"reduce a risk" is correct and usable in written English.
You can use it when talking about minimizing or lowering the chances of a negative outcome or event. For example, "We should take measures to reduce a risk of a fire in the office building."
And the regulators would be wise to reassess whether they are moving fast enough to reduce a risk that is acknowledged to be there.
Limiting the role of the new fund would reduce a risk of it getting bogged down by disagreements between its many owners.
Or are politicians simply helping to feed public panic, and then covering themselves by promising to spend lavishly against a threat which may never materialise and to reduce a risk which they do not understand?
Each product shown purported to have one of three possible targeted effects: to reduce the likelihood of a disease, to reduce a risk factor associated with a disease, or to improve personal appearance.
Staff are now banned from using restraints to maintain discipline, but the bill provides an exception, allowing it if the superintendent believes "that an emergency situation exists, or that restraining a detainee would reduce a risk to the good order or security of the detention centre".
We are not good at taking account of differences between very small risks, so if we are asked how much we would pay to reduce a risk of dying from 1 in 1,000,000 to 1 in 10,000,000, we may give the same answer as we would if asked how much we would pay to reduce the risk from 1 in 500,000 to 1 in 10,000,000.
Risk management is a decision-making process to select the optimal measures for reducing a risk to an acceptable level.
First, any action taken to reduce a target risk always poses the introduction of countervailing risks.
Taken daily, a PrEP pill can dramatically reduce a user's risk of contracting HIV.
Software can dramatically reduce a company's audit risk.
Eat smarter and reduce your risk for a heart attack?
