Prague - The Legerova street in Prague's second district, one of the most important traffic arteries of the capital city, has received the sad primacy of having the highest concentration of nitrogen dioxide in the Czech Republic in 2009. This is above all the effect of the car traffic - every day, the street sees tens of thousands of cars.

In March 2009, Prague's town hall closed the fourth lane of the Legerova street, believing it would lead to a decrease in the volume of traffic. However, this measure has had only a small effect, said Jana Ostatnická from the Czech Hydrometeorlogical Institute that conducted the study.

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In addition, Bohumil Kotlík from the National Institute of Public Health believes that closing one of the lanes made the pollution problem even worse. "I believe it is because the traffic is now more compressed, but it is only my opinion," he said.

Comparing the data from 2008, when there were still four lanes in the Legerova street, and 2009, when the fourth lane was already closed, supports Kotlík's statement.

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In 2008, the Czech Hydrometeorological Institute measured the average concentration of nitrogen dioxide to be 65.9 micrograms - the limit is 40 micrograms. This result made the Legerova street the third most polluted street in the Czech Republic, in terms of nitrogen dioxide concentration, after the Svornosti street in Prague 5 and Sokolovská street in Prague 8.

In 2009, the average concentration was 68.2 micrograms, which made the Legerova street the sad winner. The second runner, the Všebořická street in Ústí nad Labem, Northern Bohemia, had almost 10 micrograms of Nitrogen Dioxide less.

"It is possible that the reduction (of the lanes) really caused the rise in emissions," said Jana Ostatnická, adding though that the higher numbers measured in 2009 were also caused by the long and strong winter characterized by bad dispersion conditions.

Vice Mayor of Prague 2 Václav Vondruška says that closing the fourth lane in 2009 helped, arguing that nitrogen dioxide is only one of a number of harmful elements present in exhaust gases.

"What improved is the emission of small dust particles, which bind other pollutants.

"Street of Death"

In 2009, the institute measured the average concentration of microscopic dust to be 31.9 micrograms in the Legerova street, a 6.5 micrograms less in comparison with 2008.

In the Legerova street, the probability of mortality is higher by tens of percent, said Eva Rychlíková from the Central Bohemian Institute of Public Health. In the case of lung cancer it its 50 percent, in the case of cardiovascular diseases it equals 44 percent. The probability of infant mortality is higher as well.