Electro Magnetic Fields
So recently I’ve been looking at moving house. One particular house I adored happened to be right under a power line. Of course… which got me googling the effects of living close to pylons and what not. Which then got me thinking about the fact that, as humans, we surround ourselves daily with an ever increasing variety of electrical devices. Now, all of these devices give off an electric or magnetic field, or EMF for short. Working on board yachts in our daily environment, how much are we exposed to, and what’s a safe level?
There’s no doubt in the fact that in the past ten years our exposure to EMFs has gone up massively. As the World Health Organisation states, “Everyone is exposed to a complex mix of weak electric and magnetic fields, both at home and at work, from the generation and transmission of electricity, domestic appliances and industrial equipment, to telecommunications and broadcasting.” For those of us who sit in front of computer screens all day next to our WIFI boxes, to people who are constantly checking their phones, or can’t sit still without playing on a tablet, perhaps our social behaviour is damaging us in more ways than we realise? That’s a whole topic in itself, so let’s first of all see what we can find out about the biggest culprit of radiation on board a superyacht – the radar system.
Radars onboard are used to detect the presence of other moving objects, by transmitting pulses of high frequency EMFs and form an integral part of bridge navigation equipment. There have been concerns from people who work in close proximity to these systems about long term health issues ranging from cataracts, to infertility, and even to cancer. Marine radars are found on anything and everything from small power boats up to the enormous ocean going vessels and everything in between. Now, radars generate EMFs that are called Radio Frequency Fields (RFs) between 300MHz and 15GHz. So, how do these affect the human body?
Well, for that we need to look at the Specific Absorption Rate (or SAR) which is a number that indicates how the human body absorbs RFs between 1MHz and 10 GHz, and is measured in watts per kilogram; the WHO states that “A SAR of at least 3 W/kg is needed to produce known adverse health effects in people exposed to RF fields in this frequency range”. Marine radars operate at up to 30kW. Under normal circumstances the radar will be rotating; which reduces the average power density in the immediate vicinity. However, yachts will reduce this further by ensuring the radar is not “on” when any crew member is close by (i.e. a deckhand washing / cleaning) and should never use them in port. The scientific reports on the subject go into extreme detail and to be honest, this writer had the feeling they were trying to be intentionally confusing as the actual SAR from an “average” marine radar just could not be found. Reports tended to go off on tangents and seemed, perhaps intentionally, vague at best.
In the past, teams of crew working in the bridge of military vessels directly beneath the radar system would report headaches, perhaps leading to a rethink and better research in the materials used for the roofs of bridge/control rooms on vessels to limit exposure. This is of course fine for crew inside but not so great for people working outside in the vicinity.
When you’re working outside you’re already being exposed to natural radiation from the sun (by far the most common health hazard of radiation is sunburn) so we’re pretty much doomed then!? A cheery thought.
Let’s go back inside the yacht then for a moment. RFs are emitted from wifi boxes, blue tooth transmissions, and don’t forget – microwave ovens. Who’s been told not to stare at their food when it’s heating up? Well you might be relieved to know the door of the microwave has a screen built into the window which only allows visible light waves to pass through but traps the RFs. So stare away if that’s your thing. Let’s face it, it’s probably more interesting than watching Love Island on the crew telly.
There doesn’t seem to be any conclusive information readily available on the long term effects of RFs and EMFs on the human body. What is available is often at odds and contradictory. Whilst one report states there’s no effect, the next will state there’s been no long term investigations carried out, and another will state they are directly related to cancers, infertility and so on. Official government reports from across the world seem to employ terms like “may be related to” or “possibly linked to …” and everything seems incredibly ambiguous. The conspiracy theorists will happily declare that The Man is lying to all of us – and, well, maybe they have a point with their tinfoil hats. At least they’re using electromagnetic shielding. Will they have the last laugh? It seems the best we can do is to limit ourselves to exposure, and maybe, just maybe, put that phone down at dinner time in the crew mess…. But hold on I just need to check the football results first then I will.