The radiator hose transfers coolant from an engine's water pump to its radiator. There is an upper hose that connects the top of the radiator to the top of the engine. And a lower hose connects the bottom of the radiator to the water pump, which keeps coolant flowing through the system.
Its a good idea to replace the hoses every 5 years or 40,000 miles, but If you see a crack or a bulge in the radiator hose, you should have them replaced immediately. New radiator hoses are an inexpensive repair and can prevent future damage.
Because a leaking radiator hose will cause the engine not to get the proper amount of coolant, If ignored long enough, the engine will overheat, causing substantial damage.
From a safety standpoint, there is a slight safety risk, because an overheated engine might leave you stranded. From an environmental point of view, there is a significant impact, because leaking coolant can be dangerous to children, pets and animals