Why sitting in traffic snarl is really bad for you

*Motorists breathe in 40% more deadly pollutants than pedestrians develop diabetic retinopathy
Sitting in a traffic jam is enough to send even a calm person’s blood pressure soaring.

But new research has found it could be even worse for your health than previously thought.

Being stuck at a red light exposes motorists to deadly pollutants, which could seriously damage health, scientists warn.

They found pollution levels inside cars are up to 40 per cent higher in queues and at a busy junctions.

And fans, which draw in air from outside could be adding to the danger.

The latest findings were published in the journal Environmental Science: Processes & Impacts.

Car emissions take longer to disperse in built-up areas and end up accumulating in the air at traffic lights and junctions, scientists say

The World Health Organisation (WHO) has warned outdoor air pollution is as carcinogenic to humans as smoking.

It is expected to kill more than 6.5 million people a year worldwide by 2050 – twice the current number, a study has found. Globally, the problem causes around 3.3 million premature deaths annually – mainly in Asia.

The premature deaths are due to two key pollutants – fine particulate matter known as PM2.5s – and the toxic gas nitrogen dioxide, both produced by diesel cars, lorries and buses. The pollutants affect a person’s lung capacity and growth, and are linked to ailments including lung cancer and heart disease.

Almost one in three strokes are triggered by air pollution, previous research revealed. The worldwide study named the environmental hazard as a major cause of one of the leading causes of death for the first time.

Air pollution ranked among the top ten causes of stroke, along with better known risks such as smoking, high blood pressure and obesity. Microscopic particles, much of which is generated by diesel exhausts, have been shown to cause clotting, which can lead to a stroke.

Stroke claims six million lives annually and many survivors suffer paralysis, speech problems and personality changes as a result.

The research was carried out by Auckland University of Technology and published in the journal Lancet Neurology. And emissions created by traffic queues take more time to disperse, especially in built-up areas.

They end up accumulating in the air at traffic lights, a known pollution hot spot for pedestrians and road users.

But contrary to popular belief, it is drivers who are the most affected.

Researchers from the University of Surrey found those who have their windows open breathe in seven times more PM10 – pollutants up to 10 micrometres in diameter – than pedestrians at junctions. Particles of this size can be inhaled deep into the lungs and can also become trapped in the nose, mouth or throat. From here, they can then be absorbed into the blood and have a negative effect on the body.

The study monitored pollution levels at traffic lights and inside a car under five different ventilation settings over 3.7 miles (6km), passing through 10 different junctions.

However there is a simple solution. Motorists caught up in queues can slash the levels of pollutants inside their vehicle by more than three-quarters by simply closing the window and switching off the fan. Drivers should also leave more space between bumpers so exhaust fumes have greater chance to disperse, the researchers say.