Air pollution from our traffic-crowded streets is Britain’s invisible killer.
You can’t see the trillions of minute particles produced by exhaust fumes, but they are linked to potentially fatal conditions such as strokes and heart attacks.
Even if they don’t kill you, they can seriously affect your everyday life — for instance, triggering asthma attacks.
And yet, even though air pollution causes 50,000 premature deaths every year in Britain, it’s somehow not adequately recognised as one of the nation’s major lethal threats.
Dr Xand van Tulleken during filming of the BBC 2 programme Fighting For Air
I have long been worried about pollution’s perils: on a personal level, because I live in a city (London) and ride my bike everywhere.
Now, after a long cycle through town, I arrive sounding like I have a cold, my nasal passages inflamed by the chemicals that form as I inhale the pollution.
Professionally, too, as a medical doctor with a master’s degree in public health, I had some idea of the damage it wreaks on communities.
Sixteen of our big cities, including London, Manchester, Oxford and Southampton, are exposed to illegal rates of toxic fumes. As well as the individual cost in terms of ill health, this costs the country an estimated £20 billion a year in medical care and lost labour.
Clearly, the politicians aren’t doing enough to protect us. But what can we do ourselves?
The sheer size of the problem can make us feel helpless.
But as I discovered in making a documentary for BBC2, to be broadcast next Wednesday, there are steps we can take individually and as a community that can make a very real difference.
The aim of the documentary was to cut pollution emissions in a High Street in Birmingham for one day: Friday, December 1.
To be perfectly honest, at the start, I was sceptical about what might be achieved, not least because people are often simply too busy to get involved in community projects.
The area we chose, King’s Heath, is a small suburb south of the centre with a big traffic problem — its High Street is one of the more polluted streets in the city, and the local air pollution is regularly driven into the danger zone. (We’d chosen King’s Heath but, in fact, there are High Streets like this in many places in the UK.)
King’s Heath’s High Street (pictured) is one of the most polluted streets in Birmingham
And, as I discovered when I went to Edinburgh to meet Dr Mark Miller, an expert on air pollution, this can have a very immediate impact on the body.
First, I had to ‘detox’ my body — sleeping in a country hotel, then donning a chemical warfare suit so I was breathing in filtered air as I headed into town to take a set of baseline measurements.
Dr Miller analysed my blood and my heart rate and subjected me to cognitive tests. Then I removed the mask and walked through town, next to buses and idling taxis, for three hours, breathing the unfiltered air.
When we re-did the tests, the results were dramatic: even in that small space of time, my blood pressure had become consistently raised, compared with my pollution-free results.
This was because toxins in the pollution — nitrogen oxides (NOx) and tiny soot particles, known as particulate matter (PM) — had made my arteries stiffer and less flexible, as if they were ageing prematurely. My blood was also ‘stickier’, worryingly therefore a little bit more likely to clot — which is what causes strokes and heart attacks.
Meanwhile, my thinking was slowed down by the effects of the pollution on my cardiovascular system. Exactly why this happens is not clear: it may be that if you poison the lungs and cardiovascular system, the brain also suffers, but we know the smallest PMs can get into the brain.
Air pollution, from streets congested with traffic, causes 50,000 premature deaths every year in Britain
All this after just three hours on a High Street — and many of us live with pollution long-term.
But because pollution is invisible, it’s difficult to grasp its effects.
That’s where Roland Leigh comes in. A professor of air quality at the University of Leicester, he used a thermal camera that reveals pollution — in the form of heat emissions from vehicle exhausts.
What Professor Leigh showed us in the programme was shocking, with massive clouds of exhaust from cars and buses and even bigger clouds from diesel trucks.
From 2001 to November 2016, the Government gave tax breaks for diesel engines because they emit less carbon dioxide. As a result, there are now 11 million diesels in Britain — 40 per cent of everything on our roads.
Yet diesel vehicles are the monster polluters of our roads, gushing out clouds of particulate matters, especially when pulling away from a standstill (when the engine has to work hard at low speed). During filming, I discovered, too, how even our driving styles affect our exposure to pollution.
It’s not just when we pull away from standstill — emissions rise when accelerating, going over speed bumps and stopping and starting in traffic.
And, as I learnt to my surprise, you’re most exposed to fumes inside the car.
DON’T REV YOUR ENGINE!
- When driving, accelerate as smoothly as possible. Putting your foot on the throttle is the major cause of urban exhaust emissions (that can affect you inside the car, too).
- In traffic, turn the car’s air conditioning to internal circulation, so it’s only recirculating the air inside, rather than sucking in pollution from the road, particularly if behind buses and lorries.
- Avoid cycling or running on main roads during peak hours, as you’ll breathe in two to three times more air containing fumes than in a car or bus.
- If walking or cycling, choose quieter back streets. A smartphone app by King’s College London identifies polluted routes in London. Go to itunes.apple.com and search for ‘city-air’.
Meanwhile, as a pedestrian, you’re inhaling this cloud of toxic pollution before it can be diluted by mixing with air. The buildings along a High Street exacerbate this, trapping air so that it circulates around the street as the wind blows across the building tops, much as air in a bottle would swirl if you blew across the top of it.
When I began this investigation, I’d been more worried about NOx, because studies show that it can damage lung function and harm our cardiovascular health.
But then I learnt more about the particulates. These nanoparticles come out of vehicle exhausts — particularly diesels — covered in toxins that are highly poisonous.
When you breathe in these particles, the toxins invade your lung cells. In hospitals, we use nanoparticles to deliver drugs deep into patients’ organs to heal them; the traffic-fume nanoparticles are delivering things that could kill you. They end up trapped inside cells and many will stay inside you permanently.
But would the people of King’s Heath be concerned? I spent a day leafleting the High Street and lobbying for volunteers.
To my relief, we attracted a full house to a meeting to discuss how to cut pollution for our day of action. This included smoothing traffic flow (to reduce the stopping and starting).
To do this, we managed to persuade Birmingham council to suspend the parking bays along the High Street for the day, as cars pulling in and out of them cause the traffic to stop and snarl. The council also agreed to synchronise the traffic lights to keep vehicles running more continuously.
Rob MacKenzie, a professor of atmospheric science at the University of Birmingham, had suggested we place physical barriers between pedestrians and the traffic, to give the exhaust gases longer to mix and dispel in the air before they breathe them in. So we filled the parking bays with 6ft Portuguese laurel hedges.
To encourage people out of their cars, the local bus company offered 200 free tickets for the day.
One of our key aims was to get more children to walk to school. Traffic pollution stunts children’s lungs and brain development — kids are most exposed at school-run time, when the roads are jam-packed with vehicles.
To get parents to stop using their cars, at least on one day, I recruited help from the children at St Dunstan’s Catholic Primary School, just off the High Street.
We showed the kids scans that revealed how pollution particles accumulate in the lungs: we needed their pester power to persuade their parents not to drive.
So, what happened?
Disappointingly on December 1, the volume of traffic did not drop.
But there was a significant reduction in NOx in the High Street, and an even more amazing drop in the levels of particulates around the school at drop-off and pick-up times.
Our results could be replicated across all schools in Britain, meaning some 500 schools currently over the legal limit for traffic fumes would lower their pollution to legally acceptable levels.
Given all our interventions were cost-free or very cheap, there’s no reason communities across Britain couldn’t do something like this.
Furthermore, many of the things that improve air quality, such as walking, rather than driving, offer a personal gain, too, in terms of fitness. Small steps really can make a difference.
- Fighting for Air, BBC2, Wednesday, January 10, 9pm