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  • Lisamarie Lamb

Legionella and Your Windscreen

Legionella bacteria is a sneaky kind of creature – it can lurk anywhere. Although it may be more well-known for being in showers, cooling towers, and the water systems of buildings in general, there are many other places where legionella can be found, and just because that place could be considered strange or unusual, it doesn’t make the threat of that bacteria infecting someone with legionnaires’ disease any less possible.

In fact, because these ‘hidden dangers’ are less well-known and less publicised, it could even be that people are contracting legionnaires’ disease in places that ordinarily would never be considered somewhere that would make you ill. One such place is the cab of a lorry, or even the front seat of a car.

legionella in windscreens

And what about mini buses transporting elderly people to and from the shops, or taking them on a day out? What about ambulances taking those with compromised immune systems to and from hospital? What about coaches taking children on a day trip from school? Yes. All of these vehicles can be potential carriers of legionella bacteria and, without regular testing or cleaning, they could be putting our nearest and dearest at risk.

How? Well it’s nothing to do with the fuel or the way the vehicles are driven. It’s not about the air conditioning (which could be a surprise to many). It’s all about the windscreen. Or rather, the fluid used to clean the windscreen. This fluid is a spray – it comes out of the vehicles itself and then onto the windscreen where the windscreen wipers ensure that it covers the entire window. But it is the very fact that this water is a spray, and that it is kept within the engine compartment of the car – nice and warm and exactly the right kind of conditions for legionella to proliferate – that makes it so potentially dangerous.

A study in America showed that over 75% of the school buses that they tested in just one school district in Arizona contained levels of legionella bacteria. Further studies showed that the bacteria could live undisturbed within the windscreen wiper fluid for as much 14 months. In the UK, an additional study suggested that up to 20% of all cases of legionnaires’ disease in the country could be caused by the bacteria from windscreen fluid.

legionella in windscreens

And not only did it cause potential problems for those travelling within the vehicle, but imagine being in the car behind – that spray will land on your too. The same goes for pedestrians nearby; they may not even notice the very light amount of spray that flies towards them from a vehicle’s windscreen, but they could very easily breathe it in nonetheless. In the right weather and the right environment, those lethal (in 10% of all cases in legionnaires’ disease) droplets can carry on the breeze for miles, infecting innocent people going about their daily business. One squeeze of the windscreen washer trigger, and the damage could be substantial.

So what can be done?

There is little point in testing all vehicles for legionella bacteria. It simply would not be cost effective and, if the bacteria were to be found, the only course of action would be to empty the windscreen wiper fluid reservoir and replace the old water with cleaner stuff. So the best option is to do that anyway and save the expense and hassle of getting your vehicle tested. Use a premixed fluid rather than simply water – this fluid not only cleans your windscreen more effectively, but is also antibacterial, and therefore much safer.

Alternatively, once a month, or perhaps every time you fill up with fuel, empty the windscreen fluid and refill it.

If you have any concerns about legionnaires’ disease, legionella bacteria, or any aspect of water based bacteria, then please don’t hesitate to get in touch. At Assured Water, we are experts in legionella control and the health and safety of the water systems in your building (and your vehicle!).

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