There is a killer that roams the streets taking tens of thousands of lives every year. This killer sneaks into our children's playgrounds, schools and even our homes.
In London alone, this killer is responsible for around 4,000 deaths every year. But its deadly fingers extend well beyond the capital.
In the West Midlands, 3,714 people died as a result of air pollution in 2010 according to Public Health England. In the North West, the number reached almost 5,000.
In fact in every corner of the country, from Inner London to rural Wales, our reliance on motor cars and heavy industry is silently throttling us.
The elderly and the young are most at risk, with studies showing that children's lungs are being permanently damaged by the rise in air pollutants.
Across the UK, more than one in twenty deaths each year are now caused in part by air pollution. That's almost 30,000 people whose deaths could be avoided.
But while politicians queue up to warn about the dangers of sugar and passive smoking to children, very few are willing to say anything about the deaths our addiction to cars has caused.
When the so-called Saharan smog hit Britain earlier this month, a few politicians did offer some cursory words calling for something to be done.
Labour politicians, who have spent the past few years supporting Conservative plans for new road-building in London, suddenly re-discovered their environmental credentials.
But mostly, it was dismissed, with Cameron labelling it an unavoidable "natural phenomenon" and London mayor Boris Johnson claiming the air quality in the capital was still "perfectly fine."
Neither was true. The Saharan sand, may have made the high levels of pollution in the UK visible for once, but it made up just a small part of the overall pollution in the air.
Similarly high levels of pollution had been experienced multiple times over the past year, without a single major politician saying a word.
And while politicians in other countries hit by the smog had implemented vehicle bans, the UK government's only advice was for people to avoid strenuous exercise. Keep off your bikes and climb back into your cars seemed to be the astonishing signal sent out.
The reason for this wilful blindness is purely political. While the government does everything it can to cut down on smoking which mostly only harms those who choose to do it, they have done almost nothing to reduce car pollution which affects everybody.
Britain has become dangerously reliant on motor-cars and our politicians are too scared to do anything that might be seen as trying to restrict their use.
Instead our politicians fight over who can be seen as the most motorist-friendly, with both Labour and Conservative governments petrified of doing anything that might be seen as anti-car.
And as the NHS continues to suffer a funding crisis, made worse by the tens of thousands of extra cases caused by air pollution every year, motorists are continually plied with further tax cuts.
Now the Saharan dust has settled, the debate over air pollution risks blowing over as well. This would be a huge error.
Air pollution is a silent and usually invisible killer that costs tens of thousands of lives every year. It's about time our politicians wiped the Saharan sand out of their eyes and tackled it.