Pesticides, as the preceding chapter has shown, are a serious hazard to wildlife. At high dosages they not only kill insects and other invertebrates, but birds and mammals as well. And at lower dosages they inflict a range of serious, sublethal effects. In particular, they adversely affect reproductive processes and significantly alter behavioural patterns. In the face of this evidence, it seems reasonable to assume that human beings are similarly at risk. Surprisingly, as this chapter shows, the hazard is less than might be expected.