BEIJING, April 22 (Xinhuanet) -- By April 21 in Beijing, the number of days in which the air was seriously polluted this year had reached seven, even surpassing the total reported last year, according to the Beijing municipal administration of environmental protection.

    The municipal administration convened an emergency meeting on Wednesday, urging a 24-hour monitoring over the air pollution in the city, the Beijing News reported Thursday.

    According to statistics, by April 21 this year, only 58 days saw moderate or even better air quality in Beijing, compared to 69days last year, in which only five days saw serious air pollution.

    And during the first 21 days of April, only for six days could people enjoy the "blue sky", the paper said.

    This spring, the city has been hit by three sandstorms, and since April 8, it has been dominated by a warm air mass, which makes the pollutants in the air hard to be dispersed, experts said, adding that the weather in late April is forecast to be not helpful for alleviating the air pollution.

    In order to ensure good air quality, the environmental protection departments in Beijing will intensify monitoring over the construction sites, vehicles and factories in an effort to reduce the discharge of pollutants, the administration said. Enditem