Recent revelations have shown that nearly 95% of London's population - some 7.9 million people - live in areas exceeding global guidelines for toxic air particles by more than 50%. As London's Deputy Mayor for Environment and Energy, I find this completely unacceptable.
Londoners of all ages are being affected by the high level of pollution in our city. It has been linked to dementia, heart disease, strokes and our children having reduced lung capacity - and it is absolutely clear London is facing a toxic air crisis.
The reality is that thousands are dying prematurely every year as a direct result of London's filthy air. This is putting a huge strain on our NHS, with businesses and the economy also suffering. What we are witnessing is the product of successive governments pushing the issue of pollution into the long grass, which is why the Mayor has taken decisive action.
The T-Charge - a £10 surcharge on older, more polluting vehicles travelling in the centre of London - was introduced on Monday following a comprehensive advertising and email campaign. Welcomed by the likes of the British Heart Foundation, Royal College of Physicians and the co-director of Asthma UK's Centre for Applied Research, this bold policy will provide the vital protection for Londoners' health that is so urgently needed.
Not only is the T-Charge the world's toughest emission standard, it sends out a powerful message that the Mayor is tackling pollution and poor air quality head on. It is designed to create an economic incentive to swap polluting vehicles for cleaner models, public transport, walking or cycling. We've already seen it having an effect with around 15% fewer older polluting vehicles in central London and a 21% fall in the sales of diesel vehicles in August.
Some have said that we need to go further - and that's exactly what we're planning to do. The T-Charge is just part of a much wider set of measures designed to tackle London's filthy air, and will pave the way for the world's first Ultra-Low Emission Zone. Starting as a central London zone, it is planned that this will be expanded out London-wide for heavy vehicles in 2020 and to inner London for cars and other light vehicles in 2021.
Once fully implemented, the T-Charge and the Ultra-Low Emission Zone combined will reduce the road transport pollutant emissions which Londoners - young and old - have been forced to breathe by nearly 50% in central London. It will also bring in revenue, but this will be ring-fenced and ploughed straight back into initiatives designed to further improve air quality.
We must not forget that addressing London's toxic air goes beyond the issue of health - it is also an issue of social justice. Those who suffer the worst consequences of air pollution are in fact poorer Londoners - 80% of the 430 schools in areas with illegal levels of air pollution are classified as deprived as so many of their children are on free school meals. It is our duty to implement measures that tackle this public health crisis to help those who need it most.
The T-Charge will cost around £7m a year, but it's a price worth paying to help save lives and is only a fraction of the economic cost of our polluted air. An independent study by King's College London estimates that poor air quality costs the London economy £3.7bn each year as businesses - both large and small - are reliant on a healthy workforce.
Across the country, that figure rises to £20bn through incurred costs to the NHS, money lost through sick days caused by illnesses and wider economic costs linked to polluted air. This demonstrates how the problem of toxic air is not exclusive to the capital. It is one of the biggest health challenges facing the entire country.
The Mayor is doing everything he can to tackle London's filthy air, but we need the Government to step up and play its part too. It must act on a scrappage scheme that will provide substantial incentives for those with diesel cars, many of whom bought them in good faith, to change to cleaner models. This is especially important for poorer people and small businesses.
London and other devolved city administrations need to be given the powers necessary to tackle non-transport sources of pollution to bring levels of toxic air down. The Government must also commit to implementing an ambitious and effective Clean Air Act fit for the 21st century if we are going to properly tackle air pollution across the board and nationwide - including the 50% in London that comes from non-road sources including construction and the river.
London is leading the way on addressing our toxic air crisis. It is now the time for the Government to follow and take the urgent action needed to save lives.