The toxic legacy of Agent Blue
By 
Rebecca Trager2025-01-08T09:30:00
Agent Orange’s history in Vietnam is well known but one scientist is trying to raise the profile of another pesticide used during the war
Agent Orange’s use during the Vietnam War is well known. But the use of another herbicide during the war, known as Agent Blue, has remained largely unexplored. But one US researcher, who is a Vietnam Era veteran, is on a mission to raise awareness of this other so-called ‘rainbow’ arsenic-based herbicide that was used by the US military and Central Intelligence Agency during the Vietnam War and the Second Indochina War.
Recently published research by Ken Olson, a soil scientist at the University of Illinois Urbana–Champaign, reports that arsenic’s present-day persistence in the Vietnam Mekong Delta groundwater is in part due to the spraying of Agent Blue there more than five decades ago.