But with other POPs the transition to safer alternatives will require more effort. Alternatives may be more expensive and their manufacture and use more complicated. That could put developing countries in an awkward spot – struggling from day to day, the world's poor tend to use what they can afford and what is available. So it is not enough for the Convention simply to say No to its target list of POPs: It must also help governments find a way to say Yes to replacement solutions. Take the case of DDT. This pesticide harms health and the environment, but it is very good at killing and repelling.