Toxic air fears after Oklahoma twister

The Environmental Protection Agency planned to check for high lead levels Monday after a deadly tornado blew through a heavily polluted former mining town where lead-filled waste is piled into giant mounds.

The tornado was one of several that combined to kill 22 people in the Midwest and the South over the weekend, raising the nation's 2008 total to about 100, the worst toll in a decade.

This year is on pace to see the most deaths since 130 people were killed in 1998, the eighth highest total since 1950, according to the National Weather Service. The record is 519 tornado-related deaths in 1953.

In Picher, the devastation was complicated by the town's status as one of the most polluted Superfund sites in the nation. But Miles Tolbert, the Oklahoma secretary of the environment, said he did not think there was an immediate public health hazard to the 800 residents. He did say more testing is needed to be certain.

Long-term exposure to lead dust poses a health risk, particularly to young children.

On Saturday, a tornado with the second-strongest rating killed six people, destroyed a 20-block area and blew dust off mountains of mining waste, or chat piles.

"You can look at the chat piles and see that a lot of the material has blown off," said John Sparkman, head of the Picher housing authority. "We went up on a chat pile an hour and a half after the tornado hit, and you could see dust blowing fine material all over the place from that vantage point."

In all, 22 people were killed in the tornado outbreak in Oklahoma, Missouri and Georgia.

Meanwhile, law enforcement officers and the Oklahoma National Guard patrolled the Picher overnight into Monday to prevent looting, said Michelann Ooten, spokeswoman for the Oklahoma Department of Emergency Management.

National Weather Service assessment teams determined the twister that hit Picher had an EF-4 rating, the second highest rating, and was 1 mile wide at its widest point, meteorologist Mike Teague said Monday.

The tornado's winds were estimated at 165 to 175 mph, and the damage track stretched 74 miles - 29 in Oklahoma and another 45 in Missouri, where 15 people were killed

Federal authorities in the US are sending aid to the three south-central states hit by last weekend's tornadoes which killed at least 22 people.

At least 15 people died in Missouri, six in Oklahoma and one in Georgia. A number of people were also injured.

Officials warn the death toll could rise as rescuers are sifting through the rubble looking for survivors.

President George W Bush called it a "sad day", saying Washington "will be moving hard to help".

The American Red Cross has now opened shelters for those affected by the tornadoes.

'One right after another'

A tornado severely damaged the north-eastern Oklahoma town of Picher late on Saturday, killing at least six people and injuring some 150 people.

An emergencies official in Picher said a 24-street area of the town had been "virtually destroyed".

Television images showed overturned cars, homes ripped from their foundations and trees stripped of their leaves.