Sand blanketed around an eighth of China between April 14 to 18 and it's estimated that around 330,000 tons of grit fell in Beijing on Sunday night alone.

The information was released at a press conference on sand storms which was hosted by the China Meteorological Administration (CMA) in Beijing on Tuesday.

This is the 10th sandstorm in northern China this year and the eighth in Beijing, said Xiao Ziniu, deputy head of the Chinese Central Meteorological Station under the CMA.

"Most of the sand in Beijing comes from Inner Mongolia and areas abroad," Xiao explained.

Beijing reported 'Grade V' pollution which is the most serious level of grading, according to the Beijing Municipal Environmental Protection Department.

Beijing has reported four 'blue sky days' so far in April with a target of having 230 clean air days annually. So far this year the city has recorded 56 'blue sky days' which is 16 days fewer than in the same period of last year.

Many residential communities in Beijing are clearing the dust-covered roads with water rather than sweeping.

The pollution this year has been worse than the past two years, Xiao said.

The sand storms this year could be attributed to high temperatures, prolonged dry weather and frequent cold snaps, he added.

From March, the rainfall in northern China has been about 75 percent of the average figure in previous years and some regions reported rainfall to be about 20 percent down on normal.

Cold air is normal in March and April in northern China and brings gales and sand storms with it.

According to forecasts northern China will experience three further such storms between April 18 and 27.

(Xinhua News Agency April 19, 2006)