It's a scorching day in London. The warm, calm weather only exacerbates the coughing, wheezing and sniffling of a city gripped by an air pollution crisis.
But London's air problem is not just choking residents, it's stopping our hearts too. And researchers say it's past time the government does something about it.
The fine particles released by diesel vehicles causes inflammation of the lungs as well as the rest of the body, with strong evidence showing it causes heart attacks and heart failure, according to research led by Dr Nay Aung, cardiologist and Wellcome Trust research fellow at Queen Mary University of London.
That's a problem for any city with a high case of diesel emissions, with outdoor air pollution killing 40,000 people a year in the UK, according to the Royal College of Physicians. In London, air pollution levels have frequently exceed approved levels. The public health scandal has so far been met with weak response from the government.
And that makes Dr Aung's findings all the more concerning. He used MRI (magnetic resonance imaging) to measure the heart structure and function of some 4,255 participants, comparing it to the average levels of fine particulate matter (PM2.5) where they live. "We found that as PM2.5 exposure rises, the larger the heart gets and the worse it performs," said Dr Aung in a statement. "Both of these measures are associated with increased morbidity and mortality from heart disease."
"Reducing exposures to harmful pollutants is an urgent public health priority."
Dr Susan Hodgson, from the School of Public Health at Imperial College London, said his research appeared robust and the findings were in line with previous research. And while a wider look at more populations would be useful, she said it was time to take action, saying that "we do now have compelling evidence, from hundreds of epidemiological and experimental studies, of the adverse effects of air pollution on health, and as the authors note, reducing exposures to harmful pollutants is an urgent public health priority."
Such concerns have sparked London Mayor Sadiq Khan to introduce extra charges for diesel vehicles. That will start in 2019 with the most polluting vehicles charged £12.50 to enter a new ultra low emissions zone (covering the same area as the congestion zone). In subsequent years, the zone will be extended further across London and include all diesel vehicles by 2021.
Wider progress on tackling emissions has been slowed by the Conservative government's delayed plans that were criticised as "woefully inadequate" when released this year. Prime minister Theresa May's election manifesto makes one mention of the issue, saying her government will "take action against poor air quality in urban areas," but failing to detail exactly how, while pledging support for the oil and gas sector and car manufacturing industry.
Simon Birkett, founder and director of Clean Air in London, said Khan's plans were better "than the free-market anarchists who produced the Government's recent air pollution plan", but noted other cities are doing more, with Paris, Mexico City, Madrid and Athens outright banning diesel by 2025. He called for London to "ban diesel as coal and wood burning were banned so successfully 61 years ago."
A full ban might be the only way, as meeting pollution targets may not be enough to protect public health. Dr Aung noted that the average exposure level of PM2.5 seen in the study from across the UK was 10 μg/m3. That's well below the European target of 25 μg/m3, but the study still saw harmful effects. "This suggests that the current level is not safe and should be lowered," Dr Aung said, saying reducing PM2.5 should be an urgent public health priority. Today's rating in London was 64 μg/m3.
As we wait for politicians to take action, what can we do—besides choke on fine particulate matter? Dr Aung suggested avoiding rush hour, advising anyone with cardiorespiratory diseases to stay indoors during times of heavy traffic. Cyclists should find a quieter route, while walkers should stick to the part of the pavement that's further away from cars.
But as Birkett noted, "It's always a pity when the health advice is to avoid the pollution rather than tackling it."
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