PORTLAND, Ore. — Months after arriving on the job in 2003, a U.S. defense contractor trying to restore Iraq’s oil fields had blood and urine tests showing personnel with “significant exposure” to a toxic, cancer-causing industrial chemical, according to federal court documents.

The documents, first disclosed Thursday by The Oregonian newspaper, are part of a lawsuit National Guard troops filed in federal court in Portland against the contractor — Kellogg, Brown and Root of Houston. The troops allege they have health problems and increased risk of cancer and were exposed well after the dangers of sodium dichromate were known.

The company had a no-bid contract from the Bush administration, which hoped Iraqi oil revenue would help pay for the war.

Guard soldiers from Oregon, Indiana and West Virginia who provided security at the Qarmat Ali water plant are involved in suits against KBR. Their lawyers cite minutes of an Oct. 2, 2003, meeting, held at the request of Iraqi oil officials, to discuss an investigation by health, safety and environmental staff members of KBR.

“Urine and blood sample showed elevated levels of chromium, meaning that there was a significant exposure,” said the notes attributed to a KBR official, Chuck Adams. “Cannot allow personnel to be exposed, company will be liable if let this happen.”

The chemical fights rust in pipes. The plant was used for injecting water into the ground to push oil to the surface. It had been looted and ransacked, and KBR was restoring it.

Soldiers have described the chemical as a blowing orange dust that even got in their food. They said they didn’t get masks or protective gear used by workers inside the plant.

The notes attributed to Adams say, “Undetermined number of bags have been deteriorated by the weather, wind circulates these particles in the air and is inhalated. Dry dust is scattered around the site. Should do blood test to people shoveling the dust into bags, if exposed too long may cause death.”

KBR has denied knowingly exposing troops to jeopardy and issued a statement Friday saying the plaintiffs’ lawyers were trying to influence public opinion and potential jurors by releasing documents selectively.

The company said blood tests disproved Guard soldiers had injuries from exposure to the chemical at Qurmat Ali, that KBR didn’t bring the chemical and didn’t use it, that its contract required the Army to have the site clear of environmental hazards, that KBR took remedial steps the Army praised, and that the soldiers’ time at the plant was too brief for them to suffer harm from exposure to the chemical.

The case isn’t expected to go to trial until at least the second half of next year. KBR has asked the 9th U.S. Circuit Court of Appeals to intervene and dismiss the case.