Pesticides are dangerous chemicals that some farmers put on plants to kill bugs or weeds. What makes them dangerous? Well, for one thing, they are almost as toxic to us as they are to the bugs. They can cause skin or eye irritation, headaches, nausea, reproductive problems, and even increased risk of cancer. They are also dangerous to our environment. They can leak into our rivers, killing many of their inhabitants, and they can get into the atmosphere. Needless to say, these are very dangerous. Fortunately, the use of pesticides has gone down significantly since the health and environmental risks were exposed.