Toxin in Agent Orange still polluting South Vietnam, study says

http://www.chicagotribune.com/news/chi-tc-nw-vietnam-0912-0913sep13,0,7307758.story

By Jason Grotto Tribune reporter

September 13, 2009

HANOI, Vietnam - -- Results from a new study show that herbicides used by U.S. forces during the Vietnam War continue to pollute the environment and pose a health threat more than three decades after the last shots were fired.

Between 1961 and 1971, the U.S. military released more than 19 million gallons of herbicides in South Vietnam to destroy enemy crops and deny an elusive adversary cover by defoliating dense mangrove forests and triple canopy jungles.

What few knew at the time was that some of the herbicides contained a highly toxic form of dioxin, known as TCDD. The toxin was an unintended byproduct created while manufacturing mixtures such as Agent Orange, the most widely used of a handful of herbicides contaminated with TCDD.

Environmental scientists from a Canadian firm last week presented the findings from the study, which documents that high levels of TCDD from the herbicides still contaminate soil inside a former U.S. airbase in Da Nang as well as sediment from a lake that abuts it.

The study uses TCDD's chemical fingerprint to trace its movement through the food chain, from the soil and lake sediment to the fat of fish and ducks to the blood and breast milk of humans.

In the most extreme cases, the study found TCDD levels in Da Nang residents that were more than 50 times the World Health Organization standards. Because infants and expectant mothers appear to be the most susceptible, the high levels in breast milk are considered especially troubling.

Conducted by Vancouver-based Hatfield Consultants with funding from the Ford Foundation and assistance from the Vietnamese government, the study is the most definitive evidence to date that dioxin from the herbicides remains in the environment and threatens the health of those living close to the airbase, many of whom weren't even alive during war.

The findings may help focus the concern over toxic chemicals that were dispersed over roughly 10 percent of South Vietnam.

"The work we have done really demonstrates that this is a manageable problem," said Thomas Boivin, president of Hatfield. "We now know where the contamination is coming from; we just need the international financial support to get on with the cleanup."

Since the end of the war, the U.S. Environmental Protection Agency, the Institute of Medicine and hundreds of scientific studies have linked TCDD to numerous cancers and other illnesses.

jgrotto@tribune.com

'Hot spots'
Da Nang is one of three major "hot spots" identified by Hatfield Consultants and Vietnamese scientists during the past 15 years, areas where millions of gallons of herbicides were stored and loaded onto planes and helicopters that blanketed huge swaths of Vietnam with mixtures now outlawed in the U.S. because of their threat to human health.

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