One difference they did find was that children who lived very close to high voltage lines had a very small increase in their chances of developing leukemia. They found almost no differences between them. They looked at children who lived close to and far away from power lines of all voltages. They found that there was no clear link between magnetic fields and a child’s chance of developing leukemia, a kind of cancer. In 2018, a group of scientists studied all the results of 11 previous studies around the world. Scientists have done many studies on this subject. Because of this, magnetic fields are the part of electromagnetic fields (EMFs) that are often studied as a possible cause of cancer. Electrical fields are weakened by obstacles like walls. Magnetic fields are more likely to penetrate the body than electric fields. One worry is that children could have a higher risk of getting cancer as a result of living near a power line.
Some people living near high-voltage power lines worry about possible health effects. Scientists normally report data in millionths of a tesla, or microteslas (µT). It can also be represented as kg⋅s −2⋅A −1. The tesla (T) is the SI (International System of Units) unit used to describe the strength of magnetic fields. People in Canada live closer to the North geomagnetic pole, and can receive up to 60µT. People living far from the earth’s magnetic poles receive on average 30µT. Where you live in the world probably makes a big difference to the EMFs you receive. This is still ten to 20 times more exposure than you would get inside the average home in North America. For example, at 25 m away from the most powerful line you would receive about 1-2µT. This amount quickly decreases as you move away from high voltage lines. If you stood directly underneath the highest voltage power lines though, you could receive a maximum of 100µT. Household appliances usually produce fields measuring between 0.01 to 0.02 microteslas (µT). The EMFs that come from high-voltage power lines are a lot stronger than those around household appliances. The flow of energy is directed through the fields from the dry cell towards the load (light bulb).
Magnetic field lines form circular loops around the wire. Measured in volts per metre (V/m) or Newton/coulombĮlectric field lines are directed away from positively charged source charges and toward negatively charged source charges. Strength of field varies with power consumptionįield can do work (the speed and direction of particles changes)įield cannot do work (speed of particles remain constant) The greater the current, the stronger the fieldĮxists even when there is no current flowing The higher the voltage, the stronger the field The NCI also explains that EMFs are produced by many things, like power lines, electrical wiring and household appliances like televisions and microwaves.Įlectromagnetic fields combine electric fields and magnetic fields. The US National Cancer Institute (NCI) describes electromagnetic fields as “invisible areas of energy (also called radiation) that are produced by electricity”. Power lines are surrounded by an electromagnetic field (EMF) that stretches in all directions.
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Open Professional Learning × Close Professional LearningĮlectricity generation, transmission and distribution (Let’s Talk Science using an image by mathisworks via iStockphoto). Open Educational Resources × Close Educational Resources
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