That was quick. Part of London has already passed its annual limits for pollution, and it only took five days.
Law states hourly levels of nitrogen dioxide can't exceed 200 micrograms per cubic meter more than 18 times per year.
But by Jan. 5, readings on a road in the city had passed those limits. At one point, levels of the gas were about 1.75 times the legal amount.
This isn't too shocking. Last year, London passed annual limits in just a week.
Nitrogen dioxide pollution in the city is produced largely by diesel vehicles. In 2010, a study estimated up to 5,900 deaths in London could be linked to long-term exposure to the gas.
Such exposure to nitrogen dioxide has adverse effects on lung function and breathing.
But officials are trying to stop things from getting worse. London's mayor has pledged more than a billion dollars over the next five years for air quality measures.