Air pollution caused by the combustion engine can damage your health, but it turns out it may also affect your driving ability.
That is according to a study by the London School of Economics, which discovered a two per cent rise in the number of collisions when levels of nitrogen dioxide (NO2) rose by a microgramme per cubic metre.
It is thought toxic exhaust fumes, particulates of which have been proven to cause cancer, impair the driver’s fitness levels and can lead to a greater chance of an accident.
“Although it has already been shown that air pollution adversely affects human health and the ability to carry out mental tasks, this is the first published study that assesses the impact on road safety,” Granthum Research Institute on Climate Change lead researcher Lutz Sager said.
He added: “The analysis identifies a casual effect of air pollution on road accidents, but I can only speculate about the cause of the link.”
Air pollution inside a car can be twice the external level because of the way NO2 builds up, a recent study claimed, backing up the idea that such a small increase in air pollution could have such a dramatic effect.
There is a much simpler explanation.”My main theory is that air pollution impairs drivers’ fitness. However, other explanations are possible such as air pollution causing physical distractions, perhaps an itching nose or limiting visibility,” he continued.
The study looked at a five-year period between 2009 and 2014 in the UK, with accident and pollution figures provided by the Department for the Environment (Defra). The UK was divided up into 32 areas, each one around 4,784 square miles in size.
Even when compensating for the increase in road users and the increased accident level likelihood that brings with it, the figures revealed the aforementioned two per cent increase in collisions, with cities home to the biggest effect.
Two per cent may seem insignificant, but there are around 150,000 collisions every year in Britain and so even a one per cent increase would make a significant difference. Sager estimates a 30 per cent reduction in NO2 concentration would reduce road accidents by nearly five per cent every day.
NO2 levels had the biggest impact on accident numbers, the study said, with sulphur dioxide, nitrogen dioxide, carbon monoxide and small particulate matter having less of an effect.
“Although this analysis has used data for the United Kingdom, I think my findings are relevant to other parts of the world. These additional costs from traffic accidents strengthen the case for reducing air pollution, particularly in congested cities,” Sager surmised.
AA president Edmund King is unconvinced by the argument. Speaking to the Telegraph, he argued: “If you think about areas which are high in air pollution they are a lot busier, with taxis and buses and lorries and where you have a greater mix of traffic you tend to have more accidents.
“It would be hard to tease apart whether a crash is caused by a driver wiping his eyes because of air pollution or the type of traffic which is to blame.”