The invention I think has had the most negative impact on the world would be cigarettes because of four reasons. The first reason is the health impact cigarettes have on not only the person smoking them but people who inhale the second hand smoke. According to the World Health Organization smoking is the leading cause of preventable death not only in the United States but the world with around six million people a year die from smoking with five million of those coming from direct use and six hundred thousand coming from the effects of second hand smoke. The second reason is the environmental impacts cigarettes have. Cigarette butts have a number of nasty chemicals and these cigarette butts often get thrown on the ground where the get washed