Until now people are still worried about staying under the Channel High Voltage (EHV transmission lines) 500 kV. This fear apparently originated from a statement that SUTET Epidemiology expert to generate electric and magnetic fields that adversely affect human health. Society even bother to complain, although not provable cause.
The presence of electric and magnetic fields in the vicinity of human life can not be perceived by human senses, except if the intensity is big enough and was only for people who are hypersensitive. Electric and magnetic fields including the group of non-ionizing radiation. This radiation is relatively harmless, totally different types of ionizing radiation such as nuclear radiation or X-ray radiation.
Electric field and magnetic field has existed since our earth was formed. Clouds containing water potential, there is a large electric field between 3000-30000 V / m. Similarly, the earth's natural electric bermedan (100 - 500 V / m) and magnetic bermedan (0.004 to 0.007 mT). Inside the home, at work, at work or in the garage there are electric fields and artificial magnetic field. Electric and magnetic fields are usually derived from the installation and electrical equipment, among others, comes from: system installation in homes, refrigerators, air conditioners, fans, water pumps, televisions, electronic typewriters, photocopy machines, computers danprinter, welding machines, compressors , low voltage overhead line / medium (SUTR / M) are adjacent, and others. At system installation and have current-voltage electric field is always arise. But the electric field has been weakened because the distance is quite far from the source.
Under SUTM SUTR and the magnetic field varies between 0.1 to 3.5 mikrotesla. Inside the building the home, office, workshop or factory, the magnetic field because the airways are much weaker. Cultivated in the selection of SUTET not pass residential areas, protected forests and nature reserves. In some areas of dense settlement may not be avoided SUTET to pass, but both electric field and magnetic field should not be above the permitted threshold.
Electric Field under the network can lead to several things, among others: • make any noise / hissing sound on the surface due to ionization Conductor (conductor), which is sometimes accompanied by light purple, • fur / hair stand on an exposed body part due to attractive force of the electric field is small, • neon lights and-pen tests can be lit but dim, due to ease of neon gas in the tube lights and ionized-pen test, • weak shock at the first touch of the easy things that brought electricity (such as zinc roofing, metal fencing, wire clothesline and car bodies).
The relationship of electric Field and Magnetic Field in Health
Concerns about adverse effects of electric field and magnetic fields on health triggered by the publication of results of research conducted by Wertheimer and Leeper in 1979 in America. The study describes the relationship increased risk of death from cancer in children with a distance of residence near high voltage electricity transmission network. Many experts doubted the results of these studies by pointing out the various weaknesses, including lack of data measured electric field strength and magnetic field are about groups of children studied.
Amendments made by other researchers as practiced by Savitz and colleagues as well as study findings Fulton and his colleagues, it turns out that relationship does not exist. Results of research with a more refined method was performed by Maria Linett and his colleagues from the National Cancer Institute-American in 1997. Research involving approximately 1200 children reported that there was no relationship between the incidence of leukemia in children exposed to electric and magnetic fields with the children who are not exposed. These findings confirmed the rejection of the results of research conducted by Wertheimer and Leeper it. Research using experimental animals ever undertaken since the 60's with the results vary from the picture that has no effect, a change in behavior to the influence of defects in the offspring.
Indeed the results of animal studies that showed the negative influence caused by the use of strong electric field or magnetic field is very large in the experiment. Experiments with a strong electric field and magnetic field to a level that produces these abnormalities is necessary to know the occurrence of certain disorders that can be used as a basis to overcome it. Strong electric fields and magnetic fields used in these experiments is almost impossible to produce and place in the environment of human life. Effect of electric field and magnetic fields on health is highly dependent on the dose received. Small doses of course will have no effect, even a study conducted by Piekarsi from the former Soviet Union showed a positive effect on a broken bone grafting in the dog experiment.
The experts have agreed that the electric and magnetic fields from electrical network is classified as extremely low frequency with consequent ability to transfer energy is very small, and is unable to influence the chemical bonds that form the cells of the human body. Besides the human body cells have a strong electric field of about 10 million volts / m which is much more powerful than external electric field. Electric and magnetic fields with extremely low frequency is also not likely to cause a heating effect as might occur on the effects of microwave electromagnetic fields, radio frequency, and a higher frequency such as in mobile phones. The existence of some people who live close to electricity transmission network reported complaints such as headache, dizziness, palpitations and insomnia, and sexual weakness is subjective, because they are less precise perception.
Limit Exposure to Electric and Magnetic Field Field
The criteria used in determining the exposure limit using current density induced in the body. Because the currents induced in the body can not easily be measured directly, the determination of exposure limits derived from the value of the induced current criteria in the body in the form of a strong electric field (E) are not disturbed and the magnetic flux density (B). A trivial example of a homogeneous electric field with field strength of 10 kV / m will induce an effective current density of less than 4 mA/m2 with average drainage flow throughout the region to the human body or trunk (Berhardt, 1985 and Kaune & Forsythe , 1985).
A magnetic flux density of 0.5 mT at 50/60 Hz will induce an effective current density is about 1 mA/m2 on the circumference of a loop of tissue that berjejari 10 cm. UNEP, WHO and the IRPA in 1987 issued a statement about the value of induced current density on the biological effects caused by exposure to electric and magnetic fields in the frequency 50/60HZ on the human body as follows: between 1 and 10 mA/m2 not cause significant biological effects, between 10 and 100 mA/m2 proven biological effects, including effects on vision and nervous system, between 100 and 1000 mA/m2 cause stimulation of the tissues that can be stimulated and there is a possibility of danger to health and, in above 1000 mA/m2 can cause ventricular fibrasi ekstrasistole and from the heart (acute danger to health).
While waiting for the enactment of the WHO Environmental Health Criteria on electromagnetic fields, the Government will adopt the recommendations of the international radiation protection association (IRPA) and the WHO 1990 for exposure limits of electric Field and Magnetic Field 50-60 Hz as follows:
Source: Recommendations IRPA, INIRC and WHO in 1990
Standard electric field and 50/60 Hz magnetic fields in some developed countries to the level of continuous exposure in the general population group (MU) and groups of workers (KP) is as follows:
Source: IRPA, 1991; Pakpahan, 1992; WHO, 1987
In Indonesia, the safeguards against the influence of electric field and magnetic field of 50-60 Hz at 115 V voltage, regulated by the Minister of Mines and Energy Regulation No. 01.P/47/MPE / 1992, with the following provisions: to electric field
For Magnetic Field
Source: Ministry of Mines and Energy (No. 01.P/47/MPE/1992)
Electric field strength measurements 500 kV EHV transmission lines
Measurement of electric field under EHV transmission lines 500 kV network as a function of distance has been an open field with no trees on the sag of the lowest in 4 locations in Ciledug, Cirata, Ungaran and Gresik. Field strength obtained for Ciledug reached a maximum of 4 kV / m at a point below the phase conductors of 10 meters from the central axis of the channel, Cirata reach the maximum number of 17 kV / m at a point 5 m sejarak, Ungaran reach the maximum number of 4.78 kV / m sejarak point 15 m, and Gresik reached the maximum number 3.32 kV / m at a point 20 m. sejarak Strong electric field at the midpoint between two rows of smaller derived phase conductors, where it is caused by the summation vektoral electric field generated by the composition of phase conductor configuration. For other configurations obtained by the state electric field strength is slightly higher. According to the IRPA and WHO, the electric field strength exposure limits are expected to cause biological effects to the public is 5 kV / m, was measured in the field open to strong electric field under EHV transmission lines to reach the maximum number of 4.78 kV / m (in Ungaran) at the point sejarak 15 m, except in the area Cirata reached 17 kV / m but this is the place and steep cliffs that are not passed through the population. Electric field strength measurements in the house was also conducted at 3 locations on live electrical position, with the measurement as follows: in the village of Marga Hurip, Kec. Banjaran, Kab. Bandung obtained the maximum number 0.0255 kV / m; village Genuk RT. 01 Ungaran obtained the maximum number 0.0124 kV / m, and housing Bhakti Pertiwi Gresik obtained the maximum number 0.0175 kV / m. Strong electric field inside the house fired electricity in a position to show a small price. This is caused by the presence of damping home of electric field exposure. While the measurement of electric field strength at the position of electricity did not fire, the result was slightly lower than the electric field strength at the position of the flame. The result of this measurement is well below the permissible exposure limit.
Strong Magnetic Field SUTET 500 KV
Magnetic field strength measurements carried out in the open field without any influence of the presence of trees, houses and other objects. Measurement of field strength to achieve the maximum Ciledug 0.0021 milli Tesla dititik 0 yards (parallel towers), Cirata reached a maximum at the point of 0.036 milli Tesla sejarak 0 m, Ungaran reach the maximum number 0.00180 milli Tesla at the point sejarak 0 m, while Gresik reached a maximum at the point of 0.0021 milli Tesla sejarak 0 m. According to the IRPA and WHO, the magnetic field exposure limits are expected to cause biological effects to the public is 0.5 milli Tesla, as described above is the magnetic field at 500 kV EHV transmission lines open field reaches a maximum price of 0.036 milli Tesla (in Cirata) on point 0 m parallel to the tower. So still very far below the specified threshold. Measurement of magnetic field strength at the three locations were taken at electric flame, obtained the following results: in the village of Marga Hurip, Kec. Banjaran, Kab. Bandung obtained the maximum number of 0.0255 milli Tesla; in the village Genuk RT. 01 Ungaran obtained the maximum number of 0.0124 milli Tesla, and the housing Bhakti Pertiwi Gresik obtained the maximum number of 0.0175 milli Tesla. Measurement of the magnetic field inside the house with electric flame position shows a small price. This, the same as in the case of measuring the electric field, caused also by the presence of damping the house of magnetic field exposure. Similarly, measurement of magnetic field strength at the position of electricity did not fire, the result was slightly lower than the electric field strength at the position of the flame. The result of this measurement is well below the permissible exposure limit.
Technical Guidelines for Reducing Impact of Electric Field and Magnetic Field
From the research that has been done is found a strong electric field in the courtyard / outside the home is higher than inside the house, so in order to improve the environmental conditions caused by SUTET to note the following: try to get his home-ceilinged, plant as much as possible popohonan around the house on land that is empty, the roof of a house made of metal roof, should be earthed (digroundkan), residents are advised not to be outside the home, especially at night, because at that moment the current through the wire Conductor SUTET higher than during the day. Safeguards against electrostatic discharge flow needs to be done to avoid any pengutupan charges will occur on objects made of metal. To do that is to happen neutralization mentanahkan for return of all objects made of metal with a large enough size (eg wire clothesline, kabal intercom, cars and motorcycles), which is located under SUTET. This is because to avoid the charge pengutupan will happen to the objects, with mentanahkan there will be a neutralizing back. As a result of this discharge current safeguards that must be performed by a resident is: are advised not to make a clothesline above it entirely free from trees; are advised to make clothes not from the wire and iron poles, (eg wood, bamboo, plastic rope) and if forced to make clothesline that uses a conductor material shall be in tanahkan; intercom channel should be far from SUTET; when the roof instead of metal materials (tiles, asbestos, shingles), then try the roof there is no metallic material (eg TV receivers, zinc gutter): do not install the antenna TV or radio (ORARI) on the roof of the house, try to motor vehicles (cars, motorcycles, etc.) grounded to eliminate the electrostatic field induced by SUTET; try there are no materials that are conductors located on the terrace of a terraced house in EHV transmission lines; Often possible measuring the voltage with a suspected object testpen on voltage.
More Security Against Transient Voltage Induction On Electrical Appliances can be implemented with zero installation earthed. Induced voltage on the equipment under SUTET safe for humans. Security Against Voltage Step and Touch Voltage advised residents to people not go in the area around the grounding foot tower that has been given the fence by PLN.
Security Against Loss of Wire Line in Transition Hazards done for settlement of cross SUTET have planted trees, but it needs to monitor its altitude and the limits of free space, namely the top of the tree is a minimum of 15 M of cable SUTET bottom. SUTET wire rupture hazard has never encountered, which is found breakup insulators, and therefore used a double insulator and with plant trees under which monitored SUTET height then the danger if the wire can break dieleminir SUTET.
Security of electricity jump on the roof of the building keinstalasi diadasarkan on Regulation of the Minister of Mines and Energy No. 01.P/47/MPE/1992, namely the minimum distance for the building's highest point (the tree) to the lowest point of the wire Conductor 500 kV EHV transmission lines must meet the following requirements: The minimum distance the highest point fireproof building on the lowest point wire Conductor 500 kV EHV transmission lines is 8 , 5 m, the highest point of minimum distance an iron bridge lows Conductor wire 500 kV EHV transmission lines is 8.5 m, minimum distance railroad to the lowest point wire Conductor 500 kV EHV transmission lines is 15 m, the minimum distance field open to its lowest point SUTET Conductor wire 500 kV is 11 m, the highest point of minimum distance the building is not fire resistant to the lowest point wire Conductor 500 kV EHV transmission lines is 15 m, the highest point of minimum distance the building is not fire resistant to the lowest point wire Conductor 500 kV EHV transmission lines is 15 m, the minimum distance highway to the lowest point of the wire Conductor 500 kV EHV transmission lines is 15 m. Free space is the space around the Conductor that is formed by the minimum clearance along the inside SUTET SUTT or space must be freed from objects and other activities. Set free space berdeda vary in area and shape. While the safe space is a space that is outside the free space. Land or land which can still be utilized. In room safe strong influence of strong electric field and magnetic field are considered with reference to the applicable regulations. Free and secure space to set the amount of space as needed at the time of preparing rancangbangun. Safe space can be expanded by way of elevating or mempendek tower and the distance between the towers, so if there are settlements that will be crossed by SUTT / SUTET to be built inside a secure room.
(Source Technical Evaluation Report and Socialization in Public on the Impact of Electric Field and Magnetic Field in the Lower SUTT / SUTET, Energy Technology Research Project and the Electricity, Directorate General of Electricity and Energy Pengembngan)
By Ir. Nanan Tribuana is a staff Pengembngan Directorate General of Electricity and Energy, Jakarta
