US Huey helicopter spraying Agent Orange in Vietnam. Photo: Wikipedia

In nature, nothing exists alone.

-Rachel Carson, author of Silent Spring

From Vietnam to the Panama Canal is 17,300 kilometers, with nothing between except the Pacific Ocean.

During the Vietnam War, the United States sprayed on Vietnam about 40 million liters of Agent Orange and related toxic rainbow herbicides – Agents Purple, White, Green and Pink. All were defoliants aimed at disrupting the jungle canopies, rice crops and other food sources for the Viet Cong.

In a just-published paper in the Open Journal of Soils Science, called “The Long-Term Environmental Impacts of Pesticide and Herbicide Use in the Panama Canal Zone,” two authors trace the deadly odyssey of those systemic herbicides halfway around the world.

From their application for nearly a decade in a war zone to their adoption as a way to eliminate white hyacinths in Panama’s Lake Gatun and for other peacetime purposes, the authors chronicle the links of man-made solutions to nature’s fabric.

Rooted water hyacinth, Panama. Photo: Flickriver

Their paper also suggests the possibility that several thousand gallons of toxic defoliants used in Indochina during the war may have wound up helping loggers and ranchers clear-cut brush from timber stands in the American West.

Kenneth Olson is professor emeritus of soil science at the University of Illinois, Urbana. Donna Tornoe runs a program for Panama Canal Zone veterans at Slidell, a Louisiana-based Military-Veterans Advocacy.

In recent years Olson has visited Vietnam to examine the soil composition of the tunnels at Cu Chi as well as to research the human and environmental ruin these toxins have caused during and after the Vietnam War. His scholarly papers have been translated into Vietnamese and are available in several libraries in Hanoi and Ho Chi Minh City. He was awarded a Fulbright fellowship to lecture in Vietnam on Agent Orange.

Olson and Tornoe are part of a small group begun by Olson called the Merry Band of Retirees – Operation Divine Providence. (This author is a member.)  For the past five years, they have supported efforts to publicize among military veterans the disastrous effects of the “rainbow herbicides” and other toxic chemicals on humans in both Vietnam and the United States, as well as the environmental impact of these defoliants throughout Indochina.

Olson has also written about domestic pollution. His paper “How Did the Passaic River, a Superfund Site near Newark, New Jersey, become an Agent Orange Dioxin TCDD Hotspot?” was published last year in the Journal of Soil and Water Conservation. (TCDD, in case you wondered, stands for Tetrachlorodibenzo-p-dioxin.)

“It is known to be a developmental toxicant in animals, causing skeletal deformities, kidney defects, and weakened immune responses in the offspring of animals,” says the US Environmental Protection Agency.

Claimed 14 year-old Agent Orange victim Le Van O, from Vietnam’s Southern province of Kien Giang, attends an international conference on the effects of the Vietnam War defoliant Agent Orange, in Hanoi, in 2006. Photo: AFP / Hoang Dinh Nam

Why the Panama Canal? Olson and Tornoe’s paper reveals that during the Vietnam War, the Military Sea Transport Service “directly chartered merchant vessels to carry tactical herbicides through the Panama Canal.”

While there is no official evidence that these herbicides were offloaded in the Canal Zone, there is at least one other way the crucial waterway may have been contaminated. Three C-123 aircraft that were used to spray malathion (a mosquito insecticide) in Panama 1970-73 “may have been previously contaminated with tactical herbicides in Vietnam,” the paper notes. “This may have resulted in trace amounts of tactical herbicide Agent Orange and Agent Blue (arsenic-based) being added to the soils and waters of the Panama Canal Zone.”

The US government and military for 60 years have claimed that these tactical herbicides were never “offloaded in the Panama Canal Zone nor aerially sprayed on the tropical forests” of the zone, the paper says. Veterans of the Canal Zone have tried to get Department of Veterans Affairs benefits, but have been denied.

In support of the government’s position, another academic paper written in 2012 by longtime Department of Defense and VA researcher Alvin L Young (a retired Air Force colonel and professor of environmental toxicology) declares:

“The current report documents five allegations that were reported by US veterans stationed in the Canal Zone during the Vietnam Era. An extensive search of historical records of the United States Chemical Corps, United States Air Forces [cq], and the Armed Forces Pest Management Board could not verify that Agent Orange had been shipped, sprayed on or buried in the Canal Zone or Panama.”

San Antone

Olson and Tomoe write, however, that a Government Accounting Office review of DoD and VA documents identified many examples of “incomplete and inaccurate information” on the DoD’s list of tactical herbicide test and storage sites. They cite Kelly Air Force Base at San Antonio, Texas. GAO documents show that some 145,000 gallons of two toxic herbicides were stored at the base.

“After the American Vietnam War ended in 1973, the tactical herbicide Agent Orange … was apparently transferred to the US Department of Agriculture for brush control, which could have been one of the sources of the herbicides used by USDA and the Forest Service in the western United States in the 1970s to control the brush and broadleaf weeds after clear-cutting,” the report says.

This was the subject of a PBS documentary in 2021, “People vs. Agent Orange,” and also of a Vietnam News podcast by Mack Payne, a veterans activist.

‘Buckingblue,’ Agent Blue illustration. Source: Vietnam Veterans Association

The Olson/Tomoe paper worries about what became of some 174,000 gallons of the tactical herbicide Agent Blue – which, laced with arsenic, has no half-life. That means it embeds forever.

“It is not clear how this massive amount of arsenic-rich Agent Blue was disposed of after the American Vietnam War officially ended in January 1973,” the paper states. “It would have been transferred to USDA, including the Forest Service for brush control along with Herbicide Orange (Agent Orange) …. If Agent Blue was applied by the USDA, arsenic, which does not have a half-life, would have remained in the Western United States soils.”

That’s a scary thought to me. When I got out of Vietnam and the Army in 197o, I thought I was through needing to worry about what I was breathing in. No such luck, it turns out.

Because then I went back and forth twice through the Panama Canal in 1975, profiling a canal pilot. And I took to spending a lot of time with my late brother and his family in Oregon, where he worked for the Forest Service.

Mike Tharp won a Bronze Star for his US Army service in Vietnam. He was also a correspondent in Tokyo for the Wall Street Journal, New York Times, Far Eastern Economic Review and US News & World Report. He was president of the Foreign Correspondents Club of Japan 1989-90.

Mike Tharp

Mike Tharp is a former Tokyo-based correspondent for The Wall Street Journal, The New York Times, Far Eastern Economic Review and US News & World Report. He served in the US Army in Vietnam and was awarded the Bronze Star. He now writes about veterans and other issues for The Dallas Morning News.