An Air Force veteran and a one-time contractor who served in Iraq are suing military contractors Halliburton Co. and KBR Inc., accusing the companies of exposing them to toxic fumes and ash from "burn pits" for waste.

The suit, filed in U.S. District Court in Louisville on Monday by former Air Force Sgt. Sean Alexander Stough of Stanton and Charles Hicks of Bellevue, claims the military contractors burned everything from human remains to tires in open-air pits, exposing everyone nearby to harmful ash and smoke.

The men are seeking class-action status for the lawsuit.

"The burn pits are still going on," said attorney Susan Burke, who represents the two men. "It's everything you can think of."

The suit in Kentucky, which names KBR, Halliburton and a Turkish company, ERKA Ltd., is the latest in a string of litigation on behalf of former military members and contract workers who claim they were exposed to toxins from burning waste in the warzone. At least 32 suits over burn pits have been filed in 32 states against KBR and Halliburton, which are both Houston-based, and other contractors.

The suits have been merged for pretrial proceedings under U.S. District Judge Roger W. Titus in Greenbelt, Md. Burke expects the Kentucky suit to be transferred there for pretrial purposes.

KBR spokeswoman Heather Brown said the company denies the allegations and follows military regulations on the disposal of waste.

"KBR operates burn pits in accordance with guidelines approved by the Army," Brown said.

A Halliburton spokesman did not immediately return a message seeking comment on Tuesday. An e-mail sent to ERKA's offices in Adana, Turkey, was not immediately returned Tuesday.

Stanton, who was stationed at Camp Bucca, near Umm Qasr, Iraq, until April 2006, and Hicks, who was stationed at Balad Air Base north of Baghdad in 2004 and 2005, both claim exposure to the burn pits caused multiple medical issues, including pulmonary and breathing problems.

Earlier this year, several members of Congress asked Veterans Affairs Secretary Eric Shinseki to investigate potential burn pit hazards. Shinseki said his agency is conducting a health study of 30,000 Iraq and Afghanistan veterans and noted the VA "has learned important lessons from previous military conflicts" as it deals with environmental exposure questions.