president. >> terry yosi is the director of the science advisory board under president ronald reagan. >> they are trying to uproot accepted, settled, credible scientific principles and practices. >> what's the risk in that? >> we don't discover when the next flint, michigan drinking water contamination occurs. >> reporter: at trump's agriculture department, his nominee for chief scientist is a man with no science qualifications. >> a lot of what we see is junk science, so i'm skeptic. >> a former conservative radio host, but law requires trump to hire a registered scientist. staff were told to avoid terms like climate change, and agency web sites like the epa, have