A U.S. Army helicopter sprays Agent Orange over Vietnam during the Vietnam War. The U.S. is moving now to clean-up the remaining Agent Orange contamination. (Photo courtesy of the U.S. Army via Wikimedia Commons.)

The U.S. sprayed millions of gallons of the toxic defoliant known as Agent Orange over jungle areas of Vietnam, in an effort to destroy enemy cover.

In the almost 40 years since the war ended, Vietnam says several million people have been hurt by the remnants of Agent Orange in the environment. Among them are some 150,000 children born with severe birth defects because Agent Orange has seeped into the water and soil.

But, an effort to build ties between the former enemies, the United States Thursday launched a clean-up effort in Vietnam. A smaller program was also conducted last summer

"The dioxin in the ground here is a legacy of the painful past we share, but the project we undertake here today hand-in-hand with the Vietnamese is, as Secretary Clinton said, a sign of the hopeful future we are building together," said U.S. Ambassador to Vietnam David B. Shear, speaking at a ceremony in Da Nang where the project is being launched.

Susan Hammond, the Director of the War Legacies Project, called this project the first step on what could be a long road to address not only the enduring environmental damage but also the lingering health impacts as well.

"At this point, the U.S. has provided some limited funding for programs within the Da Nang area to provide services for children with disabilities, though they do not say it's directly related to Agent Orange," Hammond said.

She says U.S. Sen. Patrick Leahy, D.-Vt., has been instrumental in getting funding appropriated, including the $43 million earmarked for the current clean-up.

And while the current effort focuses on clean-up in order to prevent health problems, there remain some parts of the country that are defoliated because of the application, 40 years ago, of Agent Orange.

"On the Da Nang airport itself, you would smell the chemicals from the almost 3 million gallons of chemicals that were stored on the base," Hammond said. "You can still smell that today."