The World Health Organization has issued a warning about the consequences of Beijing’s high pollution levels for the health of visitors to the city, as well as its inhabitants. The warning comes as Beijing is starting a 4 day test of a system aiming to bring down pollution during the Olympics next year.

While the scheme being tested now - banning cars with license plates ending in odd and even number alternately - might bring down pollution levels the WHO warns this may not be enough. The city’s poor air quality could still cause asthma attacks and people with cardiovascular problems are also advised to be cautious.

Experts say attempts to limit pollution in Beijing may have little or no effect. The dangerous particles can travel great distances so any reduction in Beijing could be offset by pollution from elsewhere in China.

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