Thanks to the severe storms that hit Brisbane on February 11th, which resulted in a Ferny Grove boy being struck by lightning while taking a shower mid storm, there has been a lot of discussion about whether it is safe to take a shower or bath during a storm.
It was such a hot topic that even Doctor Karl Kruszelnicki, a popular science commentator pitched in. During an interview with ABC radio, he said that it’s safe to shower in a storm if the property is correctly earthed.
However, speaking as electrical contractors with more than our fair share of lightning damage repairs under our belt, we believe his explanation is only half correct.
While having the correct earthing in your home is important and one of the best ways to stay safe during a lightning storm, even the best earthing won’t stop a determined lightning bolt that is trying to reach the ground.
What happened to the boy, in this case, was most likely the result of a phenomenon called “Step Potential” caused by electricity travelling through the pipes and the water from the nearby lightning bolt.
Step potential is the step voltage between the feet of someone standing near an energised object such as the ground when lightning strikes nearby. It is particularly dangerous where there are high voltages involved there can be a difference in voltage from one surface/position to another.
As many of us may remember from primary school science, water is extremely conductive of electricity. Even the Myth Busters explored this with an experiment involving a Tesla coil and a water pistol. When electricity is added to your plumbing and water, your body completes the circuit resulting in a shock.
In the recent case of the Ferny Grove boy, if the shower head and pipes of the property were earthed correctly through the MEN system of the house, but the fibreglass or plastic bathtub was not, there could have been a step potential between the bath water and the tap with the person bathing in the middle of it when the lightning struck near to the house,
Being wet all over in this instance would have been a positive factor in the boy’s favour as there would have been a large surface area for the voltage to disperse over around his body rather than going directly through him and damaging his heart.
Overall, if you want to take a shower, soak in a hot bath, jump in the spa or catch up on dishwashing during an electric thunderstorm, our best advice is to wait until after the storm passes.