Does Living Near High-Voltage Power Lines Cause Cancer?

Every day, you use technologies that you probably take for granted. Things like the microwave that cooks your meals, the lights that let you see in the dark and the television that entertains you. What do these technologies have in common? They all need electricity to work. 

Our need for electricity is growing. So is the number of transmission towers and overhead electrical wires in the places we live. But what if spending time near the electrical and magnetic energy from high-voltage wires causes health problems? Thankfully, research indicates that it probably doesn’t. At least not in the case of childhood leukemia. 

High-voltage overhead transmission lines carry electricity from electrical power plants to transformer substations. Transformer substations are closer to where the electricity is actually used.

Power lines are surrounded by an electromagnetic field (EMF) that stretches in all directions. The US National Cancer Institute (NCI) describes electromagnetic fields as “invisible areas of energy (also called radiation) that are produced by electricity”. The NCI also explains that EMFs are produced by many things, like power lines, electrical wiring and household appliances like televisions and microwaves.

Electromagnetic fields combine electric fields and magnetic fields. 

Based on a chart by EMsafety

The EMFs that come from high-voltage power lines are a lot stronger than those around household appliances. Household appliances usually produce fields measuring between 0.01 to 0.02 microteslas (µT). If you stood directly underneath the highest voltage power lines though, you could receive a maximum of 100µT. That is 10 000 times as much. 

This amount quickly decreases as you move away from high voltage lines. For example, at 25 m away from the most powerful line you would receive about 1-2µT. This is still ten to 20 times more exposure than you would get inside the average home in North America. 

Where you live in the world probably makes a big difference to the EMFs you receive. People living far from the earth’s magnetic poles receive on average 30µT. People in Canada live closer to the North geomagnetic pole, and can receive up to 60µT.

Did you know? 

The tesla (T) is the SI (International System of Units) unit used to describe the strength of magnetic fields. It can also be represented as kg⋅s⁻²⋅A⁻¹. Scientists normally report data in millionths of a tesla, or microteslas (µT). 

Some people living near high-voltage power lines worry about possible health effects. One worry is that children could have a higher risk of getting cancer as a result of living near a power line. 

Did you know? 

Magnetic fields are more likely to penetrate the body than electric fields. Electrical fields are weakened by obstacles like walls. Because of this, magnetic fields are the part of electromagnetic fields (EMFs) that are often studied as a possible cause of cancer.

Scientists have done many studies on this subject. In 2018, a group of scientists studied all the results of 11 previous studies around the world. They found that there was no clear link between magnetic fields and a child’s chance of developing leukemia, a kind of cancer. They looked at children who lived close to and far away from power lines of all voltages. They found almost no differences between them. 

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. This didn’t always happen though. And children living near stronger magnetic fields did not have a stronger chance of developing leukemia. So, scientists don’t know what causes this problem. 

Childhood cancer doesn’t happen very often. So, it’s difficult to measure if this number is changing, even a little bit. In Canada, 1,230 children were diagnosed with leukemia between 2012 and 2016. 

We are exposed to EMFs all the time. From power lines and appliances to where you live on the Earth. The field of research into the health impacts of EMFs is still fairly new. Scientists still have many questions and a lot to learn about how EMFs from different sources can affect our health.