The filthy air conundrum

[[R_H]]

BBC

Beijing is taking drastic measures to improve its air quality in the run-up to the Olympics. But is it possible to conquer air pollution in a short space of time?

In China's capital city, emergency measures are afoot.

It is nine days until the games begin. Beijing has a reputation for bad air pollution and if the national stadium is shrouded in smog on the first day of the games, the embarrassment will be palpable.

Driving through the city is restricted to cars with even or odd number plates on alternating days. Factory emissions have been reduced and some building sites shut down.

The aim is to reduce air pollution so when athletes and tourists arrive for the Olympics, they can see blue sky above the bird's nest stadium. They also want competitors concerned over health risks to rest easy.

But the BBC's James Reynolds has been monitoring air quality in Beijing since the measures came into force and the results are not good. A measurement of PM10 (particles smaller than 10 micrometres) shows things got worse - at a given snapshot moment each day - for five successive days after the introduction of the measures.

Despite lower emissions, levels of pollution are still bad. The authorities are even talking about more severe "ultra-emergency" measures immediately prior to key events, with 90% of cars off the roads and much industry shut down.

Whether the weather

It is possible to tackle air pollution in the short term, says Hugh Coe, professor of atmospheric composition at Manchester University.

you put carbon dioxide in the atmosphere and it lasts for decades. Air quality is a short term problem. If you stop emitting, your air quality could improve very quickly."

But it's not quite as simple as just turning off the pollution tap, says Prof Coe.

"It's about the rate at which you pump this stuff into the atmosphere and the meteorological conditions. There is not too much you can do about the latter."

The weather is the great variable in any efforts to clear the air.

Frank Kelly, professor of environmental health at King's College London, says the worst case scenario is "very, very low winds, high atmospheric pressure, an anti-cyclone building up above the city - it acts like a saucepan with the lid on".

Pollution needs to be able to rise into the atmosphere and blown by winds to properly disperse.

The worst case scenario is a situation like London's Great Smog of December 1952. Then there was almost certainly increased coal burning because of the cold weather, but the main culprit was a rather nasty weather pattern, known as an inversion layer.

Normally the air gets colder the higher you go. In an inversion layer, this is reversed with a layer of cold air held in place by a warmer "lid". The result in 1952 was a city choked with smog and at least 4,000 extra deaths.

"The weather conditions were unique. The whole of London's pollution didn't go anywhere," says Prof Kelly.

BBC Weather forecaster Dan Corbett says meteorological patterns in Beijing over the summer are not conducive to dispersing pollution, with high pressure and inversion layers common.

"It is like taking a pan of soup off the hob. It steams, but put a lid on it and everything just sits under the lid."

Gobi dust

And as well as weather conditions trapping smog in, there are conditions that suck in pollution. Take a coastal city like Newcastle. When the wind blows out to sea it's perfect for dispersing pollution, but should there be a south-easterly wind it can bring in new pollution from continental Europe and boost readings.

In Beijing the issue is serious, with winds carrying pollution from all over the surrounding region as well as dust from the Gobi desert in spring.

Then there's the effect of sunlight. Nitrogen oxide and hydrocarbons can form ozone as long as there's bright sunlight. Ground-level ozone is hazardous and a major component of photochemical smog.

In London in 1952, the concentration of the pollution was visible, largely a result of coal, which produces black smoke consisting of large particles. The sulphurous type of coal then used also produced large quantities of sulphur dioxide that caused smog.

In the West today, less and cleaner coal is used. Now the threat is usually less visible and comes in the form of nitrogen dioxide, volatile organic compounds - such as paint thinner or solvents - and smaller particulate pollution under 10 micrometres in size, known as PM10.

"Modern pollution is coming from motor vehicles," says Prof Kelly. "Particles emitted are much, much smaller. They are not as visible, people feel safer but the real problem is that because they are smaller they get deep down into the lungs where the coal particles didn't get."

Asthma attacks

And being of a size that can penetrate deep into the airways and settle in the lungs, these PM10 particles are among the most dangerous forms of air pollution, says environmental epidemiologist Prof Tanja Pless-Mulloli, of Newcastle University.

more likely to have an asthma attack. There is an impact on the number of hospital visits and there is an impact on mortality, even at concentrations that many countries experience."

The health concerns over air pollution have prompted some places to employ drastic measures along the lines of Beijing.

Athens tried the odd/even registration plate restrictions, starting in the 1980s. Not the hardest restriction to circumvent, many motorists bought an old banger with the other plate. Atlanta put traffic restrictions in place for the 1996 Olympics.

On 1 September 1990, Dublin banned the sale and burning of bituminous coal. A study published in the Lancet by Luke Clancy, Pat Goodman, Hamish Sinclair, and Douglas W Dockery - comparing the six years before the ban and the six years after - found dramatic results.

Black smoke concentrations in Dublin fell 70%, and the authors estimated there would have been 116 fewer respiratory deaths and 243 fewer cardiovascular deaths a year in the city after the ban.

And in Santiago, Chile, short-term emergency action was taken in the 90s when there were extraordinary bursts of smog, says Nigel Bell, professor of environmental pollution at Imperial College London.

"It put a lot of babies in hospital. Santiago has got a ring of mountains round it and a lot of vehicles. They closed a lot of factories. The smog went but I don't know how much one could ascribe it to the actions taken."

And one dramatic change in the atmosphere came after 9/11, says Prof Coe. All flights were grounded in the US and the vapour trails which form many cirrus clouds were thereby removed. These cirrus clouds reflect some radiation from the sun, as well as absorbing some of the heat energy escaping to space from the earth.

The difference in radiation levels at the surface would have been measurable during the grounding, says Prof Coe.

Emissions can be controlled, particularly by aggressive government action, but no power on earth can control the weather patterns that carry those emissions around our atmosphere.

Switching off air pollution is possible, but only if the weather lets us.

[KlavoHunter]

One wonders why the city was chosen in the first place if it was so notoriously smoggy. They could have picked somewhere else in China that wasn't such an environmental disaster.

[Strider]

One wonders why the Olympics were allowed to be in China at all...

[Isolder74]

One wonders why the city was chosen in the first place if it was so notoriously smoggy. They could have picked somewhere else in China that wasn't such an environmental disaster.

its the capitol. That's all the explanation you need.

[KlavoHunter]

its the capitol. That's all the explanation you need.

Wow. I feel sorry for the athletes and everyone who has to go there to watch them.

[fgalkin]

One wonders why the Olympics were allowed to be in China at all...

Why not?

Have a very nice day.
-fgalkin

[Molyneux]

One wonders why the Olympics were allowed to be in China at all...

Why not?

Have a very nice day.
-fgalkin

Because their human rights record is atrocious (yes, the American record has taken hits but it's still FAR better), their government is evil and the air quality in the country will likely do permanent damage to the lungs of any athletes competing there?

[Adrian Laguna]

I don't think their government can really be called evil. China's not an easy place to rule, and I don't think it's even possible to rule it effectively without being at least a bit heavy handed.

[Molyneux]

I don't think their government can really be called evil. China's not an easy place to rule, and I don't think it's even possible to rule it effectively without being at least a bit heavy handed.

You're fucking kidding me, right?
China jails rights activist outspoken on Tibet
China reviews `apartheid' for 900m peasants
China tells living Buddhas to obtain permission before they reincarnate
China torture 'still widespread'
China leads world in executions, report finds

Need I go on? That's not heavy-handed, that is pure and simple evil.

[Saxtonite]

I don't think their government can really be called evil. China's not an easy place to rule, and I don't think it's even possible to rule it effectively without being at least a bit heavy handed.

They would decentralize their government or something similarly or fulfill the people's desires.