The problems above are more like political and social issues rather than strictly a medical challenge. This means, unfortunately, many in medical fields (especially doctors) are not in a position to give basic solutions. But there is still something important doctors can do, that is, they can play a role as "supporters".
First, solutions to stop exploitation can be considered with the idea that doctors are engaged in these problems by giving evidence to the data. For or against their will, doctors are substantially the only group which can scientifically prove how bad labour environment affects the human body. And words of people who try to improve the situation are given evidence by back-up from doctors. In addition, there are people trying very hard to stop exploitation and fight for human rights. In most cases, when they appeal social action, their words are based on medical data. So, to summarize, doctors can contribute to the matter by helping such people by providing essential information from the field related to these problems. This may sound like doctors take a kind of political role, but it is required since it is not always enough for one group to take only one role. Giving evidence so that more people know about the problems is the best and most effective way of solving them.
Second, we must find solutions for the lack of proper knowledge about sex. The medical field has a direct role here, namely, health nurses are a specialized group who can start to solve this problem. On the other hand, doctors have a supportive role again which is quite indirect. What doctors can do is explain proper knowledge of sex to patients and tell them to educate thier children so that the same thing is never repeated. It is also possible that doctors themselves not restrict themselves to their hospitals and go into the community to educate people who lack sexual knowledge. When they start this, doctors will be carrying on a political role here again.
Third, general education is not a specific area for the medical field but for the educational field. The tragedies referred to in the first paragraph are not anything but the product of lack of basic reading skills which are suppossed to have been learned in primary school. It is clearly a job for teachers to change the situation. Then, what can doctors do here? Thinking of children as a future generation of adolescents gives one answer. That is, children need education about the basics which include reading and other skills for maintaining their health. In some areas of the world, doctors are needed before teachers since education simply doesn't work, because children are not in a good health condition to take education. To get their health back is followed by education. Then education can directly show its ability to stop tragedies such as intaking poisonous substances because of lack of reading ability.
Health is never achieved by doctors only. There are rather political and social aspects outside of medicine. So cooperation among a diversity of specialized groups is highly required. The medical field sometimes takes a central role and sometimes a supportive one. When just curing patients doesn't bring about basic solutions, doctors should shift their role from the former to the latter.