‘Doctors need to speak up’
Schraufnagel is concerned that many doctors are unaware of this wide-ranging damage associated with air pollution.
“Some have no idea air pollution affects the organs they specialise in. But it affects their organs too and they had better pay attention,” he said. “They need to educate their patients and then they should speak up” in favour of action.
Researchers cannot experiment on people and so by necessity many studies show significant associations between poor air quality and disease, but cannot prove cause and effect.
However, Schraufnagel said particularly compelling evidence comes from three types of study: where air pollution and illness change in tandem over time, where the “dose” of pollution correlates with levels of disease and from animal studies.
For example, government action to slash pollution before the Beijing Olympics in 2008 led to a rise in birth weights in the city.
“Harmful effects occur even at levels below air quality standards previously considered to be safe,” warn the review scientists, who between them represent every continent. But they add: “The good news is that the problem of air pollution can be addressed.”
“The best way to reduce exposure is to control it at its source,” said Schraufnagel. Most air pollution comes from burning fossil fuels to generate electricity, heat homes and power transport.
“We need to work on these factors in a very dramatic way,” said Neira. “We are probably the first generation in history to be exposed to such a high level of pollution. People will say that in London or other places it was worse 100 years ago, but now we are talking about an incredible number of people exposed for a long time.”
“We have megacities where all the citizens are breathing toxic air,” she said. “However, with all the tonnes of evidence we are collecting now, politicians will not be able to say we didn’t know.”