According to the above figure, the number of people impacted by Agent Orange in Vietnam War is greater than the total number of deaths and injuries. The number of casualties in Agent Orange clearly illustrates this chemical weapon caused significant impact on Vietnam War.

​        Agent Orange is a type of defoliants and herbicides. In the beginning, it was used for removing forest cover, destroying crops, and clearing vegetation in Vietnam by militaries in USA. However, what was striking that Agent Orange not only removed forest but also had effect on health hazard. In the process of chemical reactions of Agent Orange, it would form the carcinogenic chemical pollutant-Dioxin. Dioxin with high concentration still could be found in breast milk and blood of people although the Vietnam War was over. Even after the  Vietnam War ended, Agent Orange caused many infants and children with physical and mental defect, and it also generated carcinogenicity for adults. Agent Orange had a serious negative impact on people's health in its aftermath.

       The Tokyo Subway Sarin Attack was another terrible chemical weapon event in history.