Joanne Ward was 30 when she had her second son eight years ago. It was a straightforward birth and she was happy to go home soon thereafter. Four days later, she was back in the hospital after a heart attack. She has learnt to cope with her coronary condition, but one problem she did not anticipate was air pollution.

“It’s bizarre,” she says, explaining that she never had so much as hay fever before her heart attack, but now has days when she goes outside and “it’s like you have a thousand knives going into your chest”, especially on a busy city street.

Ms Ward’s concerns are not isolated. Researchers know smog raises the risk of heart problems, but a study this week suggests it can also worsen the condition of people with existing heart disease.

If she lived in Beijing or New Delhi or any other highly polluted city, that would be one thing. But she is from Sheffield in northern England, once a powerhouse of the industrial revolution and now, like so many other European centres, a much quieter, cleaner place. Yet today — almost 60 years after Europe began cleaning up the soot and grime that once choked its biggest cities — air pollution remains a concern, especially for people with heart or lung problems.

Up to 95 per cent of EU city dwellers are still exposed to levels of fine particulate matter — one of the most dangerous types of pollution — that exceed World Health Organisation (WHO) guidelines, European Environment Agency data show.

That is worrying news for people in those parts of the world that are just embarking on the industrialisation that created so much wealth in Europe and then the United States. Their pollution is now an increasingly international concern as it blows over to countries with cleaner skies.

2 Million PREMATURE DEATHS

One of the most important environmental questions today is whether these countries can learn from the experience of their Western counterparts to combat a pollution problem that researchers say is causing the premature deaths of more than two million people each year.

One thing is certain: There is a the need to act quickly. Following an unprecedented movement of people away from farms, more than half the world’s seven billion people live in urban areas, increasingly in so-called mega-cities with a population of 10 million or more.

The United Nations predicts the number of huge cities will increase to 37 from 23 during the next 12 years, and most will be in Asia. In China alone, 250 million people are forecast to move from the countryside to towns and cities in coming years.

Although urbanisation by itself does not necessarily cause air pollution, it can exacerbate health problems as higher concentrations of people start living near busy roads and other sources of pollution.

The potential hazards are underlined by three studies published in the past week. One, funded by the British Heart Foundation, shows that even short-term exposure to most “major” air pollutants increases the risk of being hospitalised or dying from heart failure. Another shows that the risk of lung cancer rises after prolonged exposure to fine particulate matter, even at levels below those set in the EU.

BEIJING AIR: WORSE THAN A SMOKERS’ LOUNGE

But the most eye-catching finding comes in a ground-breaking study by a team of international researchers who report that people in southern China live five-and-a-half years longer on average than their counterparts in the north, where the government has for years handed out free coal for winter heating.

China’s smog has made it notorious. But many Chinese cities look very similar to what Los Angeles or London did decades ago, a time still remembered for events such as the Great Smog of London in 1952.

The smoky fog that engulfed the capital for five December days is estimated to have contributed to the deaths of at least 3,000 people and reportedly caused cows to choke to death in fields.

In January this year, Beijing’s smog levels soared to staggering heights, leaving residents to breathe air worse than that of an airport smokers’ lounge and prompting officials to hastily promise measures to address the problem.

Especially alarming was the amount of fine particulate matter known as PM2.5 — tiny airborne particles less than 2.5 microns wide, about a 30th of the width of a human hair.

They are produced by almost any type of combustion, from motor cars to the coal-fulled power stations, on which China depends so heavily, and they are dangerous. Once inhaled they are small enough to pass from the lungs into the bloodstream, unleashing a range of health problems.

In January, PM2.5 concentrations in some parts of Beijing neared 900 micrograms per cubic metre of air. That was nearly 40 times the daily average of 25 deemed acceptable by the WHO and well above the annual average level of 70 to 80 that city officials reported for 2010. (In contrast, annual average PM2.5 levels in London were 13.5 in 2008, and 14.8 in Los Angeles, according to the most recent data reported to WHO.)

NATIONAL GOVERNMENTS MUST ACT

China’s pollution does not stay in China, however. Its impact abroad has become a growing issue in Japan and South Korea and is making it harder for other countries to keep improving their air quality as it drifts as far as California and beyond.

“Background pollution in Europe is also slightly increasing because of the growing global sources of air pollution from abroad, such as from China,” says Mr Martin Adams of the European Environment Agency.

But the way Western cities tackled their pollution levels is of big interest in China, says Ms Catherine Witherspoon, a former Executive Officer of the California Air Resources Board.

It took California 35 years to halve its famed smog levels, she says, and while individual cities did a certain amount, it was broadly national governments that had to do the heavy lifting of launching clean air standards, pollution fines and the other steps needed to transform once-blighted cities in the US and Europe.

“The real secret to those turn-arounds — beyond lots of time, steady incremental improvements and scores of regulations — was the choice to grow economically without coal,” she says. “There was a dramatic change in air quality when California got off heavy fuel oil during the 1970s energy crisis. We never went back, which caused natural gas to be locked in as the fuel of choice.

It was a similar story with coal in some European countries, she says, adding: “A number of us are trying to figure out how far China can get without massive reductions in coal, since emission control technologies have advanced tremendously since then.”

EVEN WHEN IT SEEMS CLEAR

Those advances suggest that China might be able to tackle its pollution woes faster than the EU and the US.

Significant advances have been made since the 1950s in developing sources of cleaner energy, with solar and wind power, for example, and in understanding the impact of diesel on air pollution.

This has prompted cities around the world to come up with measures such as congestion charging, driverless days and cycle paths and develop well designed mass public transport systems.

Some of the most innovative of these were launched in emerging economies, such as the rapid transit bus system the Brazilian city of Curitiba began building almost 40 years ago. Fast, cheap, reliable and heavily used, it has become a model for cities around the world.

But even when countries get smog levels down to a certain point, the improvements that health experts deem satisfactory can prove stubbornly hard to achieve. This is even the case in Europe, pioneer of some of the world’s leading renewable energy and climate change policies, where 2013 has been declared The Year of Air.

Cities such as the British capital have worryingly high levels of some pollutants, says Mr Simon Birkett of the Clean Air in London campaign group. It has the highest level of toxic nitrogen dioxide of any capital in Europe, he says, even though London is awash with measures such as the congestion charge, low emission zones and a public bicycle hire scheme.

In spite of these measures, the pollution problem persists because too many diesel trucks, cars, buses and taxis ply the city’s streets, says Mr Birkett. It is a similar story elsewhere in the EU, which has started to lag behind other parts of the world, experts say.

“I would say Europe has been stagnant on air pollution improvements, which the US has not,” says Dr Carlos Dora of the WHO’s Department of Public Health and Environment.

The Financial Times Limited

ABOUT THE AUTHOR:

Pilita Clark is the Financial Times’ Environment Correspondent