“危险性”的英语？

我对所有这些药物的危险性了如指掌。I've read up on the dangers of all these drugs.科学已经探明其危险性非常小。Science has determined that the risk is very small.一些发言者认为拳击的危险性比橄榄球运动小。Some speakers argued that boxing was less dangerous than rugby....