Advocates for troops exposed to open air burn pits are recruiting allies on Capitol Hill to persuade the Department of Veterans Affairs to expand health care and compensation for sickened veterans.

Taking their fight to Congress on Tuesday, the group Burn Pits 360, joined by civilian physicians and researchers who treat and study affected veterans, met with lawmakers and staff to press the VA into action.

Service members in Iraq, Afghanistan and elsewhere were exposed to chemicals and fumes from large open air burn pits used to dispose of garbage, plastics and other hazardous materials. Some have respiratory diseases, rare cancers and neurological disorders their doctors attribute to environmental exposures.

Rep. Tulsi Gabbard, D-Hawaii, a member of the Army National Guard who served in Iraq in 2005, has sponsored a bill, H.R. 663, that would require the Defense Department to ensure that service members are enrolled in a VA registry for troops exposed to burn pits.

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"Daily reality was this dark cloud of smoke and toxins that came from the burn pits in our camps. ... The stench was ever-present. We've seen the devastating toll it's taken with many of our friends," Gabbard said.

More than 175,000 service members have signed on to the VA's Airborne Hazards and Open Air Burn Pit Registry. Millions more may have been exposed but are not in the registry, Gabbard said, a shortcoming that affects the understanding of the pits' impact.

"Every day that passes without urgent action being taken by our government, more service members suffer," she said.

A measure similar to Gabbard's has been introduced in the Senate by Amy Klobuchar, D-Minnesota.

Other bills now under consideration would allow family members of deceased or incapacitated veterans to add their service member's name and experiences to the registry or, at the very least, update the registry when a veteran dies.

The Family Member Access to Burn Pit Registry Act, H.R. 1001, sponsored by Rep. Joaquin Castro, D-Texas, and the Burn Pit Registry Enhancement Acts, H.R. 1381 and S. 554, would let a designated person enroll a veteran or update the registry.

Castro also has introduced a bill that would change the VA's disability ratings process for obliterative bronchiolitis, a lung condition often mistaken for asthma that some troops exposed to burn pits have developed.

The bill, H.R. 1005, would create a diagnostic code and a disability rating for the condition.

"We can't afford to cast a blind eye to the level of exposure and, with it, the impact," Castro said. "Our service men and women's exposure to this toxicity is undeniable, and the level cannot be questioned."

More than 250 burn pits were used at U.S. military bases in Iraq, Afghanistan and Djibouti to burn solid waste, including garbage, rubber, plastics, petroleum and medical waste.

Dozens of service members filed a lawsuit against the contracting firm KBR, which operated many of the burn pits, but the Supreme Court in January rejected an appeal to a lower court's ruling that the issue is one Congress and the president need to solve.

Sen. Tom Udall, D-New Mexico, was instrumental in 2013 in creating the VA burn pit registry. He expressed concern that the department plans to reduce its research budget by $17 billion and feels the government should be "fast-tracking" studies on burn pit-related illnesses.

"Veterans sickened by burn pits deserve eligibility for lifesaving health care," Udall said. "We must make sure these patriots receive care for the illnesses and injuries they received in service to our nation. It's basically as simple as that."

Rep. Raul Ruiz, D-California, sponsored the Burn Pit Registry Enhancement Act, which passed the House and now awaits a Senate vote. He said he will introduce a bill that would make veterans with burn pit-related pulmonary illnesses automatically eligible for compensation and expanded health care.

"We don't have time for the perfect 20- to 30-year longitudinal cohort study ... to recognize that burn pits are a risk factor and toxic to veterans' health," said Ruiz, an emergency room physician. "We need to act now. We needed to act yesterday."

The Airborne Hazards and Open Burn Pit Registry is available to personnel who served in Operations Enduring Freedom, Iraqi Freedom and New Dawn; those stationed in Djibouti on or after Sept. 11, 2001; and veterans of Desert Shield and Desert Storm or anyone who served in the southwest Asia operational theatre on or after Aug. 2, 1990.

According to Burn Pits 360, 130 of its members have died from diseases related to environmental exposures. Nearly 100 members have been diagnosed with brain cancer, including glioblastoma, a relatively rare disease in persons younger than 45. An additional 139 have skin cancer, and 116 have lymphoma.

Burn Pits 360 Executive Director Rosie Torres said the VA, which has contracted with the National Academies of Sciences, Engineering and Medicine to conduct a systemic review of available scientific literature on the topic, is engaging in "delay tactics."

"Our fate now rests in Congress," she said in a news release.

-- Patricia Kime can be reached at Patricia.Kime@Military.com. Follow her on Twitter at @patriciakime.