The enormous human and economic cost of the deadly fumes and tiny poisonous particles which fill our city streets barely registers as a political issue. However, a campaigning new book is about to change all that. We speak to author Chris Woodford about the 21st century’s next big public health crisis

WE’VE all noticed it. The change that came as lockdown hit – the way the air was cleaner when the roads were quieter. And then as lockdown eased, that old familiar tang of pollution in the air as cars dirtied city streets again.

As a society, we barely think of air pollution, though. You can’t see the toxic gases and microscopic particles filling the air around you, after all, so the “invisibility” of air pollution means it’s quite literally out of sight and out of mind. If, as a nation, we ever do pause to consider air pollution it’s mostly as a side issue in the debate about how to deal with climate change – a concern labelled “abstract”, far off in the future, and all but impossible to tackle.

How wrong we are. Air pollution is far from abstract – it’s the biggest killer on Earth today. Chris Woodford, the science writer behind Breathless: Why Air Pollution Matters And How It Affects You, has crunched the numbers. Air pollution alone kills between seven and 10 million people globally a year, more than strokes which kill six million. That puts air pollution in the top four killers already – joining high blood pressure (10 million), cancer (10 million), and heart disease (9.5 million). But as Woodford points out, it’s obvious that air pollution contributes to all these other killers too. Inhaling toxic fumes filled with tiny particles of filth into your lungs is inevitably going to contribute to stokes, cancers and heart attacks. Chillingly, the latest science also indicates a strong link between exposure to air pollution and dementia – in some studies, the closer a person lives to a major road the higher the rate of dementia. Air pollution also damages the unborn baby in its mother’s womb. It’s a killer which haunts us from cradle to grave. Globally, 92 per cent of us are breathing polluted air.

“The original title of my book was How Air Pollution Became the World’s Biggest Killer,” Woodford says. He and his publishers didn’t want to scare people though – they wanted to encourage readers to learn about the risks of air pollution, not deter them, so went for the softer title. Woodford adds: “We shouldn’t have changed it. It is the world’s biggest killer if you add it all up. Not only does it contribute to all these illnesses, quite possibly it causes a lot too.”

Scotland’s streets

Air pollution levels in Scotland fell dramatically at the height of lockdown. In Glasgow, Scotland’s most polluted city, air pollution was regularly breaching World Health Organisation guidelines before Covid brought life to a halt. On Hope Street in the city centre, often Scotland’s most polluted thoroughfare, levels of nitrogen dioxide (a key pollutant) came in at over 56 micrograms per cubic metre. The WHO level is 40. Amid lockdown, levels at Hope Street plummeted to just under 19 – way below WHO guidance. The same pattern could be seen in Edinburgh’s most polluted areas like Nicolson Street – and across the rest of the UK, in cities like London.

This week, Woodford gathered a sample of “live” laboratory maps to show Herald on Sunday readers how pollution builds up in Scotland’s biggest city over the course of a single day from traffic fumes. The maps show the centre of Glasgow at 6am, 12 noon, 2pm, 4pm and 9pm. In the morning, the city looks healthy – the lack of air pollution defined by green streets.

As the day goes on, though, green fades and streets turn orange. By 4pm, the city’s main arteries are turning red and come night, there’s only red and orange on the map, no green. Evidently, the readings will be much worse when lockdown ends.

Laws around pollution are laughably weak. Regulations, for example, allow for 18 breaches of air pollution limits a year. London can max out its entire year’s supply of permitted breaches by the end of the first week in January. As Woodford points out, any fines for breaches are footed by the taxpayer – no-one is really punished. At best, it’s a name-and-shame exercise.

During lockdown, Asthma UK and the British Lung Foundation surveyed more than 14,000 people living with breathing conditions and found that one in six were reporting reduced symptoms. Come autumn last year, however, as lockdown eased, the Centre for Cities found that in most urban areas “pollution levels were at least back to pre-lockdown levels”.

It’s not just roads though. The rail system is a deadly contributor to air pollution too. Levels of one dangerous type of air pollution – fine particulates known as PM2.5 and PM10 – ooze from our major train stations in dangerous levels, which have gone as high as nine times the WHO limit in Scotland. Wood burning – in stoves and fires – is also a big contributor.

The crippling costs

WOODFORD says that in pure number terms, the cost of air pollution in the UK –which he estimates to be about £50 billion annually – is enough to build 100 new hospitals ever year. These kind of figures, he says, need put front and centre to counter wrong-headed claims that tackling air pollution costs money and reduces productivity. In fact, says Woodford, the reverse is true: reducing air pollution brings economic benefits.

The global cost of air pollution is astonishing. Woodford has crunched the numbers here too. The annual cost to the world a year in terms of death, illness, days missed from work and school, plus clean-ups, comes in at about $5 trillion dollars. India’s annual GDP is $3trn. To get an equivalent to the $5trn price-tag, you would need to spend $5 million a day, every day, since the fall of the Roman Empire.

However, the monetary gain from tackling air pollution – even in piecemeal form – is huge. The economic benefits far outweigh the costs, says Woodford. When steps are taken to improve air pollution, “it works out at a benefit-to-cost ratio of 30 to one – so you get £30 back for every £1 you spend” in terms of money saved and jobs created.

When the benefits are expressed like that, Woodford adds “it’s a no-brainer”. He says: “And because the benefits of tackling air pollution also benefit the climate as well it’s a double no-brainer. Once it’s put in those terms, the arguments are compelling.”

Woodford suggests that for every project which adds to air pollution, a cost-benefit analysis should be done which shows how the same money could improve health. So, “when Boris Johnson says ‘let’s build a bridge from Scotland to Northern Ireland’, and it might cost £20 billion”, he should also, Woodford believes, be compelled to say what the UK could use the money for in terms of environmental clean-up.

“You could do incredible things for £20bn,” says Woodford. “Manchester, for example, was given £15 million to buy 70 electric buses. That means £1bn buys you 5,000 buses. There are 32,000 old diesel buses in the whole of the UK – so for £5bn or £6bn you can green the entire fleet.

“That’s a third of the cost of a bridge between Scotland and Northern Ireland.”

Clean Air Acts

A GOOD example of the economic benefits of tackling air pollution can be found in the Clean Air Act of the United States, first passed in 1963 but last updated over 30 years ago. It’s the best recent big anti-air pollution initiative the world has seen on a scale significant enough to really measure economic benefits. It is estimated that in one year alone, the measures prevented 230,000 early deaths. Between 1970 and 1990, use of the American Clean Air Act saved around $22.2trn in terms of deaths, hospital visits and lost days at school and work.

One of the most chilling findings regarding the benefits of the Clean Air Act in America was that it prevented the loss of an estimated 10.4 million IQ points in US children whose intelligence would have suffered due to the damaging effects of pollution on the brain.

Self-evidently, the US Clean Air Act is old legislation and needs radically updated for the 21st century. The British Clean Air Act, which came into being after the infamous Great London Smog of 1952 killed up to 12,000 people, and was last updated in 1993.

The science deficit

THE science of air pollution moves fast. “The laws of today reflect the problems of yesterday,” says Woodford. He wants UK legislation updated and “a new Clean Air Act that reflects today’s air pollution challenges”.

Ten years ago, Woodford adds, “everybody thought air pollution was just about the lungs. We now realise it goes well beyond that. Air pollution can have an effect on pretty much every organ in the body, and potentially every cell within every organ”.

Thinking about air pollution as only affecting human lungs, says Woodford, “is a bit like thinking of terrorists coming into the country, arriving at the ports and all they do is stay at the port”.

Today, science is concentrating on some of the known microscopic particles in air pollution – “particulate matter” like PM2.5 which is 30 times smaller than the width of a human

hair. “Scientists haven’t really even begun to probe yet smaller particulates, of which there are many,” says Woodford. “They go 10 times smaller, 100 times smaller, even smaller than that. All the figures for global mortality are based on relatively large particulates.”

With science at its current stage, Woodford says “in 10 or 20 years, the chances are we’ll find that actually the mortality figures increase substantially … We’re learning more about the scary aspects of air pollution faster than we’re developing solutions”.

Lockdown lessons

COVID, Woodford points out, has killed around 2.5million people so far in around one year. “Air pollution in the same period,” he says, “killed three or four times as many people – and it’s been doing that for decades, and will go on doing that for decades, long after Covid is hopefully a memory. If we devoted even a fraction of the money, time and scientific research for air pollution we’d make a big difference to global health.”

Woodford worries that we won’t learn the lessons that lockdown have taught us about air pollution. After those huge falls in pollutants like nitrogen dioxide, Woodford says we’re drifting “back to where we were before”, and come summer or autumn “we’re going to be back with pollution that’s at least at their ‘normal’ levels. It’s a red light”.

Woodford points to the fact that The Herald on Sunday is speaking to him over Zoom, and says that at a minimum lockdown has shown us we don’t need to travel the way we did for business. “This will be one of the lasting benefits,” he says.

But more people using Zoom than flying between Scotland and London is clearly not enough. Clean energy would be a game changer – or rather “cleaner” energy as don’t forget the power needed to drive an electric car pollutes the air badly too, especially if the electricity for the battery is generated by fossil fuels rather than green energy like wind, wave or solar power.

New technology

NONE of the solutions needed are the stuff of rocket science. It doesn’t take a genius to see that a properly integrated public transport system would help wean people off their dependency on cars.

Think of the near impossibility of travelling anywhere in Scotland beyond the central belt and main cities without a car. People can’t be blamed for using a car if there’s no alternative provided by the Government.

Woodford has little time for some of the wilder flights of fancy from scientists trying to develop devices to deal with air pollution – like building materials which absorb nasty gases, or outlandish gizmos which some inventors have trialled to suck pollutants out of the air.

There was one idea – which Woodford describes as “bonkers” – to give roads a pollution-absorbing coating.

Technology works best, says Woodford, “at the point where you’re making the pollution.

So, a pollution-sucking bus shelter is a bit stupid.

“It’s not sucking enough air to make any difference. We need to stop making the air dirty, rather than try to make the dirty air clean. It’s far cheaper and more cost effective to get people onto a bus than to build some elaborate smog-absorbing tower, which is just nonsensical.”

The public health approach

THE perils of air pollution, Woodford believes, need to be talked about as a public health issue – not an environmental issue.

“People see environmentalism as a sort of dilettantism,” he says, and air pollution should be treated as a public health risk like “alcohol, diet or smoking”.

People trust doctors, Woodford says. Doctors aren’t “scary environmentalists trying to get them to wear sandals and eat yogurt. With a pubic health message you bypass all that”.

Woodford isn’t a prophet of doom, however. Air pollution is a clear and present danger to global health –probably the world’s worst killer, as he has already pointed out – but humanity has come a long way in recent decades, although most of the success has been in the West. “It’s not as though the world is getting dirtier and dirtier,” he says. “In a sense, it’s getting cleaner and cleaner.”

The key is that as time has marched on, our scientific understanding of the risks of air pollution has increased and, as Woodford says, “we realise everything is much more dangerous”.

He adds: “It’s important to bear in mind that it’s not as though [in the West] we’re in the position we were 50 or 100 years ago.”

These incremental improvements over the years, though, might be one reason why tackling air pollution seems to have stalled: we think we’ve got clean air when in fact we don’t. Then add in the essentially unseen nature of air pollution, as another cause for slow progress. If you can’t see something, you tend not to worry about it.

“The general public,” says Woodford, “isn’t that aware of air pollution – isn’t thinking about it as a problem – precisely because today’s air pollution is substantially invisible. Pollution from the Great London Smog was a “pea souper”. You couldn’t go into a cinema during the Great London Smog and see the screen –that’s how bad it was. We don’t have that now.

“Pollution is invisible and so perhaps people don’t see it as a problem … If ordinary people aren’t aware of it, then it’s no surprise that politicians don’t take it seriously as there’s nobody pressing their buttons. That’s why I wrote this book – to reach ordinary people.”

The future

WHILE campaigners like Woodford are pushing the issue of air pollution up the political agenda, “air pollution denial” is starting to worm its way into political lobbying – just as it did with smoking and climate change.

It is also important to bear in mind that we in the West are busily outsourcing our pollution to the developing world. So, just as we send our garbage overseas, a lot of our air pollution is also effectively outsourced overseas too.

Factories which build the goods we buy – and pump pollutants into the air – are now more than likely to be found in China or India. “It’s very difficult not to make pollution in China even if you’re living an ethical existence in the UK,” says Woodford.

Obviously, as nations like China rapidly develop and industrialise, their own emissions boom too. Which all adds up to an increasing threat when it comes to climate change.

And that, as campaigners like Woodford are painfully aware, is an even bigger, more intractable, and potentially much deadlier problem, than cleaning the air we breathe.