A combination picture shows the tomography examination of the mason Eduardo Leite in Rio de Janeiro August 17, 2012. (Reuters/RICARDO MORAES)

A 24-year-old construction worker is alive after a two-metre iron bar pierced his head at a construction site south of Rio de Janeiro, Brazil, on Wednesday, local media report.

Eduardo Leite had five hours of surgery to remove the metal rod and is lucid and talking normally, doctors say.

Leite was kneeling on the ground floor when the bar fell from the fifth floor of the building, pierced his helmet, went through the top of his head and exited between his eyes.

He was still conscious and talking as firefighters sawed through the bar and took him to hospital with a half-metre of the rod still left in his head.

The head of neurosurgery at Miguel Couto Municipal Hospital said the bar pierced through the front part of Leite's brain between the area that co-ordinates behaviour and emotions and the region that controls movement.

If the bar had been one centimetre further back, Leite could have been paralyzed, or two centimetres to the right, he would have lost an eye, Ruy Monteiro told the Globo TV Network.

Leite will need a further evaluation to determine whether he'll suffer any cognitive, memory or emotional problems, added neurosurgeon Nilton Lara Jr.

For the next two weeks he'll be fed antibiotics intravenously to reduce the risk of infection, doctors said.