Before the 2008 Beijing Olympics, there were widespread fears about the effects of air pollution on the performance, and even the health, of participating athletes. It is an issue that has followed the summer Olympics around the globe, from the high altitudes of Mexico City in 1968 to the crowded roads of Athens in 2004.
Beijing implemented an extraordinarily varied series of measures to achieve a level of air quality accceptable for athletic competition. Factories were closed – in some cases permanently, traffic levels controlled, and consumption of coal reduced in order to meet targets set by the World Health Organisation and the International Olympic Committee.
Beijing’s measures were largely successful, at least for the period of the games. Levels of sulphur dioxide, nitrogen dioxide, carbon monoxide and particulate matter dropped by between 40 and 60% compared to the same period the previous summer, and fears of visible adverse effects on the performance of the competitors proved unfounded. Nevertheless, these fears created their own impact: at one stage there were calls for British athletes to don so-called 'smog masks', and the concern was enough for the great Ethiopian runner Haile Gebrselassie to withdraw from the marathon.
A particular problem for cities hosting games in the height of summer is that of ozone, which has been shown to have a demonstrably deleterious effect on lung function even at marginally elevated levels. Ozone is formed by the action of ultraviolet light and production is therefore enhanced in the summer and by factors that are, to a large extent, outside human control. Long-distance runners, particularly those with a history of asthma, are most at risk.
|Pollutant||2008 Olympic target||Regular target in England|
|Ozone||150 µg/m3 mean daily 8-hour maximum||100 µg/m3 8-hour average, 355 days per year|
|Nitrogen dioxide||400 µg/m3 1-hour maximum||200 µg/m3 1-hour mean, 347 days per year|
|PM10||150 µg/m3 24-hour average||50 µg/m3 24-hour average, 330 days per year|
|PM2.5||75 µg/m3 24-hour average||25 µg/m3 annual average|
|Sulphur dioxide||125 µg/m3 24-hour average||125 µg/m3 24-hour average, 362 days per year|
In London this summer, air pollution will be closely monitored, especially in relation to any increase in traffic density at the time of the Games, and remains an issue that arouses strong opinion. London, though, starts from a somewhat more fortunate base than Beijing. It routinely attempts to abide by somewhat more stringent directives than the ones imposed at the 2008 Games (see table), and as the recent Diamond Jubilee demonstrated, there is no guarantee of uniformly hot weather during the English summer.