WASHINGTON — Federal health officials said Agent Orange and other herbicides sprayed at a Canadian military base posed no health risks to the thousands of National Guard members from Maine and other states who trained there for decades.

The U.S. Centers for Disease Control and Prevention’s findings are unlikely to satisfy veterans who think their health problems are linked to weeks they spent training in the dirt at Canadian Forces Base Gagetown in New Brunswick.

U.S. Sen. Susan Collins, R-Maine, expressed disappointment at the scope of the review.

“While I appreciate that the CDC shares my concerns about the health of our service members and veterans who trained at Gagetown, I am disappointed that it does not appear that the thorough investigation the administration promised to undertake went beyond a review of the pre-existing Canadian report,” Collins said Tuesday.

In June 2012, Collins asked the CDC’s Agency for Toxic Substances and Disease Registry to review a 2007 Canadian study of health risks from herbicides used at Gagetown and advise her office on levels of chemicals sprayed at the base. The CDC found no qualms with the Canadian report’s findings.

“We concluded that concentrations of contaminants at CFB Gagetown did not represent a public health hazard to members of the U.S. military or National Guard,” CDC Director Thomas Frieden wrote to Collins in a March 1 letter accompanying the report. “While exposures may have occurred during training at CFB, the levels of herbicide were below levels of concern for both cancerous and non-cancerous health effects.”

Located southeast of Fredericton, New Brunswick, the Gagetown training base was used by thousands of National Guard members from Maine, Massachusetts, New Hampshire and other states from 1971 to 2006. Units often spent two weeks training at the sprawling base, which encompassed more than 250,000 acres, 700-plus buildings and 1,500 miles of roads. More than 300,000 Canadian military personnel served or trained at Gagetown as well.

Veterans on both sides of the border — including more than 100 in Maine — have been struggling for years to qualify for disability benefits for ailments they blame on use of herbicides and defoliants at Gagetown.

At the top of the list of chemicals is Agent Orange, a defoliant widely used during the Vietnam War that has been linked to cancer, Hodgkin’s disease, birth defects and a host of other diseases. However, Canadian officials also sprayed large quantities of other herbicides and defoliants at Gagetown over the decades.

Veterans affairs officials in the U.S. and Canada have rejected almost all claims except those filed by people who served at Gagetown in 1966 and 1967 when the U.S. military tested Agent Orange there. Many veterans whose claims were denied believe the other chemicals — including close relatives to Agent Orange — may be causing their health problems, however.

The CDC did not conduct its own investigation of conditions at Gagetown. Instead, the agency reviewed the Canadian government’s 2007 report on herbicide use between 1952 and 2004 at Gagetown. The CDC agreed with the original report’s conclusions after determining that the soil sampling methods, tests and risk assessment standards were the same as the CDC would have used.

“There is little to no increased risk of adverse effects on blood-forming tissues, the liver, and the central nervous system, and the risk of skin disorders or developmental effects is not enough to represent a public health hazard,” reads the report.

Collins suggested Tuesday that she had expected the CDC to probe deeper, however. Her June 2012 request specifically asked the agency to review the 2007 report but also posed a series of questions about the amounts and concentration of herbicides used and safety precautions.

“I would have hoped that the CDC would have sought to interview medical providers treating those who were possibly exposed to harmful chemicals and became ill,” Collins said in a statement. “It is unclear from the letter I received, or the report itself, whether those investigative steps were taken.”

Richard Pelletier, a veteran and American Legion service officer who has been one of the most forceful advocates on the Gagetown issue, bristled that Collins “should have known better” than to ask a U.S. government office to look into the matter. Like many affected veterans on both sides of the border, Pelletier believes the U.S. and Canadian governments are covering up the issue to limit liability.

Instead, he said, an independent panel needs to investigate.

“It doesn’t surprise me it is the same decision. It is going to be the same decision” absent an independent review, Pelletier said Tuesday night. “We didn’t get any farther. It’s six or seven months later and we still have the same story.”

A spokeswoman for the U.S. Department of Veterans Affairs said Tuesday that the department still is reviewing the report and is unable to comment.

Kevin Miller — 317-6256

kmiller@mainetoday.com

Twitter: @KevinMillerDC