The worldwide shortage of helium supplies continues to bite, and some experts believe it will only get worse.

Dave Sifers of helium supplier Airgas says supplies were cut short because of plant maintenance and shutdowns. Helium is produced in the U.S., Poland, Russia, Algeria and Qatar and plant shutdowns in November certainly affected supplies. However, there seems little explanation of why the shortage has lingered.

Greg Griffin of Praxair Distribution Inc., said in the past, helium was just used for balloons and in welding. Today, the gas is used by the aerospace industry, scuba divers, in fiber optics and by the medical industry.

The shortage has prompted some suppliers to tack on surcharges that can inflate the price of balloons and other goods that depend on helium. For the record, Airgas and Praxair both say they have been able to supply customers despite the shortage. Sifers said Airgas in Redding is getting about 70 percent of its normal supply.

$quot;For any medical customers that use helium, they get it first. Everybody else takes a back seat,$quot; Sifers said. But new and used car dealerships are the biggest consumers of helium, Sifers said.

The American Chemical Society in May 2001 warned of the coming helium shortage, going so far as predicting U.S. reserves will dry up by 2015