Watch CineCalidad. Fifty years ago, Rachel Carson’s Silent Spring warned of the danger of widespread use of pesticides, helping to launch the environmental movement in the US. Around the same time, the US military began to spray defoliants in Vietnam to deny cover to guerrilla forces. The defoliants, including Agent Orange, were contaminated with the deadly toxin, dioxin. Agent Orange continues to affect the children and grandchildren of those exposed in Vietnam and America to this day.