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Air pollution, although no longer at pea-souper levels, remains a problem.

The 'pea-souper' enshrouded the stadium to such a degree that the referee insisted both his assistants run the same side of the pitch.

An event synonymous with bold primary colours, in the sky and on the court, at risk of being stifled by a pea-souper.

The worst in recent memory was London's "pea-souper" of December 1952, which contributed to the deaths of an estimated 4,000 people.

But China offers a vision of environmental degradation far in excess of the pea-souper fogs of 1950s London or Manchester.