The problem has been well known for many years and that's why DDT was banned a long time ago in many countries. But pesticides are used to boost crop yields and, hence, food production. So doing without them is also a problem. Many of the developing countries rely on pesticides and fertilizers to reach their production targets and without such chemicals or substitutes many people would face starvation or further economic hardship. That is why global action is needed.
Financing is needed to find replacement pesticides for example.
For pesticides, for example, there are replacements - at a price. The reason that many developing countries continue to use toxaphene is that it is cheap to produce and to use. Most of the effects have been reported in the northern latitudes in animals and human beings who eat these animals, in particular those people who eat fatty sea foods like fish and seals. There is thus a tendency for the arctic population to be hit much more than others. As you can see, these POP's potentially contribute to many of the modern-day diseases.