Fuming.

Three powerhouse plaintiff's firms are the latest to sue the welding industry, claiming that workers were exposed to dangerous fumes that caused neurological damage similar to Parkinson's disease.

L.A.'s Greene Broillet & Wheeler LLP and Panish Shea & Boyle LLP, along with San Francisco firm Lieff Cabraser Heimann & Bernstein LLP, sued on behalf of 18 welders in California who claim they would not have worked in the industry had they known they were exposed to fumes containing manganese, a chemical known to cause neurological damage. They are seeking an undetermined amount of damages.

"There is a wealth of knowledge that goes back where this was well known," said Browne Greene, partner at Greene Broillet. "These defendants knew about it, and they took steps, like the tobacco industry, to hide the information concerning its effects."

The suit, filed in Los Angeles Superior Court, is the latest of about a dozen similar lawsuits filed in recent years against the nation's largest manufacturers and distributors of welding products.

Among the dozens of defendants in the recent case are Unocal Corp. and California Welding Supply Co.

The welding companies deny the allegations.

"It's turned into a situation where somebody who used to be a welder who gets sick blames it on welding fume," said John Beisner, a partner at O'Melveny & Myers LLP in Washington D.C. who has represented the welding defendants in other big cases. "There is no causal link between mild steel welding and the ailments they allege."

Staff reporter Amanda Bronstad can be reached at [phone], ext. 225, or at [e-mail].