified that it has been known for some time that under certain circumstances, EMF can interfere with pacemakers.

For this reason the American Conference of Industrial Hygienists issued EMF guidelines for workers with pacemakers. At the power frequency of 60 Hz the guidelines are 1 G (1,000 mG) for magnetic fields and 1 kV / m for electric fields. (Power Line Facts, 1) She also proceeded to say, the EMF is specifically related to those external electric fields that could potentially interfere with the pacemaker's ability to sense normal electrical activity in the heart. (Power Line Facts, 2) Here is one example that there maybe a health effect involved with the EMF.

This is a small example of a health effect that has been being studied. I found a study that was done by the UK on Childhood Cancer Study (UKCCS) this was a report that Lancet Editors had put out on the study. This was dated December 4, 1999. The UK did a study on exposure to power frequency magnetic fields and risk of childhood cancer. Studies conducted by the US National Research Council, WHO, and the National Institute of Environmental Health Sciences (NIEHS) suggested there was a weak link between exposure to power-frequency magnetic fields and childhood leukemia, with odds ratio of about 1-5. The NIEHS rated exposure to power-frequency fields as a category 2 B, a possible human carcinogen.

WHO through its EMF project has been promoting research that attempts to address the 2 B classification. WHO feels that UKCCS is large and well conducted it's not the definitive study that scientists have been hoping for. There are a couple of reasons that they felt that way. One is that this study was designed many years ago so the exposure assessment relies on time weighted average (TWA) fields. They feel that TWA should be used in there studies but they feel that other measures should also be used.

(Lancet, 1) The second reason is the low number of children in the higher number categories. As the UKCCS investigators state, only 2-3% of their controls had been exposed to magnetic fields over 0-2 uT. Although this percentage is similar to that in Germany (2%), in the US study it was 11-4% and in the Canadian studies 15-4%. This difference reflects, in part, the line voltage in North America of about 110 V, and in Europe of 220 V. (Lancet, 1) It went on to say that, Thus for the same power consumption North Americans use twice as much current as Europeans do so they are exposed to about double the magnetic field strength.

Another factor that would influence the magnetic-field level exposure between the two continents relates to how the power is distributed, for example how electrical writing is configured in homes and how the currents are earthed. The small numbers in the higher exposure means that the UKCCS provided evidence only for exposures of up to 0-2 uT. (Lancet, 1) The third reason is The number of cases and controls in the higher exposure categories are unlikely to significantly affect the results of previous meta-analyses and reviews suggesting a weak link between power-frequency magnetic-field exposure and childhood leukemia. (Lancet, 1) I think that with all the different studies there are always going to be areas that weren t covered and areas that could have been covered a little better. In this same article by Lancet Editors there was another research letter stating that they had new data from a New Zealand study but they had the same information that the UKCCS provided.

According to this article a Japan's National Institute of Environmental Studies is coming out with a new study. There will be, 1500 cases of children that have been exposed to magnetic fields. 1000 will have leukemia and 500 will have brain tumors. And similar number of matching controls will be recruited. Being that Japan is highly industrialized the study is expected to have large numbers in the high exposure groups. (Lancet, 2) Maybe this will give us some input for the high exposure areas seeing that the US is highly exposed.

I came across another study that uses the larva of a fly; this test was done by the Columbia University in 1997. This study is of two biological systems, stress response in which special proteins are synthesize in response to potentially damaging external environmental chemical or physical agents such as elevated temperature. The second system involves modulation of the activity of a membrane ion transport enzyme-sodium, potassium ATPase (Na, K-ATPase) an enzyme which plays a role in cellular signal transduction. (Powerline Facts, 3) This test was to provide them with information to see how these systems respond to EMF exposure. The stress response was tested by using the salivary glands of the larva of a fly, there was a couple testing done with this.

One test was lowering the temperature or exposes them to low frequency magnetic fields. The way they characterized it was measuring protein. This told them the molecular weight, isoelectric point, and protein quality. There was also membrane activity study. They also studied for upper levels of electric fields. They came up with similar effects in both in type and magnitude, for temperature elevation (thermal shock) and for exposure to magnetic fields (Powerline Facts, 4).

The study discusses the potential significance of these findings to human health, noting that both beneficial and adverse effects are possible (Powerline Facts, 4). Another study I can across was a study on plant life near the Power lines, it was actually an article on different outcomes of studies. Most of the studies are positive bio effects rather than indications of cellular injuries (Info ventures, 1). Plant growth can be stimulated or inhibited, in different tissues, by electric fields either applied directly or induced by time varying magnetic fields (EMF-Link, 1). The article went on to say some reasons why it was positive and it said why it was negative. It's funny to see that for many years we have been testing and testing to see if the power lines are harmful to humans but humans aren t the only ones affected by this.

How do scientists study possible effects of EMFs on people They use a type of research called epidemiology. This study consists of patterns and possible causes of diseases in human populations. Epidemiologists study short-term epidemics such as outbreaks of food poisoning and long-term diseases such as cancer and heart disease. Results of these studies are reported in terms of statistical associations between various factors and disease.

The challenge is to discover whether the statistical results indicate a true causal association. This includes assessing possible effects of other factors.