Why must scientists often deal with politics?

Science provides us with facts.But what we do with these facts is political. We have scientific data on pollution and we know that Pollution is harmful for people. But the decision on what to do in response to the the data is political. What research the scientists do or rather they won't do is again based on political decisions too.This is because certain researches may lead to increase in knowledge but at the same time they may be harmful as well.eg. decisions on protecting patients from unethical experimentation.These ethical decisions sometimes change with elections. The scientific researches require funding from Government and funding allocations are made by politicians. Deciding what science we find valuable is not a scientific decision but a political one. To conclude, we may say, science and politics are closely related. When we say science is the pursuit of knowledge, we know knowledge is power and we also must know that power is Politics.