Ask HN: What are your favorite examples of science driving good policy?

History is littered with examples of science being used to cause enormous harm - eugenics, phrenology, lobotomies, MKUltra, The four pests campaign, lysenkoism, introduction of cane toads into Australia, etc, etc, etc.

What are the best counterexamples? The unsung victories that go beyond taking lead out of paint and gasoline, and the closing of the ozone hole?